[From the U.S. Government Printing Office, www.gpo.gov]



 ReprintedCEMBER 1992
          Classification of
             Wetlands and
    Deepwater Habitats
   of the United States










U.S. Department of the Interior
~la4  and Wildlife Service
u53










    The Biological Services Program was established within the U.S. Fish and
Wildlife Service to supply scientific information and methodologies on key
environmental issues which have an impact on fish and wildlife resources and
their supporting ecosystems. The mission of the Program is as follows:

    1 . To strengthen the Fish and Wildlife Service in its role as a primary source
        of information on natural fish and wildlife resources, particularly with
        respect to environmental impact assessment.

    2.  To gather, analyze, and present information that will aid decisionmakers
        in the identification and resolution of problems associated with major land
        and water use changes.

    3.  To provide better ecological information and evaluation for Department
        of the Interior development programs, such as those relating to energy
        development.

    Information developed by the Biological Services Program is intended for use
in the planning and decisionmaking process, to prevent or minimize the impact
of development on fish and wildlife. Biological Services research activities and
technical assistance services are based on an analysis of the issues, the decision-
makers involved and their information needs, and an evaluation of the state-of-
the-art to identify information gaps and determine priorities. This is a strategy to
assure that the products produced and disseminated will be timely and useful.


    Biological Services projects have been initiated in the following areas:

      Coal extraction and conversion

      Power plants

      Geothermal, mineral, and oil shale development

      Water resource analysis, including stream alterations and western water
      allocation

      Coastal ecosystems and Outer Continental Shelf development

      Systems and inventory, including National Wetlands Inventory, habitat
      classification and analysis, and information transfer



    The Program consists of the Office of Biological Services in Washington, D.C.,
which is responsible for overall planning and management; National Teams which
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                                                                                     FWS/OBS-79/31
                                                                                     December 1979

                          CLASSIFICATION OF WETLANDS AND DEEPWATER
                                  HABITATS OF THE UNITED STATES

                                                  By

                                          Lewis M. Cowardin
                                      U.S. Fish and Wildlife Service
                                Northern Prairie Wildlife Research Center
                                    Jamestown, North Dakota 58401

                                            Virginia Carter
                                         U.S. Geological Survey
                                        Reston, Virginia 22092

                                            Francis C. Golet
                                 Department of Natural Resources Science
                                       University of Rhode Island
                                     Kingston, Rhode Island 02881

                                                 and

                                           Edward T. LaRoe
                        U.S. National Oceanographic and Atmospheric Administration
                                   Office of Coastal Zone Management
                                        Washington, D.C. 20235


















                                             Performed for

                                     U.S. Department of the Interior
                                        Fish and Wildlife Service
                                       Office of Biological Services
                                        Washington, D.C. 20240


                        For sale by the Superintendent of Documents, U.S. Government Printing Office
C" Washington, D.C. 20402
                    LIBRARY
co                    NOAA/CCEH
               1990 HOBSON AVE.
              CHAS. SC 29408-2628














































Library of Congress Cataloging in Publication Data

United States, Fish and Wildlife Service
   Classification of wetlands and deepwater habitats of the United States.
   (Biological services program; FWS/OBS-79/31)
   1. Wetlands-United States-Classification.  2. Wetland ecology-United
States. 3. Aquatic ecology-United States. I. Cowardin, Lewis M. II. Title.
III. Series: United States. Fish and Wildlife Service. Biological services
program; FWS/OBS-79/31.
QH76.U54a  79/31  [QH104]  574.5'0973s  [574.5'2632]  79-607795














                                                 Foreward

  Wetlands and deepwater habitats are essential breeding, rearing, and feeding grounds for many species of fish
and wildlife. They may also perform important flood protection and pollution control funtions. Increasing National
and international recognition of these values has intensified the need for reliable information on the status and ex-
tent of wetland resources. To develop comparable information over large areas, a clear definition and classification
of wetlands and deepwater habitats is required.
  The classification system contained in this report was developed by wetland ecologists, with the assistance of many
private individuals and organizations and local, State, and Federal agencies. An operational draft was published in
October 1977, and a notice of intent to adopt the system for all pertinent Service activities was published December
12, 1977 (42 FR 62432).
  The Fish and Wildlife Service is officially adopting this wetland classification system. Future wetland data bases
developed by the Service, including the National Wetlands Inventory, will utilize this system. A one-year transition
period will allow for training of Service personnel, amendment of administrative manuals, and further development
of the National Wetlands Inventory data base. During this period, Service personnel may continue to use the old
wetland classification described in Fish and Wildlife Service Circular 39 for Fish and Wildlife Coordination Act reports,
wetland acquisition priority determinations, and other activities in conjunction with the new system, where immediate
conversion is not practicable.
  Upon completion of the transition period, the Circular 39 system will no longer be officially used by the Fish and
Wildlife Service except where applicable laws still reference that system or when the only information available is
organized according to that system and cannot be restructured without new field surveys.
  Other Federal and State agencies are encouraged to convert to the use of this system. No specific legal authorities
require the use of this system-or any other system for that matter. However, it is expected that the benefits of
National consistency and a develpping wetland data base utilizing this system will result in acceptance and use by
most agencies involved in wetland management. Training can be provided to users by the Service, depending on
availability of resources. Congressional committees will be notified of this adoption action and will be encouraged
to facilitate general adoption of the new system by amending any laws that reference the Circular 39 system.
  This is a new system and users will need to study and learn the terminology. The Service is preparing a document
to aid in comparing and translating the new system to the Service's former classification system. In the coming year,
the Fish and Wildlife Service, in conjunction with the Soil Conservation Service, also plans to develop initial lists
of hydrophytic plants and hydric soils that will support interpretation and use of this system.
  We believe that this system will provide a suitable basis for information gathering for most scientific, educational,
and administrative purposes; however, it will not fit all needs. For instance, historical or potentially restorable wetlands
are not included in this system, nor was the system designed to accommodate all the requirements of the many recently
passed wetland statutes. No attempt was made to define the proprietary or jurisdictional boundaries of Federal, State,
or local agencies. Nevertheless, the basic design of the classification system and the resulting data base should assist
substantially in the administration of these programs.
  This report represents the most current methodology available for wetland classification and culminates a long-
term effort involving many wetland scientists. Although it may require revision from time to time, it will serve us
well in the years ahead. We hope all wetland personnel in all levels of government and the private sector come to
know it and use it for the ultimate benefit of America's wetlands.








                                                                                   Lynn A. Greenwalt, Director
                                                                                   U.S. Fish and Wildlife Service














                                                   Preface

  Since its publication in 1979, Classification of Wetlands and Deepwater Habitats of the United States has been used
in the National inventory of wetlands conducted by the U.S. Fish and Wildlife Service. The system has been widely
used throughout the United States and is often cited in the scientific literature. There has also been considerable
international interest in use of the classification.
 Copies from the first printing have been expended and demand requires this reprinting. We have taken this oppor-
tunity to correct a number of minor typographical errors, bring plant names into conformity with the National List
of Scientific Plant Names (U.S. Dept. Agriculture 1982), and to upgrade the quality of plates as well as furnish addi-
tional plates. No changes have been made that either alter the structure of the classification or the meaning of the
definitions. Such major revisions must be deferred until certain prerequisite tasks are accomplished.
  Completion of the list of hydrophytes and other plants occurring in wetlands and the list of hydric soils (see page
3) has been a task of far greater complexity than we envisioned when writing the classification. These lists have
received extensive review and are being prepared as computer data bases. In addition, the lists will contain a great
deal of ancillary information that will make possible the development of methodologies for their use in both the delinea-
tion and classification of wetlands. When the lists and methodologies are completed, reviewed, and tested we will
revise the classification and use the lists to add precision to the definitions. At the same time, we will address specific
technical problems that have arisen during application of the classification.
  The plates at the end of this publication are included primarily to illustrate a variety of examples of wetland classifica-
tion. We have attempted to include photographs from various regions of the country insofar as possible; however,
final selection of plates was based on the availability of both high-quality photographs and the detailed field data
required for accurate classification. While on sabbatical leave from the University of Rhode Island in 1985, Dr. Frank
Golet took numerous photographs of Alaskan wetlands. Addition of many of these and several photographs from
other regions helps somewhat to correct a regional imbalance.
  We acknowledge the assistance of Dr. J. Henry Sather who served as editor for the reprinting. He spent many
hours compiling minor errors and inconsistencies and preparing final copy for the printer. We thank Mr. Jon Hall,
National Wetlands Inventory Coordinator for the Alaska region, for his assistance to Dr. Golet during his stay in Alaska.




                                                                                    Lewis Mv. Cowardin
                                                                                    Virginia Carter
                                                                                    Francis C. Golet
                                                                                    Edward T. LaRoe
                                                                                          September 24, 1985




















                                                        iv













                        Contents

                                                      Page

Abstract ..1............................
Wetlands and Deepwater Habitats...................                                              3
 Concepts and Definitions......................                                               3
  Wetlands............................                                                       3
  Deepwater Habitats........................                                                 3
 Limits..............................                                                         3
The Classification System .......................4
 Hierarchical Structure ........................4
  Systems and Subsystems ......................4
   Marine System..........................4
   Estuarine System ........................4
   Riverine System.........................7
   Lacustrine System.......................                                                 9
   Palustrine System ........................10
  Classes, Subclasses, and Dominance Types...............10
   Rock Bottom ..........................13
   Unconsolidated Bottom ......................14
   Aquatic Bed...........................15
   Reef ..............................16
    Streambed ...........................16
    Rocky Shore...........................17
    Unconsolidated Shore.......................18
    Moss-Lichen Wetland.......................19
    Emergent Wetland........................19
    Scrub-Shrub Wetland.......................20
    Forested Wetland ........................20
  Modifiers.............................21
    Water Regime Modifiers .....................21
   Water Chemistry Modifiers ....................22
     Salinity Modifiers........................22
     pH1 Modifiers..........................23
    Soil Modifiers ..........................23
    Special Modifiers.........................24
Regionalization for the Classification System ...............24
Use of the Classification System.....................26
 Hierarchical Levels and Modifiers ...................27
 Relationship to Other Wetland Classifications ..............27
Acknowledgments...........................31
References..............................31
Appendix A. Scientific and common names of plants............35
Appendix B. Scientific and common names of animals ...........38
Appendix C. Glossary of terms .....................40
Appendix D. Criteria for distinguishing organic
          soils from mineral soils..................42
Appendix E. Artificial key to the Systems ................44
         Artificial key to the Classes.................44





                            V













                                        Tables

No.

 1   Distribution of Subclasses within the classification hierarchy.
 2   Salinity modifiers used in this classification system.
 3   pH modifiers used in this classification system.
 4   Comparison of wetland types described in U.S. Fish and Wildlife Service Circular
     39 with some of the major components of this classification system.
 5   Comparison of the zones of Stewart and Kantrud's (1971) classification with the water
     regime modifiers used in the present classification system.


                                       Figures

No.

 I   Classification hierarchy of wetlands and deepwater habitats, showing Systems, Sub-
     systems, and Classes. The Palustrine System does not include deepwater habitats.
 2   Distinguishing features and examples of habitats in the Marine System.
 3   Distinguishing features and examples of habitats in the Estuarine System.
 4   Distinguishing features and examples of habitats in the Riverine System.
 5   Distinguishing features and examples of habitats in the Lacustrine System.
 6   Distinguishing features and examples of habitats in the Palustrine System.
 7   Ecoregions of the United States after Bailey (1976) with the addition of 10 Marine
     and Estuarine Provinces proposed in our classification.
 8   Comparison of the Water Chemistry Subclasses of Stewart and Kantrud (1972) with
     Water Chemistry Modifiers used in the present classification system.



























                                          vi












            Classification of Wetlands and Deepwater
                      Habitats of the United States

                                              by
                                    Lewis M. Cowardin
                               U.S. Fish and Wildlife Service
                        Northern Prairie Wildlife Research Center
                             Jamestown, North Dakota 58401

                                      Virginia Carter
                     U.S. Geological Survey, Reston, Virginia 22092

                                      Francis C. Golet
                        Department of Natural Resources Science
               University of Rhode Island, Kingston, Rhode Island 02881
                                             and
                                      Edward T. LaRoe
             U.S. National Oceanographic and Atmospheric Administration
                           Office of Coastal Zone Management
                                  Washington, D.C. 20235

                                          Abstract

 This classification, to be used in a new inventory of wetlands and deepwater habitats of the United
States, is intended to describe ecological taxa, arrange them in a system useful to resource managers,
furnish units for mapping, and provide uniformity of concepts and terms. Wetlands are defined by
plants (hydrophytes), soils (hydric soils), and frequency of flooding. Ecologically related areas of deep
water, traditionally not considered wetlands, are included in the classification as deepwater habitats.
  Systems form the highest level of the classification hierarchy; five are defined-Marine, Estuarine,
Riverine, Lacustrine, and Palustrine. Marine and Estuarine Systems each have two Subsystems, Sub-
tidal and Intertidal; the Riverine System has four Subsystems, Tidal, Lower Perennial, Upper Peren-
nial, and Intermittent; the Lacustrine has two, Littoral and Limnetic; and the Palustrine has no
Subsystems.
 Within the Subsystems, Classes are based on substrate material and flooding regime, or on vegetative
life form. The same Classes may appear under one or more of the Systems or Subsystems. Six Classes
are based on substrate and flooding regime: (1) Rock Bottom with a substrate of bedrock, boulders,
or stones; (2) Unconsolidated Bottom with a substrate of cobbles, gravel, sand, mud, or organic material;
(3) Rocky Shore with the same substrates as Rock Bottom; (4) Unconsolidated Shore with the same
substrates as Unconsolidated Bottom; (5) Streambed with any of the substrates; and (6) Reef with
a substrate composed of the living and dead remains of invertebrates (corals, mollusks, or worms).
The bottom Classes, (1) and (2) above, are flooded all or most of the time and the shore Classes, (3)
and (4), are exposed most of the time. The Class Streambed is restricted to channels of intermittent
streams and tidal channels that are dewatered at low tide. The life form of the dominant vegetation
defines the five Classes based on vegetative form: (1) Aquatic Bed, dominated by plants that grow
principally on or below the surface of the water; (2) Moss-Lichen Wetland, dominated by mosses or
lichens; (3) Emergent Wetland, dominated by emergent herbaceous angiosperms; (4) Scrub-Shrub
Wetland, dominated by shrubs or small trees; and (5) Forested Wetland, dominated by large trees.
 The Dominance Type, which is named for the dominant plant or animal forms, is the lowest level
of the classification hierarchy. Only examples are provided for this level; Dominance Types must be
developed by individual users of the classification.
 Modifying terms applied to the Classes or Subclasses are essential for use of the system. In tidal
areas, the type and duration of flooding are described by four Water Regime Modifiers: subtidal,
irregularly exposed, regularly flooded, and irregularly flooded. In nontidal areas, eight Regimes are
used: permanently flooded, intermittently exposed, semipermanently flooded, seasonally flooded,
saturated, temporarily flooded, intermittently flooded, and artificially flooded. A hierarchical system




                                                                                                             1









2


             of Water Chemistry Modifiers, adapted from the Venice System, is used to describe the salinity of
             the water. Fresh waters are further divided on the basis of pH. Use of a hierarchical system of soil
             modifiers taken directly from U.S. soil taxonomy is also required. Special modifiers are used where
             appropriate: excavated, impounded, diked, partly drained, farmed, and artificial.
               Regional differences important to wetland ecology are described through a regionalization that com-
             bines a system developed for inland areas by R. G. Bailey in 1976 with our Marine and Estuarine
             provinces.
               The structure of the classification allows it to be used at any of several hierarchical levels. Special
             data required for detailed application of the system are frequently unavailable, and thus data gather-
             ing may be prerequisite to classification. Development of rules by the user will be required for specific
             map scales. Dominance Types and relationships of plant and animal communities to environmental
             characteristics must also be developed by users of the classification. Keys to the Systems and Classes
             are furnished as a guide, and numerous wetlands and deepwater habitats are illustrated and classified.
             The classification system is also compared with several other systems currently in use in the United
              States.







 The U.S. Fish and Wildlife Service conducted an inven-  southern  cypress-gum  (Taxodium  distichum-Nyssa
tory of the wetlands of the United States (Shaw and   aquatica) in the same category, with no provisions in the
Fredine 1956) in 1954. Since then, wetlands have under-   system for distinguishing between them. Because of the
gone considerable change, both natural and man related,  central emphasis on waterfowl habitat, far greater atten-
and their characteristics and natural values have become   tion was paid to vegetated areas than to nonvegetated
better defined and more widely known. During this inter-  areas. Probably the greatest single disadvantage of the
val, State and Federal legislation has been passed to   Martin et al. system was the inadequate definition of types,
protect wetlands, and some Statewide wetland surveys   which led to inconsistencies in application.
have been conducted.                                        Numerous other classifications of wetlands and deep-
  In 1974, the U.S. Fish and Wildlife Service directed its  water habitats have been developed (Stewart and Kan-
Office of Biological Services to design and conduct a new   trud 1971; Golet and Larson 1974; Jeglum et al. 1974;
National inventory of wetlands. Whereas the single pur-   Odum et al. 1974; Zoltai et al. 1975; Millar 1976), but most
pose of the 1954 inventory was to assess the amount and   of these are regional systems and none would fully satisfy
types of valuable waterfowl habitat, the scope of the new   National needs. Because of the weaknesses inherent in
project is considerably broader (Montanari and Townsend   Circular 39, and because wetland ecology has become
1977). It will provide basic data on the characteristics and   significantly better understood since 1954, the U.S. Fish
                                                             significantly better understood since 1954, the U.S. Fish
extent of the Nation's wetlands and deepwater habitats   and Wildlife Service elected to construct a new National
and should facilitate the management of these areas on   classification system as the first step toward a new Na-
                                                             classification system as the first step toward a new Na-
a sound, multiple-use basis.
               a sound, multiple-use basis.               tional inventory. The new classification, presented here,
  Before the 1954 inventory was begun, Martin et al.
                Before the 1954 inventory was begun, Martin et al.  has been designed to meet four long-range objectives: (1)
(1953) had devised a wetland classification system to serve 
                                                             to describe ecological units that have certain homogeneous
as a framework for the National inventory. The results  t a     ribe  og     units i          e
                                                             natural attributes; (2) to arrange these units in a system
of the inventory and an illustrated description of the 20    atl atiutesr            ange     ent            t
wetland types were published as U.S. Fish and Wildlife that will aid decisions about resource management; (3) to
Service Circular 39 (Shaw and Fredine 1956). This cir-  furnish units for inventory and mapping; and (4) to pro-
Service Circular 39 (Shaw and Fredine 1956). This cir-
cular has been one of the most common and most influen-   vide uniformity in concepts and terminology throughout
tial documents used in the continuous battle to preserve   the United States.
a critically valuable but rapidly diminishing National      Scientific and common names of plants (Appendix A)
resource (Stegman 1976). However, the shortcomings of  and animals (Appendix B) were taken from various sources
this work are well known (e.g., see Leitch 1966; Stewart   cited in the text. No attempt has been made to resolve
and Kantrud 1971).                                        nomenclatorial problems where there is a taxonomic
  In attempting to simplify their classification, Martin et  dispute. Many of the terms used in this classification have
al. (1953) not only ignored ecologically critical differences,   various meanings even in the scientific literature and in
such as the distinction between fresh and mixosaline in-  some instances our use of terms is new. We have provided
land wetlands but also placed dissimilar habitats, such as   a glossary (Appendix C) to guide the reader in our usage
forests of boreal black spruce (Picea mariana) and of  of terms.












    WETLANDS  AND  DEEPWATER                            tion of salts may prevent the growth of hydrophytes; (3)
                    HABITATS                             areas with hydrophytes but nonhydric soils, such as
                                                          margins of impoundments or excavations where hydro-
                                                          phytes have become established but hydric soils have not
           Concepts and Definitions                      yet developed; (4) areas without soils but with hydrophytes
                                                          such as the seaweed-covered portion of rocky shores; and
  Marshes, swamps, and bogs have been well-known terms  (5) wetlands without soil and without hydrophytes, such
for centuries, but only relatively recently have attempts   as gravel beaches or rocky shores without vegetation.
been made to group these landscape units under the single    Drained hydric soils that are now incapable of support-
term "wetlands." This general term has grown out of a  ing hydrophytes because of a change in water regime are
need to understand and describe the characteristics and  not considered wetlands by our definition. These drained
values of all types of land, and to wisely and effectively  hydric soils furnish a valuable record of historic wetlands,
manage wetland ecosystems. There is no single, correct,  as well as an indication of areas that may be suitable for
indisputable, ecologically sound definition for wetlands,  restoration.
primarily because of the diversity of wetlands and because    Wetlands as defined here include lands that are iden-
the demarcation between dry and wet environments lies  tified under other categories in some land-use classifica-
along a continuum. Because reasons or needs for defin-  tions. For example, wetlands and farmlands are not
ing wetlands also vary, a great proliferation of definitions  necessarily exclusive. Many areas that we define as wet-
has arisen. The primary objective of this classification is  lands are farmed during dry periods, but if they are not
to impose boundaries on natural ecosystems for the pur-  tilled or planted to crops, a practice that destroys the
poses of inventory, evaluation, and management.          natural vegetation, they will support hydrophytes.


                       Wetlands                                           Deepwater Habitats

  In general terms, wetlands are lands where saturation      DEEPWATER HABITATS are permanently flooded lands
with water is the dominant factor determining the nature  lying below the deepwater boundary of wetlands. Deep-
of soil development and the types of plant and animal corn-  water habitats include environments where surface water
munities living in the soil and on its surface. The single  is permanent and often deep, so that water, rather than
feature that most wetlands share is soil or substrate that  air, is the principal medium within which the dominant
is at least periodically saturated with or covered by water.   organisms live, whether or not they are attached to the
The water creates severe physiological problems for all  substrate. As in wetlands, the dominant plants are hydro-
plants and animals except those that are adapted for life  phytes; however, the substrates are considered nonsoil
in water or in saturated soil.                           because the water is too deep to support emergent vegeta-
  WETLANDS are lands transitional between terrestrial  tion (U.S. Soil Conservation Service, Soil Survey Staff
and aquatic systems where the water table is usually at  1975).
or near the surface or the land is covered by shallow water.  Wetlands and deepwater habitats are defined separately
For purposes of this classification wetlands must have one  because traditionally the term wetland has not included
or more of the following three attributes: (1) at least  deep permanent water; however, both must be considered
periodically, the land supports predominantly hydro-  in an ecological approach to classification. We define five
phytes;' (2) the substrate is predominantly undrained   major Systems: Marine, Estuarine, Riverine, Lacustrine,
hydric soil;2 and (3) the substrate is nonsoil and is  and Palustrine. The first four of these include both wetland
saturated with water or covered by shallow water at some   and deepwater habitats but the Palustrine includes only
time during the growing season of each year.             wetland habitats.
  The term wetland includes a variety of areas that fall
into one of five categories: (1) areas with hydrophytes and                     Limits
hydric soils, such as those commonly known as marshes,
swamps, and bogs; (2) areas without hydrophytes but with    The upland limit of wetland is designated as (1) the boun-
hydric soils-for example, flats where drastic fluctuation   dary between land with predominantly hydrophytic cover
in water level, wave action, turbidity, or high concentra-   and land with predominantly mesophytic or xerophytic
                                                          cover; (2) the boundary between soil that is predominant-
'The U.S. Fish and Wildlife Service is preparing a list of hydro-  ly hydric and soil that is predominantly nonhydric; or (3)
phytes and other plants occurring in wetlands of the United  in the case of wetlands without vegetation or soil, the
States.                                                  boundary between land that is flooded or saturated at
2The U.S. Soil Conservation Service is preparing a preliminary  some time during the growing season each year and land
list of hydric soils for use in this classification system.  that is not.









4


 The boundary between wetland and deepwater habitat  Estuarine System (Caspers 1967). As Bormann and Likens
in the Marine and Estuarine Systems coincides with the  (1969) pointed out, boundaries of ecosystems are defined
elevation of the extreme low water of spring tide; per-  to meet practical needs.
manently flooded areas are considered deepwater habitats
in these Systems. The boundary between wetland and
deepwater habitat in the Riverine and Lacustrine Systems   Marine System
lies at a depth of 2 m (6.6 feet) below low water; however,  Definition. The Marine System (Fig. 2) consists of the
if emergents, shrubs, or trees grow beyond this depth at  open ocean overlying the continental shelf and its asso-
any time, their deepwater edge is the boundary.          ciated high-energy coastline. Marine habitats are exposed
  The 2-m lower limit for inland wetlands was selected  to the waves and currents of the open ocean and the water
because it represents the maximum depth to which emer-   regimes are determined primarily by the ebb and flow of
gent plants normally grow (Welch 1952; Zhadin and Gerd   oceanic tides. Salinities exceed 300/oo, with little or no
1963; Sculthorpe 1967). As Daubenmire (1968:138) stated,  dilution except outside the mouths of estuaries. Shallow
emergents are not true aquatic plants, but are "amphib-   coastal indentations or bays without appreciable fresh-
ious," growing in both permanently flooded and wet,   water inflow, and coasts with exposed rocky islands that
nonflooded soils. In their wetland classification for  provide the mainland with little or no shelter from wind
Canada, Zoltai et al. (1975) also included only areas with   and waves, are also considered part of the Marine System
water less than 2 m deep.                                because they generally support typical marine biota.
                                                            Limits. The Marine System extends from the outer
                                                          edge of the continental shelf shoreward to one of three
                                                          lines: (1) the landward limit of tidal inundation (extreme
    THE  CLASSIFICATION  SYSTEM                          high water of spring tides), including the splash zone from
                                                          breaking waves; (2) the seaward limit of wetland emer-
  The structure of this classification is hierarchical,  gents, trees, or shrubs; or (3) the seaward limit of the
progressing from Systems and Subsystems, at the most   Estuarine System, where this limit is determined by fac-
general levels, to Classes, Subclasses, and Dominance   tors other than vegetation. Deepwater habitats lying
Types. Figure 1 illustrates the classification structure to  beyond the seaward limit of the Marine System are out-
the class level. Table 1 lists the Classes and Subclasses   side the scope of this classification system.
for each System and Subsystem. Artificial keys to the    Description. The distribution of plants and animals in
Systems and Classes are given in Appendix E. Modifiers  the Marine System primarily reflects differences in four
for water regime, water chemistry, and soils are applied  factors: (1) degree of exposure of the site to waves; (2)
to Classes, Subclasses, and Dominance Types. Special  texture and physicochemical nature of the substrate; (3)
modifiers describe wetlands and deepwater habitats that  amplitude of the tides; and (4) latitude, which governs
have been either created or highly modified by man or  water temperature, the intensity and duration of solar
beavers.                                                 radiation, and the presence or absence of ice.
                                                            Subsystems.
                                                             Subtidal.--The substrate is continuously submerged.
            Hierarchical Structure                          Intertidal.--The substrate is exposed and flooded by
                                                          tides; includes the associated splash zone.

              Systems and Subsystems                       Classes. Rock Bottom, Unconsolidated Bottom, Aquatic
                                                          Bed, Reef, Rocky Shore, and Unconsolidated Shore.
  The term SYSTEM refers here to a complex of wetlands
and deepwater habitats that share the influence of similar
hydrologic, geomorphologic, chemical, or biological fac-   tuarine System
tors. We further subdivide Systems into more specific    Definition. The Estuarine System (Fig. 3) consists of
categories called SUBSYSTEMS.                            deepwater tidal habitats and adjacent tidal wetlands that
  The characteristics of the five major Systems-Marine,   are usually semienclosed by land but have open, partly
Estuarine, Riverine, Lacustrine, and Palustrine-have   obstructed, or sporadic access to the open ocean, and in
been discussed at length in the scientific literature and   which ocean water is at least occasionally diluted by fresh-
the concepts are well recognized; however, there is fre-  water runoff from the land. The salinity may be periodical-
quent disagreement as to which attributes should be used  ly increased above that of the open ocean by evaporation.
to bound the Systems in space. For example, both the limit  Along some low-energy coastlines there is appreciable dilu-
of tidal influence and the limit of ocean-derived salinity  tion of sea water. Offshore areas with typical estuarine
have been proposed for bounding the upstream end of the  plants and animals, such as red mangroves (Rhizophora










                                                                                                     5

               System                            Subsystem                            Class
                                                                            Rock Bottom
                                                 -'Subtidal                      Unconsolidated Bottom
                                                                         Aquatic Bed
                                                                             Reef
               Marine
                                                                         - Aquatic Bed
                                             Intertidal                           Reef
                                                                            Rocky Shore
                                                                            Unconsolidated Shore

                                                                         - Rock Bottom
                                             Subtidal                            Unconsolidated Bottom
                                                                         -- Aquatic Bed
                                                                         i  Reef
           L- Estuarine                                                               Aquatic Bed
                                                                            Reef
                                                                             Streambed
                                             Intertidal                       =  Rocky Shore
                                                                            Unconsolidated Shore
                                                                             Emergent Wetland
                                                                             Scrub-Shrub Wetland
                                                                             Forested Wetland

     En Rock Bottom
                                                                            Unconsolidated Bottom
                       a~Ev~~~~~~~~ ~--t~~~~  ~Aquatic Bed
                                             Tidal                               Streambed
                                                                         -- Rocky Shore
                                                                         -:  e  Unconsolidated Shore
                                                                         E  Emergent Wetland

                                                                           iRock Bottom
                      Xw~~~~~~~~  Unconsolidated Bottom
                                             Lower Perennial -                   Aquatic Bed
                                                                         - Rocky Shore
     Z      -- Riverine -                                                               Unconsolidated Shore
                                                                            Emergent Wetland

     Z                                                                                  Rock Bottom
                       ï¿½~a~~~~~~~~~~~~~~~ -~Unconsolidated Bottom
                                             Upper Perennial                     Aquatic Bed
                                                                         B   Rocky Shore
                                                                            Unconsolidated Shore

                                             Intermittent                        Streambed

                                                                            Rock Bottom
                                             Limnetic                         L  Unconsolidated Bottom
                                                                            Aquatic Bed
               Lacustrine 
                                                                             Rock Bottom
                                                                            Unconsolidated Bottom
                                             Littoral                           Aquatic Bed
                                                                            Rocky Shore
                                                                           Unconsolidated Shore
                                                                            Emergent Wetland

                                                                            Rock Bottom
                                                                            Unconsolidated Bottom
                                                                            Aquatic Bed
                                                                         -Unconsolidated Shore
                                                                         Moss-Lichen Wetland
                                                                            Emergent Wetland
                                                                            Scrub-Shrub Wetland
                                                                            Forested Wetland

Fig. 1. Classification hierarchy of wetlands and deepwater habitats, showing Systems, Subsystems, and Classes. The Palustrine
 System does not include deepwater habitats.










6


                      Table 1. Distribution of Subclasses within the classification hierarchy.

                                                                 System and Subsystema
                                 Marine        Estuarine                Riverine                 Lacustrine      Palustrine
Class/Subclass                 ST       IT      ST      IT      TI     LP       UP      IN       LM      LT
Rock Bottom
 Bedrock                       X               X               X                X               X        X           X
 Rubble                        X               X               X                X               X        X           X

Unconsolidated Bottom
 Cobble-Gravel                 X               X               X       X        X               X        X           X
 Sand                          X               X               X    X           X               X        X           X
 Mud                           X               X               X    X    X                       X    X              X
 Organic                                       X               X       X                         X       X           X

Aquatic Bed
 Algal                         X       X       X       X       X       X        X                X       X           X
 Aquatic Moss                                                  X       X        X                X       X           X
 Rooted Vascular               X       X       X       X       X       X        X                X       X           X
  Floating Vascular                             X       X       X       X        X               X        X           X

Reef
  Coral                         X       X
  Mollusk                                       X       X
  Worm                          X    X    X    X

Streambed
  Bedrock                                               X       X                        X
  Rubble                                                X       X                        X
  Cobble-Gravel                                         X       X                        X
  Sand                                                  X       X                        X
  Mud                                                   X    X                           X
  Organic                                               X       X                        X
  Vegetated                                                                              X

Rocky Shore
  Bedrock                               X               X       X       X        X                        X
  Rubble                                X               X       X       X        X                        X

Unconsolidated Shore
  Cobble-Gravel                         X               X       X       X        X                        X           X
  Sand                                  X               X       X       X        X                        X           X
  Mud                                   X               X    X    X              X                        X           X
  Organic                               X               X       X       X        X                        X           X
  Vegetated                                                     X       X        X                        X           X

Moss-Lichen Wetland
  Moss                                                                                                                X
  Lichen                                                                                                              X

Emergent Wetland
  Persistent                                            X                                                             X
  Nonpersistent                                         X       X       X        X                        X           X

Scrub-Shrub Wetland
  Broad-leaved Deciduous                                X                                                             X
  Needle-leaved Deciduous                               X                                                             X
  Broad-leaved Evergreen                                X                                                             X
  Needle-leaved Evergreen                               X                                                             X
  Dead                                                  X                                                             X









                                                                                                                7


Table 1. Continued.

                                                            System and Subsystema
                              Marine       Estuarine              Riverine              Lacustrine     Palustrine
Class/Subclass               ST     IT     ST      IT     TI     LP      UP      IN     LM      LT
Forested Wetland
 Broad-leaved Deciduous                           X                                                        X
 Needle-leaved Deciduous                          X                                                        X
 Broad-leaved Evergreen                           X                                                        X
 Needle-leaved Evergreen                          X                                                        X
 Dead                                             X                                                        X
aST=Subtidal, IT=Intertidal, TI=Tidal, LP=Lower Perennial, UP=Upper Perennial, IN=Intermittent, LM=Limnetic,
LT = Littoral.


mangle) and eastern oysters (Crassostrea virginica), are    Classes. Rock Bottom, Unconsolidated Bottom, Aquatic
also included in the Estuarine System.3                   Bed, Reef, Streambed, Rocky Shore, Unconsolidated
  Limits. The Estuarine System extends (1) upstream and   Shore, Emergent Wetland, Scrub-Shrub Wetland, and
landward to where ocean-derived salts measure less than   Forested Wetland
0.50/oo during the period of average annual low flow; (2)
to an imaginary line closing the mouth of a river, bay, or   Riverine System
sound; and (3) to the seaward limit of wetland emergents,   Definition. The Riverine System (Fig. 4) includes all
shrubs, or trees where they are not included in (2). The   wetlands and deepwater habitats contained within a chan-
Estuarine System also includes offshore areas of contin-  nel, with two exceptions: (1) wetlands dominated by trees,
uously diluted sea water.                                 shrubs, persistent emergents,  emergent mosses, or
  Description. The Estuarine System includes both es-  lichens, and (2) habitats with water containing ocean-
tuaries and lagoons. It is more strongly influenced by its  derived salts in excess of 0.50/oo. A channel is "an open
association with land than is the Marine System. In terms   conduit either naturally or artificially created which
of wave action, estuaries are generally considered to be   periodically or continuously contains moving water, or
low-energy systems (Chapman 1977:2).                      which forms a connecting link between two bodies of
  Estuarine water regimes and water chemistry are   standing water" (Langbein and Iseri 1960:5).
affected by one or more of the following forces: oceanic    Limits. The Riverine System is bounded on the land-
tides, precipitation, freshwater runoff from land areas,   ward side by upland, by the channel bank (including
evaporation, and wind. Estuarine salinities range from   natural and man-made levees), or by wetland dominated
hyperhaline to oligohaline (Table 2). The salinity may be   by trees, shrubs, persistent emergents, emergent mosses,
variable, as in hyperhaline lagoons (e.g., Laguna Madre,   or lichens. In braided streams, the system is bounded by
Texas) and most brackish estuaries (e.g., Chesapeake Bay,   the banks forming the outer limits of the depression within
Virginia-Maryland); or it may be relatively stable, as in  which the braiding occurs.
sheltered euhaline embayments (e.g., Chincoteague Bay,     The Riverine System terminates at the downstream end
Maryland) or brackish embayments with partly obstructed   where the concentration of ocean-derived salts in the
access or small tidal range (e.g., Pamlico Sound, North   water exceeds 0.5ï¿½/oo during the period of annual average
Carolina). (For an extended discussion of estuaries and   low flow, or where the channel enters a lake. It terminates
lagoons see Lauff 1967.)                                  at the upstream end where tributary streams originate,
  Subsystems.                                             or where the channel leaves a lake. Springs discharging
    Subtidal. -The substrate is continuously submerged.   into a channel are considered part of the Riverine System.
    Intertidal. -The substrate is exposed and flooded by    Description. Water is usually, but not always, flowing
tides; includes the associated splash zone.               in the Riverine System. Upland islands or Palustrine wet-
                                                          lands may occur in the channel, but they are not included
3The Coastal Zone Management Act of 1972 defines an estuary  in the Riverine System  Palustrine Moss-Lichen Wet
as "that part of a river or stream or other body of water having  lands Emergent Wetlands Scrub-Shrub Wetlands and
unimpaired connection with the open sea, where the sea-water
is measurably diluted with freshwater derived from land  Forested Wetlands may occur adjacent to the Riverine
drainage." The Act further states that "the term includes estuary-  System, often on a floodplain. Many biologists have sug-
type areas of the Great Lakes." However, in the present system  gested that all the wetlands occurring on the river flood-
we do not consider areas of the Great Lakes as Estuarine.  plain should be a part of the Riverine System because they












                                                                       Seaward Limit of Marine System - -
 UPLAND                                                 MARINE







                       =                                                                                  _

                       3   z I  m                 ï¿½-
                                                  0w   '"                                                    0












          a,!%                                               .......... EHWS

                                                              bI-tJL~.                                    ELWS

                                            a IRREGULARLY FLOODED
                                            b REGULARLY FLOODED
                                            c IRREGULARLY EXPOSED
                                            d SUBTIDAL

Fig. 2. Distinguishing features and examples of habitats in the Marine System. EHWS = extreme high water of spring tides;
 ELWS = extreme low water of spring tides.

consider their presence to be the result of river flooding.   nial Subsystem. The floodplain is typically well developed.
However, we concur with Reid and Wood (1976:72,84) who      Lower Perennial. -The gradient is low and water veloc-
stated, "The floodplain is a flat expanse of land border-   ity is slow. There is no tidal influence, and some water
ing an old river. . .. Often the floodplain may take the form flows throughout the year. The substrate consists mainly
of a very level plain occupied by the present stream chan-   of sand and mud. Oxygen deficits may sometimes occur,
nel, and it may never, or only occasionally, be flooded...,   the fauna is composed mostly of species that reach their
It is this subsurface water [the ground water] that con-   maximum abundance in still water, and true planktonic
trols to a great extent the level of lake surfaces, the flow   organisms are common. The gradient is lower than that
of streams, and the extent of swamps and marshes."        of the Upper Perennial Subsystem and the floodplain is
  Subsystems. The Riverine System is divided into four   well developed.
Subsystems: the Tidal, the Lower Perennial, the Upper       Upper Perennial. -The gradient is high and velocity of
Perennial, and the Intermittent. Each is defined in terms   the water fast. There is no tidal influence and some water
of water permanence, gradient, water velocity, substrate,   flows throughout the year. The substrate consists of rock,
and the extent of floodplain development. The Subsystems   cobbles, or gravel with occasional patches of sand. The
have characteristic flora and fauna (see Illies and Botosa-   natural dissolved oxygen concentration is normally near
neau 1963; Hynes 1970; Reid and Wood 1976). All four   saturation. The fauna is characteristic of running water,
Subsystems are not necessarily present in all rivers, and   and there are few or no planktonic forms. The gradient
the order of occurrence may be other than that given  is high compared with that of the Lower Perennial Sub-
below.                                                    system, and there is very little floodplain development.
  Tidal. -The gradient is low and water velocity fluctuates    Intermittent. -In this Subsystem, the channel contains
under tidal influence. The streambed is mainly mud with   flowing water for only part of the year. When the water
occasional patches of sand. Oxygen deficits may sometimes   is not flowing, it may remain in isolated pools or surface
occur and the fauna is similar to that in the Lower Peren-   water may be absent.












 UPLAND                  ESTUARINE                  UPLAND                         ESTUARINE


            INTERTIDAL   SUBTIDAL   INTERTIDAL                    INTERTIDAL                 SUBTIDAL





               IFZ                                                                                      a Z '
                I x E                                  ia IL 
               ,,,                                                                    O Uj              z
               ;E        : ~-      -E                              D                  '                 z

               I-                                                                                   I












                                           a IRREGULARLY FLOODED
                                           b REGULARLY FLOODED
                                           c IRREGULARLY EXPOSED
                                           d SUBTIDAL


Fig. 3. Distinguishing features and examples of habitats in the Estuarine System. EHWS = extreme high water of spring tides;
 ELWS = extreme low water of spring tides.



 Classes. Rock Bottom, Unconsolidated Bottom, Aquatic   emergents, emergent mosses, or lichens. Lacustrine
Bed, Streambed, Rocky Shore, Unconsolidated Shore, and   Systems formed by damming a river channel are bounded
Emergent Wetland (nonpersistent).                         by a contour approximating the normal spillway elevation
                                                        or normal pool elevation, except where Palustrine wet-
Lacustrine System                                         lands extend lakeward of that boundary. Where a river
 Definition. The Lacustrine System (Fig. 5) includes wet-   enters a lake, the extension of the Lacustrine shoreline
lands and deepwater habitats with all of the following   forms the Riverine-Lacustrine boundary.
characteristics: (1) situated in a topographic depression   Description. The Lacustrine System includes perma-
or a dammed river channel; (2) lacking trees, shrubs, per-  nently flooded lakes and reservoirs (e.g., Lake Superior),
sistent emergents, emergent mosses or lichens with   intermittent lakes (e.g., playa lakes), and tidal lakes with
greater than 30% areal coverage; and (3) total area ex-  ocean-derived salinities below 0.50/oo (e.g., Grand Lake,
ceeds 8 ha (20 acres). Similar wetland and deepwater   Louisiana). Typically, there are extensive areas of deep
habitats totaling less than 8 ha are also included in the   water and there is considerable wave action. Islands of
Lacustrine System if an active wave-formed or bedrock   Palustrine wetland may lie within the boundaries of the
shoreline feature makes up all or part of the boundary,   Lacustrine System.
or if the water depth in the deepest part of the basin ex-    Subsystems.
ceeds 2 m (6.6 feet) at low water. Lacustrine waters may     Limnetic. -All deepwater habitats within the Lacus-
be tidal or nontidal, but ocean-derived salinity is always   trine System; many small Lacustrine Systems have no
 l   ess than 0.5Systemoo.       is boundedbyupland Limnetic Subsystem.
 Limits. The Lacustrine System is bounded by upland         Littoral.-All wetland habitats in the Lacustrine
or by wetland dominated by trees, shrubs, persistent  System. Extends from the shoreward boundary of the









10


                          Table 2. Salinity Modifiers used in this classification system.
                                                                                                      Approximate
                                                                                                   specific conductance
Coastal Modifiers'              Inland Modifiersb           Salinity (parts per thousand)            (pMhos at 25'C)
Hyperhaline                       Hypersaline                         >40                                   >60,000
Euhaline                          Eusaline                             30.0-40                        45,000-60,000
Mixohaline (Brackish)             Mixosaline'                           0.5-30                           800-45,000
 Polyhaline                        Polysaline                         18.0-30                         30,000-45,000
 Mesohaline                        Mesosaline                          5.0-18                          8,000-30,000
 Oligohaline                       Oligosaline                         0.5-5                             800- 8,000
Fresh                             Fresh                                <0.5                                    <800
aCoastal Modifiers are used in the Marine and Estuarine Systems.
blnland Modifiers are used in the Riverine, Lacustrine, and Palustrine Systems.
'The term Brackish should not be used for inland wetlands or deepwater habitats.

system to a depth of 2 m (6.6 feet) below low water or   current, as they do not belong, strictly speaking, to the
to the maximum extent of nonpersistent emergents, if  running water habitat." There are often great similarities
these grow at depths greater than 2 m.                      between wetlands lying adjacent to lakes or rivers and
  Classes. Rock Bottom, Unconsolidated Bottom, Aquatic   isolated wetlands of the same class in basins without open
Bed, Rocky Shore, Unconsolidated Shore, and Emergent   water.
Wetland (nonpersistent).                                       Subsystems. None.
                                                              Classes. Rock Bottom, Unconsolidated Bottom, Aquatic
                                                            Bed, Unconsolidated Shore, Moss-Lichen Wetland, Emer-
  Definition. The Palustrine System (Fig. 6) includes all  gent  Wetland,  Scrub-Shrub  Wetland,  and  Forested
nontidal wetlands dominated by trees, shrubs, persistent   Wetland.
emergents, emergent mosses or lichens, and all such wet-
lands that occur in tidal areas where salinity due to ocean-
derived salts is below 0.50/oo. It also includes wetlands
lacking such vegetation, but with all of the following four      Classes, Subclasses, and Dominance Ty
characteristics: (1) area less than 8 ha (20 acres); (2) ac-
                                                              The CLASS is the highest taxonomic unit below the Sub-
tive wave-formed or bedrock shoreline features lacking;
    (3)  depth in the deepest part of basin less than 2 m    system level. It describes the general appearance of the
(3) water depth in the deepest part of basin less than 2 m
                 waterl~~~~  l   *          l .z   ,        habitat in terms of either the dominant life form of the
at low water; and (4) salinity due to ocean-derived salts   vegetation or the physiography and composition of the
less than 0.5ï¿½/oo.                                          vegetation or the physiography and composition of the
                                                            substrate-features that can be recognized without the aid
  Limits. The Palustrine System is bounded by upland or   of detailed environmental measurements. Vegetation is
by any of the other four Systems.                           used at two different levels in the classification. The life
  Description. The Palustrine System was developed to   forms-trees, shrubs, emergents, emergent mosses, and
group the vegetated wetlands traditionally called by such   lichens-are used to define Classes because they are
names as marsh, swamp, bog, fen, and prairie, which are   relatively easy to distinguish, do not change distribution
found throughout the United States. It also includes the   rapidly, and have traditionally been used as criteria for
small, shallow, permanent or intermittent water bodies   classification of wetlands.4 Other forms of vegetation, such
often called ponds. Palustrine wetlands may be situated   as submerged or floating-leaved rooted vascular plants,
shoreward of lakes, river channels, or estuaries; on river   free-floating vascular plants, submergent mosses, and
floodplains; in isolated catchments; or on slopes. They may   algae, though frequently more difficult to detect, are used
also occur as islands in lakes or rivers. The erosive forces
of wind and water are of minor importance except dur-
ing severe floods.                                          'Our initial attempts to use familiar terms such as marsh, swamp,
  The emergent vegetation adjacent to rivers and lakes   bog, and meadow at the Class level were unsuccessful primarily
is often referred to as "the  shore zone" or the "zone of  because of wide discrepancies in the use of these terms in various
               ismertent vegettion "     (Reid ane  Woor 1e azndse  regions of the United States. In an effort to resolve that difficulty,
                                                            we based the Classes on the fundamental components (life form,
erally considered separately from the river or lake. As an   water regime, substrate type, water chemistry) that give rise to
example, Hynes (1970:85) wrote in reference to riverine   such terms. We believe that this approach will greatly reduce the
habitats, "We will not here consider the long list of emer-   misunderstandings and confusion that result from the use of the
gent plants which may occur along the banks out of the   familiar terms.













 UPLAND   PALUSTRINE                           RIVERINE                             PALUSTRINE        UPLAND








                                              *                                       Z       = 















                                   %\ AVERAGE WATER ' ) -
                            UJ                                               Z
                                            TEMPORARILY FLOODED










                                           HIGH WATER                                        M6--




                                           a TEMPORARILY FLOODED
                                           b SEASONALLY FLOODED
                                           ï¿½ SEMIPERMANENTLY FLOODED
                                           d INTERMITTENTLY EXPOSED
                                           a PERMANENTLY FLOODED

                    Fig. 4. Distinguishing features and examples of habitats in the Riverine System.



to define the Class Aquatic Bed. Pioneer species that brief-  pioneer species) is 30% or greater, the wetland is assigned
ly invade wetlands when conditions are favorable are  to the appropriate Class for the predominant life form
treated at the Subclass level because they are transient  below the shrub layer. Finer differences in life forms are
and often not true wetland species.                      recognized at the SUBCLASS level. For example, Forested
 Use of life forms at the Class level has two major advan-   Wetland is divided into the Subclasses Broad-leaved Decid-
tages: (1) extensive biological knowledge is not required   uous, Needle-leaved Deciduous, Broad-leaved Evergreen,
to distinguish between various life forms, and (2) it has   Needle-leaved Evergreen, and Dead. Subclasses are
been established that various life forms are easily recog-   named on the basis of the predominant life form.
nizable on a great variety of remote sensing products (e.g.,    If vegetation covers less than 30% of the substrate, the
Radforth 1962; Anderson et al. 1976). If vegetation (ex-  physiography and composition of the substrate are the
cept pioneer species) covers 30% or more of the substrate,  principal characteristics used to distinguish Classes. The
we distinguish Classes on the basis of the life form of the   nature of the substrate reflects regional and local varia-
plants that constitute the uppermost layer of vegetation   tions in geology and the influence of wind, waves, and cur-
and that possess an areal coverage 30% or greater. For   rents on erosion and deposition of substrate materials.
example, an area with 50% areal coverage of trees over   Bottoms, Shores, and Streambeds are separated on the
a shrub layer with a 60% areal coverage would be classified  basis of duration of inundation. In the Riverine, Lacus-
as Forested Wetland; an area with 20% areal coverage   trine, and Palustrine Systems, Bottoms are submerged
of trees over the same (60%) shrub layer would be  all or most of the time, whereas Streambeds and Shores
classified as Scrub-Shrub Wetland. When trees or shrubs   are exposed all or most of the time. In the Marine and
alone cover less than 30% of an area but in combination   Estuarine Systems, Bottoms are Subtidal, whereas
cover 30% or more, the wetland is assigned to the Class   Streambeds and Shores are Intertidal. Bottoms, Shores,
Scrub-Shrub. When trees and shrubs cover less than 30%   and Streambeds are further divided at the Class level on
of the area but the total cover of vegetation (except  the basis of the important characteristic of rock versus










12


 UPLAND                                    LACUSTRINE                                  PALUSTRINE    UPLAND

                    LITTORAL                       LIMNETIC                 LITTORAL




             I--   ~Z                                              Z              S I
                        .Jz                          W U~ z                          :2 - 
             w3    21                                                             21_
                 -_ -co                           t        o o                    I  l:  z,
                 Ujw  w                                                                    a-
             00                                                           2
                V) cc W-                                                          I.- 0F-     I.-
                   I- 2 0                                                        Z W          WL'
             O     w~z                                                            0 0  02
















                                             a TEMPORARILY FLOODED
                                             b SEASONALLY FLOODED
                                             c SEMIPERMANENTLY FLOODED
                                             d INTERMITTENTLY EXPOSED
                                             o PERMANENTLY FLOODED

                   Fig. 5. Distinguishing features and examples of habitats in the Lacustrine System.


unconsolidated substrate. Subclasses are based on finer  of vegetation used to determine the Subclass.5 For exam-
distinctions in substrate material unless, as with  pie, a Needle-leaved Evergreen Forested Wetland with
Streambeds and Shores, the substrate is covered by, or   70% areal cover of black spruce (Picea mariana) and 30%
shaded by, an areal coverage of pioneering vascular plants  areal cover of tamarack (Larix laricina) would be desig-
(often nonhydrophytes) of 30% or more; the Subclass is  nated as a Picea mariana Dominance Type. When the
then simply "vegetated." Further detail as to the type of  relative abundance of codominant species is nearly equal,
vegetation must be obtained at the level of Dominance   the Dominance Type consists of a combination of species
Type. Reefs are a unique class in which the substrate itself  names. For example, an Emergent Wetland with about
is composed primarily of living and dead animals.   equal areal cover of common cattail (Typha latifotia) and
Subclasses of Reefs are designated on the basis of the type   hardstem bulrush (Scirpus acutus) would be designated
of organism that formed the reef.                        a Typha latifotia-Scirpus acutus Dominance Type.
  The DOMINANCE TYPE is the taxonomic category sub-    When the Subclass is based on substrate material, the
ordinate to Subclass. Dominance Types are determined   Dominance Type is named for the predominant plant or
on the basis of dominant plant species (e.g., Jeglum et al.
1974), dominant sedentary or sessile animal species (e.g.,
Thorson 1957), or dominant plant and animal species (e.g.,   Percent areal cover is seldom measured in the application of this
Stephenson and Stephenson 1972). A dominant plant  system, but the term must be defined in terms of area. We sug-
                            W~~~~~
                   . .                                  gest 2 m2 for herbaceo UJ










































species has traditionally meant one that has control over  ges 2 m2frhraeu   n   os iaes  6m  o  hu
the community (Weaver and Clements 1938:91), and this  laers, and4 100 mhe fortrcee elayer~asc( MuerllereDo~mybo~issatnd Ellen-
plant is also usually the predominant species (Cain and   boundaries between units of the classification, it may occasion-
Castro 1959:29). When the Subclass is based on life form,  ally be necessary to measure cover on plots, in order to maintain
we name the Dominance Type for the dominant species  uniformity of ocular estimates made in the field or interpretations

or combination of species (codominants) in the same layer   made from aerial photographs.
                                               W~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                              _    .  ~~~AVERAGE WATER-
                              '~~-- ~~LOW WATER


                                             a TEMPORARILY FLOODED
                                             b SEASONALLY FLOODED
                                             c SEMIPERMANENTLY FLOODED
                                             d INTERMITTENTLY EXPOSED
                                             a PERMANENTLY FLOODED

                   Fig. 5. Distinguishing features and examples of habitats in the Lacustrine System.


unconsolidated substrate. Subclasses are based on finer of vegetation used to determine the Subclass.6 For exam-
distinctions in substrate material unless, as with ple, a Needle-leaved Evergreen Forested Wetland with
Streamnbeds and Shores, the substrate is covered by, or 70% areal cover of black spruce (Picea mariana) and 30%
shaded by, an areal coverage of pioneering vascular plants areal cover of tamarack (Larix laricina) would be desig-
(often nonhydrophytes) of 30% or more; the Subclass is nated as a Picea mariana Dominance Type. When the
then simply "vegetated." Further detail as to the type of relative abundance of codominant species is nearly equal,
vegetation must be obtained at the level of Dominance the Dominance Type consists of a combination of species
Type. Reefs are a unique class in which the substrate itself names. For example, an Emergent Wetland with about
is composed primarily of living and dead animials. equal areal cover of common cattail (Typha latifolia) and
Subclasses of Reefs are designated on the basis of the type hardstemn bulrush (Seirpus acutus) would be designated
of organism that formed the reef. a Typha latifolia-Scirpus acutus Dominance Type.
  The DOMINANCE TYPE is the taxonomic category sub- When the Subclass is based on substrate material, the
ordinate to Subclass. Dominance Types are determined Dominance Type is named for the predominant plant or
on the basis of dominant plant species (e.g., Jeglum et a].
1974), dominant sedentary or sessile animal species (e.g.,
              Thorson 19~~~~~~~~~~~~~57) rdm n n   l   n           n   nmlseis(~.Percent areal cover is seldom measured in the application of this
              Stephnson nd Sephenon 172).   domnant    lantsystem, but the term must be defined in terms of area. We sug-
species has traditionally meant one that has control overget2i'frhbaouanmsslys,1 'frsrb
              the  ommuity Weavr an Cleents193891),and hislayers, and 100 m2' for tree layers (Mueller-Dombois and Ellen-
                                                          berg 1974:74). When percent areal cover is the key for establishing
plant is also usually the predominant species (Cain and boundaries between units of the classification, it may occasion-
Castro 1959:29). When the Subclass is based on life form, ally be necessary to measure cover on plots, in order to maintain
we name the Dominance Type for the dominant species uniformity of ocular estimates made in the field or interpretations
or combination of species (codominants) in the same layer made from aerial photographs.













UPLAND  PALUSTRINE  UPLAND        PALUSTRINE        UPLAND                  PALUSTRINE                  UPLAND





                                              -~~~~~~~~~~~~~~~                                 Z
                                            zI                                           C


           I--- _ =-                         -                      = _ _r _
                m j               co                               J m  I_ w             wz  a)






                                                                                  ' ~      ~        '
                    M A                                                          -< 3X Axï¿½i 0 c          -
              @   z  3            o  3      7        A         z 3      m       cs       en O  en Ad    b








                                                           b                                    W     HIGH ~~~~~~~~~WATER
                                                                        n               2      2   1


                              aNeepag Zojn  _Ioa                                                  AVERAGE WATER

                                            a TEMPORARILY FLOODED                                     LOW WATER
                                            b SEASONALLY FLOODED           -------
                                            c SEMIPERMANENTLY FLOODED
                                            d INTERMITTENTLY EXPOSED
                                            e PERMANENTLY FLOODED
                                             f SATURATED


                   Fig. 6. Distinguishing features and examples of habitats in the Palustrine System.


sedentary or sessile macroinvertebrate species, without   of plants and animals to develop. Rock Bottoms are usually
regard for life form. In the Marine and Estuarine Systems,   high-energy habitats with well-aerated waters. Tempera-
sponges, alcyonarians, mollusks, crustaceans, worms, asci-  ture, salinity, current, and light penetration are also im-
dians, and echinoderms may all be part of the community   portant factors in determining the composition of the ben-
represented by the Macoma balthica Dominance Type.   thic community. Animals that live on the rocky surface
Sometimes it is necessary to designate two or more co-  are generally firmly attached by hooking or sucking
dominant species as a Dominance Type. Thorson (1957)  devices, although they may occasionally move about over
recommended guidelines and suggested definitions for  the substrate. Some may be permanently attached by
establishing community types and dominants on level  cement. A few animals hide in rocky crevices and under
bottoms.                                                  rocks, some move rapidly enough to avoid being swept
                                                         away, and others burrow into the finer substrates between
              ~~~~~~~~Rock Bottom  ~boulders. Plants are also firmly attached (e.g., by hold-
                                                         fasts), and in the Riverine System both plants and animals
 Definition. The Class Rock Bottom includes all wetlands   are commonly streamlined or flattened in response to high
and deepwater habitats with substrates having an areal   water velocities.
cover of stones, boulders, or bedrock 75% or greater and    Subclasses and Dominance Types.
vegetative cover of less than 30%. Water regimes are         Bedrock.-Bottoms in which bedrock covers 75% or
restricted to subtidal, permanently flooded, intermittently   more of the surface
exposed, and semipermanently flooded.                        Rubble.-Bottoms with less than 75% areal cover of
 Description. The rock substrate of the rocky benthic or  bedrock, but stones and boulders alone, or in combination
bottom zone is one of the most important factors in deter-  with bedrock, cover 75% or more of the surface.
mining the abundance, variety, and distribution of organ-   Examples of Dominance Types for these two Subclasses
isms. The stability of the bottom allows a rich assemblage   in the Marine and Estuarine Systems are the encrusting









14


sponges Hippospongia, the tunicate Cnemidocarpa, the  in one type of substrate than in others. According to Hynes
sea urchin Strongylocentrotus, the sea star Pisaster, the  (1970:208), "The larger the stones, and hence the more
sea whip Muricea, and the American lobster Homarus   complex the substratum, the more diverse is the inverte-
americanus. Examples of Lacustrine, Palustrine, and  brate fauna." In the Lacustrine and Palustrine Systems,
Riverine Dominance Types are the freshwater sponges   there is usually a high correlation, within a given water
Spongilla and Heteromeyenia, the pond snail Lymnaea,   body, between the nature of the substrate and the number
the mayfly Ephemerella, various midges of the Chirono-  of species and individuals. For example, in the profundal
midae, the caddisfly Hydropsyche, the leech Helobdella,  bottom of eutrophic lakes where light is absent, oxygen
the riffle beetle Psephenus, the chironomid midge Eukief-  content is low, and carbon dioxide concentration is high,
feriella, the crayfish Procambarus, and the black fly  the sediments are ooze-like organic materials and species
Simulium.                                                 diversity is low. Each substrate type typically supports
  Dominance Types for Rock Bottoms in the Marine and   a relatively distinct community of organisms (Reid and
Estuarine Systems were taken primarily from Smith   Wood 1976:262).
(1964) and Ricketts and Calvin (1968), and those for Rock  Subclasses and Dominance Types.
Bottoms in the Lacustrine, Riverine, and Palustrine          Cobble-Gravel. -The unconsolidated particles smaller
Systems from Krecker and Lancaster (1933), Stehr and   than stones are predominantly cobble and gravel, although
Branson (1938), Ward and Whipple (1959), Clarke (1973),  finer sediments may be intermixed. Examples of Domi-
Hart and Fuller (1974), Ward (1975), Slack et al. (1977),  nance Types for the Marine and Estuarine Systems are
and Pennak (1978).                                       the mussels Modiolus and Mytilus, the brittle star Am-
                                                         phipholis, the soft-shell clam Mya, and the Venus clam
Unconsolidated Bottom                                    Saxidomus. Examples for the Lacustrine, Palustrine, and
                                                         Riverine Systems are the midge Diamesa, stonefly-midge
               Def on  The Class Unconsodated Bottom   ludes   Nemoura-Eukiefferiella (Slack et al. 1977), chironomid
all wetland and deepwater habitats with at least 25% cover   midge-caddisfly-snail Chironomus-Hydropsyche-Physa
of particles smaller than stones, and a vegetative cover   (Krecker and Lancaster 1933), the pond snail Lymnaea,
less than 30%. Water regimes are restricted to subtidal,   the mayfly Baetis, the freshwater sponge Eunapius, the
permanently flooded, intermittently exposed, and semi-  oligochaete worm Lumbriculus, the scud Gammarus, and
permanently flooded.                                      the  freshwater  mollusks Anodonta,  Elliptio, and
  Description. Unconsolidated Bottoms are characterized   Lampsilis.
by the lack of large stable surfaces for plant and animal    Sand.-The unconsolidated particles smaller than
attachment. They are usually found in areas with lower   stones are predominantly sand, although finer or coarser
energy than Rock Bottoms, and may be very unstable. Ex-   sediments may be intermixed. Examples of Dominance
posure to wave and current action, temperature, salinity,  Types in the Marine and Estuarine Systems are the wedge
and light penetration determines the composition and   shell Donax, the scallop Pecten, the tellin shell Tellina, the
distribution of organisms.                                heart urchin Echinocardium, the lugworm Arenicola, the
  Most macroalgae attach to the substrate by means of  sand dollar Dendraster, and the sea pansy Renilla. Ex-
basal hold-fast cells or discs; in sand and mud, however,   amples for the Lacustrine, Palustrine, and Riverine
algae penetrate the substrate and higher plants can suc-   Systems are the snail Physa, the scud Gammarus, the
cessfully root if wave action and currents are not too  oligochaete worm Limnodrilus, the mayfly Ephemerella,
strong. Most animals in unconsolidated sediments live  the freshwater mollusks Elliptio and Anodonta, and the
within the substrate, e.g., Macoma and the amphipod   fingernail clam Sphaerium.
Melita. Some, such as the polychaete worm Chaetopterus,      Mud.-The unconsolidated particles smaller than
maintain permanent burrows, and others may live on the   stones are predominantly silt and clay, although coarser
surface, especially in coarse-grained sediments.          sediments or organic material may be intermixed. Organ-
  In the Marine and Estuarine Systems, Unconsolidated   isms living in mud must be able to adapt to low oxygen
Bottom communities are relatively stable. They vary from   concentrations. Examples of Dominance Types for the
the Arctic to the tropics, depending largely on temper-   Marine and Estuarine Systems include the terebellid worm
ature, and from the open ocean to the upper end of the  Amphitrite, the boring clam Platyodon, the deep-sea
estuary, depending on salinity. Thorson (1957) summarized   scallop Placopecten, the quahog Mercenaria, the macoma
and described characteristic types of level-bottom com-   Macoma, the echiurid worm  Urechis, the mud snail
munities in detail.                                      Nassarius, and the sea cucumber Thyone. Examples of
  In the Riverine System, the substrate type is largely   Dominance Types for the Lacustrine, Palustrine, and
determined by current velocity, and plants and animals   Riverine Systems are the sewage worm Tubifex, fresh-
exhibit a high degree of morphologic and behavioral adap-   water mollusks Anodonta, Anodontoides, and Elliptio, the
tation to flowing water. Certain species are confined to  fingernail clams Pisidium and Sphaerium, and the midge
specific substrates and some are at least more abundant   Chironomus.









                                                                                                              15


   Organic.-The unconsolidated material smaller than    Inland, the stoneworts Chara, Nitella, and Tolypella are
stones is predominantly organic. The number of species  examples of algae that look much like vascular plants and
is limited and faunal productivity is very low (Welch 1952).  may grow in similar situations. However, meadows of
Examples of Dominance Types for Estuarine and Marine   Chara may be found in Lacustrine water as deep as 40 m
Systems are the soft-shell clam Mya, the false angel wing   (131 feet) (Zhadin and Gerd 1963), where hydrostatic
Petricola pholadiformis, the clam worm Nereis, and the  pressure limits the survival of vascular submergents
mud snail Nassarius. Examples for the Lacustrine, Palus-  (phanaerogams) (Welch 1952). Other algae bearing less
trine, and Riverine Systems are the sewage worm Tubifex,  resemblance to vascular plants are also common. Mats of
the snail Physa, the harpacticoid copepod Canthocamptus,   filamentous algae may cover the bottom in dense blankets,
and the oligochaete worm Limnodrilus.                    may rise to the surface under certain conditions, or may
  Dominance Types for Unconsolidated Bottoms in the  become stranded on Unconsolidated or Rocky Shores.
Marine and Estuarine Systems were taken predominant-        Aquatic Moss. -Aquatic mosses are far less abundant
ly from Miner (1950), Smith (1964), Abbott (1968), and   than algae or vascular plants. They occur primarily in the
Ricketts and Calvin (1968). Dominance Types for Uncon-   Riverine System and in permanently flooded and inter-
solidated Bottoms in the Lacustrine, Riverine, and Palus-  mittently exposed parts of some Lacustrine systems. The
trine Systems were taken predominantly from Krecker   most important Dominance Types include genera such as
and Lancaster (1933), Stehr and Branson (1938), Johnson  Fissidens, Drepanocladus, and Fontinalis. Fontinalis may
(1970), Brinkhurst and Jamieson (1972), Clarke (1973),  grow to depths as great as 120 m (394 feet) (Hutchinson
Hart and Fuller (1974), Ward (1975), and Pennak (1978).  1975). For simplicity, aquatic liverworts of the genus Mar-
                                                         supella are included in this Subclass.
Aquatic Bed                                                  Rooted Vascular.-Rooted Vascular Beds include a
  Definition. The Class Aquatic Bed includes wetlands   large array of vascular species in the Marine and Estu-
and deepwater habitats dominated by plants that grow   arine Systems. They have been referred to by others as
principally on or below the surface of the water for most   temperate grass flats (Phillips 1974); tropical marine
of the growing season in most years. Water regimes in-  meadows (Odum 1974); and eelgrass beds, turtlegrass
clude subtidal, irregularly exposed, regularly flooded,  beds, and seagrass beds (Akins and Jefferson 1973;
permanently flooded, intermittently exposed, semiperm-   Eleuterius 1973; Phillips 1974). The greatest number of
anently flooded, and seasonally flooded.                 species occur in shallow, clear tropical, or subtropical
                                                         waters of moderate current strength in the Caribbean and
  Description. Aquatic Beds represent a diverse group of  along the Florida and Gulf Coasts. Principal Dominance
plant communities that requires surface water for opti-  Types in these areas include turtle grass (Thalassia testu-
mum growth and reproduction. They are best developed   dinum), shoalgrass (Halodule wrightii), manatee grass
in relatively permanent water or under conditions of re-  (Cymodoeeafiliformis), widgeon grass (Ruppia maritima),
peated flooding. The plants are either attached to the   sea grasses (Halophila spp.), and wild celery (Vallisneria
substrate or float freely in the water above the bottom   americana).
or on the surface.                                         Five major vascular species dominate along the tem-
  Subclasses and Dominance Types.                        perate coasts of North America: shoalgrass, surf grasses
   Algal.-Algal Beds are widespread and diverse in the  (Phyllospadix scouleri, P. torreyi), widgeon grass, and eel-
Marine and Estuarine Systems, where they occupy sub-  grass (Zostera marina). Eelgrass beds have the most ex-
strates charactt :'.ed by a wide range of sediment depths   tensive distribution, but they are limited primarily to the
and textures. They occur in both the Subtidal and Inter-  more sheltered estuarine environment. In the lower salin-
tidal Subsystems and may grow to depths of 30 m (98 feet).  ity zones of estuaries, stands of widgeon grass, pondweed
Coastal Algal Beds are most luxuriant along the rocky  (Potamogeton), and wild celery often occur, along with
shores of the Northeast and West. Kelp (Macrocystis) beds   naiads (Najas) and water milfoil (Myriophyllum).
are especially well developed on the rocky substrates of    In the Riverine, Lacustrine, and Palustrine Systems,
the Pacific Coast. Dominance Types such as the rockweeds   rooted vascular aquatic plants occur at all depths within
Fucus and Ascophyllum and the kelp Laminaria are com-   the photic zone. They often occur in sheltered areas where
mon along both coasts. In tropical regions, green algae,  there is little water movement (Wetzel 1975); however,
including forms containing calcareous particles, are more   they also occur in the flowing water of the Riverine
characteristic; Halimeda and Penicillus are common ex-  System, where they may be streamlined or flattened in
amples. The red alga Laurencia, and the green algae  response to high water velocities. Typical inland genera
Caulerpa, Enteromorpha, and Ulva are also common   include pondweeds,  horned pondweed (Zannichellia
Estuarine and Marine dominance types; Enteromorpha   palustris), ditch grasses (Ruppia), wild celery, and water-
and Ulva are tolerant of fresh water and flourish near the  weed (Elodea). The riverweed (Podostemum ceratophyl-
upper end of some estuaries. The stonewort Chara is also  lum) is included in this class despite its lack of truly
found in estuaries.                                      recognizable roots (Sculthorpe 1967).









16


  Some of the rooted vascular species are characterized  arily their elevation, wave exposure, the age of the Reef,
by floating leaves. Typical dominants include water lilies  and its exposure to waves.
(Nymphaea, Nuphar), floating-leaf pondweed (Potamoge-       Mollusk. -This Subclass occurs in both the Intertidal
ton natans), and water shield (Brasenia schreberi). Plants  and Subtidal Subsystems of the Estuarine System. These
such as yellow water lily (Nuphar luteum) and water   Reefs are found on the Pacific, Atlantic, and Gulf Coasts
smartweed (Polygonum amphibium), which may stand   and in Hawaii and the Caribbean. Mollusk Reefs may
erect above the water surface or substrate, may be con-  become extensive, affording a substrate for sedentary and
sidered either emergents or rooted vascular aquatic plants,  boring organisms and a shelter for many others. Reef
depending on the life form adopted at a particular site.  mollusks are adapted to great variations in water level,
 Floating Vascular.-Beds of floating vascular plants  salinity, and temperature, and these same factors control
occur mainly in the Lacustrine, Palustrine, and Riverine   their distribution. Examples of Dominance Types for this
Systems and in the fresher waters of the Estuarine Sys-   Subclass are the oysters Ostrea and Crassostrea (Smith
tem. The plants float freely either in the water or on its  1964; Abbott 1968; Ricketts and Calvin 1968).
surface. Dominant plants that float on the surface include   Worm.-Worm Reefs are constructed by large col-
the duckweeds (Lemna, Spirodela), water lettuce (Pistia  onies of Sabellariid worms living in individual tubes con-
stratiotes), water hyacinth (Eichhornia crassipes), water   structed from cemented sand grains. Although they do
nut (Trapa natans), water ferns (Salvinia spp.), and mos-   not support as diverse a biota as do Coral and Mollusk
quito ferns (Azolla). These plants are found primarily in  Reefs, they provide a distinct habitat which may cover
protected portions of slow-flowing rivers and in the  large areas. Worm Reefs are generally confined to tropical
Lacustrine and Palustrine Systems. They are easily moved   waters, and are most common along the coasts of Florida,
about by wind or water currents and cover a large area   Puerto Rico, and the Virgin Islands. They occur in both
of water in some parts of the country, particularly the   the Intertidal and Subtidal Systems of the Marine and
Southeast. Dominance Types for beds floating below the   Estuarine Systems where the salinity approximates that
surface include bladderworts (Utricularia), coontails  of sea water. The reefworm Sabellaria is an example of
(Ceratophyllum), and watermeals (Wolffia) (Sculthorpe   a Dominance Type for this Subclass (Ricketts and Calvin
1967; Hutchinson 1975).                                  1968).


Reef                                                     Streambed
  Definition. The Class Reef includes ridge-like or mound-  Definition. The Class Streambed includes all wetland
like structures formed by the colonization and growth of  contained within the Intermittent Subsystem of the River-
sedentary invertebrates. Water regimes are restricted to  ine System and all channels of the Estuarine System or
subtidal, irregularly exposed, regularly flooded, and   of the Tidal Subsystem of the Riverine System that are
irregularly flooded.                                     completely dewatered at low tide. Water regimes are
  Description. Reefs are characterized by their elevation  restricted to irregularly exposed, regularly flooded irreg
                                                          ularly flooded, seasonally flooded, temporarily flooded, and
above the surrounding substrate and their interference
with normal wave flow; they are primarily subtidal, but  intermttently flooded.
parts of some reefs may be intertidal as well. Although    Description. Streambeds vary greatly in substrate and
corals, oysters, and tube worms are the most visible  form depending on the gradient of the channel, the veloc-
organisms and are mainly responsible for reef formation,  ity of the water, and the sediment load. The substrate
other mollusks, foraminifera, coralline algae, and other  material frequently changes abruptly between riffles and
forms of life also contribute substantially to reef growth.   pools, and complex patterns of bars may form on the con-
Frequently, reefs contain far more dead skeletal material   vex side of single channels or be included as islands within
and shell fragments than living matter.                  the bed of braided streams (Crickmay 1974). In mountain-
  Subclasses and Dominance Types.                        ous areas the entire channel may be cut through bedrock.
  Subclasses and Dominance Types.
    Coral. -Coral Reefs are widely distributed in shallow   In most cases streambeds are not vegetated because of
    Coral.--Coral Reefs are widely distributed in shallow
waters of warm seas, in Hawaii, Puerto Rico, the Virgin  the scouring effect of moving water but like Uncon
Islands, and southern Florida. They were characterized   solidated Shores, they maybe colonized by "pioneering"
                                                          annuals or perennials during periods of low flow or they
by Odum (1971) as stable, well-adapted, highly diverse,
and highly productive ecosystems with a great degree of  may have perennial emergents and shrubs that are too
internal symbiosis. Coral Reefs lie almost entirely within   scattered to qualify the area for classification as Emer-
                                                          gent Wetland or Scrub-Shrub Wetland.
the Subtidal Subsystem of the Marine System, although   gent Wetland or Scrub-Shrub Wetland.
the upper part of certain Reefs may be exposed. Examples   Subclasses and Dominance Types.
of Dominance Types are the corals Porites, Acropora, and     Bedrock.--This Subclass is characterized by a bedrock
Montipora. The distribution of these types reflects prim-  substrate covering 75% or more of the stream channel.









                                                                                                              17


It occurs most commonly in the Riverine System in high   unlike that of Emergent Wetlands, is usually killed by
mountain areas or in glaciated areas where bedrock is ex-  rising water levels or sudden flooding. A typical Domi-
posed. Examples of Dominance Types are the mollusk An-   nance Type is Panicum capillare.
cylus, the oligochaete worm Limnodrilus, the snail Physa,   Dominance Types for Streambeds in the Estuarine Sys-
the fingernail clam Pisidium, and the mayflies Caenis and   tem were taken primarily from Smith (1964), Abbott
Ephemerella.                                              (1968), and Ricketts and Calvin (1968) and those for
   Rubble.-This Subclass is characterized by stones,   streambeds in the Riverine System from Krecker and Lan-
boulders, and bedrock that in combination cover more than   caster (1933), Stehr and Branson (1938), van der Schalie
75% of the channel. Like Bedrock Streambeds, Rubble   (1948), Kenk (1949), Cummins et al. (1964), Clarke (1973),
Streambeds are most common in mountainous areas and   and Ward (1975).
the dominant organisms are similar to those of Bedrock
and are often forms capable of attachment to rocks in flow-  Rocky Shore
ing water.                                                  Definition. The Class Rocky Shore includes wetland en-
    Cobble-Gravel.-In this Subclass at least 25% of the   vironments characterized by bedrock, stones, or boulders
substrate is covered by unconsolidated particles smaller   which singly or in combination have an areal cover of 75%
than stones; cobbles or gravel predominate. The Subclass   or more and an areal coverage by vegetation of less than
occurs in riffle areas or in the channels of braided streams.   30%. Water regimes are restricted to irregularly exposed,
Examples of Dominance Types in the Intermittent Subsys-   regularly flooded, irregularly flooded, seasonally flooded,
tem of the Riverine System are the snail Physa, the oligo-  temporarily flooded, and intermittently flooded.
chaete worm Limnodrilus, the mayfly Caenis, the midge
                                                           Description. In Marine and Estuarine Systems, Rocky
Chironomus, and the mosquito Anopheles. Examples of 
Dominance Types in the Estuarine System or Tidal Sub-   Shores are generally high-energy habitats which lie ex-
Dominance Types in the Estuarine System or Tidal Sub-
system of the Riverine System are the mussels Modiolus   posed as a result of continuous erosion by wind-driven
and Mytilus.                                              waves or strong currents. The substrate is stable enough
    Sand.-In this Subclass, sand-sized particles predom- .to permit the attachment and growth of sessile or seden-
   Sand.-In this Subclass, sand-sized particles predom-
inate among the particles smaller than stones. Sand   tary invertebrates and attached algae or lichens. Rocky
Streambed often contains bars and beaches interspersed   Shores usually display a vertical zonation that is a func-
                                                         tion of tidal range, wave action, and degree of exposure
with Mud Streambed or it may be interspersed with
Cobble-Gravel Streambed in areas of fast flow or heavy   to the sun. In the Lacustrine and Riverine Systems Rocky
sediment load. Examples of Dominance Types in the   Shores support sparse plant and animal communities.
Riverine System are the scud Gammarus, the snails Physa     Subclasses and Dominance Types.
and Lymnaea,  and the midge Chironomus;  in the              Bedrock.-These wetlands have bedrock covering 75%
Estuarine System the ghost shrimp Callianassa is a com-   or more of the surface and less than 30% areal coverage
mon Dominance Type.                                       of macrophytes.
   Mud.-In this Subclass, the particles smaller than         Rubble.-These wetlands have less than 75% areal
stones are chiefly silt or clay. Mud Streambeds are com-   cover of bedrock, but stones and boulders alone or in com-
mon in arid areas where intermittent flow is character-   bination with bedrock cover 75% or more of the area. The
istic of streams of low gradient. Such species as tamarisk   areal coverage of macrophytes is less than 30%.
(Tamarix gallica) may occur, but are not dense enough       Communities or zones of Marine and Estuarine Rocky
to qualify the area for classification as Scrub-Shrub   Shores have been widely studied (Lewis 1964; Ricketts and
Wetland. Mud Streambeds are also common in the Estu-   Calvin 1968; Stephenson and Stephenson 1972). Each zone
arine System and the Tidal Subsystem of the Riverine   supports a rich assemblage of invertebrates and algae or
System. Examples of Dominance Types for Mud Stream-   lichens or both. Dominance Types of the Rocky Shores
beds include the crayfish Procambarus, the pouch snail  often can be characterized by one or two dominant genera
Aplexa, the fly Tabanus, the snail Lymnaea, the finger-  from these zones.
nail clam Sphaerium, and (in the Estuarine System) the    The uppermost zone (here termed the littorine-lichen
mud snail Nassarius.                                      zone) is dominated by periwinkles (Littorina and Nerita)
    Organic. -This Subclass is characterized by channels   and lichens. This zone frequently takes on a dark, or even
formed in peat or muck. Organic Streambeds are common   black appearance, although abundant lichens may lend a
in the small creeks draining Estuarine Emergent Wet-   colorful tone. These organisms are rarely submerged, but
lands with organic soils. Examples of Dominance Types   are kept moist by sea spray. Frequently this habitat is
are the mussel Modiolus in the Estuarine System and the   invaded from the landward side by semimarine genera
oligochaete worm Limnodrilus in the Riverine System.   such as the slater Ligia.
    Vegetated.--These  streambeds are exposed long    The next lower zone (the balanoid zone) is commonly
enough to be colonized by herbaceous annuals or seedling  dominated by mollusks, green algae, and barnacles of the
herbaceous perennials (pioneer plants). This vegetation,   balanoid group. The zone appears white. Dominance Types












such as the barnacles Balanus, Chthamalus, and Tetra-  in this Class. Unconsolidated Shores are found adjacent
clita may form an almost pure sheet, or these animals may   to Unconsolidated Bottoms in all Systems; in the Palus-
be interspersed with mollusks, tube worms, and algae such  trine and Lacustrine Systems, the Class may occupy the
as Pelvetia, Enteromorpha, and Ulva.                     entire basin. As in Unconsolidated Bottoms, the particle
 The transition between the littorine-lichen and balanoid  size of the substrate and the water regime are the impor-
zones is frequently marked by the replacement of the  tant factors determining the types of plant and animal
periwinkles with limpets such as Acmaea and Siphonaria.   communities present. Different substrates usually support
The limpet band approximates the upper limit of the  characteristic invertebrate fauna. Faunal distribution is
regularly flooded intertidal zone.                       controlled by waves, currents, interstitial moisture, salin-
  In the middle and lower intertidal areas, which are  ity, and grain size (Hedgpeth 1957; Ranwell 1972; Riedl
flooded and exposed by tides at least once daily, lie a  and McMahan 1974).
number of other communities which can be characterized
by dominant genera. Mytilus and gooseneck barnacles    Subclasses and Dominance Types.
(Pollicipes) form communities exposed to strong wave         Cobble-Gravel. -The unconsolidated particles smaller
action. Aquatic Beds dominated by Fucus and Laminaria   than stones are predominantly cobble and gravel. Shell
lie slightly lower, just above those dominated by coralline  fragments, sand, and silt often fill the spaces between the
algae (Lithothamnion). The Laminaria Dominance Type   larger particles. Stones and boulders may be found scat-
approximates the lower end of the Intertidal Subsystem;   tered on some Cobble-Gravel Shores. In areas of strong
it is generally exposed at least once daily. The Lithotham-   wave and current action these shores take the form of
nion Dominance Type forms the transition to the Subtidal
                                                         beaches or bars, but occasionally they form extensive flats.
Subsystem and is exposed only irregularly.               Examples of Dominance Types in the Marine and Estu-
  In the Palustrine, Riverine, and Lacustrine Systems
                 In the Palustrine, Riverine, and Lacustrine Systems   arine Systems are: the acorn barnacle Balanus, the limpet
various species of lichens such as Verrucaria spp. and Der-
                                                         Patella, the periwinkle Littorina, the rock shell Thais, the
matocarpon fluviatile, as well as blue-green algae, fre-  mussels Mytilus and Modiolus  and the Venus clam Sax-
                                                         mussels Mytilus and Modiolus, and the Venus clam Sax-
quently form characteristic zones on Rocky Shores. The
quently form characteristic zones on Rocky Shores. The   idomus. In the Lacustrine, Palustrine, and Riverine Sys-
distribution of these species depends on the duration of
                                                         terns examples of Dominance Types are the freshwater
flooding or wetting by spray and is similar to the zona-
tion of species in the Marine and Estuarine Systems (Hut-   mollusk Elliptio, the snails Lymnaea and Physa the toad
chinson 1975). Though less abundant than lichens, aquatic   bug Gelastocoris, the leech Erpodella, and the springtail
liverworts such as Marsupella emarginata var. aquatica  Agrenia.
or mosses such as Fissidens julianus are found on the       Sand.-The unconsolidated particles smaller than
Rocky Shores of lakes and rivers. If aquatic liverworts or  stones are predominantly sand which may be either cal-
mosses cover 30% or more of the substrate, they should   careous or terrigenous in origin. They are prominent
be placed in the Class Aquatic Bed. Other examples of  features of the Marine, Estuarine, Riverine, and Lacus-
Rocky Shore Dominance Types are the caddisfly Hydro-   trine Systems where the substrate material is exposed to
psyche and the fingernail clam Pisidium.                 the sorting and washing action of waves. Examples of
                                                         Dominance Types in the Marine and Estuarine Systems
                                                         are the wedge shell Donax, the soft-shell clam Mya, the
                                                         quahog Mercenaria, the olive shell Oliva, the blood worm
  Definition. The Class Unconsolidated Shore includes all  Euzonus, the beach hopper Orchestia, the pismo clam
wetland habitats having three characteristics: (1) uncon-   Tivela stultorum, the mole crab Emerita, and the lugworm
solidated substrates with less than 75% areal cover of  Arenicola. Examples of Dominance Types in the Riverine,
stones, boulders, or bedrock; (2) less than 30% areal cover   Lacustrine, and Palustrine Systems are the copepods
of vegetation other than pioneering plants; and (3) any   Parastenocaris and Phyllognathopus, the oligochaete
of the following water regimes: irregularly exposed,   worm Pristina, the freshwater mollusks Anodonta and
regularly flooded, irregularly flooded, seasonally flooded,  Elliptio, and  the fingernail  clams Pisidium  and
temporarily flooded, intermittently flooded, saturated, or  Sphaerium.
artificially flooded. Intermittent or intertidal channels of  Mud.-The unconsolidated particles smaller than
the Riverine System and intertidal channels of the Estu-   stones are predominantly silt and clay. Anaerobic condi-
arine System are classified as Streambed.                tions often exist below the surface. Mud Shores have a
  Description. Unconsolidated Shores are characterized   higher organic content than Cobble-Gravel or Sand
by substrates lacking vegetation except for pioneering   Shores. They are typically found in areas of minor wave
plants that become established during brief periods when   action. They tend to have little slope and are frequently
growing conditions are favorable. Erosion and deposition  called flats. Mud Shores support diverse populations of
by waves and currents produce a number of landforms   tube-dwelling and burrowing invertebrates that include
such as beaches, bars, and flats, all of which are included   worms, clams, and crustaceans (Gray 1974). They are com-








                                                                                                             19


monly colonized by algae and diatoms which may form a  Moss-Lichen Wetland
crust or mat.                                              Definition. The Moss-Lichen Wetland Class includes
  Irregularly flooded Mud Shores in the Estuarine System   areas where mosses or lichens cover substrates other than
have been called salt flats, pans, or pannes. They are   rock and where emergents, shrubs, or trees make up less
typically high in salinity and are usually surrounded by,   than 30% of the areal cover. The only water regime is
or lie on the landward side of, Emergent Wetland (Mar-  saturated.
tin et al. 1953, Type 15). In many arid areas, Palustrine
and Lacustrine Mud Shores are encrusted or saturated    Description. Mosses and lichens are important compo-
with salt. Martin et al. (1953) called these habitats inland   nents of the flora in many wetlands, especially in the north,
saline flats (Type 9); they are also called alkali flats, salt  but these plants usually form a ground cover under a domi-
flats, and salt pans. Mud Shores may also result from   nant layer of trees, shrubs, or emergents. In some in-
removal of vegetation by man, animals, or fire, or from   stances higher plants are uncommon and mosses or lichens
the discharge of thermal waters or pollutants.           dominate the flora. Such Moss-Lichen Wetlands are not
  Examples of Dominance Types in the Marine and Estu-  common, even in the northern United States where they
arine Systems include the fiddler crab Uca, the ghost   occur most frequently.
shrimp Callianassa, the mud snails Nassarius and
Macoma, the clam worm Nereis, the sea anemone Cerian-      Subclasses and Dominance Types.
thus, and the seacucumber Thyone. In the Lacustrine,       Moss. -Moss Wetlands are most abundant in the far
Palustrine, and Riverine Systems, examples of Dominance   north. Areas covered with peat mosses (Sphagnum spp.)
Types are the fingernail clam Pisidium, the snails Aplexa   are usually called bogs (Golet and Larson 1974; Jeglum
and Lymnaea, the crayfish Procambarus, the harpacticoid  et al. 1974; Zoltai et al. 1975), whether Sphagnum or
copepods Canthocamptus and Bryocamptus, the fingernail  higher plants are dominant. In Alaska, Drepanocladus and
clam Sphaerium, the freshwater mollusk Elliptio, the  the liverwort Chiloscyphusfragilis may dominate shallow
shore bug Saldula, the isopod Asellus, the crayfish Cam-   pools with impermanent water; peat moss and other
barus, and the mayfly Tortopus.                          mosses (Campylium stellatum, Aulacomnium palustre,
                                                         and Oncophorus wahlenbergii) are typical of wet soil in
   Organic.-The unconsolidated material smaller than   this region (Britton 1957; Drury 1962).
stones is predominantly organic soils of formerly vege-     Lichen.-Lichen  Wetlands are also a northern
tated wetlands. In the Marine and Estuarine Systems,   Subclass. Reindeer moss (Cladina rangiferina) forms the
Organic Shores are often dominated by microinvertebrates   most important Dominance Type. Pollett and Bridgewater
such as foraminifera, and by Nassarius, Littorina, Uca,  (1973) described areas with mosses and lichens as bogs
Modiolus, Mya, Nereis, and the false angel wing Petricola   or fens, the distinction being based on the availability of
pholadiformis. In the Lacustrine, Palustrine, and River-  nutrients and the particular plant species present. The
ine Systems, examples of Dominance Types are Cantho-  presence of Lichen Wetlands has been noted in the Hud-
camptus, Bryocamptus, Chironomus, and the backswim-  son Bay Lowlands (Sjdrs 1959) and in Ontario (Jeglum et
mer Notonecta.                                           al. 1974).
    Vegetated.-Some nontidal shores are exposed for a
sufficient period to be colonized by herbaceous annuals or  Emergent Wetland
seedling herbaceous perennials (pioneer plants). This    Definition. The Emergent Wetland Class is charac-
vegetation, unlike that of Emergent Wetlands, is usually  terized by erect, rooted, herbaceous hydrophytes, ex-
killed by rising water levels and may be gone before the  eluding mosses and lichens. This vegetation is present for
beginning of the next growing season. Many of the pioneer  most of the growing season in most years. These wetlands
species are not hydrophytes but are weedy mesophytes   are usually dominated by perennial plants. All water
that cannot tolerate wet soil or flooding. Examples of  regimes are included except subtidal and irregularly
Dominance Types in the Palustrine, Riverine, and Lacus-  exposed.
trine Systems are cocklebur (Xanthium strumarium) and
barnyard grass (Echinochloa crusgalli).                    Description. In areas with relatively stable climatic con-
  Dominance Types for Unconsolidated Shores in the Mar-   ditions, Emergent Wetlands maintain the same appear-
ine and Estuarine Systems were taken primarily from   ance year after year. In other areas, such as the prairies
Smith (1964), Morris (1966), Abbott (1968), Ricketts and   of the central United States, violent climatic fluctuations
Calvin (1968), and Gosner (1971). Dominance Types for  cause them to revert to an open water phase in some years
Unconsolidated Shores in the Lacustrine, Riverine, and   (Stewart and Kantrud 1972). Emergent Wetlands are
Palustrine Systems were taken primarily from Stehr and   found throughout the United States and occur in all
Branson (1938), Kenk (1949), Ward and Whipple (1959),  Systems except the Marine. Emergent Wetlands are
Cummins et al. (1964), Johnson (1970), Ingram (1971),  known by many names, including marsh, meadow, fen,
Clarke (1973), and Hart and Fuller (1974).               prairie pothole, and slough. Areas that are dominated by








20


pioneer plants which become established during periods    Description. Scrub-Shrub Wetlands may represent a
of low water are not Emergent Wetlands and should be  successional stage leading to Forested Wetland, or they
classified as Vegetated Unconsolidated Shores or Vege-   may be relatively stable communities. They occur only in
tated Streambeds.                                        the Estuarine and Palustrine Systems, but are one of the
                                                         most widespread classes in the United States (Shaw and
 Subclasses and Dominance Types.
   Persistent. -Persistent Emergent Wetlands are domi-   Fredine 1956). Scrub-Shrub Wetlands are known by many
                                                         names, such as shrub swamp (Shaw and Fredine 1956)
nated by species that normally remain standing at least                       swamp (Shaw and Fredine 1956),
                                                         shrub carr (Curtis 1959), bog (Heinselman 1970), and poco-
until the beginning of the next growing season. This  sin (Kologiski 1977). For practical reasons we have also
Subclass is found only in the Estuarine and Palustrine     cluded forests composed of young trees less than 6 m
Systems.                                                 tall
 Persistent Emergent Wetlands dominated by saltmarsh
cordgrass (Spartina alterniflora), saltmeadow cordgrass    Subclasses and Dominance Types.
(S. patens), big cordgrass (S. cynosuroides), needlerush    Broad-leaved Deciduous.-In Estuarine System Wet-
(Juncus roemerianus), narrow-leaved cattail (Typha   lands the predominant deciduous and broad-leaved trees
angustifolia), and southern wild rice (Zizaniopsis miliacea)  or shrubs are plants such as sea-myrtle (Baccharis halimi-
are major components of the Estuarine systems of the  folia) and marsh elder (Ivafrutescens). In the Palustrine
Atlantic and Gulf Coasts of the United States. On the   System typical Dominance Types are alders (Alnus spp.),
Pacific Coast, common pickleweed (Salicornia virginica),  willows (Salix spp.), buttonbush (Cephalanthus occiden-
sea blite (Suaeda californica), arrow grass (Triglochin  talis), red osier dogwood (Cornus stolonifera), honeycup
maritimum), and California cordgrass (Spartinafoliosa)  (Zenobia pulverulenta), spirea (Spiraea douglasii), bog
are common dominants.                                    birch (Betula pumila), and young trees of species such as
 Palustrine Persistent Emergent Wetlands contain a vast  red maple (Acer rubrum) or black spruce (Picea mariana).
array of grasslike plants such as cattails (Typha spp.),    Needle-leaved Deciduous.--This Subclass, consisting
bulrushes (Scirpus spp.), saw grass (Cladiumjamaicense),  of wetlands where trees or shrubs are predominantly
sedges (Carex spp.); and true grasses such as reed   deciduous and needle-leaved, is represented by young or
(Phragmites australis), manna grasses (Glyceria spp.),  stunted trees such as tamarack or bald cypress (Taxodium
slough grass (Beckmannia syzigachne), and whitetop   distichum).
(Scolochloafestucacea). There is also a variety of broad-    Broad-leaved Evergreen. -In the Estuarine System,
leaved persistent emergents such as purple loosestrife  vast wetland acreages are dominated by mangroves
(Lythrum salicaria), dock (Rumex mexicanus), water-   (Rhizophora mangle, Languncularia racemosa, Conocar-
willow (Decodon verticillatus), and many species of smart-  pus erectus, and Avicennia germinans) that are less than
weeds (Polygonum).                                       6 m tall. In the Palustrine System, the broad-leaved ever-
   Nonpersistent. -Wetlands in this Subclass are domi-   green species are typically found on organic soils. North-
nated by plants which fall to the surface of the substrate   ern representatives are labrador tea (Ledum groenlan-
or below the surface of the water at the end of the grow-   dicum), bog rosemary (Andromeda glaucophylla), bog
ing season so that, at certain seasons of the year, there  laurel (Kalmia polifolia), and the semi-evergreen leather-
is no obvious sign of emergent vegetation. For example   leaf (Chamaedaphne ealyculata). In the south, fetterbush
wild rice (Zizania aquatica) does not become apparent in  (Lyonia lucida), coastal sweetbells (Leucothoe axillaris),
the North Central States until midsummer and fall, when   inkberry (Ilex glabra), and the semi-evergreen black ti-ti
it may form dense emergent stands. Nonpersistent emer-   (Cyrilla racemiflora) are characteristic broad-leaved
gents also include species such as arrow arum (Peltandra   evergreen species.
virginica), pickerelweed (Pontederia cordata), and arrow-    Needle-leaved Evergreen.--The dominant species in
heads (Sagittaria spp.). Movement of ice in Estuarine,  Needle-leaved Evergreen Wetlands are young or stunted
Riverine, or Lacustrine Systems often removes all traces  trees such as black spruce or pond pine (Pinus serotina).
of emergent vegetation during the winter. Where this         Dead. -Dead woody plants less than 6 m tall dominate
occurs, the area should be classified as Nonpersistent   Dead Scrub-Shrub Wetlands. These wetlands are usual-
Emergent Wetland.                                        ly produced by a prolonged rise in the water table resulting
                                                         from impoundment of water by landslides, man, or
Scrub-Shrub Wetland                                      beavers. Such wetlands may also result from various other
                                                         factors such as fire, salt spray, insect infestation, air pollu-
 Definition. The Class Scrub-Shrub Wetland includes  tion, and herbicides.
areas dominated by woody vegetation less than 6 m
(20 feet) tall. The species include true shrubs, young trees,  Forested Wetland
and trees or shrubs that are small or stunted because of    Definition. The Class Forested Wetland is characterized
environmental conditions. All water regimes except sub-  by woody vegetation that is 6 m tall or taller. All water
tidal are included.                                      regimes are included except subtidal.









                                                                                                               21


  Description. Forested Wetlands are most common in                            Modifiers
the eastern United States and in those sections of the West
where moisture is relatively abundant, particularly along    To fully describe wetlands and deepwater habitats, one
rivers and in the mountains. They occur only in the Palus-  must apply certain Modifiers at the Class level and at lower
trine and Estuarine Systems and normally possess an   levels in the classification hierarchy. The Modifiers
overstory of trees, an understory of young trees or shrubs,   described below were adapted from existing classifications
and a herbaceous layer. Forested Wetlands in the Estu-   or were developed specifically for this system.
arine System, which include the mangrove forests of
Florida, Puerto Rico, and the Virgin Islands, are known
by such names as swamps, hammocks, heads, and bottoms.                  Water Regime Modifiers
These names often occur in combination with species
names or plant associations such as cedar swamp or    Precise description of hydrologic characteristics requires
bottomland hardwoods.                                     detailed knowledge of the duration and timing of surface
  Subclasses and Dominance Types.                         inundation, both yearly and long-term, as well as an under-
   Broad-leaved Deciduous.--Dominant trees typical of  standing of groundwater fluctuations. Because such in-
Broad-leaved Deciduous Wetlands, which are represented   formation is seldom available, the water regimes that, in
throughout the United States, are most common in the   part, determine characteristic wetland and deepwater
South and East. Common dominants are species such as   plant and animal communities are described here in only
red maple, American elm (Ulmus americana), ashes (Frax-  general terms. Water regimes are grouped under two ma-
inus pennsylvanica and F. nigra), black gum (Nyssa   jor-headings, Tidal and Nontidal.
sylvatica), tupelo gum (N. aquatica), swamp white oak       Tidal Water Regime Modifiers are used for wetlands and
(Quercus bicolor), overcup oak (Q. lyrata), and basket oak   deepwater habitats in the Estuarine and Marine Systems
(Q. michauxii). Wetlands in this subclass generally occur   and Nontidal Modifiers are used for all nontidal parts of
on mineral soils or highly decomposed organic soils.      the Palustrine, Lacustrine, and Riverine Systems. The
   Needle-leaved Deciduous.-The southern representa-  Tidal Subsystem of the Riverine System and tidally in-
tive of the Needle-leaved Deciduous Subclass is bald  fluenced parts of the Palustrine and Lacustrine Systems
cypress (Taxodium distichum), which is noted for its ability  require careful selection of Water Regime Modifiers. We
to tolerate long periods of surface inundation. Tamarack   designate subtidal and irregularly exposed wetlands and
is characteristic of the Boreal Forest Region, where it  deepwater habitats in the Palustrine, Riverine, and Lacus-
occurs as a dominant on organic soils. Relatively few other  trine Systems as permanently flooded-tidal rather than
species are included in this Subclass.                    subtidal, and Palustrine, Riverine, and Lacustrine wet-
   Broad-leaved Evergreen.-In the Southeast, Broad-   lands regularly flooded by the tide as regularly flooded.
leaved Evergreen Wetlands reach their greatest develop-  If Palustrine, Riverine, and Lacustrine wetlands are on-
ment. Red bay (Persea borbonia), loblolly bay (Gordonia   ly irregularly flooded by tides, we designate them by the
lasianthus), and sweet bay (Magnolia virginiana) are   appropriate nontidal Water Regime Modifier with the
prevalent, especially on organic soils. This Subclass also  word tidal added, as in seasonally flooded-tidal.
includes red mangrove, black mangrove (Avicennia ger-
minans), and white mangrove (Languncularia racemosa),   Tidal
which are adapted to varying levels of salinity.            The water regimes are largely determined by oceanic
   Needle-leaved Evergreen. -Black spruce, growing on   tides.
organic soils, represents a major dominant of the Needle-
leaved Evergreen Subclass in the North. Though black          tidal. The substrate is permanently flooded with
spruce is common on nutrient-poor soils, Northern white
cedar (Thuja occidentalis) dominates northern wetlands      Irregularly Exposed. The land surface is exposed by
on more nutrient-rich sites. Along the Atlantic Coast,   tides less often than daily.
Atlantic white cedar (Chamaecyparis thyoides) is one of    Regularly Flooded. Tidal water alternately floods and
the most common dominants on organic soils. Pond pine   exposes the land surface at least once daily.
is a common needle-leaved evergreen found in the South-
east in association with dense stands of broad-leaved       Irregularly Flooded. Tidal water floods the land surface
evergreen and deciduous shrubs.                           less often than daily.
   Dead.-Dead Forested Wetlands are dominated by           The periodicity and amplitude of tides vary in different
dead woody vegetation taller than 6 m (20 feet). Like Dead   parts of the United States, mainly because of differences
Scrub-Shrub Wetlands, they are most common in, or  in latitude and geomorphology. On the Atlantic Coast, two
around the edges of, man-made impoundments and beaver   nearly equal high tides are the rule (semidiurnal). On the
ponds. The same factors that produce Dead Scrub-Shrub   Gulf Coast, there is frequently only one high tide and one
Wetlands produce Dead Forested Wetlands.                  low tide each day (diurnal); and on the Pacific Coast there









22


are usually two unequal high tides and two unequal low  tion. The dominant plant communities under this regime
tides (mixed semidiurnal).                              may change as soil moisture conditions change. Some
  Individual tides range in height from about 9.5 m (31  areas exhibiting this regime do not fall within our defini-
feet) at St. John, New Brunswick (U.S. National Oceanic  tion of wetland because they do not have hydric soils or
and Atmospheric Administration 1973) to less than 1 m   support hydrophytes.
(3.3 feet) along the Louisiana coast (Chabreck 1972). Tides    Artificially Flooded. The amount and duration of flood-
of only 10 cm (4.0 inches) are not uncommon in Louisi-  ing is controlled by means of pumps or siphons in com-
                                                          ing is controlled by means of pumps or siphons in com-
ana. Therefore, though no hard and fast rules apply, the  bination with dikes or dams. The vegetation growing on
division between regularly flooded and irregularly flooded  these areas cannot be considered a reliable indicator of
water regimes would probably occur approximately at  water regime. Examples of artificially flooded wetlands
mean high water on the Atlantic Coast, lowest level of  are some agricultural lands managed under a rice-soybean
the higher high tide on the Pacific Coast, and just above   rotation, and wildlife management areas where forests
mean tide level of the Gulf Coast. The width of the inter-
                                                          crops, or pioneer plants may be flooded or dewatered to
tidal zone is determined by the tidal range, the slope of  attract wetland wildlife. Neither wetlands within or
                                                       ofattract wetland wildlife. Neither wetlands within or
the shoreline, and the degree of exposure of the site to  resulting from leakage from man-made impoundments,
wind and waves.
              ~~~~~wind and waves.  ~nor irrigated pasture lands supplied by diversion ditches
                                                          or artesian wells, are included under this modifier.
Nontidal
  Though not influenced by oceanic tides, nontidal water
regimes may be affected by wind or seiches in lakes. Water          Water Chemistry Modifiers
regimes are defined in terms of the growing season, which
we equate to the frost-free period (see the U.S. Depart-    The accurate characterization of water chemistry in
ment of Interior National Atlas 1970:110-111 for gen-  wetlands and deepwater habitats is difficult, both because
eralized regional delineation). The rest of the year is  of problems in measurement and because values tend to
defined as the dormant season, a time when even extended   vary with changes in the season, weather, time of day,
periods of flooding may have little influence on the devel-  and other factors. Yet, very subtle changes in water
opment of plant communities.                            chemistry, which occur over short distances, may have a
                                                          marked influence on the types of plants or animals that
  Permanently Flooded. Water covers the land surface
                hrm nt   Foed  year i years. Vgthatn isucoed inhabit an area. A description of water chemistry, there-
throughout the year in all years. Vegetation is composed
              ofhrobiughoat theyerinallyears Vfore, must be an essential part of this classification system.
of obligate hydrophytes.
                                                            The two key characteristics employed in this system are
  Intermittently Exposed. Surface water is present  salinity and hydrogen-ion concentration (pH). All habitats
throughout the year except in years of extreme drought.   are classified according to salinity, and freshwater habitats
  Semipermanently Flooded. Surface water persists  are further subdivided by pH levels.
throughout the growing season in most years. When sur-
face water is absent, the water table is usually at or very  Salinity Modifiers
near the land surface.
                                                            Differences in salinity are reflected in the species com-
  Seasonally Flooded. Surface water is present for ex-  position of plants and animals. Many authors have sug-
tended periods especially early in the growing season, but  gested using biological changes as the basis for subdividing
is absent by the end of the season in most years. When   the salinity range between sea water and fresh water
surface water is absent, the water table is often near the  (Remane and Schlieper 1971). Others have suggested a
land surface.                                           similar subdivision for salinity in inland wetlands (Moyle
  Saturated. The substrate is saturated to the surface for  1946; Bayly 1967; Stewart and Kantrud 1971). Since the
extended periods during the growing season, but surface  gradation between fresh and hypersaline or hyperhaline
water is seldom present.                                waters is continuous, any boundary is artificial, and few
                                                         classification systems agree completely.
  Temporarily Flooded. Surface water is present for brief    Estuarine and Marine waters are a complex solution of
               perids drin thegroing easo, bt th waer tbleEstuarine and Marine waters are a complex solution of
periods during the growing season, but the water table salts, dominated by sodium chloride (NaCl). The term
usually lies well below the soil surface for most of the  haline is used to indicate the dominance of ocean salt. The
              season. Plants t~~~~~~~~hat rwbtnulansadwtlnshaie is used to indicate the dominance of ocean salt. The
season. Plants that grow both in uplands and wetlands   relative proportions of the various major ions are usually
              are characteristic of the temporarily flooded regime.  similar to those found in sea water, even if the water is
 Intermittently Flooded. The substrate is usually ex-  diluted below sea water strength. Dilution of sea water
posed, but surface water is present for variable periods   with fresh water and concentration of sea water by
without detectable seasonal periodicity. Weeks, months,   evaporation result in a wide range of recorded salinities
or even years may intervene between periods of inunda  in both surface water and interstitial (soil) water.









                                                                                                               28


  We have modified the Venice System, suggested at a   lands into mineral-rich and mineral-poor categories (Sjbrs
"Symposium on the Classification of Brackish Waters"   1950; Heinselman 1970; Jeglum 1971; Moore and Bellamy
in 1958, for use in the Marine and Estuarine Systems   1974). We have instituted pH modifiers for freshwater
(Table 2). The System has been widely used during recent   wetlands (Table 3) because pH has been widely used to
years (Macan 1961, 1963; Burbank 1967; Carriker 1967;  indicate the difference between mineral-rich and mineral-
Reid and Wood 1976), although there has been some   poor sites, and because it is relatively easy to determine.
criticism of its applicability (den Hartog 1960; Price and   The ranges presented here are similar to those of Jeglum
Gunter 1964).                                            (1971), except that the upper limit of the circumneutral
  The salinity of inland water is dominated by four major   level (Jeglum's mesotrophic) was raised to bring it into
cations, calcium (Ca), magnesium (Mg), sodium (Na), and   agreement with usage of the term in the United States.
potassium (K); and three major anions, carbonate (C03),  The ranges given apply to the pH of water. They were
sulfate (SO4), and chloride (Cl) (Wetzel 1975). Salinity is  converted from Jeglum's moist-peat equivalents by adding
governed by the interactions between precipitation, sur-  0.5 pH units.
face runoff, groundwater flow, evaporation, and some-
times evapotranspiration by plants. The ionic ratios of
inland waters usually differ appreciably from those in the                  Soil Modifiers
sea, although there are exceptions (Bayly 1967). The great
chemical diversity of these waters, the wide variation in    Soil is one of the most important physical components
physical conditions such as temperature, and often the  of wetlands. Through its depth, mineral composition,
relative impermanence of surface water, make it extreme-  organic matter content, moisture regime, temperature
ly difficult to subdivide the inland salinity range in a mean-reianchmsytexcssasrognfucevr
                                                          regime, and chemistry, it exercises a strong influence over
dinffultwy ay(97 attemp              subdividetheinlandsaionityr e in ahea- the types of plants that live on its surface and the kinds
basis of animal life; Moyle (1945) and Stewart and Kan-   o  raim  htdelwti  t  nadtotentr
              ingfl wy. ayly(197) ttemteda  sbdivsio ontheof organisms that dwell within it. In addition, the nature
trud (1971) have suggested two very different divisions      soil is a crtical the thickness pl anic
on the basis of plant life. We employ a subdivision that  soil, is or buitical For    thes e        and     on-
is identical to that used in the Estuarine and Marine
                                                          reasons, it is essential that soil be considered in the
  The term saline is used to indicate that any of a num-   classification of wetlands.
ber of ions may be dominant or codominant. The term        According to the U.S. Soil Conservation Service, Soil
brackish has been applied to inland waters of intermediate   Survey Staff (1975:1-2), soil is limited to terrestrial situa-
salinity (Remane and Schlieper 1971; Stewart and Kan-  tions and shallow waters; however, "areas are not con-
trud 1971), but is not universally accepted (see Bayly   sidered to have soil if the surface is permanently covered
1967:84); therefore, mixosaline is used here. In some in-  by water deep enough that only floating plants are
land wetlands, high soil salinities control the invasion or  present... . Since emergent plants do not grow beyond
establishment of many plants. These salinities are ex-   a depth of about 2 m in inland waters, the waterward limit
                                                          of soil is virtually equivalent to the waterward limit of
pressed in units of specific conductance as well as percent
salt (Ungar 1974) and they are also covered by the salin-  wetland, according to our definition. Wetlands can then
ity classes in Table 2.                                  be regarded as having soil in most cases, whereas deep-
                                                          water habitats are never considered to have soil.
pH Modifiers                                               The most basic distinction in soil classification in the
  Acid waters are, almost by definition, poor in calcium   United States is between mineral soil and organic soil (U.S.
                                                          Soil Conservation Service, Soil Survey Staff 1975). The
and often generally low in other ions, but some very soft  Soil Conservation Service  Soil   Su        rvey  of
waters may have a neutral pH (Hynes 1970). It is difficult  mineral soils nine order of
              to sparte he ffecs o hih cncetratonsof ydrgenmineral soils and one order of organic soils (Histosols) in
to separate the effects of high concentrations of hydrogen ittaomyThrclsfctonsheacialndp-
ions from low base content, and many studies suggest that   its the description    is hi eral and  pe         r
acidity may never be the major factor controlling the pre-
sence or absence of particular plants and animals. Never-  example, suborders of Histosols are recognized according
theless, some researchers have demonstrated a good   to the degree of decomposition of the organic matter.
correlation between pH levels and plant distribution (Sjdrs
1950; Jeglum 1971). Jeglum (1971) showed that plants can          Table 3. pH Modifiers used in this
be used to predict the pH of moist peat.                                 classification system.
 There seems to be little doubt that, where a peat layer  Modifier                                 pH of Water
isolates plant roots from the underlying mineral substrate,
the availability of minerals in the root zone strongly in-  Acid                                           <5.5
fluences the types of plants that occupy the site. For this  Circumneutral                               5.5-7.4
reason, many authors subdivide freshwater, organic wet-  Alkaline








24


 We  use the Modifiers mineral and organic in this             REGIONALIZATION  FOR  THE
classification. Mineral soils and organic soils are differen-CLSICAONYTE
tiated on the basis of specific criteria that are enumeratedCLSI                 CA      ON     Y TE
in soil taxonomy (U.S. Soil Conservation Service, Soil  I         hscasfcto  ytm  ie ao a opr
Survey Staff 1975:13-14, 65). These criteria are restated     I  hscasfcto  ytm    ie  ao  a  opr
              in or Apendx Dfor ead refrene. I a ore etaled ticular regional alliance; its representatives may be found
classification is desired, the U.S. Soil Conservation Ser-   in one or manyprsothUnedSas.Hwv,
vice classification system should be used.                 regional variations in climate, geology, soils, and vegeta-
                                                          tion are important in the development of different wetland
                                                          habitats; and management problems often differ greatly
                                                          in different regions. For these reasons, there is a need
                  Special Modifiers                       to recognize regional differences. Regionalization is
                                                          designed to facilitate three activities: (1) planning, where
  Many wetlands and deepwater habitats are man-made,  it is necessary to study management problems and poten-
and natural ones have been modified to some degree by   tial solutions on a regional basis; (2) organization andI
the activities of man or beavers. Since the nature of these   retrieval of data gathered in a resource inventory; and (3)
modifications often greatly influences the character of  interpretation of inventory data, including differences in
such habitats, special modifying terms have been included   indicator plants and animals among the regions.
here to emphasize their importance. The following Mod-      We recommend the classification and map (Fig. 7) of
ifiers should be used singly or in combination wherever   Bailey (1976) to fill the need for regionalization inland.
they apply to wetlands and deepwater habitats.             Bailey's classification of ecoregions is hierarchical. The
                                                          upper four levels are domain (defined as including sub-
Excavated                                                 continental areas of related climates), division (defined as
  Lies within a basin or channel excavated by man.         including regional climate at the level of K~ppen's [1931]
                                                          types), province (defined as including broad vegetational
Impounded                                                 types), and section (defined as including climax vegeta-I
                                                          tion at the level of Kflchler's [1964] types). On the map,
  Created or modified by a barrier or dam which pur-  the boundaries between the different levels are designated
posefully or unintentionally obstructs the outflow of water.   by lines of various widths and the sections are numbered
Both man-made dams and beaver dams are included.          with a four-digit code; digits 1 through 4 represent the
                                                          first four levels in the hierarchy. The reader is referred
Diked                                                     to Bailey (1976, 1978) for detailed discussion and descrip-
  Created or modified by a man-made barrier or dike   tion of the units appearing on his map, reproduced in our
designed to obstruct the inflow of water.                  Fig. 7.
                                                            The Bailey system terminates at the ocean, whereas the
Partly Drained                                            present wetland classification includes Marine and E stu-
                                                          arine habitats. Many workers have divided Marine and
  The water level has been artificially lowered, but the   Estuarine realms into series of biogeographic provinces
area is still classified as wetland because soil moisture is  (e.g., U.S. Senate 1970; Ketchum 1972). These provinces
sufficient to support hydrophytes. Drained areas are not   differ somewhat in detail, but the broader concepts are
considered  wetland if they can no longer support   similar. Figure 7 shows the distribution of 10 Marine and
hydrophytes.                                               Estuarine provinces that we offer for North America.
Farmed                                                      o Arctic Province extends from the southern tip of New-
                                                          foundland (Avalon Peninsula), northward around Canada
  The soil surface has been mechanically or physically   to the west coasts of the Arctic Ocean, Bering Sea, and
altered for production of crops, but hydrophytes will  Baffin and Labrador basins. It is characterized by the
become reestablished if farming is discontinued.           southern extension of floating ice, the 40C summer iso-
                                                          therm, and Arctic biota.
Artificial                                                   * Acadian Province extends along the Northeast Atlan-
  Refers to substrates classified as Rock Bottom, Uncon-   tic Coast from the Avalon Peninsula to Cape Cod and is
solidated Bottom, Rocky Shore, and Unconsolidated Shore   characterized by a well developed algal flora and boreal
that were emplaced by man, using either natural materials   biota. The shoreline is heavily indented and frequently
such as dredge spoil or synthetic materials such as dis-  rocky. It has a large tidal range and is strongly influenced
carded automobiles, tires, or concrete. Jetties and break-   by the Labrador Current.
waters are examples of Artificial Rocky Shores. Man-made     * Virginian Province extends along the Middle Atlan-
reefs are an example of Artificial Rock Bottoms.           tic Coast from Cape Cod to Cape Hatteras. The province














                                                                                                                                                                              25






                                  9 FJORD                                                                                                              1. ARCTIC


















                           ï¿½O~~~~~~.~~~ 0~~42nS20$A2,,44~~~o$~~  3Lt221  -1 1









                                   \xor                                     ,2512g,                                t           ;           /         )<or                 30UNDARIES OF













                              1  P0    O                       94t   |                                                   Km                                        10 MARINE AND ESTUARINE
                                                                  31131       ,:          I    zlrr /   /7                                                               ii 21.?

















        our  classification.


ecoregions are designated M mountain, P plateau, and A altiplano.


1000 Polar                                                       2000 Humid Temperate                                                    300   Sty
                           2100  arm  onanntal3123 























      2121 Barenb ang                            MAIedc Forest 2n313  DonlAIr F res
                                                                               0  Nt  Me242 RO o  I BuestI                              P     30        PoNdeoa 

        MINS  LArr Forest 131420 Wyom                                                                                                                                Sasin





           22110 L pa lacian   Oak Forest                            F00 Prairi                                                                       3    1 
          22111 OaHicr. Forest 21                                 MARINE AN 3  ESTUARINE




















   21Fig. 7. Ecoregions of the United States afte r                                           Bailey (1976) with the addition of 10 Marine and Estuarine Provinces proposed in
      23 our clarwossificate                                                                         k                                             31    Cion.oteu


   21    eoregions a r                    e designated M mountain, P plateau, an             d A altiplano.

 1000 Polar 2000 Hu mid Tempe                                                                                                  rate 3000 Dry
        1200   Tundra                                                                                             2400  Mari.e  3100                                        Steppe








       1210  Arctic Tunder m 2410 Wlaette-Pget Forest                                                                                          M3110  Rocky MeMountain Forestd
      1220 Bering Tadra                                              M2410 Pacific Forest  (in contrm inous U.S.) M3111 Gryo                                      d-fir-Duglas-fing Forest
    M1210             Brooks Range                                         M2411 Sitka  Spicce-Cdar-Hemlock Forest  M3112 DgBlaas-fir Forest
   1300  Sub     a rctic                                                    M2412 Redstod Forest                                                      M3113 Ponder    sa Pine-Da  g la-fir Forest
      1310 Yakon ParlBas     d                                              M2413 Cedi r-Hemaock-Dygl-ase-fr Po.reist                           3120 Pal.esert  Grasl
      1320 Yuko          n      Forest                                     M2414 California Mixed Evergreen Forest M3120 Upper Gi                             l. Mounta is Forest

200            0 Horid T emp erate M24 10 Pacific                                          Forest (i Alaska)                                           32131 SGalebo h-Wheatgras
   2100 Warom                                     Continenta  l                                                                                        3132 Lhontara-   tbrs h-Gteasd
      2110 LaOurental Mlied  Forest                                 2500 Prairie 332 Great Basin   Sebrus                                                                       h
          2111 Sp-c-Fir Forest 2510 Prairie prkland 3134 Bonneville Saltb3soeBased
          2112 Northern Fadwoods-Fir Forest 2611  rak                                    -Hickory-Bluesbter parkland                                  3132 PondCeos            Shrub Forest
          2 113 Northe ern iHxdeods Forest                                 2512 O ak    + Bleatemr Parkland P3130 Cl ormd                             o        Plateau
                  2114 Northe                        r Hrdds-Spr F o r  st 2520 Prairie Bshland                                                      P3131   Jgiper-eiyee  Woodland +0 Sagebrush
                      ~M21 10 Colum~bia Forest 2521 M3quates-Buffalo Grass                                                                    S40         tug     sh Mosaic
                M~2111 Dglas-fir Forest 2522 Junipr-Oak-M                                          esquite  P3132 Grama-Gallete. Steppe +                                           Juipe r-Pnyons


       2210  Eate Deciduous Forest 2531 Blutem Prairie                                                                                           A3140 Wyoming Basin

          2212 Beech-Mple Forest 2533 Bluestem-Grama Pr                                             airie                                                     A3142 Sgebrush-Whe a tgrass




       2310 Otr Cosa Plai Forest 3000 Dry 3220 American Desert



                                                                          3113 Gramna-Buf ao Grass 4110 Everglades
                                                                                                                                 4200  Rainforest
                                                                                                                                   M4210 Hawaiian Islan          ds









26


is transitional between the Acadian and Carolinian   biota is largely endemic and composed of tropical and sub-
Provinces. The biota is primarily temperate, but has some   tropical forms. The tidal range is small.
boreal representatives. The Labrador Current occasionally   Use of Bailey's sections for the Riverine, Lacustrine,
extends down to Cape Hatteras and winter temperatures   and Palustrine Systems and the Provinces defined above
may approach 40C. The tidal range is moderate.            for the Marine and Estuarine Systems provides a regional
  * Carolinian Province is situated along the South Atlan-   locator for any wetland in the United States.
tic Coast from Cape Hatteras to Cape Kennedy. It con-
tains extensive marshes and well developed barrier
islands. Waters are turbid and productive. The biota is       USE  OF  THE  CLASSIFICATION
temperate but has seasonal tropical elements. The Gulf                         SYSTEM
Stream is the primary influence, and winter temperatures
reach a minimum of 100C; summer temperatures are    This System was designed for use over an extremely
tropical (in excess of 200C). The tidal range is small to  wide geographic area and for use by individuals and organ-
moderate.                                                izations with varied interests and objectives. The classi-
  a West Indian Province extends from Cape Kennedy to  fication employs 5 System names, S Subsystem names,
Cedar Key, Florida, and also includes the southern Gulf  11 Class names, 28 Subclass names, and an unspecified
of Mexico, the Yucatan Peninsula, Central America, and  number of Dominance Types. It is, of necessity, a com-
the Caribbean Islands. The shoreland is usually low-lying  plex System when viewed in its entirety, but use of the
limestone with calcareous sands and marls, except for  System for a specific purpose at a local site should be sim-
volcanic islands. The biota is tropical and includes reef cor-  ple and straightforward. Artificial keys to the Systems
als and mangroves. Minimum winter temperatures are  and Classes (Appendix E) are furnished to aid the user
about 200C and the tidal range is small.                 of the classification, but reference to detailed definitions
  * Louisianian Province extends along the northern  in the text is also required. The purpose of this section
coast of the Gulf of Mexico from Cedar Key to Port Aran-  is to illustrate how the System should be used and some
sas, Texas. The characteristics of the province are similar  of the potential pitfalls that could lead to its misuse.
to those of the Carolinian, reflecting the past submergence    Before attempting to apply the System, the user should
of the Florida Peninsula. The biota is primarily temper-   consider four important points:
ate and the tidal range is small.                          (1) Information about the area to be classified must be
  * Californian Province extends along the Pacific Coast  available before the System can be applied. This informa-
from Mexico northward to Cape Mendocino. The shore-  tion may be in the form of historical data, aerial photo-
land is strongly influenced by coastal mountains and the  graphs, brief on-site inspection, or detailed and intensive
coasts are rocky. Freshwater runoff is limited. In the  studies. The System is designed for use at varying degrees
southern part volcanic sands are present; marshes and  of detail. There are few areas for which sufficient infor-
swamps are scarce throughout the province. The climate  mation is available to allow the most detailed application
is Mediterranean and is influenced by the California Cur-  of the System. If the level of detail provided by the data
rent. The biota is temperate, and includes well developed  is not sufficient for the needs of the user, additional data
offshore kelp beds. The tidal range is moderate.         gathering is mandatory.
  *Columbian Province extends along the northern Pacific    (2) Below the level of Class, the System is open-ended
Coast from Cape Mendocino to Vancouver Island. Moun-   and incomplete. We give only examples of the vast number
tainous shorelands with rocky foreshores are prevalent.  of Dominance Types that occur. The user may identify
Estuaries are strongly influenced by freshwater runoff.  additional Dominance Types and determine where these
The biota is primarily temperate with some boreal com-  fit into the classification hierarchy. It is also probable that
ponents, and there are extensive algal communities. The a h ytmi sdtene o diinlSblse
province                         iinlecdbbohteAetaanClfr-will become apparent.
nia Currents. The tidal range is moderate to large.
  a Fjord Province extends along the Pacific Coast from    (3) One of the main purposes of the new classification
Vancouver Island to the southern tip of the Aleutian  is to ensure uniformity throughout the United States. It
Islands. Precipitous mountains, deep estuaries (some with  is important that the user pay particular attention to the
glaciers), and a heavily indented shoreline subject to winter  definitions in the classification. Any attempt at modifica-
icing are typical of the coast. The biota is boreal to sub-  tion of these definitions will lead to lack of uniformity in
Arctic. The province is influenced by the Aleutian and   application.
Japanese Currents, and the tidal range is large.           (4) One of the principal uses of the classification system
  *Pacific Insular Province surrounds all the Hawaiian   will be the inventory and mapping of wetlands and deep-
Islands. The coasts have precipitous mountains and wave   water habitats. A classification used in the mapping is

action is stronger than in most of the other provinces. The   scale-specific, both for the minimum size of units mapped









             F 1~~~~~~~~~~~~~~~~~~~~27


and for the degree of detail attainable. It is necessary for   Duncan 1974; MacDonald and Barbour 1974; Ungar 1974),
the user to develop a specific set of mapping conventions   and a number of floristic and ecological studies have
for each application and to demonstrate their relationship   described plants that are indicators of salinity (e.g., Pen-
to the generalized classification described here. For ex-  found and Hathaway 1938; Moyle 1945; Kurz and Wagner
ample, there are a number of possible mapping conven-   1957; Dillon 1966; Anderson et al. 1968; Chabreck 1972;
tions for a small wetland basin 50 m (164 feet) in diam-  Stewart and Kantrud 1972; Ungar 1974).
eter with concentric rings of vegetation about the deepest  In areas where the Dominance Types to be expected
zone. At a scale of 1:500 each zone may be classified and   under different water regimes and types of water chem-
mapped; at 1:20,000 it might be necessary to map the en-  istry conditions have not been identified, detailed regional
tire basin as one zone and ignore the peripheral bands;   studies will be required before the classification can be ap-
and at 1:100,000 the entire wetland basin may be smaller  plied in detail. In areas where detailed soil maps are
than the smallest mappable unit, and such a small-scale  available, it is also possible to infer water regime and
map is seldom adequate for a detailed inventory and must   water chemistry from soil series (U.S. Soil Conservation
be supplemented by information gathered by sampling.   Service, Soil Survey Staff 1975).
In other areas, it may be necessary to develop mapping      Some of the Modifiers are an integral part of this system
conventions for taxa that cannot be easily recognized; for  and their use is essential; others are used only for detailed
instance, Aquatic Beds in turbid waters may have to be   applications or for special cases. Modifiers are never used
mapped simply as Unconsolidated Bottom.                   with Systems and Subsystems; however, at least one
                                                         Water Regime Modifier, one Water Chemistry Modifier,
                                                         and one Soil Modifier must be used at all lower levels in
     Hierarchical Levels and Modifiers                    the hierarchy. Use of the Modifiers listed under mixosaline
                                                         and mixohaline (Table 2) is optional but these finer
  We have designed the various levels of the system for  categories should be used whenever supporting data are
specific purposes, and the relative importance of each will  available. The user is urged not to rely on single observa-
vary among users. The Systems and Subsystems are most   tions of water regime or water chemistry. Such measure-
important in applications involving large regions or the   ments give misleading results in all but the most stable
entire country. They serve to organize the Classes into  wetlands. If a more detailed Soil Modifier, such as soil
meaningful assemblages of information for data storage   order or suborder (U.S. Soil Conservation Service, Soil
and retrieval.                                            Survey Staff 1975) can be obtained, it should be used in
  The Classes and Subclasses are the most important part   place of the Modifiers, mineral and organic. Special
of the system for many users and are basic to wetland   Modifiers are used where appropriate.
mapping. Most Classes should be easily recognizable by
users in a wide variety of disciplines. However, the Class
designations apply to average conditions over a period of              Relationship to Other
years, and since many wetlands are dynamic and subject                Wetland Classifications
to rapid changes in appearance, the proper classification
of a wetland will frequently require data that span a period  There are numerous wetland classifications in use in the
of years and several seasons in each of those years.      United States. Here we relate this system to three pub-
  The Dominance Type is most important to users in-  lished classifications that have gained widespread accep-
terested in detailed regional studies. It may be necessary   tance. It is not possible to equate these systems directly
to identify Dominance Types in order to determine which   for several reasons: (1) the criteria selected for establish-
modifying terms are appropriate, because plants and   ing categories differ; (2) some of the classifications are
animals present in an area tend to reflect environmental   not applied consistently in different parts of the country;
conditions over a period of time. Water regime can be   and (3) the elements classified are not the same in various
determined from long-term hydrologic studies where these  classifications.
are available. The more common procedure will be to    The most widely used classification system in the United
estimate this characteristic from the Dominance Types.   States is that of Martin et al. (1953) which was republished
Several studies have related water regimes to the pres-  in U.S. Fish and Wildlife Service Circular 39 (Shaw and
ence and distribution of plants or animals (e.g., Stephen-   Fredine 1956). The wetland types are based on criteria
son and Stephenson 1972; Stewart and Kantrud 1972;  such as water depth and permanence, water chemistry,
Chapman 1974).                                           life form of vegetation, and dominant plant species. In
  Similarly, we do not intend that salinity measurements   Table 4 we compare some of the major components of our
be made for all wetlands except where these data are re-  system with the type descriptions listed in Circular 39.
quired; often plant species or associations can be used to    In response to the need for more detailed wetland
indicate broad salinity classes. Lists of halophytes have   classification in the glaciated Northeast, Golet and Lar-
been prepared for both coastal and inland areas (e.g.,  son (1974) refined the freshwater wetland types of










28


Table 4. Comparison of wetland types described in U.S. Fish and Wildlife Service Circular 39 with some of the major
                                     components of this classification system.

Circular 39 type and references for examples of typical vegetation
                                                                                                            Water
                                                                      Classes          Water regimes       chemistry
Type 1-Seasonally flooded basins or flats
 Wet meadow (Dix and Smeins 1967; Stewart and                   Emergent Wetland  Temporarily Flooded   Fresh
   Kantrud 1972)                                                Forested Wetland   Intermittently         Mixosaline
  Bottomland hardwoods (Braun 1950)                                                   Flooded
  Shallow-freshwater swamps (Penfound 1952)

Type 2-Inland fresh meadows
  Fen (Heinselman 1963)                                          Emergent Wetland  Saturated               Fresh
  Fen, northern sedge meadow (Curtis 1959)                                                                 Mixosaline
Type 3-Inland shallow fresh marshes
  Shallow marsh (Stewart and Kantrud 1972; Golet and             Emergent Wetland  Semipermanently         Fresh
   Larson 1974)                                                                       Flooded             Mixosaline
                                                                                    Seasonally Flooded
Type 4-Inland deep fresh marshes
  Deep marsh (Stewart and Kantrud 1972; Golet and                Emergent Wetland  Permanently Flooded  Fresh
   Larson 1974)                                                 Aquatic Bed         Intermittently        Mixosaline
                                                                                     Exposed
                                                                                    Semipermanently
                                                                                     Flooded
Type 5-Inland open fresh water
 Open water (Golet and Larson 1974)                             Aquatic Bed         Permanently Flooded  Fresh
  Submerged aquatic (Curtis 1959)                                Unconsolidated      Intermittently        Mixosaline
                                                                  Bottom             Exposed
Type 6-Shrub swamps
  Shrub swamp (Golet and Larson 1974)                            Scrub-Shrub         All nontidal regimes   Fresh
  Shrub-carr, alder thicket (Curtis 1959)                          Wetland            except Permanently
                                                                                      Flooded
Type 7-Wooded swamps
 Wooded swamp (Golet and Larson 1974)                           Forested Wetland   All nontidal regimes   Fresh
  Swamps (Penfound 1952; Heinselman 1963)                                             except Permanently
                                                                                      Flooded
Type 8-Bogs
 Bog (Dansereau and Segadas-vianna 1952; Heinselman 1963)       Scrub-Shrub         Saturated             Fresh
 Pocosin (Penfound 1952; Kologiski 1977)                          Wetland                                   (acid only)
                                                                Forested Wetland
                                                                Moss-Lichen
                                                                  Wetland
Type 9-Inland saline flats
 Intermittent alkali zone (Stewart and Kantrud 1972)            Unconsolidated      Seasonally Flooded    Eusaline
                                                                  Shore            Temporarily Flooded   Hypersaline
                                                                                    Intermittently
                                                                                     Flooded
Type 10-Inland saline marshes
 Inland salt marshes (Ungar 1974)                               Emergent Wetland  Semipermanently         Eusaline
                                                                                     Flooded
                                                                                    Seasonally Flooded
Type 11-Inland open saline water
 Inland saline lake community (Ungar 1974)                      Unconsolidated      Permanently Flooded  Eusaline
                                                                  Bottom            Intermittently
                                                                                     Exposed
Type 12-Coastal shallow fresh marshes
 Marsh (Anderson et al. 1968)                                   Emergent Wetland  Regularly Flooded       Mixohaline
 Estuarine bay marshes, estuarine river marshes                                     Irregularly Flooded    Fresh
   (Stewart 1962)                                                                   Semipermanently
 Fresh and intermediate marshes (Chabreck 1972)                                       Flooded-Tidal










                                                                                                                  29


Table 4. Continued.

                                                                   Classification of wetlands and deepwater habitats
Circular 39 type and references for examples of vegetation
                                                                                                            Water
                                                                     Classes          Water regimes       chemistry
Type 13-Coastal deep fresh marshes
 Marsh (Anderson et al. 1968)                                   Emergent Wetland  Regularly Flooded       Mixohaline
 Estuarine bay marshes, estuarine river marshes                                     Semipermanently       Fresh
   (Stewart 1962)                                                                     Flooded-Tidal
 Fresh and intermediate marshes (Chabreck 1972)

Type 14-Coastal open fresh water
 Estuarine bays (Stewart 1962)                                  Aquatic Bed         Subtidal              Mixohaline
                                                               Unconsolidated     Permanently            Fresh
                                                                 Bottom             Flooded-Tidal
Type 15-Coastal salt flats
 Panne, slough marsh (Redfield 1972)                            Unconsolidated      Regularly Flooded     Hyperhaline
 Marsh pans (Pestrong 1965)                                       Shore             Irregularly Flooded    Euhaline

Type 16-Coastal salt meadows
 Salt marsh (Redfield 1972; Chapman 1974)                       Emergent Wetland  Irregularly Flooded    Euhaline
                                                                                                         Mixohaline
Type 17-Irregularly flooded salt marshes
 Salt marsh (Chapman 1974)                                      Emergent Wetland  Irregularly Flooded    Euhaline
 Saline, brackish, and intermediate marsh (Eleuterius 1972)                                               Mixohaline

Type 18-Regularly flooded salt marshes
 Salt marsh (Chapman 1974)                                      Emergent Wetland  Regularly Flooded       Euhaline
                                                                                                         Mixohaline
Type 19-Sounds and bays
 Kelp beds, temperate grass flats (Phillips 1974)               Unconsolidated      Subtidal              Euhaline
 Tropical marine meadows (Odum 1974)                              Bottom            Irregularly Exposed   Mixohaline
 Eelgrass beds (Akins and Jefferson 1973; Eleuterius 1973)      Aquatic Bed         Regularly Flooded
                                                               Unconsolidated     Irregularly Flooded
                                                                 Shore
Type 20-Mangrove swamps
 Mangrove swamps (Walsh 1974)                                   Scrub-Shrub         Irregularly Exposed   Hyperhaline
 Mangrove swamp systems (Kuenzler 1974)                           Wetland           Regularly Flooded     Euhaline
 Mangrove (Chapman 1976)                                        Forested Wetland   Irregularly Flooded    Mixohaline
                                                                                                         Fresh


Circular 39 by writing more detailed descriptions and sub-   here. Although our system does not include size categories
dividing classes on the basis of finer differences in plant   and site types, this information will be available from the
life forms. Golet and Larson's classes are roughly equi-   results of the new inventory of wetlands and deepwater
valent to Types 1-8 of Circular 39, except that they restrict  habitats of the United States.
Type 1 to river floodplains. The Golet and Larson system      Stewart and Kantrud (1971) devised a new classifica-
does not recognize the coastal (tidal) fresh wetlands of   tion system to better serve the needs of researchers and
Circular 39 (Types 12-14) as a separate category, but   wetland managers in the glaciated prairies. Their system
classifies these areas in the same manner as nontidal   recognizes seven classes of wetlands which are distin-
wetlands. In addition to devising 24 subclasses, they also   guished by the vegetational zone occupying the central or
created 5 size categories, 6 site types giving a wetland's   deepest part and covering 5% or more of the wetland
hydrologic and topographic location; 8 cover types   basin. The classes thus reflect the wetland's water regime;
(modified from Stewart and Kantrud 1971) expressing the   for example, temporary ponds (Class II) are those where
distribution and relative proportions of cover and water;   the wet-meadow zone occupies the deepest part of the
3 vegetative interspersion types; and 6 surrounding   wetland. Six possible subclasses were created, based on
habitat types. Since this system is based on the classes   differences in plant species composition that are correlated
of Martin et al. (1953), Table 4 may also be used to com-   with variations in average salinity of surface water. The
pare the Golet and Larson system with the one described   third component of classification in their system is the












cover type, which represents differences in the spatial rela-   Table 5. Comparison of the zones of Stewart and Kantrud's
tion of emergent cover to open water or exposed bottom         (1971) classification with the Water Regime Modifiers
soil. The zones of Stewart and Kantrud's system are            used in the present classification system.
readily related to our water regime modifiers (Table 5),
and the subclasses are roughly equivalent to our Water              Zone                   Water Regime Modifier
Chemistry Modifiers (Fig. 8).                                Wetland-low-prairie     Non-wetland by our definition
                                                          Wet meadow             Temporarily flooded
 Wetlands represent only one type of land and the classi-  Shallow marsh            Seasonally flooded
fication of this part separate from the rest is done for prac-   Deep marsh          Semipermanently flooded
tical rather than for ecological reasons (Cowardin 1978).                            Intermittently exposed
Recently there has been a flurry of interest in a holistic   Intermittent-alkali     Intermittently flooded (with eusaline
approach to land classification (in Land Classification                               or hypersaline water)
Series, Journal of Forestry, vol. 46, no. 10). A number   Permanent-open-            Permanently flooded (with mixo-
of classifications have been developed (e.g., Radford 1978)    water                haline water)
or are under development (e.g., Driscoll et al. 1978). Parts   Fen (alkaline bog)    Saturated


                                       APPROXIMATE
                                         SPECIFIC
   STEWART AND KANTRUD    CONDUCTANCES                               THIS CLASSIFICATION
                (1972)                    (pMhos)


              SALINE
                                                                            HYPERSALINE
                                          60,000                                EUSALINE
                                          45,000
                                                         POLYSALIN E
                                          30,000
            SUBSALINE

                                          1 5,000        MESOSALINE

             BRACKISH
                                            8,000
                                                                                        MIXOSALINE
                                            5,000

   MODERATELY BRACKISH
                                                         OLIGOSALINE
                                            2,000


     SLIGHTLY BRACKISH
                                              800

                                              500

                                                                              FRESH
             FRESH






 Fig. 8. Comparison of the water chemistry subclasses of Stewart and Kantrud (1972) with Water Chemistry Modifiers used in
 the present classification system.









                                                                                                                        31


of this wetland classification can be incorporated into   Bailey, R. G. 1976. Ecoregions of the United States, U.S. Forest
broader hierarchical land classifications.                      Service, Ogden, Utah. (Map only; scale 1:7,500,000.)
  A classification system is most easily learned through   Bailey, R. G. 1978. Ecoregions of the United States. U.S. Forest
use. To illustrate the application of this system, we have      Service, Intermountain Region, Ogden, Utah. 77 pp.
classified a representative group of wetlands and deep-   Bayly, I. A. E. 1967. The general biological classification of
water habitats of the United States (Plates 1-86; pages         aquatic environments with special reference to those of
                                                                Australia. Pages 78-104 in A. H. Weatherley, ed. Australian
                                                                inland waters and their fauna. Australian National University
                                                                 Press, Canberra.
            ACKNOWLEDGMENTS                                   Black, C. A. 1968. Soil plant relationships. John Wiley & Sons,
                                                                 Inc., New York. 792 pp.
  The breadth and complexity of preparing this classifica-   Bormann, F. H., and G. E. Likens, 1969. The watershed-eco-
tion caused us to solicit help and advice from individuals      system concept and studies of nutrient cycles. Pages 49-76 in
                  too numerous to list here. Frequently the recommenda-  G. M. VanDyne, ed. The ecosystem concept in natural resource
too numerous to list here. Frequently the recommenda-
tions were in conflict and we take responsibility for the       management. Academic Press, New York.
                                                               Braun, E. L. 1950. Deciduous forests of eastern North America.
decisions we have made but acknowledge all suggestions          Hafner Publishing Co., New York and London. 596 pp.
including those not accepted. Several meetings were   Brinkhurst, R. 0., and B. G. M. Jamieson. 1972. Aquatic oligo-
crucial in formulating the present classification and in        chaetes of the world. University of Toronto Press, Toronto. 860
modifying earlier drafts. We thank those who attended           pp.
the formative meeting at Bay St. Louis, Mississippi,   Britton, M. E. 1957. Vegetation of the Arctic tundra. Oregon
January 1975; The National Wetland Classification and           State Univ. Biol. Colloq. 18:26-61.
Inventory Workshop at College Park, Maryland, July   Burbank, W. D. 1967. Evolutionary and ecological implications
1975; and the review panels assembled at Sapelo Island,         of the zoogeography, physiology and morphology of Cyanthura
Georgia, and at St. Petersburg, Florida. We also thank          (Isopoda). Pages 564-573 in G. H. Lauff, ed. Estuaries. Am.
those individuals and agencies who responded to distribu-       Assoc. Adv. Sci. Publ. 83.
tion of the operational draft. Special credit is due the   Cain, S. A., and G. M. de Oliveira Castro. 1959. Manual of vege-
regional coordinators of the National Wetlands Inventory        tation analysis. Harper & Brothers, New York. 325 pp.
   and P.  B. Reed, who have furnished continuing consulta-   Carriker, M. R. 1967. Ecology of estuarine benthic invertebrates:
and P. B. Reed, who have furnished continuing consulta-
                                              toonaeLaboratories  a perspective. Pages 442-487 in G. H. Lauff, ed. Estuaries. Am
tion on application of the system. Martel LabAssoc. Adv. Sci. Publ. 83.
field-tested the system and furnished specific criticisms.   Caspers, H. 1967. Estuaries: analysis of definitions and biological
We were advised by J. Everett on geomorphology, K. K.           considerations. Pages 6-8 in G. H. Lauff, ed. Estuaries. Am.
Young and 0. Carter on soil taxonomy, R. P. Novitzki on         Assoc. Adv. Sci. Publ. 83.
hydrology, and R. H. Chabreck on coastal wetland ecology.   Chabreck, R. H. 1972. Vegetation, water and soil characteristics
M. L. Heinselman and R. H. Hofstetter helped with dif-    of the Louisiana coastal region. La. Agric. Exp. Stn. Bull. 664.
ficult problems of peatland ecology and terminology. R. L.      72 pp.
Kologiski aided with botanical problems. J. H. Montanari,   Chapman, V. J. 1974. Salt marshes and salt deserts of the world.
W. O. Wilen, and the entire National Wetlands Inventory         2nd supplemented edition. J. Cramer, Lehre. 392 pp.
staff furnished encouragement and logistic support. The   Chapman, V. J. 1976. Mangrove vegetation. J. Cramer, Leuter-
staff of the Northern Prairie Wildlife Research Center con-     hausen. 447 pp.
tributed substantially to completion of the classification.   Chapman, V. J. 1977. Introduction. Pages 1-30 in V. J. Chap-
Art work and graphics were prepared by J. Rodiek, R. L.         man, ed. Wet coastal ecosystems. Ecosystems of the world 1.
Duval, and C. S. Shaiffer. J. H. Sather worked closely with     Elsevier Scientific Publishing Co., New York.
                                                               Clarke, A. H. 1973. The freshwater mollusks of the Canadian In-
us and served as editor on previous drafts.                     teor Basin. Malacologia 13(1-2):1-509.
                                                                 terior Basin. Malacologia 13(1-2):1-509.
                                                               Cowardin, L. M. 1978. Wetland classification in the United States.
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                                                                                                          35

                                            APPENDIX A


                                  Scientific and Common Names
                                                of Plants

Scientific namea                Common nameb            Scientific namea                Common nameb
Acer rubrum L.                  Red maple               Cassiope tetragona (L.)
Alisma plantago-aquatica L.    (Water plantain)           D. Don                        Lapland cassiope
Alnus spp.                      Alders                  Caulerpa spp.                   (Green algae)
A. rugosa (DuRoi) Spreng.       Speckled alder          Cephalanthus occidentalis L.    Buttonbush
A. tenuifolia Nutt.             Thinleaf alder          Ceratophyllum spp.              Coontails
Alopecurus aequalis Sobol.      Foxtail                 Chamaecyparis thyoides (L.)
Andromeda glaucophylla Link   Bog rosemary                B.S.P.                        Atlantic white cedar
Arctophila fulva (Trin.)                                Chamaedaphne calyculata (L.)
  Anderss.                      Pendent grass             Moench                        Leatherleaf
Aristida stricta Michx.         (Three-awn)             Chara spp.                      (Stoneworts)
Ascophyllum spp.                (Rockweeds)             Chenopodium glaucum L.          (Goosefoot)
A. nodosum (L.) LeJol.          Knotted wrack           Chiloscyphus fragilis (Roth)
Aulacomnium palustre                                      Schiffn.                      (Liverwort)
  (Hedw.) Schwaegr.             (Moss)                  Chondrus crispus Stackhouse    Irish moss
Avicennia germinans (L.) L.    Black mangrove           Cladina spp.                    Reindeer mosses
Azolla spp.                     Mosquito ferns          C. rangiferina (L.) Harm        (Reindeer moss)
Baccharis halimifolia L.        Sea-myrtle              Cladium jamaicense Crantz       Saw grass
Beckmannia syzigachne                                   Colocasia esculenta (L.) Scott   Taro
  (Steud.) Fernald              Slough grass            Conocarpus erectus L.           Buttonwood
Betula nana L.                  Dwarf birch             Cornus stolonifera Michx.       Red osier dogwood
B. pumila L.                    Bog birch               Cymodocea filiformis (Kuetz)
Brasenia schreberi                                        Correll                       Manatee grass
  J. F. Gmel.                   Water shield            Cyperus spp.                    Nut sedges
Calamagrostis canadensis                                Cyrilla racemiflora L.          Black ti-ti
  (Michx.) Beauv.               Bluejoint               Decodon verticillatus (L.)
Calopogon spp.                  Grass pinks               Elliott                       Water willow
Caltha palustris L.             Marsh marigold         Dendranthema arcticum (L.)
Campylium stellatum (Hedw.)                               Tzvel.                        Arctic daisy
  C. Jens                       (Moss)                  Dermatocarpon fluviatile
Carex spp.                      Sedges                   G. H. Web) Th. Fr.             (Lichen)
C. aquatilis Wahlenb.           (Sedge)                 Distichlis spicata (L.) Greene    (Salt grass)
C. atherodes Spreng.            Slough sedge            Drepanocladus spp.              (Moss)
C. bipartita All.               (Sedge)                Dryas integrifolia Vahl          (Dryas)
C. lacustris Willd.             (Sedge)                 Echinochloa crusgalli (L.)
C. lasiocarpa Ehrh.             (Sedge)                   Beauv.                        Barnyard grass
C. lyngbyei Hornem.             (Sedge)                 Eichhornia crassipes (Mart.)
C. paleacea Schreb.                                       Solms                         Water hyacinth
  ex Wahlenb.                   (Sedge)                 Eleocharis sp.                  (Spike rush)
C. pluriflora Hulten            (Sedge)                E. palustris (L.) Roem. &
C. ramenskii Kom.               (Sedge)                   J. A. Schultes                (Spike rush)
C. rariflora (Wahlenb.)                                 Elodea spp.                     Water weeds
  J. E. Smith                   (Sedge)                 Elymus arenarius L.             (Lyme grass)
C. rostrata J. Stokes           Beaked sedge            Empetrum nigrum L.              Crowberry
                                                       Enteromorpha spp.               (Green algae)
aTaxonomy of vascular plants is according to the National List  Eriophorum spp.         Cotton grasses
of Scientific Plant Names (U.S. Dept. Agriculture 1982).  E. russeolum Fr.              (Cotton grass)
bGeneral common names that refer to a higher taxon and names  E. vaginatum L.           (Cotton grass)
for which there is little agreement are shown in parentheses.   Fissidens spp.          (Moss)








36

Scientific namea                Common nameb            Scientific namea                Common nameb
F. julianus (Mont.) Schimper    (Moss)                  Nuphar luteum (L.) Sibth. &
Fontinalis spp.                 (Moss)                    J. E. Smith                   (Yellow water lily)
Fraxinus nigra Marshall         Black ash               Nymphaea spp.                   (Water lilies)
F. pennsylvanica Marshall       (Red ash)               N. odorata Soland. in Ait.      (White water lily)
Fucus spp.                      Rockweeds               Nyssa aquatica L.               Tupelo gum
F. spiralis L.                  (Rockweed)              N. sylvatica Marshall            Black gum
F. vesiculosus L.               (Rockweed)              Oncophorus wahlenbergii
Glyceria spp.                   Manna grasses             Brid.                         (Moss)
Gordonia lasianthus (L.)                                Panicum capillare L.            Old witch grass
  J. Ellis                      Loblolly bay            Pedicularis sp.                  (Lousewort)
Habenaria spp.                  (Orchids)               Peltandra virginica (L.)
Halimeda spp.                   (Green algae)             Kunth                          Arrow arum
Halodule wrightii Aschers.      Shoal grass             Pelvetia spp.                    (Rockweeds)
Halophila spp.                  (Sea grass)             Penicillus spp.                  (Green algae)
Hippuris tetraphylla L.f.       (Mare's tail)           Persea borbonia (L.) Spreng.    Red bay
Hydrilla verticillata Royle     (Hydrilla)              Phragmites australis (Cav.)
Ilex glabra (L.) Gray           Inkberry                  Trin. ex Steud.                Reed
I. verticillata (L.) Gray       Winterberry             Phyllospadix scouleri Hook.     (Surfgrass)
Iva frutescens L.               Marsh elder             P. torreyi S. Wats.              (Surfgrass)
Juncus spp.                     Rushes                  Picea mariana (Mill.) B.S.P.     Black spruce
J. gerardii Loiseleur           Black grass             P. sitchensis (Bong.) Carriere    Sitka spruce
J. militaris Bigel.             Bayonet rush            Pinus contorta Dougl.
J. roemerianus Scheele          Needlerush                ex Loudon                      Lodgepole pine
Kalmia angustifolia L.          Sheep laurel            P. palustris Mill.               Longleaf pine
K. polifolia Wangenh.           Bog laurel              P. serotina Michx.               Pond pine
Kochia scoparia (L.) Schrad.    Summer cypress          Pistia stratiotes L.            Water lettuce
Languncularia racemosa (L.)                             Plantago maritima L.             Seaside plantain
  C. F. Gaertn.                 White mangrove          Podostemum ceratophyllum
Laminaria spp.                  (Kelps)                   Michx.                         Riverweed
Larix laricina (DuRoi)                                  Polygonum spp.                   Smartweeds
  K. Koch                       Tamarack                P. amphibium L.                 Water smartweed
Laurencia spp.                  (Red algae)             P. bistorta L.                   Bistort
Ledum decumbens (Ait.)          Narrowleaf Labrador   Pontederia cordata L.              Pickerelweed
  Small                           tea                   Potamogeton spp.                 Pondweeds
L. groenlandicum Oeder          Labrador tea            P. gramineus L.                  (Pondweed)
Lemna spp.                      (Duckweeds)             P. natans L.                     Floating-leaf
L. minor L.                     Common duckweed                                           pondweed
Leucothoe axillaris (Lam.)                              Populus balsamifera L.           Balsam poplar
  D. Don                        Coastal sweetbells      P. deltoides W. Bartram
Ligusticum scothicum L.         Beach lovage              ex Marshall                    Cottonwood
Lithothamnion spp.              Coralline algae         Potentilla anserina L.           Silverweed
Lycopodium alopecuroides L.    Foxtail clubmoss         P. fruticosa L.                  Shrubby cinquefoil
Lyonia lucida (Lam.) K. Koch   Fetterbush               P. palustris (L.) Scop.          Marsh cinquefoil
Lythrum salicaria L.            Purple loosestrife      Puccinellia grandis Swallen      (Alkali grass)
Macrocystis spp.                (Kelps)                 Quercus bicolor Willd.           Swamp white oak
Magnolia virginiana L.          Sweet bay               Q. lyrata Walter                 Overcup oak
Marsupella spp.                 (Liverworts)            Q. michauxii Nutt.               Basket oak
M. emarginata (Ehrenberg)                               Ranunculus pallasii Schlecht.   (Crowfoot)
  Dumortier                     (Liverwort)             R. trichophyllus D. Chaix        White water
Myrica gale L.                  Sweet gale                                                crowfoot
Myriophyllum spp.               Water milfoils          Rhizophora mangle L.             Red mangrove
M. spicatum L.                  (Water milfoil)         Rhododendron maximum L.          Great laurel
Najas spp.                      Naiads                  Rhynchospora spp.                Beak rushes
Nelumbo lutea (Willd.) Pers.    American lotus          Rubus chamaemorus L.             Cloudberry
Nitella spp.                    (Stoneworts)            Rumex maritimus L.               Golden dock








                                                                                                                        37

             Scientific name'                Common nameb            Scientific name'                 Common nameb
             R. mexicanus Meisn.             (Dock)                  Suaeda californica S. Wats.      (Sea blite)
             Ruppia spp.                     Ditch grasses           Tamarix gallica L.               Tamarisk
             R. maritima L.                  Widgeon grass           Taxodium distichum (L.)
             Sagittaria spp.                 Arrowheads                L. C. Rich.                    Bald cypress
             Salicornia, spp.                Glassworts              Thalassia testudinum
             S. europaect L.                 (Samphire)                K. D. Koenig                   Turtle grass
             S. virginica L.                 (Common pickleweed)  Thuja occidentalis L.               Northern white cedar
             Salix spp.                      Willows                 Tolypella spp.                   (Stoneworts)
             S. alaxensis (Anderss.) Coville  Feltleaf willow        Trapa natans L.                  Water nut
             S. fusceseens Anderss.          Alaska bog willow       Triglochin maritimum L.          Arrow grass
             S. ovalifolia Trautv.           Ovalleaf willow         Typha spp.                       Cattails
             S. planifolia Pursh             Diamondleaf willow      T. angustifoblia L.              Narrow-leaved cattail
             S. reticulata L.                Netleaf willow          T. latifolia L.                  Common cattail
             Salvinia spp.                   Water ferns             Ulmus americana L.               American elm
             Sarcobatus vermiculatus                                 Ulva spp.                        Sea lettuce
               (Hook.) Torr.                 Greasewood              Utricularia spp.                 Bladderworts
             Scir'pus spp.                   Bulrushes               U. macrorhiza LeConte            (Bladderwort)
             S. acutus Muhl. ex Bigel.       Hardstem bulrush        Vaccinium corymbosum L.          Highbush blueberry
             S. americanus Pers.             Common threesquare   V. oxycoccos L.                     Small cranberry
             S. robustus Pursh               (Bulrush)               V. uliginosum L.                 Bog blueberry
             Scolochloa fe~stucacea                                  V. vitis-idaea L.                Mountain cranberry
               (Willd.) Link                 Whitetop                Vallisneria americana Michx.   Wild celery
             Solidago sempervirens L.        Seaside goldenrod       Verrucaria spp.                  (Lichens)
             Sparganium hyperboreum                                  Wolffia spp.                     Watermeals
               Laest.                        (Bur-reed)              Woodwardia virgi~nia (L.)
             Spartina alterniflora                                     J. E. Smith                    Virginia chain-fern
               Loiseleur                     Saltmarsh cordgrass    Xanthium strumarium L.            (Cocklebur)
             S. cynosuroides (L.) Roth       Big cordgrass           Xyris spp.                       Yellow-eyed grasses
             S. foliosa Trin.                California cordgrass    Xyris smalliana Nash             (Yellow-eyed grass)
             S. patens (Ait.) Muhl.          Saltmeadow              Zannichellia palustris L.        Horned pondweed
                                               cordgrass             Zenobia pulverulenta
             Sphagnum spp.                   Peat mosses               (W. Bartram) Pollard           Honeycup
             Spiraea beauverdiana                                    Zizania aquatica L.              Wild rice
               C. K. Schneid.                Alaska spiraea          Zizaniopsis miliacea (Michx.)
F          ~ ~~~S. douglasii Hook.            (Spiraea)                Doell & Aschers.               Southern wild rice
             Spirodela spp.                  Big duckweeds           Zostera marina L.                Eelgrass
             Stellaria spp.                  (Chickweed)             Zosterella dubia (Jacq.) Small    Water stargrass








38

                                              APPENDIX B


                                   Scientific and Common Names
                                                of Animals

 Scientific name                 Common namea            Scientific name                  Common namea
Acmaea spp.                      Limpets                Homarus americanus
Acropora spp.                    Staghorn corals          Milne-Edwards                  American lobster
Agrenia spp.                     Springtails            Hydropsyche spp.                 Caddisflies
Amphipholis spp.                Brittle stars           Lampsilis spp.                   Freshwater mollusks
Amphitrite spp.                 Terebellid worms        Ligia spp.                       Slaters
Ancylus spp.                     Freshwater mollusks   Limnodrilus spp.                  Oligochaete worms
Anodonta spp.                    Freshwater mollusks   Littorina spp.                    Periwinkles
Anodontoides spp.               Freshwater mollusks   Lumbriculus spp.                   Oligochaete worms
Anopheles spp.                   Mosquitos              Lymnaea spp.                     Pond snails
Aplexa spp.                      Pouch snails           Macoma spp.                      Macomas
Arenicola spp.                   Lugworms               M. balthica (Linne)              Baltic macoma
Asellus spp.                     Isopods                Melita spp.                      Amphipods
Baetis spp.                      Mayflies               Mercenaria spp.                   Quahogs
Balanus spp.                     Acorn barnacles        Modiolus spp.                    Mussels
Bryocamptus spp.                 Harpacticoid           Montipora spp.                   Corals
                                  copepods             Muricea spp.                      Sea whips
Caenis spp.                     Mayflies                Mya spp.                         Soft-shell clams
Callianassa spp.                Ghost shrimp            Mytilus spp.                     Mussels
Cambarus spp.                   Crayfishes              Nassarius spp.                   Mud snails
Canthocamptus spp.              Harpacticoid            Nemoura spp.                     Stone flies
                                  copepods             Nereis spp.                       Clam worms
Cerianthus spp.                 Sea anemones            Nerita spp.                      Nerites
Chaetopterus spp.               Polychaete worms        Notonecta spp.                   Back swimmers
Chironomus spp.                 Midges                  Oliva spp.                       Olive shells
Chironomidae                    Midges                  Orchestia spp.                   Beach hoppers
Chthamalus spp.                 Acorn barnacles          Ostrea spp.                     Oysters
Cnemidocarpa spp.               Tunicates               Parastenocaris spp.              Copepods
Crassostrea spp.                Oysters                 Patella spp.                     Limpets
C. virginica (Geml.)            Eastern oyster          Pecten spp.                      Scallops
Dendraster spp.                  Sand dollars            Petricola pholadiformis Lam.    False angel wing
Diamesa spp.                     Midges                  Phyllognathopus viguieri
Donax spp.                      Wedge shells               Maryek                         Copepod
Echinocardium spp.               Heart urchins          Physa spp.                        Snails
Elliptio spp.                    Freshwater mollusks   Pisaster spp.                      Sea stars
Emerita spp.                     Mole crabs             Pisidium spp.                     Fingernail clams
Ephemerella spp.                 Mayflies                Placopecten spp.                 Deep-sea scallops
Erpobdella spp.                  Leeches                 Platyodon spp.                   Boring clams
Eukiefferiella spp.              Midges                  Pollicipes spp.                  Gooseneck barnacles
Eunapius spp.                    Freshwater sponges    Porites spp.                       Corals
Euzonus spp.                     Blood worms             Pristina spp.                    Oligochaete worms
Gammarus spp.                   Scuds                   Procambarus spp.                  Crayfish
Gelastocoris spp.               Toad bugs               Psephenus spp.                    Riffle beetles
Gordonia ventalina L.           Common sea fan          Renilla spp.                      Sea pansies
Helobdella spp.                  Leeches                 Sabellaria spp.                  Reef worms
Heteromeyenia spp.               Horse sponges           Saldula spp.                     Shore bugs
Hippospongia spp.                Encrusting sponges    Saxidomus spp.                     Venus clams
                                                        Simulium spp.                    Black flies
                                                        Siphonaria spp.                  False limpets
aMost common names refer only to general groupings.      Sphaerium spp.                   Fingernail clams









                                                                                                              39

Scientific name                  Common namea              Scientific name                   Common namea
Spongilla spp.                    Freshwater sponges    Thyone spp.                          Sea cucumbers
Strongylocentrotus spp.           Sea urchins              Tivela stultorum (Mawe)           Pismo clam
Tabanus spp.                      Flies                    Tortopus spp.                     Mayflies
Tellina spp.                     Tellin shells             Tubifex spp.                      Sewage worms
Tetraclita spp.                  Acorn barnacles           Uca spp.                          Fiddler crabs
Thais spp.                       Rock shells               Urechis spp.                      Echiurid worms










40

                                                   APPENDIX C


                                                 Glossary of Terms


acid Term applied to water with a pH less than 5.5.              evergreen stand A plant community where evergreen trees or
alkaline Term applied to water with a pH greater than 7.4.         shrubs represent more than 50% of the total areal coverage
bar An elongated landform generated by waves and currents,         of trees and shrubs. The canopy is never without foliage;
 usually running parallel to the shore, composed predominant-     however, individual trees or shrubs may shed their leaves
 ly of unconsolidated sand, gravel, stones, cobbles, or rubble and  (Mueller-Dombois and Ellenberg 1974).
 with water on two sides.                                        extreme high water of spring tides The highest tide occurring
beach A sloping landform on the shore of larger water bodies,      during a lunar month, usually near the new or full moon. This
 generated by waves and currents and extending from the water     is equivalent to extreme higher high water of mixed semidiurnal
 to a distinct break in landform or substrate type (e.g., a fore-    tides.
 dune, cliff, or bank).                                         extreme low water of spring tides The lowest tide occurring
brackish Marine and Estuarine waters with Mixohaline salin-        during a lunar month, usually near the new or full moon. This
 ity. The term should not be applied to inland waters (see page   is equivalent to extreme lower low water of mixed semidiurnal
 25).                                                             tides.
boulder Rock fragments larger than 60.4 cm (24 inches) in   flat A level landform composed of unconsolidated sediments-
 diameter.                                                        usually mud or sand. Flats may be irregularly shaped or
broad-leaved deciduous Woody angiosperms (trees or shrubs)         elongate and continuous with the shore, whereas bars are
 with relatively wide, flat leaves that are shed during the cold  generally elongate, parallel to the shore, and separated from
 or dry season; e.g., black ash (Fraxinus nigra).                 the shore by water.
broad-leaved evergreen Woody angiosperms (trees or shrubs)   floating plant A non-anchored plant that floats freely in the
 with relatively wide, flat leaves that generally remain green    water or on the surface; e.g., water hyacinth (Eichhornia
 and are usually persistent for a year or more; e.g., red man-    crassipes) or common duckweed (Lemna minor).
 grove (Rhizophora mangle).                                      floating-leaved plant A rooted, herbaceous hydrophyte with
calcareous Formed of calcium carbonate or magnesium car-           some leaves floating on the water surface; e.g., white water
 bonate by biological deposition or inorganic precipitation in suf-    lily (Nymphaea odorata), floating-leaved pondweed (Potamoge-
 ficient quantities to effervesce carbon dioxide visibly when      ton natans). Plants such as yellow water lily (Nuphar luteum)
 treated with cold 0.1 normal hydrochloric acid. Calcareous sands  which sometimes have leaves raised above the surface are con-
 are usually formed of a mixture of fragments of mollusk shell,   sidered floating-leaved plants or emergents, depending on their
 echinoderm spines and skeletal material, coral, foraminifera,    growth habit at a particular site.
  and algal platelets (e.g., Halimeda).                          floodplain "a flat expanse of land bordering an old river..."
channel "An open conduit either naturally or artificially created  (see Reid and Wood 1976:72, 84).
 which periodically or continuously contains moving water, or   fresh Term applied to water with salinity less than 0.50/oo
 which forms a connecting link between two bodies of standing     dissolved salts.
 water" (Langbein and Iseri 1960:5).                             gravel A mixture composed primarily of rock fragments 2 mm
channel bank The sloping land bordering a channel. The bank        (0.08 inch) to 7.6 cm (3 inches) in diameter. Usually contains
 has steeper slope than the bottom of the channel and is usual-   much sand.
 ly steeper than the land surrounding the channel.               growing season The frost-free period of the year (see U.S.
circumneutral Term applied to water with a pH of 5.5 to 7.4.       Department of Interior, National Atlas 1970:110-111 for
codominant Two or more species providing about equal areal         generalized regional delineation).
 cover which in combination control the environment.             haline Term used to indicate dominance of ocean salt.
cobbles Rock fragments 7.6 cm (3 inches) to 25.4 cm (10 inches)   herbaceous With the characteristics of an herb; a plant with no
 in diameter.                                                     persistent woody stem above ground.
deciduous stand A plant community where deciduous trees or   histosols Organic soils (see Appendix D).
 shrubs represent more than 50% of the total areal coverage   hydric soil Soil that is wet long enough to periodically produce
 of trees or shrubs.                                               anaerobic conditions, thereby influencing the growth of plants.
dominant The species controlling the environment.                hydrophyte, hydrophytic Any plant growing in water or on a
dormant season That portion of the year when frosts occur (see     substrate that is at least periodically deficient in oxygen as a
 U.S. Department of Interior, National Atlas 1970:110-111 for     result of excessive water content.
 generalized regional delineation).                              hyperhaline Term to characterize waters with salinity greater
emergent hydrophytes Erect, rooted, herbaceous angiosperms         than 400/o, due to ocean-derived salts.
 that may be temporarily to permanently flooded at the base   hypersaline Term to characterize waters with salinity greater
 but do not tolerate prolonged inundation of the entire plant;    than 400/oo, due to land-derived salts.
 e.g., bulrushes (Scirpus spp.), saltmarsh cordgrass.            macrophytic algae Algal plants large enough either as individ-
emergent mosses Mosses occurring in wetlands, but generally        uals or communities to be readily visible without the aid of
 not covered by water.                                            optical magnification.
eutrophic lake Lake that has a high concentration of plant   mean high water The average height of the high water over 19
 nutrients such as nitrogen and phosphorus.                       years.










                                                                                                                             41



mean higher high tide The average height of the higher of two      tion. This level (the compensation level) usually occurs at the
 unequal daily high tides over 19 years.                          depth of 1% light penetration and forms the lower boundary
mean low water The average height of the low water over 19         of the zone of net metabolic production.
 years.                                                         pioneer plants Herbaceous annual and seedling perennial plants
mean lower low water The average height of the lower of two        that colonize bare areas as a first stage in secondary succession.
 unequal daily low tides over 19 years.                         polyhaline Term to characterize water with salinity of 18 to
mean tide level A plane midway between mean high water and         30%100, due to ocean salts.
  mean low water.                                                polysaline Term to characterize water with salinity of 18 to
mesohaline Term to characterize waters with salinity of 5 to       300/oo, due to land-derived salts.
  18/loo, due to ocean-derived salts.                            saline General term for waters containing various dissolved salts.
mesophyte, mesophytic Any plant growing where moisture and         We restrict the term to inland waters where the ratios of the
  aeration conditions lie between extremes. (Plants typically found  salts often vary; the term haline is applied to coastal waters
  in habitats with average moisture conditions, not usually dry    where the salts are roughly in the same proportion as found
  or wet.)                                                         in undiluted sea water (see page 25).
mesosaline Term to characterize waters with salinity of 5 to   salinity The total amount of solid material in grams contained
  180/00, due to land-derived salts.                               in 1 kg of water when all the carbonate has been converted to
mineral soil Soil composed of predominantly mineral rather than    oxide, the bromine and iodine replaced by chlorine, and all the
  organic materials (see page 44).                                 organic matter completely oxidized.
mixohaline Term to characterize water with salinity of 0.5 to   sand Composed predominantly of coarse-grained mineral sedi-
  30%100, due to ocean salts. The term is roughly equivalent to    ments with diameters larger than 0.074 mm (Black 1968) and
  the term brackish.                                               smaller than 2 mm (Liu 1970; Weber 1973).
mixosaline Term to characterize waters with salinity of 0.5 to   shrub A woody plant which at maturity is usually less than 6
  300/oo00, due to land-derived salts.                             m (20 feet) tall and generally exhibits several erect, spreading,
mud Wet soft earth composed predominantly of clay and silt-        or prostrate stems and has a bushy appearance; e.g., speckled
  fine mineral sediments less than 0.074 mm in diameter (Black     alder (Alnus rugosa) or buttonbush (Cephalanthus occidentalis).
  1968; Liu 1970).                                               sound A body of water that is usually broad, elongate, and
needle-leaved deciduous Woody gymnosperms (trees or shrubs)        parallel to the shore between the mainland and one or more
  with needle-shaped or scale-like leaves that are shed during the  islands.
  cold or dry season; e.g., bald cypress (Taxodium distichum).   spring tide The highest high and lowest low tides during the
needle-leaved evergreen Woody gymnosperms with green,              lunar month.
  needle-shaped, or scale-like leaves that are retained by plants   stone Rock fragments larger than 25.4 cm (10 inches) but less
  throughout the year; e.g., black spruce (Picea mariana).         than 60.4 cm (24 inches).
nonpersistent emergents Emergent hydrophytes whose leaves   submergent plant A vascular or nonvascular hydrophyte, either
  and stems break down at the end of the growing season so that    rooted or nonrooted, which lies entirely beneath the water sur-
  most above-ground portions of the plants are easily transported  face, except for flowering parts in some species; e.g., wild celery
  by currents, waves, or ice. The breakdown may result from nor-   (Vallisneria americana) or the stoneworts (Chara spp.).
  mal decay or the physical force of strong waves or ice. At cer-   terrigenous Derived from or originating on the land (usually
  tain seasons of the year there are no visible traces of the plants  referring to sediments) as opposed to material or sediments
  above the surface of the water; e.g., wild rice (Zizania aquatica),    produced in the ocean (marine) or as a result of biologic activity
  arrow arum (Peltandra virginica).                                (biogenous).
obligate hydrophytes Species that are found only in wetlands-    tree A woody plant which at maturity is usually 6 m (20 feet)
  e.g., cattail (Typha latifolia) as opposed to ubiquitous species  or more in height and generally has a single trunk, unbranched
  that grow either in wetland or on upland-e.g., red maple (Acer   for 1 m or more above the ground, and a more or less definite
  rubrum).                                                         crown; e.g., red maple (Acer rubrum), northern white cedar
oligohaline Term to characterize water with salinity of 0.5 to     (Thuja occidentalis).
  5.0ï¿½/00, due to ocean-derived salts.                           water table The upper surface of a zone of saturation. No water
oligosaline Term to characterize water with salinity of 0.5 to     table exists where that surface is formed by an impermeable
  5.00/oo, due to land-derived salts.                              body (Langbein and Iseri 1960:21).
organic soil Soil composed of predominantly organic rather than   woody plant A seed plant (gymnosperm or angiosperm) that
  mineral material. Equivalent to Histosol (see page 44).          develops persistent, hard, fibrous tissues, basically xylem; e.g.,
persistent emergent Emergent hydrophytes that normally re-         trees and shrubs.
  main standing at least until the beginning of the next growing   xerophyte, xerophytic Any plant growing in a habitat in which
  season; e.g., cattails (Typha spp.) or bulrushes (Scirpus spp.).  an appreciable portion of the rooting medium dries to the wilt-
photic zone The upper water layer down to the depth of effec-      ing coefficient at frequent intervals. (Plants typically found in
  tive light penetration where photosynthesis balances respira-    very dry habitats.)










42 

                                                    APPENDIX D


                                     Criteria for Distinguishing Organic
                                             Soils from Mineral Soils


  The criteria for distinguishing organic soils from mineral      and depends in part on the nature of the materials. A thick
soils in the United States (U.S. Soil Conservation Service,       layer of sphagnum has a very low bulk density and contains
Soil Survey Staff 1975:13-14, 65) are quoted here so that         less organic matter than a thinner layer of well-decomposed
those without ready access to a copy of the Soil Taxonomy          muck. It is much easier to measure thickness of layers in the
may  employ this information in the classification of             field than it is to determine tons of organic matter per hec-
                                                                   tare. The definition of a mineral soil, therefore, is based on
wetlands:
                                                                   thickness of the horizons or layers, but the limits of thick-
    For purposes of taxonomy, it is necessary, first, to define   ness must vary with the kinds of materials. The definition
                                                                   ness must vary with the kinds of materials. The definition
  the limits that distinguish mineral soil material from organic  that follows is intended to classify as mineral soils those that
                                                                   that follows is intended to classify as mineral soils those that
  soil material and, second, to define the minimum part of a      have no more organic material than the amount permitted
  soil that should be mineral if the soil is to be classified as  in the histic epipedon, which is defined later in this chapter.
                                                                   in the histic epipedon, which is defined later in this chapter.
  a mineral soil.
                                                                     To determine whether a soil is organic or mineral, the
    Nearly all soils contain more than traces of both mineral     thickness of horizons is measured from the surface of the
  and organic components in some horizons, but most soils are     soil whether that is the surface of a mineral or an organic
  dominantly one or the other. The horizons that are less than    horizon. Thus, any 0 horizon at the surface is considered an
  about 20 to 35 percent organic matter by weight have prop- organic horizon, if it meets the requirements of organic soil
                  ertis tht ar moe nerly hos    of   inerl tan o orgnicorganic horizon, if it meets the requirements of organic soil
  erties that are more neary those of mineral than of organic     material as defined later, and its thickness is added to that
  soils. Even with this separation, the volume of organic matter of any other organic horizons to determine the total thick-
  at the upper limit exceeds that of the mineral material in      ness of organic soil materials.
                  the fine-earth fraction. ~~~~~ness of organic soil materials.
  the fine-earth fraction.
                                                                   DEFINITION OF MINERAL SOILS
  MINERAL SOIL MATERIAL                                             Mineral soils, in this taxonomy, are soils that meet one of
    Mineral soil material either                                  the following requirements:
  1. Is never saturated with water for more than a few days       1. Mineral soil material <2 mm in diameter (the fine-earth
  and has <20 percent organic carbon by weight; or                fraction) makes up more than half the thickness of the up-
  2. Is saturated with water for long periods or has been         per 80 cm (31 in.);
  artificially drained, and has                                   2. The depth to bedrock is <40 cm and the layer or layers
    a. Less than 18 percent organic carbon by weight if 60 per-   of mineral soil directly above the rock either are 10 cm or
    cent or more of the mineral fraction is clay;                 more thick or have half or more of the thickness of the over-
    b. Less than 12 percent organic carbon by weight if the       lying organic soil material; or
    mineral fraction has no clay; or                             S3. The depth to bedrock ism40 cm, the mineral soil material
    c. A proportional content of organic cabon between 12 and     immediately above the bedrock is 10 cm or more thick, and
    18 percent if the clay content of the mineral fraction is be-  either
    tween zero and 60 percent.                                      a. Organic soil material is <40 cm thick and is decomposed
    Soil material that has more organic carbon than the             (consisting of hemic or sapric materials as defined later)
  amounts just given is considered to be organic material,          or has a bulk density of 0.1 or more; or
                                                                     b. Organic soil material is <60 cm thick and either is un-
  DISTINCTION BETWEEN MINERAL SOILS AND                             decomposed sphagnum or moss fibers or has a bulk density
  ORGANIC SOILS                                                     that is <0.1.
    Most soils are dominantly mineral material, but many
  mineral soils have horizons of organic material. For simplicity  ORGANIC SOIL MATERIALS
  in writing definitions of taxa, a distinction between what is     Organic soil materials and organic soils
  meant by a mineral soil and an organic soil is useful. In a     1. Are saturated with water for long periods or are arti-
  mineral soil, the depth of each horizon is measured from the    ficially drained and, excluding live roots, (a) have 18 percent
  top of the first horizon of mineral material. In an organic     or more organic carbon if the mineral fraction is 60 percent
  soil, the depth of each horizon is measured from the base       or more clay, (b) have 12 percent or more organic carbon
  of the aerial parts of the growing plants or, if there is no    if the mineral fraction has no clay, or (c) have a proportional
  continuous plant cover from the surface of the layer of         content of organic carbon between 12 and 18 percent if the
  organic materials. To apply the definitions of many taxa,       clay content of the mineral fraction is between zero and 60
  therefore, one must first decide whether the soil is mineral    percent; or
  or organic.                                                     2. Are never saturated with water for more than a few days
    If a soil has both organic and mineral horizons, the relative  and have 20 percent or more organic carbon.
  thickness of the organic and the mineral soil materials must      Item 1 in this definition covers materials that have been
  be considered. At some point one must decide that the           called peats and mucks. Item 2 is intended to include what
  mineral horizons are more important. This point is arbitrary    has been called litter or 0 horizons. Not all organic soil










                                                                                                                            43


materials accumulate in or under water. Leaf litter may rest         is moss fibers or the moist bulk density is <0.1 g per cubic
on a lithic contact and support a forest. The only soil in this      centimeter (6.25 lbs per cubic foot);
situation is organic in the sense that the mineral fraction is       (2) 40 cm or more if
appreciably less than half the weight and is only a small              (a) The organic soil material is saturated with water
percentage of the volume of the soil.                                  for long periods (>6 months) or is artificially drained;
                                                                       and
                                                                       (b) The organic material consists of sapric or hemic
DEFINITION OF ORGANIC SOILS                                            materials or consists of fibric materials that are less
  Organic soils (Histosols) are soils that                             than three-fourths moss fibers by volume and have a
1. Have organic soil materials that extend from the surface            moist bulk density of 0.1 or more; and
to one of the following:                                           b. Have organic soil materials that
  a. A depth within 10 cm or less of a lithic or paralithic con-     (1) Do not have a mineral layer as much as 40 cm thick
 tact, provided the thickness of the organic soil materials         either at the surface or whose upper boundary is within
  is more than twice that of the mineral soil above the con-         a depth of 40 cm from the surface; and
 tact; or                                                           (2) Do not have mineral layers, taken cumulatively, as
 b. Any depth if the organic soil material rests on frag-           thick as 40 cm within the upper 80 cm.
  mental material (gravel, stones, cobbles) and the interstices      It is a general rule that a soil is classed as an organic
 are filled with organic materials, or rests on a lithic or para-  soil (Histosol) either if more than half of the upper 80 cm
  lithic contact; or                                               (32 in.) [sic] of soil is organic or if organic soil material of
2. Have organic materials that have an upper boundary              any thickness rests on rock or on fragmental material
within 40 cm of the surface and                                    having interstices filled with organic materials.
 a. Have one of the following thicknesses:                         Soils that do not satisfy the criteria for classification as
   (1) 60 cm or more if three-fourths or more of the volume      organic soils are mineral soils.









44

                                            APPENDIX E


                          Artificial Keys to the Systems and Classes

                                           Key to the Systems

1. Water regime influenced by oceanic tides, and salinity due to ocean-derived salts 0.50/oo or greater.
  2. Semi-enclosed by land, but with open, partly obstructed or sporadic access to the ocean. Halinity wide-ranging
     because of evaporation or mixing of seawater with runoff from land .......................   ESTUARINE
  2. Little or no obstruction to open ocean present. Halinity usually euhaline; little mixing of water with runoff
     from land ..................................................................................3
     3. Emergents, trees, or shrubs present ................................................ESTUARINE
     3. Emergents, trees, or shrubs absent ....................................................       MARINE
1. Water regime not influenced by ocean tides, or if influenced by oceanic tides, salinity less than 0.50/oo.
  4. Persistent emergents, trees, shrubs, or emergent mosses cover 30% or more of the area .....  PALUSTRINE
  4. Persistent emergents, trees, shrubs, or emergent mosses cover less than 30% of substrate but nonpersistent
     emergents may be widespread during some seasons of year ...................................... .       5
     5. Situated in a channel; water, when present, usually flowing ..............................RIVERINE
     5. Situated in a basin, catchment, or on level or sloping ground; water usually not flowing .......... ..6
        6. Area 8 ha (20 acres) or greater ................................................      LACUSTRINE
        6. Area less than 8 ha .....................................................................7
           7. Wave-formed or bedrock shoreline feature present or water depth 2 m (6.6 feet)
             or more ...................................................................LACUSTRINE
           7. No wave-formed or bedrock shoreline feature present and water less than 2 m deep .PALUSTRINE



                                            Key to the Classes

1. During the growing season of most years, areal cover by vegetation is less than 300%.
  2. Substrate a ridge or mound formed by colonization of sedentary invertebrates (corals, oysters,
     tube worms) ......................................................................REEF
  2. Substrate of rock or various-sized sediments often occupied by invertebrates but not formed by colonization
     of sedentary invertebrates ....................................................................3
     3. Water regime subtidal, permanently flooded, intermittently exposed, or semipermanently flooded. Substrate
        usually not soil ...........................................................................4
        4. Substrate of bedrock, boulders, or stones occurring singly or in combination covers 75% or more of the
          area .................................................................... ROCK BOTTOM
        4. Substrate of organic material, mud, sand, gravel, or cobbles with less than 75% areal cover of stones,
          boulders, or bedrock ................... ............................ UNCONSOLIDATED BOTTOM
     3. Water regime irregularly exposed, regularly flooded, irregularly flooded, seasonally flooded, temporarily
        flooded, intermittently flooded, saturated, or artificially flooded. Substrate often a soil .............. 5
        5. Contained within a channel that does not have permanent flowing water (i.e., Intermittent Subsystem
          of Riverine System or Intertidal Subsystem of Estuarine System) ...................   . STREAMBED
        5. Contained in a channel with perennial water or not contained in a channel ...................  ..6
          6. Substrate of bedrock, boulders, or stones occurring singly or in combination covers 75% or more of
             the area ................................................................. ROCKY SHORE
          6. Substrate of organic material, mud, sand, gravel, or cobbles; with less than 75% of the cover consisting
             of stones, boulders, or bedrock ...................    ................. UNCONSOLIDATED SHORE
1. During the growing season of most years, percentage of area covered by vegetation 30% or greater.
  7. Vegetation composed of pioneering annuals or seedling perennials, often not hydrophytes, occurring only at
     time of substrate exposure .................................................................8
     8. Contained within a channel that does not have permanent flowing water .....STREAMBED (VEGETATED)
     8. Contained within a channel with permanent water, or not contained
        in a channel ................... ......................... UNCONSOLIDATED SHORE (VEGETATED)









                                                                                                  45


7. Vegetation composed of algae, bryophytes, lichens, or vascular plants that are usually hydrophytic
  perennials ..................................................................................9
     9. Vegetation composed predominantly of nonvascular species ..................................10
        10. Vegetation macrophytic algae, mosses, or lichens growing in water or the
           splash zone of shores .....................................................AQUATIC BED
        10. Vegetation mosses or lichens usually growing on organic soils and always outside the splash zone
           of shores ......................................................MOSS-LICHEN WETLAND
     9. Vegetation composed predominantly of vascular species .....................................11
        11. Vegetation herbaceous .............................................................12
           12. Vegetation emergents ..........................................EMERGENT WETLAND
           12. Vegetation submergent, floating-leaved, or floating ........................AQUATIC BED
        11. Vegetation trees or shrubs ..........................................................13
           13. Dominants less than 6 m (20 feet) tall ..........................SCRUB-SHRUB WETLAND
           13. Dominants 6 m tall or taller .....................................FORESTED WETLAND










46




















































Plate 1.-Classification: SYSTEM Marine, SUBSYSTEM Subtidal, CLASS Rock Bottom, SUBCLASS Bedrock, WATER REGIME Subtidal,
 WATER CHEMISTRY Euhaline. This underwater photograph shows colonies of common sea fans (Gorgonia ventalina) and other
 gorgonians living on bedrock. Bare rock is visible in the center and lower left corner of the photo. (Monroe County, Florida; July
 1969; Photo by E. T. LaRoe)










                                                                                                                     47





















































Plate 2.-Classification: SYSTEM Marine, SUBSYSTEM Subtidal, CLASS Reef, SUBCLASS Coral, WATER REGIME Subtidal, WATER
 CHEMISTRY Euhaline. This underwater photograph shows corals (Acropora and Porites) as well as several species of gorgonians.
 (Monroe County, Florida; August 1970; Photo by E. T. LaRoe)


































































Plate 3.-Two habitats are shown here. Classification of landward (lighter) zone: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS
 Rocky Shore, SUBCLASS Bedrock, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Euhaline. Classification of seaward
 (darker) zone: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS Aquatic Bed, SUBCLASS Algal, DOMINANCE TYPE Fucus spiralis,
 WATER REGIME Regularly Flooded, WATER CHEMISTRY Euhaline. Subordinate plants in the aquatic bed include rockweed (Fucus
 vesiculosus), knotted wrack (Ascophyllum nodosum), and Irish moss (Chondrus crispus). This photo was taken at low tide. (Newport
 County, Rhode Island; July 1977; Photo by F. C. Golet)








































































(Washington County, Rhode Island; July 1977; Photo by F. C. Golet)






50












      Age~~~~~~~~~~~~~


















Plate 5.-Classification: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore, SUBCLASS Sand, WATER REGIMES
 Regularly Flooded (seaward from the woman to the breaking waves) and Irregularly Flooded (landward from the woman to the
 base of the sand dunes), WATER CHEMISTRY Euhaline. Lines of wrack (dead Fucus spp., Ascophyllum nodosum, and Zostera marina)
 on the beach mark the landward limit of various high tides during the past several days. The photo was taken at low tide. (Parker
 River National Wildlife Refuge, Essex County, Massachusetts; September 1985; Photo by F. C. Golet)










                                                                                                                      51





















































Plate 6.-Classification: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore, SUBCLASS Sand, WATER REGIMES
 Regularly Flooded (lower two-thirds of beach) and Irregularly Flooded (upper one-third of beach near base of cliffs), WATER
 CHEMISTRY Euhaline. (Point Reyes National Seashore, Marin County, California; August 1975; Photo by V. Carter)










52































~_!



















Plate 7.-Classification: SYSTEM Estuarine, SUBSYSTEM Subtidal, CLASS Unconsolidated Bottom, SUBCLASS Sand, WATER REGIME
  Subtidal, WATER CHEMISTRY Mixohaline. An irregularly flooded persistent-emergent wetland dominated by saltmarsh cordgrass
  (Spartina alterniflora) and saltmeadow cordgrass (Spartina patens) is shown in the right background (Washington County, Rhode
  Island; July 1977; Photo by F. C. Golet)












                          IS1!~~~~~~~~ |   I |~~~~~53



















                     fif~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~6 fff          Rf 


































Plate 8.-Classification: SYSTEM Estuarine, SUBSYSTEM Subtidal, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME
 Subtidal, WATER CHEMISTRY Mixohaline. This site lies within the Fjord Biogeographic Province. Glacier-mantled mountains plunge
 steeply into water more than 180 m (600 ft) deep. (Lynn Canal, Haines Borough, Alaska; June 1985; Photo by F. C. Golet)





54























Plate 9.-Classification: SYSTEM Estuarine, SUBSYSTEM Subtidal, CLASS Aquatic Bed, SUBCLASS Rooted Vascular, DOMINANCE TYPE
  Myriophyllum spicatum, WATER REGIME Subtidal, WATER CHEMISTRY Mixohaline. Subordinate plant species include mare's tail
  (Hippuris tetraphylla) and crowfoot (Ranunculus pallasii). This pond is located on coastal tundra; it is flooded with tidal water
  only during exceptionally high tides (less often than monthly). Plants characterizing the aquatic bed are shown in the photo-inset.
  (Between Azun and Narokachik Rivers, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by F. C. Golet)
                                  X   l  | i |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                                  | 1E g ME1 |  |  |  Q S  0 | I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~






                                                                                              55











_III_&itig
















Plate 10.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Reef, SUBCLASS Mollusk, DOMINANCE TYPE Crassostrea
 zirginica, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline. An individual red mangrove (Rhizophora mangle)
 has become established on this oyster reef. (Rookery Bay Sanctuary, Collier County, Florida; January 1978; Photo by E. T. LaRoe)









56











































Plate 11.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Streambed, SUBCLASS Mud, WATER REGIME Regularly
  Flooded, WATER CHEMISTRY Mixohaline. This photo was taken at low tide; at high tide, the entire channel is flooded. The channel
  is flanked by irregularly flooded persistent-emergent wetland supporting such plants as: lyme grass (Elymus arenarius), beach
  lovage (Ligusticum scothicum), silverweed (Potentilla anserina), sedges (Carex ramenskii, C. bipartita), ovalleaf willow (Salix
  ovalifolia). and Arctic daisy (Dendranthema arcticum). This site lies 100 m from Angyoyaravak Bay, on the Bering Sea. (Tutakoke
  River area, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by F. C. Golet)
                                     Xa:; r: . g f f | |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~











                                                                                                                           57























































Plate 12.-Two habitats lie at the edge of this manmade breakwater. Classification of upper (lighter) zone: SYSTEM Estuarine, suB-
  SYSTEM Intertidal, CLASS Rocky Shore, SUBCLASS Rubble, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Euhaline,
  SPECIAL MODIFIER Artificial. Classification of lower (darker) zone: SYSTEM Estuarine,                SUBSYSTEM Intertidal, CLA SS Aquatic Bed,
 SUBCLASS Algal, DOMINANCE TYPE Fucus vesiculosus, WATER REGIME Regularly Flooded, WATER CHEMISTRY Euhaline, SPECIAL
 MODIFIER Artificial. (Washington County, Rhode Island; July 1977; Photo by F. C. Golet)










58




















































Plate 13.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore, SUBCLASS Cobble-Gravel, WATER
  REGIMES Regularly Flooded (darker zone at edge of water) and Irregularly Flooded (remainder of shore), WATER CHEMISTRY
  Euhaline. Mean tidal range in this area of the Arctic Ocean is approximately 15 cm (6 in). (Mikkelsen Bay, North Slope Borough,
  Alaska; July 1985; Photo by F. C. Golet)








                                                                                                                59



















           I~~~

















Plate 14.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIME
 Regularly Flooded, WATER CHEMISTRY Mixohaline. Turnagain Arm, a large bay off Cook Inlet, is 4-7 km (2.5-4 mi) wide at this
 location. Mean tidal range is 9.2 m (30 ft), and the entire area shown here is dewatered at low tide. (Municipality of Anchorage,
 Alaska; June 1985; Photo by F. C. Golet)










60










                                  !~:~~~~~ ~ ~ ~     :    ; !  ~  .i  ~  'l ~/  ~i !~~i~i~i  .~!!?  ':'?  :' ~'~." :  ' 0    ~' ?' ' :  ~?"' ~ ~? ? ......
                                                 ? ~? ii:z:   :-i   i    ii !i ! 15: i   !i;;    :   g :iS  !'?:: !:i  !  :!: tV  :~  ~i1:!  (!!  ;:i          ~









































Plate 15.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, C LAS S Unconsolidated Shore, SUBCLASS Mud, WATER REGIME
  Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Alkali grass (Puccinellia grandis) grows in widely scattered
  clumps at the right-hand edge of the photo. Mean tidal range at Fire Island (background left) is 7.4 m (24.4 ft). The cracks on
  these mud flats are evidence of the irregularly flooded tidal regime. (Municipality of Anchorage, Alaska; June 1985; Photo by
  F. C. Golet)











                                                                                                                         61






















































Plate 16.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Spartina alternifora, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Saltmarsh cord-
 grass is the only plant growing in the regularly flooded zone of this salt marsh. Saltmeadow cordgrass (Spartina patens), seaside
 goldenrod (Solidago sempervirens), and the sedge, Carex paleacea, grow at the landward edge of the marsh. The photo was taken
 at high tide. (Essex County, Massachusetts; September 1985; Photo by F. C. Golet)











62























































Plate 17.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Spartinafoliosa, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. The most common sub-
 ordinate plants are glassworts (Salicornia spp.). This wetland borders an irregularly flooded emergent wetland dominated by
 glasswort. The photo was taken at high tide. (San Mateo County, California; August 1976; Photo by V. Carter)










                                                                                                                        63














                                                                             " qalim Cl ,;   qp- N  TE F    1,1  N









































Plate 18.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Carex lyngbyei, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Organic. The photo was taken at
 low tide. (Coos County, Oregon; May 1977; Photo by D. D. Peters)










64






















































Plate 19.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
  TYPE Triglochin maritinum, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Subordinate plants
  include samphire (Salicornia europaea) and seaside plantain (Plantago maritima). This stand is located at the seaward edge of
  the irregularly flooded zone where it is inundated by most, but not all, high tides. Water depth is less than 5 cm (2 in). Slightly
  more elevated stands of Triglochin maritimum contain little or no standing water between periods of inundation. (Municipality
  of Anchorage, Alaska      ; June 1985; Photo by F. C. Golet)










                                                                                                                       65





















































Plate 20.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Phragmites australis, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Saltmeadow cord-
 grass (Spartina patens) and saltmarsh cordgrass (Spartina alterniflora) are subordinate species. (Washington County, Rhode
 Island; July 1977; Photo by F. C. Golet)










66





















































Plate 21.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Scirpus americanus, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Organic. Subordinate species
 include saltmeadow cordgrass (Spartina patens) and saltmarsh cordgrass (Spartina alterniflora); these appear as a fringe at the
 water's edge. (Dorchester County, Maryland; June 1974; Photo by V. Carter)










                                                                                                                             67











                                     ::\~~~~~                       ~~  ,:: ....::,..










































Plate 22.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
 TYPE Carex lyngbyei, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Oligohaline, SOIL Mineral. Subordinate species in-
 clude sedge (Carex pluriflora), silverweed (Potentilia anserina), arrow grass (Triglochin maritimum), and mare's tail (Hippuris
  tetraphylla). Located on the floodplain of a tidal river, this site receives freshwater runoff from the Chugach Mountains and the
 Twenty-mile Glacier (center background), and is also inundated by exceptionally high tides. Soil salinity during October 1985
 was 3.0%o. (Muncipality of Anchorage, Alaska; June 1985; Photo by F. C. Golet)










68






















































Plate 23.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE
  TYPE Hippuris tetraphylla, WATER REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. This stand of mare's
  tail lies at the landward limit of the regularly flooded zone, where the substrate is covered with several centimeters of water
  at high tide. The Azun River, source of the tidal water, is just visible at the right-hand edge of the photo. (Mouth of Azun River,
  Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by F. C. Golet)
































































Plate 24.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Deciduous,
 DOMINANCE TYPE Ivafrutescens, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Subordinate
 plants growing beneath the marsh elder are black grass (Juncus gerardii), salt grass (Distichlis spicata), and saltmeadow cord-
 grass (Spartina patens). This wetland lies toward the landward edge of an irregularly flooded persistent-emergent wetland dominated
 by saltmarsh cordgrass (Spartina alternifiora), saltmeadow cordgrass, and salt grass (background). (Washington County, Rhode
 Island; July 1977; Photo by F. C. Golet)










70













                         1 b 3 3 3 IF ~                       3                      3~ 3!             3 i  ia  5m  t.! i !5 -! iX myI -yr  ! i  id o-t




   S ,o.z;... . : ?~ ~i .,i0''!~~i ~i l',; ~ii2~ii~  i~ -'  0     ; . ,-:a=. .. ;-: - |-13;W ~,,0  




































Plate 25.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Evergreen,
  DOMINANCE TYPE Rhizophora mangle, WATER REGIMES Regularly Flooded (along waterways) and Irregularly Flooded (at some
 distance from waterways), WATER CHEMISTRY Oligohaline, SOIL Organic. This mangrove swamp is located in the southern part
 of the Florida Everglades. (Dade County, Florida; December 1975; Photo by V. Carter)










                                                                                                                     71





















































Plate 26.-Classification: SYSTEM Riverine, SUBSYSTEM Tidal, CLASS Aquatic Bed, SUBCLASS Rooted Vascular, DOMINANCE TYPE
 Myriophyllum spicatum-Hydrilla verticillata-Heteranthera dubia, WATER REGIME Permanently Flooded-Tidal, WATER CHEMISTRY
 Fresh-Circumneutral. (Prince Georges County, Maryland; October 1985; Photo by V. Carter)










72





















































Plate 27.-Two habitats are shown here. Classification of nonvegetated zone: SYSTEM Riverine, SUBSYSTEM Tidal, CLASS Uncon-
 solidated Shore, SUBCLASS Mud, WATER REGIME Regularly Flooded, WATER CHEMISTRY Fresh-Circumneutral. Classification of
 vegetated zone: SYSTEM Riverine, SUBSYSTEM Tidal, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE TYPE
 Peltandra virginica, WATER REGIME Regularly Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral. The photo was
 taken at low tide. (Cecil County, Maryland; July 1972; Photo by V. Carter)









                                                                                                                               73











































             Plate 28.--Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Unconsolidated Bottom, SUBCLASS Cobble-Gravel,
               WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh. The channel bottom is composed primarily of gravel and sand.
               The stream meanders through a grassy annual floodplain which is flanked by a more elevated floodplain supporting cottonwoods
               (Populus deltoides). (Crook County, Wyoming; May 1985; Photo by F. C. Golet)
I.                                       _







74











                                 i;;: A i; Al!, ago,   if  ï¿½ae w    Errs I.  u en~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!%: i~ii i  









                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I 
      _k~~~~~~~~~g~~ gia_                                                                                               _



















Plate 29.-Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Unconsolidated Bottom, SUBCLASS Sand, WATER
  REGIME Permanently Flooded, WATER CHEMISTRY Fresh. Channel meanders, a typical feature of lower perennial streams, are
  especially well developed along this section of the Yellowstone River. (Yellowstone National Park, Park County, Wyoming; May
  1985; Photo by F. C. Golet)










                                                                                                                          75























































Plate 30.-Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Aquatic Bed, SUBCLASS Rooted Vascular, DOMINANCE
 TYPE Nymphaea odorata, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SPECIAL MODIFIER
 Excavated. This channel was dug by man in an unsuccessful attempt to drain the wetland. Plants in the Palustrine wetland bordering
 the channel include sedge (Carex lasiocarpa), sweet gale (Myrica gale), leatherleaf (Chamaedaphne calyculata), and Atlantic white
 cedar (Chamaecyparis thyoides). (Washington County, Rhode Island; July 1977; Photo by F. C. Golet)
























     f9: ,Hi-iSHii:,S;k,, g                 0 g  t t a g                                                                   i






   ae  C;as                                                                                                 if  c a n- ...,



























Plate 31.-Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Unconsolidated Shore, SUBCLASS Cobble-Gravel,
  WATER REGIME Temporarily Flooded, WATER CHEMISTRY Fresh. Feltleaf willow (Salix alaxensis) grows along the edge of the
  stream. The entire channel is flooded for only a few weeks after snowmelt each year. (Kavik River, North Slope Borough, Alaska;
  July 1985; Photo by F. C. Golet)











                                                                                                                       77


























































REGIME Seasonally Flooded, WATER CHEMISTRY Mixosaline SOIL Mineral. Young tamarisk (Tamarix gallica) plants are scattered
over this sand flat. (Socorro County, New Mexico; April 1978; Photo by P. B. Reed)
over this sand flat. (Socorro County, New Mexico; April 1978; Photo by P. B. Reed)










78























































Plate 33.-Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Emergent Wetland, SUBCLASS Nonpersistent,
 DOMINANCE TYPE Peltandra virginica-Pontederia cordata, WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Fresh-
 Circumneutral, SOIL Mineral. This wetland lies in a bay of the Chicopee River. (Hampden County, Massachusetts; July 1970; Photo
 by R. C. Smardon)








                                                                                                                  79
























         @~~~~~                                                                                             . ~















Plate 34.-Two habitats are shown here. Classification of channel: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Rock
 Bottom, SUBCLASS Bedrock, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh. Classification of shore: SYSTEM
 Riverine, SUBSYSTEM Upper Perennial, CLASS Rocky Shore, SUBCLASS Bedrock, WATER REGIME Seasonally Flooded, WATER
 CHEMISTRY Fresh. (Penobscot County, Maine; October 1977; Photo by R. W. Tiner)










80






















































Plate 35.-Classification: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Rock Bottom, SUBCLASS Rubble, WATER REGIME
 Permanently Flooded, WATER CHEMISTRY Fresh. Many of the boulders in this river exceed I m (3.3 ft) in diameter. (Matanuska-
  Susitna Borough, Alaska; June 1985; Photo by F. C. Golet)

























































Plate 36.-Classification: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Unconsolidated Bottom, SUBCLASS Cobble-Gravel,
  WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral. (Washington County, Rhode Island; July 1977;
  Photo by F. C. Golet)
                            ~                ,,~    ;                             ii   ~i    :~ 

                                             (s ~       ï¿½~  ~~?                                  ~











                                                                                  '~;~i~~i~~ 'i~s
                                                       "~~~~~~~~ i -i~~ ~                     ...
                                                                    ~ ~~~~~~~~~~~~iï¿½.














                             Plae 3.-Clasifcaion SSTE RiefneSUBYSEM   ppr  Prenia, CAS Unonsliate Boto, SBCASSCobleGrael










82
























































Plate 37. -Classification: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Unconsolidated Shore, SUBCLASS Cobble-Gravel,
 WATER REGIME Temporarily Flooded, WATER CHEMISTRY Fresh. This high-gradient mountain stream arises in the Alaska Range.
 The gravel piled at the left-hand edge of the photo had accumulated in the channel during flood stage and was bulldozed to its
 present position to prevent flooding of a highway just downstream. (Fairbanks North Star Borough, Alaska; July 1985; Photo
 by F. C. Golet)










                                                                                                                       83























































Plate 38.-Classification: SYSTEM Riverine, SUBSYSTEM Intermittent, CLASS Streambed, SUBCLASS Sand, WATER REGIME Inter-
 mittently Flooded, WATER CHEMISTRY Mixosaline. The average annual discharge for this river, the Rio Salado, is 14.6 hm3/yr
 (11,880 acre-ft/yr). (Socorro County, New Mexico; April 1978; Photo by P. B. Reed)










84






















































Plate 39.-Classification: SYSTEM Riverine, SUBSYSTEM Intermittent, CLASS Streambed, SUBCLASS Mud, WATER REGIME Intermit-
  tently Flooded. Streambeds such as this are common throughout the and West. They carry water for brief periods after snowmelt
  and following rainstorms which are irregular and unpredictable in occurrence. (Badlands National Monument, Jackson County,
  South Dakota; May 1985; Photo by F. C. Golet)







!                                                                                                                                          85

































                 Plate 40.-Classification: SYSTEM Lacustrine, SUBSYSTEM Limnetic, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME
                   Permanently Flooded, WATER CHEMISTRY Fresh. In the narrow Littoral zone of Yellowstone Lake, where water is less than 2
                   m (6.6 ft) deep, the bottom consists primarily of gravel and sand. (Yellowstone National Park, Teton County, Wyoming; May
                   1985; Photo by F. C. Golet)
I

I A














    |            ~~~~Plate 40.-Classification: SYSTEM Lacustrine, SUBSYSTEM Limnetic, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME
     |             ~~~~Permanently Flooded, WATER CHEMISTRY Fresh. In the narrow Littoral zone of Yellowstone Lake, where water is less than 2
     I             ~~~~m (6.6 ft) deep, the bottom consists primarily of gravel and sand. (Yellowstone National Park, Teton County, Wyoming; May
                   1985; Photo by F. C. Golet)










86




















































Plate 41.-Classification: SYSTEM Lacustrine, SUBSYSTEM Limnetic, CLASS Aquatic Bed, SUBCLASS Rooted Vascular, DOMINANCE
 TYPE Nymphaea odorata, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral. Subordinate plants
  in the Aquatic Bed include bladderworts (Utricularia spp.). Yellow-eyed grass (Xyris smalliana) grows on floating mats of peat
  along the shore (foreground). Water depth in this 0.8-ha (2-acre) bog lake exceeds 3 m (10 ft). (Washington County, Rhode Island;
  July 1977; Photo by F. C. Golet)








                                                                                                                            87















             by; ,,,                                                                 F. C. G                             , l 























             Plate 42.-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Cobble-Gravel, WATER
              REGIME Seasonally Flooded, WATER CHEMISTRY Fresh. At the time of photography, the level of Yellowstone Lake was near its
              seasonal low point. Due to snowmelt, the level of the lake rises to a peak in early July and then slowly declines until the following
              spring. This entire beach is inundated each summer. (Yellowstone National Park, Teton County, Wyoming; May 1985; Photo
              by F. C. Golet)
I__llll         








88













                                                                                                              J~~~~~~~~~~~~~

























Plate 43.--Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Sand, WATER REGIME
  Intermittently Flooded, WATER CHEMISTRY Fresh. Water levels in the Great Lakes generally fluctuate little during a single year,
  but they may rise and fall considerably over a period of several years. The water level in Lake Michigan was at an all-time high
  when this photo was taken. As a result of long-term changes in lake levels and seiches produced by storms, lake waters inundate
  part or all of this beach on an irregular basis. (Indiana Dunes National Lakeshore, Porter County, Indiana; May 1985; Photo
  by F. C. Golet)







                                                                                                                                         89
































             Plate 44.-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIMES
              Temporarily Flooded and Seasonally Flooded, WATER CHEMISTRY Fresh, SOIL Mineral, SPECIAL MODIFIER Impounded. The flats
               exposed along the shore of this reservoir are temporarily flooded; the seasonally flooded zone is still inundated at the time of
              this spring photograph. (Park County, Wyoming; May 1985; Photo by F. C. Golet)
~~~~~~~~N ; d ''--- IfAy>     

I~ ~ ~~~ nt0  ;ffi;00Id   ?                                '         3        -   













90



































                                      io~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i 
































Plate 45.-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIME
              Seasonally Flooded, WATER CHEMISTRY Hypersaline. (Salt Lake County, Utah; June 1973; Photo by V. Carter)
                             :                                                  :      a:  ;    :  i::f  -:  wi:: :t  ;:t;  ::  : :      0



        - ~ ~ ~ ~ ~ ~~~~~~~t  ;            ?   ;f:;  0   ;           :   :   ::



































                        Pl te  :t f;; tid ic t   0 j SYSTEM Lacst;  ;SU  STEM :ttoral, CLASS Uncon d S , S S .u, ::TR R :
                         Seasonally Flo :;ed,    :; f:} ;;I~iST l; fi;; :; tV lt0's:  lin t; :0j;alt : a:e Co nt::  ::ah; June 1973; iS V      0 t;:   :y ;. C










                                                                                                                         91























































Plate 46.-Two habitats are shown here. Classification of exposed areas: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Uncon-
 solidated Shore, SUBCLASS Mud, WATER REGIMES Intermittently Flooded (light-colored soil) and Seasonally Flooded (darker soil
 along water's edge), WATER CHEMISTRY Mixosaline, SOIL Mineral. Classification of inundated areas: SYSTEM Lacustrine, SUB-
 SYSTEM Littoral, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Semipermanently Flooded, WATER CHEMISTRY
 Mixosaline, SOIL Mineral. Greasewood (Sarcobatus vermiculatus), salt grass (Distichlis spicata), and rushes (Juncuas spp.) are scattered
 across the flats. Because annual precipitation averages only about 18 cm (7 in) here, these wetlands are heavily dependent upon
  snowpack in the surrounding mountains as a source of water. (Saguache County, Colorado; Photo by R. M. Hopper)










92




















































Plate 47.-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Organic, WATER REGIME
  Seasonally Flooded, WATER CHEMISTRY Fresh. This beach is only 15 m (50 ft) long and 2 m (6-7 ft) wide. Such organic shores
  are common in certain areas of the Yukon-Kuskokwim Delta, and many are considerably larger than the one shown here. Evidence
  of the decline in lake levels over the summer can be seen in the series of low ridges in the peat. Surrounding vegetation includes
  sedge (Carez lyngbyei), bluejoint (Calamagrostis canadensis), and willows (Salix spp.). (Talik River area, Yukon-Kuskokwim Delta,
  Alaska; July 1985; Photo by F. C. Golet)











                                                                                                                    93
























































Plate 48.-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE
 TYPE Nelumbo lutea, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutrai, SOIL Mineral, SPECIAL
 MODIFIER Impounded. Subordinate plants are duckweeds (Lemna spp.) and bald cypress (Taxodium distichum). (Obion County,
 Tennessee; September 1975; Photo by V. Carter)
 Tennessee; September 1975; Photo by V. Carter)










94






















































Plate 49-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE
 TYPE Jucus militaris, WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral. Subor-
 dinate plants include common threesquare (Scirpus americanus) and pickerelweed (Pontederia cordata). During the spring, emergent
 vegetation is not evident at this site, and waves break on the gravel shore visible in the foreground. (Washington County, Rhode
 Island; July 1977; Photo by F. C. Golet)








                                                                                                                        95








































Plate 50.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Sand, WATER REGIME Intermittently Ex-
 posed, WATER CHEMISTRY Fresh-Alkaline. Rushes (Juncus spp.), spike rush (Eleocharis sp.) and smartweed (Polygonum sp.) grow
 in shallow water along the shore of this 0.4-ha (1-acre) pond which occupies a depression amidst sand dunes on the southern shore
 of Lake Michigan. (Indiana Dunes National Lakeshore, Porter County, Indiana; May 1985; Photo by F. C. Golet)
    :'l            _    g 5'-? !~   ;'i' -?  ',:' "i~ '  .' ;   ii?~~

 ,~                                                    '                      A l '   i!',     : ~ ii

























Plate 50.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Sand, WATER REGIME Intermittently Ex-
 posed, WATER CHEMISTRY Fresh-Alkaline. Rushes (Juncus spp.), spike rush (Eleocharis sp.), and smartweed (Polygonurn sp.) grow
 in shallow water along the shore of this 0.4-ha (1-acre) pond which occupies a depression amidst sand dunes on the southern shore
 of Lake Michigan. (Indiana Dunes National Lakeshore, Porter County, Indiana; May 1985; Photo by F. C. Golet)










96






















































Plate 51.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Permanently Flooded,
  WATER CHEMISTRY Fresh-Circumneutral, SPECIAL MODIFIER Impounded. This beaver pond is situated in the San Juan Moun-
  tains. (Gunnison County, Colorado; Photo by R. M. Hopper)











                                                                                                                       97























































Plate 52.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Semipermanently
 Flooded, WATER CHEMISTRY Mesosaline, SOIL Mineral. This photo was taken during drouth conditions; the bottom is being in-
 vaded by pioneer species including summer cypress (Kochia scoparia), golden dock (Rumex maritimus), and goosefoot (Chenopodium
 glaucum). (Stutsman County, North Dakota; August 1961; Photo by R. E. Stewart)



































                                             o       a~i~i ~               i.;k``-:T~  8;~1.ï¿½                   rr~k
93                                                                                                                                                        I
                                                                                       e~~~~~~~~~ ï¿½I;~~~~~~~~~~~~~~










                       1 k S 1 ~~~~~;   Zli                                                                 -  -
                                                 "UI~~~~~~~~~                                        IP


Plate 53.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Semipermanently
 Flooded, WATER CHEMISTRY Fresh-Alkaline, SOIL Mineral, SPECIAL MODIFIER Impounded. A sparse stand of water plantain (Alisma
 plantago-aquatica) appears along the edge of the impoundment. (Billings County, North Dakota; July 1970; Photo by J. T. Lokemoen)












                                                                                                                   99






















































Plate 54.-Classification: SYSTEM Palustrine, CLASS Aquatic Bed, SUBCLASS Rooted Vascular, DOMINANCE TYPE Ranunculus
 trichophyllus, WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Oligosaline, SOIL Mineral. (Stutsman County, North
 Dakota; August 1966; Photo by R. E. Stewart)










100























































Plate 55.-Classification: SYSTEM Palustrine, CLASS Moss-Lichen Wetland, SUBCLASS Moss, WATER REGIME Saturated, WATER
  CHEMISTRY Fresh-Acid, SOIL Organic. The dominant plant is peat moss (Sphagnum spp.). Subordinate plants include reindeer
  moss (Cladina spp.), leatherleaf (Chamaedaphne calyculata), crowberry (Empetrum nigrum), and cottongrass (Eriophorum spp.).
  (Campobello Island International Park, Maine-Canada; June 1976; Photo by V. Carter)















































                     Plate 56.-Classification: SYSTEM Palustrine, CLASS Moss-Lichen Wetland, SUBCLASS Moss, WATER REGIME Saturated, WATER
                       CHEMISTRY Fresh. Peat moss (Sphagnum spp.) is the dominant plant. Subordinate plants include sedges (Carex rarflora, C. aquatilis),
                       cottongrass (Eriophorum russeolum), and reindeer moss (Cladina spp.). While sedges are present, their combined cover is less
                       than 30%. Mosses cover 100% of the area. (Narokachik-Azun Rivers area, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo
                       by F. C. Golet)
I                     ta  0.Mse   oe   0%o  h  ra  Nrkci-znRvr  ra   uo-ukki   etAak;Jl  95  ht






102























                                                                                                                                                      I



Plate 57.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Typha latifolia,
 WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh, SPECIAL MODIFIER Impounded. Persistent emergents such as
 these cattails remain standing at least until the beginning of the next growing season. Note that the adjacent lake is ice-covered
 at the time of photography. (Knox County, Maine; April 1978; Photo by P. B. Reed)
                                        | *-i_,                              5 9                                      11~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~










                                                                                                                     103





















































Plate 58.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Scirpus robustus-
 Se/rpus acutus, WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Mixosaline, SOIL Mineral. (Stutsman County, North
 Dakota; August 1962; Photo by R. E. Stewart)












104





















                                ;~~~~~~~~~~~~~
       f   i;;;    ;  i  - i70ii    '               - ti                              ii  iii.  :ii-'t"s-*- l  i   -iti iS  i    '1 i00    ;-  








           A -T FA  - 
























   Florida Everglades. (Dade County, Florida; December 1975; Photo by V. Carter)
                        AMA~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i iA~j~~,r4
                                                l~~~~~~~~~~~~~~~~~~ï¿½i                 :ï¿½lï¿½Ai;i $p  liAAlï¿½; 'A-A








                                                                             I' ~~:  li'i 8ir ---ii;;;;;~4























Plate 59.--Classiflcation: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Cladiumjamatcense,
 WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Organic. This photo was taken in the
 Florida Everglades. (Dade County, Florida; December 1975; Photo by V. Carter)










                                                                                                                     105




















































Plate 60.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Carex lasiocar-
 pa, WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Organic. Subordinate plants include sedges
 (Carex laeustris, C. rostrata), water smartweed (Polygonum amphibium), bladderwort (Utricularia macrorhiza), bluejoint
 (Calamagrostis canadensis), and pondweed (Potamogeton gramineus). (Chippewa National Forest, Beltrami County, Minnesota;
 June 1972; Photo by J. H. Richmann)










106





















































Plate 61.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Eleocharis palustris,
 WATER REGIME Seasonally Flooded, WATER CHEMISTRY Polysaline, SOIL Mineral. Subordinate plants include water smartweed
 (Polygonum amphibium), slough sedge (Carex atherodes), and foxtail (Alopecurus aequalis). (Stutsman County, North Dakota;
 August 1962; Photo by R. E. Stewart)










                                                                                                                         107























































Plate 62.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally Flooded,
 WATER CHEMISTRY Mixosaline, SOIL Mineral. The principal plants are sedges (Carex spp.), bulrushes (Scirpus spp.), rushes (Jun-
 cus spp.), and foxtail (Alopecurus aequalis). This wetland is typical of irrigated hay in the West. Water may be diverted from
 rivers or may come from artesian wells as in this photo. (Saguache County, Colorado; Photo by R. M. Hopper)










108
























































Plate 63.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Carex rariflora-
  Eriophorum russeolum, WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh. Subordinate plants include marsh cinque-
  foil (Potentilla palustris), bluejoint (Calamagrostis canadensis), Alaska bog willow (Salixfuscescens), crowberry (Empetrum nigrum),
  dwarf birch (Betula nana), and peat moss (Sphagnum sp.). This type of patterned wetland is commonly referred to as "string
  bog" or "strangmoor." Seasonally flooded troughs alternate with elongated bog-like ridges or "strings." Strings here rise only
  30-45 cm (12-18 in) above the troughs. (Manokinak River area, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by F. C. Golet)
































































Plate 64.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Colocasia esculenta,
 WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh, SOIL Mineral, SPECIAL MODIFIER Farmed. This photograph il-
 lustrates a Hawaiian taro field. (Kauai County, Hawaii; September 1972; Photo by E. Krider)































































Plate 65.-Classification (foreground): SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Aristida
 stricta, WATER REGIME Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Mineral. Subordinate plants include beak rushes (Rhyn-
 chospora spp.), longleaf pine (Pinus palustris), orchids (Habenaria spp.), yellow-eyed grasses (Xyris spp.), grass pinks (Calopogon
 spp.), and foxtail clubmoss (Lycopodium alopecuroides). (Brunswick County, North Carolina; December 1975; Photo by V. Carter)










                                .W t.$-l~~~~~~~~~~~g E f ~~~~I  i111






















































Plate 66.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Saturated, WATER
 CHEMISTRY Fresh. The dominant plants in this montane meadow are sedges (Carex spp.). (Lassen County, California; August
 1975; Photo by V. Carter)










112






















































Plate 67.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Eriophorum
  vaginatum, WATER REGIME Saturated, WATER CHEMISTRY Fresh, SOIL Mineral. Subordinate plants include: netleaf willow (Salix
  reticulate), diamondleaf willow (S. planifolia), dryas (Dryas integrifolia), bistort ( Polygonum bistorta), lousewort (Pedicularis
  sp.), chickweed (Stellaria sp.), and lapland cassiope (Cassiope tetragona). This type of wetland, referred to by Walker (1983) as
  "moist tussock sedge dwarf shrub tundra," covers much of the North Slope of Alaska. At this site, permafrost lies within 15
  cm (6 in) of the surface. All of the land in this photo is wetland. (Franklin Bluffs, North Slope Borough, Alaska; July 1985; Photo
  by F. C. Golet)

























            Plate 68.--Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE TYPE Carex aquatilis,
              WATER REGIME Saturated, WATER CHEMISTRY Fresh. Subordinate plants include: narrowleaf Labrador tea (Ledum decumbens),
              dwarf birch (Betula nana), small cranberry (Vaccinium oxycoccos), crowberry (Empetrum nigrum), peat moss (Sphagnum spp.),
              and foliose lichens. (Narokachik River area, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by F. C. Golet)
I                               ||
1                            g |    |

I                         |g       |







114

































Plate 69.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Temporarily Flooded,
 WATER CHEMISTRY Oligosaline, SOIL Mineral, SPECIAL MODIFIER Farmed. All natural vegetation in this wetland has been removed,
 and water stands in stubble from the previous year's wheat crop. (Stutsman County, North Dakota; March 1967; Photo by H. A.
 Kantrud)
                                           .,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                                    a== = f ft _~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~










                                                                                                                         115




















































Plate 70.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Temporarily Flooded,
 WATER CHEMISTRY Fresh, SOIL Mineral, SPECIAL MODIFIER Farmed. Principal plants include nut sedge (Cyperus sp.), arrow arum
 (Peltandra virginica), and barnyard grass (Echinochloa crusgalli). (Dade County, Florida; January 1978; Photo by P. B. Reed)










116





















































Plate 71.-Two habitats are shown here. Classification of darker zone (edge of water body): SYSTEM Palustrine, CLASS Emergent
  Wetland, SUBCLASS Nonpersistent, DOMINANCE TYPE Arctophilafulva, WATER REGIME Permanently Flooded, WATER CHEMISTRY
  Fresh. Classification of lighter zone (foreground): SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, DOMINANCE
  TYPE Carex aquatilis, WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh. Marsh marigold (Caltha palustris) is also
  present in the seasonally flooded zone. This wetland lies on coastal tundra within 2 km (1.2 mi) of the Arctic Ocean. (Between
  Canning and Kavik Rivers, North Slope Borough, Alaska; July 1985; Photo by F. C. Golet)








                                                                                                                                       117







































                   Plate 72.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE TYPE Hippuris
                     tetraphylla, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh. A semipermanently flooded persistent-emergent
                     wetland dominated by sedge (Carex lyngbyei) surrounds the Hippuris marsh. Burreed (Sparganium hyperboreum) grows in shallow
                     water between the Hippuris and the sedges. (Narokachik River area, Yukon-Kuskokwim Delta, Alaska; July 1985; Photo by
                     F. C. Golet)






I










118




















































Plate 73.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Nonpersistent, DOMINANCE TYPE Nuphar luteum,
 WATER REGIME Semipermanently Flooded, WATER CHEMISTRY Fresh. The principal subordinate plant is common duckweed (Lemna
 minor). (Cass County, Michigan; May 1985; Photo by F. C. Golet)










                                                                                                                      119






















































Plate 74.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Deciduous, WATER REGIME
 Seasonally Flooded, WATER CHEMISTRY Fresh-Acid, SOIL Organic. The dominant plants are willows (Salix spp.). Subordinate
 species include Sitka spruce (Picea sitchensis) and lodgepole pine (Pinus contorta). (Coos County, Oregon; May 1977; Photo by
 D. D. Peters)










120




















































Plate 75.-Classificaton: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Deciduous, DOMINANCE TYPE
  Betula nana, WATER REGIME Saturated, WATER CHEMISTRY Fresh, SOIL Mineral. Subordinate plants include cotton grass
  (Eriophorum vaginatum), peat moss (Sphagnum spp.), cloudberry (Rubus chamaemorus), mountain cranberry (Vaccinium vitis-
  idaea), and narrowleaf Labrador tea (Ledum decumbens). Shrubs here are less than 20 cm (8 in) tall. This area of moist tundra
  is underlain by permafrost at a depth of 45 cm (18 in). (Vicinity of Toolik Lake, North Slope Borough, Alaska; July 1985; Photo
  by F. C. Golet)







                                                                                                                                        121

































              Plate 76.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Deciduous, DOMINANCE TYPE
                Alnus tenuifolia, WATER REGIME Temporarily Flooded, WATER CHEMISTRY Fresh, SOIL Mineral. Subordinate plants include feltleaf
                willow (Salix alaxensis) and balsam poplar (Populus balsamifera). Shrubs are nearly 6 m (20 ft) tall, the height that separates
                Scrub-Shrub from Forested Wetland. This site is flooded only for brief periods after snowmelt and during times of most rapid
                melting of nearby glaciers. (Tanana River, Fairbanks North Star Borough, Alaska; July 1985; Photo by F. C. Golet)

I                                     I










122























































Plate 77.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Needle-leaved Deciduous, DOMINANCE TYPE
 Larix laricina, WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh. The tamarack saplings are 2-3 m (6.6-10 ft) tall
 and cover 40-45% of the site. Subordinate plants include: dwarf birch (Betula nana), bluejoint (Calamagrostis canadensis), black
 spruce (Picea mariana), leatherleaf (Chamaedaphne calyculata), diamondleaf willow (Salix planifolia), narrowleaf Labrador tea
 (Ledum decumbens), cotton grass (Eriophorum sp.), bog blueberry (Vaccinium uliginosum), marsh cinquefoil (Potentilla palustris),
 and shrubby cinquefoil (P. fruticosa). (Vicinity of Big Delta, Alaska; July 1985; Photo by F. C. Golet)










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Plate 78.-Classification: SYSTEM Palustrine, CLASSYScrub-Shrub Wetland, SUBCLASS Broad-leaved Evergreen, DOMINANCE TYPE
 Ledum groenlandicum-Kalmia angustifolia-Chamaedaphne calyculata, WATER REGIME Saturated, WATER CHEMISTRY Fresh-
 Acid, SOIL Organic. Subordinate plants include peat moss (Sphagnum spp.), crowberry (Empetrum nigrum), cloudberry (Rubus
 chamaemorus), and black spruce (Picea mariana). (Washington County, Maine; June 1976; Photo by V. Carter)










124




















































Plate 79.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Evergreen, DOMINANCE TYPE
  Ledum decumbens, WATER REGIME Saturated, WATER CHEMISTRY Fresh, SOIL Mineral. Subordinate species include: cloudberry
  (Rubus chamaemorus), mountain cranberry (Vaccinium vitis-idaea), crowberry (Empetrum nigrum), dwarf birch (Betula nana),
  reindeer moss (Cladina spp.), sedge (Carex aquatilis), bluejoint (Calamagrostis canadensis), and Alaska spiraea (Spiraea beauver-
  diana). Shrubs are less than 20 cm (8 in) tall. Although this site looks like a dry heath, permafrost at a depth of only 15-20 cm
  (6-8 in) keeps the soil saturated near the surface throughout the growing season. (Talik River area, Yukon-Kuskokwim Delta,
  Alaska; July 1985; Photo by F. C. Golet)
                                     # | | |    d    |    M    i    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(










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Plate 80.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved Evergreen, DOMINANCE TYPE
 Cyrilla racemiflora, WATER REGIME Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Organic. Subordinate plants include: honeycup
 (Zenobia pulverulenta), leatherleaf (Chamaedaphne calyculata), peat moss (Sphagnum spp.), highbush blueberry (Vaccinium corym-
 bosum), loblolly bay (Gordonia lasianthus), pond pine (Pinus serotina), and highbush blueberry (Vaccinium corymbosum). Locally,
 these wetlands are referred to as evergreen shrub bogs or "pocosins." (Brunswick County, North Carolina; December 1975; Photo
 by V. Carter)










126






















































Plate 81.-Classification: SYSTEM Palustrine, CLASS Scrub-Shrub Wetland, SUBCLASS Needle-leaved Evergreen, DOMINANCE TYPE
 Picea mariana, WATER REGIME Saturated, WATER CHEMISTRY Fresh. Subordinate plants include: dwarf birch (Betula nana), cotton
 grass (Eriophorum vaginatum), bog blueberry (Vaccinium uliginosum), Labrador tea (Ledum groenlandicum), and peat moss
 (Sphagnum spp.). This wetland type, commonly known as "muskeg," is abundant in the forested regions of Alaska; it also occurs
 in northern New England and in the Great Lakes States. (Vicinity of Coldfoot, Alaska; July 1985; Photo by F. C. Golet)










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Plate 82.-Classification: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS Broad-leaved Deciduous, DOMINANCE TYPE Acer
 rubrum, WATER REGIME Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Organic. Subordinate plants in this red maple swamp
 include black gum (Nyssa sylvatica), highbush blueberry (Vaccinium corymbosum), great laurel (Rhododendron mazimum), and
 winterberry (Ilez verticillata). (Washington County, Rhode Island; June 1977; Photo by F. C. Golet)










128






















































Plate 83.-Two habitats are shown here. Classification of the forested area: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS
 Needle-leaved Deciduous, DOMINANCE TYPE Taxodium distichum, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh.
 Classification of the open area: SYSTEM Palustrine, CLASS Aquatic Bed, SUBCLASS Floating Vascular, DOMINANCE TYPE Pistia
 stratiotes, WATER REGIME Permanently Floqded, WATER CHEMISTRY Fresh. Emergent plants growing in the bed of water lettuce
 are arrowheads (Sagittaria spp.). (Corkscrew Swamp Sanctuary, Collier County, Florida; January 1978; Photo by E. T. LaRoe)










                                                                                                                        129




















































Plate 84.-Classification: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS Needle-leaved Evergreen, DOMINANCE TYPE
 Chamaecyparis thyoides, WATER REGIME Seasonally Flooded, WATER CHEMISTRY Fresh-Acid, SOIL Organic. Subordinate plants
 in this Atlantic white cedar swamp include: highbush blueberry (Vaccinium corymbosum), winterberry (flex verticillata), red maple
 (Acer rubrum), and peat moss (Sphagnum spp.). Low vegetation in the foreground includes leatherleaf (Chamaedaphne calyculata)
 and Virginia chain-fern (Woodwardia virginica). (Washington County, Rhode Island; July 1977; Photo by F. C. Golet)




130

















Plate 85.-Classification: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS Needle-leaved Evergreen, DOMINANCE TYPE Picea
 mariana, WATER REGIME Saturated, WATER CHEMISTRY Fresh, SOIL Mineral. Subordinate plants in this black spruce forest in-
 clude Labrador tea (Ledum groenlandicum), mountain cranberry (Vaccinium vitis-idaea), crowberry (Empetrum nigrum), and
 peat moss (Sphagnum sp.). Permafrost is present within 45 cm (18 in) of the surface. (Vicinity of Glennallen, Alaska; July 1985;
 Photo by F. C. Golet)
                               F ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I       b
                               | g | | S | g g ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                               gE S N . E ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~





































































Plate 86.-Classification: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS Dead, WATER REGIME Permanently Flooded,
  WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral, SPECIAL MODIFIER Impounded. (Humphreys County, Tennessee; September
  1975; Photo by V. Carter)
















* U.S. GOVERNMENTPRINTING OFFICE: 1992-318-224












                 As the Nation's principal conservation agency, the Department of the
               Interior has responsibility for most of our nationally owned public lands and
               natural resources. This includes fostering the wisest use of our land and water
               resources, protecting our fish and wildlife, preserving the environmental and
               cultural values of our national parks and historical places, and providing for
               the enjoyment of life through outdoor recreation. The Department assesses
               our energy and mineral resources and works to assure that their develop-
               ment is in the best interests of all our people. The Department also has a
               major responsibility for American Indian reservation communities and for peo-
               ple who live in island territories under U.S. administration.

                                       SERVICE











U.S. Department of the Interior
                                                                       POSTAGE AN D FEES PAID
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