Classification of wetlands and deepwater habitats of the United States 1979

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Biological Services Program

FWS/OBS-79/31
DECEMBER 1979

Coastal Zone
Information
Center
Classmifi ion Of
Wetlands and
Dee r Habmitats
of t e Unimted States

ON
IN

GB
624
.C6
1979

Wildlife Service
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,-U.S. Department of the Interior

Biological Services Program

FWS/OBS-79/31
DECEMBER 1979

Coastal Zone
Classi ic ion Of
Wetlands and
Dee r Hab'Itats
of t e Uniu-ted States

2 A

SOW_-

GB
624
.C6
1979
f at

pvy@te

Wildlife Service
U.S. Department of the Interior

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FWS/OBS-79/31
December 1979

CLASSIFICATION OF WETLANDS AND DEEPWATER
HABITATS OF THE UNITED STATES

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 Forest and Wildlife Management
University of Rhode Island
Kingston, Rhode Island 02881

and

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

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Fish and Wildlife Service
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For sale by the Superintendent of Documents, U.S. Government Printing Office
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Library of Congress Catalog Ing 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.
11. Title. Ill. Series: United States. Fish and Wildlife Service. Biological
services program; FWS/OBS-79/31.
QH76.U54a 79/31 [QH1041 574.5'0973s [574.5'26321 79-607795

Foreword

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 functions. Increasing
national and international recognition of these values has intensified the need for reliable information on the
status and extent 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 developing wetland data base utilizing this system will result in ac-
ceptance 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 aU 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

Contents

Page

Abstract 1
Wetlands and Deepwater Habitats ............. I ......................... 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 ................................................. 9
Lacustrine System ............................................... 11
Palustrine System ............................................... 12
Classes, Subclasses, and Dominance Types ............................. 12
Rock Bottom .................................................... 15
Unconsolidated Bottom ........................................... 15
Aquatic Bed .................................................... 16
Reef ........................................................... 17
Streambed ...................................................... 18
Rocky Shore .................................................... 19
Unconsolidated Shore ............................................. 20
Moss-Lichen Wetland ............................................ 21
Emergent Wetland ............................................... 21
Scrub-Shrub Wetland ............................................ 22
Forested Wetland ................................................ 22
Modifiers ......................................................... 23
Water Regime Modifiers .......................................... 23
Water Chemistry Modifiers ........................................ 24
Salinity Modifiers .............................................. 24
pH Modifiers .................................................. 25
Soil Modifiers ................................................... 25
Special Modifiers ................................................ 25
Regionalization for the Classification System .............................. 26
Use of the Classification System ......................................... 28
Hierarchical Levels and Modifiers ...................................... 29
Relationship to Other Wetland Classifications ............................ 29
Acknowledgments .................................................... 32
References ........................................................... 33
Appendix A. Scientific and common names of plants ......................... 37
Appendix B. Scientific and common names of animals ....................... 40
Appendix C. Glossary of terms .......................................... 42
Appendix D. Criteria for distinguishing organic
soils from mineral soils ................................... 44
Appendix E. Artificial key to the systems ................................. 46
Artificial key to the classes .................................. 46

Tables

No.

1 Systems, classes, and subclasses with examples of dominance types.
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.

1 Classification hierarchy of wetlands and deepwater habitats, showing systems,
subsystems, 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.

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 Forest and Wildlife Management
University of Rhode Island, Kingston, Rhode Island 02881
and

Edward T. LaRoel
U.S. National Oceanic 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. Eco-
logically 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, Subtidal and Intertidal; the Riverine system has four subsystems, Tidal, Lower
Perenriial, Upper Perennial, and Intermittent; the Lacustrine has two, Littoral and Linmetic; and
the Palustrine has no subsystem.
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 sub-
systems. Six classes are based on substrate and flooding regime: (1) Rock Bottom with a sub-
strate of bedrock, boulders, or stones; (2) Unconsolidated Bottom with a substrate of cobbles,
gravel, sand, rnud, or organic material; (3) Rocky Shore with the same substrate as Rock Bottom;
(4) Unconsolidated Shore with the same substrate as Unconsolidated Bottom; (5) Streambed with
any of the substrates; and J6) Reef with a substrate composed of the living and dead remains of
invertebrates (corals, mollusks, or worms). The bottorn 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 Stream-
bed 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 aninial forms, is the lowest level
of the classification hierarchy, Only examples are provided for this level; doininance types must
be developed by individual users of the classification.

tPresent address: Department of Environmental Regulations, 2562 Executive Center Circle, East Mont-
gomery Building, Tallahassee, Florida 32301.

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, six regimes are
used: permanently flooded, intermittently exposed, sernipermanently flooded, seasonally flooded,
saturated, temporarily flooded, intermittently flooded, and artificially flooded. A hierarchical
system 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
combines 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 gathering 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 com-
munities 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 (Picea mariana) and of southern cypress-gum (Taxo-
inventory of the wetlands of the United States (Shaw dium distichum-Nyssa aquatica) in the same category,
and Fredine 1956) in 1954. Since then, wetlands have with no provisions in the system for distinguishing be-
undergone considerable change, both natural and man- tween them. Because of the central emphasis on water-
related, and their characteristics and natural values fowl habitat, far greater attention was paid to vege-
have become better defined and more widely known. tated areas than to nonvegetated areas. Probably the
During this interval, State and Federal legislation has greatest single disadvantage of the Martin et al.
been passed to protect wetlands, and some statewide system was the inadequate definition of types, which
wetland surveys have been conducted. led to inconsistencies in application.
In 1974 the U.S. Fish and Wildlife Service directed Numerous other classifications of wetlands and
its Office of Biological Services to design and conduct deepwater habitats have been developed (Stewart and
a new national inventory of wetlands. Whereas the Kantrud 1971; Golet and Larson 1974; Jeglum et al.
single purpose of the 1954 inventory was to assess the 1974; Odum et al. 1974; Zoltai et al. 1975; Millar 1976),
amount and types of valuable waterfowl habitat, the but most of these are regional systems and none would
scope of the new project is considerably broader (Mon- fully satisfy national needs. Because of the weaknesses
tanari and Townsend 1977). It will provide basic data inherent in Circular 39, and because wetland ecology
on the characteristics and extent of the Nation's has become significantly better understood since 1954,
wetlands and deepwater habitats and should facilitate the U. S. Fish and Wildlife Service elected to construct
the management of these areas on a sound, multiple- a new national classification system as the first step
use basis. toward a new national inventory. The new classifi-
Before the 1954 inventory was begun, Martin et al. cation, presented here, has been designed to meet four
(1953) had devised a wetland classification system to long-range objectives: (1) to describe ecological units
serve as a framework for the national inventory. The that have certain homogeneous natural attributes; (2)
results of the inventory and an illustrated description
of the 20 wetland types were published as U. S. Fish to arrange these units in a system that will aid deci-
and Wildlife Service Circular 39 (Shaw and Fredine sions about resource management; (3) to furnish units
1956). This Circular has been one of the most common for inventory and mapping; and (4) to provide uni-
and most influential documents used in the continuous formity in concepts and terminology throughout the
battle to preserve a critically valuable but rapidly United States.
diminishing national resource (Stegman 1976). Scientific and common names of plants (Appendix
However, the shortcomings of this work are well A) and animals (Appendix B) were taken from various
known (e.g., see Leitch 1966; Stewart and Kantrud sources cited in the text. No attempt has been made to
1971). resolve nomenclatorial problems where there is a taxo-
In attempting to simplify their classification, nomic dispute. Many of the terms used in this classifi-
Martin et al. (1953) not only ignored ecologically criti- cation have various meanings even in the scientific lit-
cal differences, such as the distinction between fresh erature and in some instances our use of terms is new.
and mixosaline inland wetlands but also placed dis- We have provided a glossary (Appendix C) to guide the
similar habitats, such as forests of boreal black spruce reader in our usage of terms.

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

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

flooded or saturated at some time each year and land bounding the upstream end of the Estuarine System
that is not. (Caspers 1967). As Bormann and Likens (1969) pointed
The boundary between wetland and deepwater out, boundaries of ecosystems are defined to meet
habitat in the Marine and Estuarine systems coincides practical needs.
with the elevation of the extreme low water of spring
tide; permanently flooded areas are considered deep- Marine System
water habitats in these systems. The boundary be- Definition. The Marine System (Fig. 2) consists of
tween wetland and deepwater habitat in the Riverine, the open ocean overlying the continental shelf and its
Lacustrine, and Palustrine systems lies at a depth of associated high-energy coastline. Marine habitats are
2 m (6.6 feet) below low water; however, if emergents, exposed to the waves and currents of the open ocean
shrubs, or trees grow beyond this depth at any time, and the water regimes are determined primarily by the
their deepwater edge is the boundary. ebb and flow of oceanic tides. Salinities exceed 30 I/oo,
The 2-m lower limit for inland wetlands was selected with little or. no dilution except outside the mouths of
because it represents the maximum depth to which estuaries. Shallow coastal .indentations or bays
emergent plants normally grow (Welch 1952; Zhadin without appreciable freshwater inflow, and coasts with
and Gerd 1963; Sculthorpe 1967). As Daubenmire exposed rocky islands that provide the mainland with
(1968:138) stated, emergents are not true aquatic little or no shelter from wind and waves', are also
plants, but are "amphibious," growing in both perma- considered part of the Marine System because they
nently flooded and wet, nonflooded soils. In their g .enerally support typical marine biota.
wetland classification for Canada, Zoltai et al. (1975) Limits. The Marine System extends from the outer
also included only areas with water less than 2 m deep.
edge of the continental shelf shoreward to one of three
lines: (1) the landward limit of tidal inundation
THE CLASSIFICATION SYSTEM (extreme high water of spring tides), including the
splash zone from breaking waves; (2) the seaward limit
The structure of this classification is hierarchical, of wetland emergents, trees, or 'Shrubs; or (3) the
progressing from systems and subsystems, at the seaward limit of the Estuarine System, where this
most general levels, to classes, subclasses, and domi- limit is determined by factors other than vegetation.
nance types. Figure 1 illustrates the classification Deepwater habitats lying beyond the seaward limit of
structure to the class level. Table 1 lists the classes the Marine System are outside the scope of this
and subclasses for each system and gives an example classification system.
of a dominance type for each subclass. Artificial keys Description, The distribution of plants and animals
to the systems and classes are given in Appendix E. in the Marine System primarily reflects differences in
Modifiers for water regime, water chemistry, and soils four factors: (1) degree of exposure of the site to waves,
are applied to classes, subclasses, and dominance (2) texture and physicochernical nature of the sub-
types. Special modifiers describe wetlands and deep-
water habitats that have ,been either created Ior highly strate; (3) amplitude of the tides; and (4) latitude,
which governs water temperature, the intensity and
modified by man or beavers.
duration of solar radiation, and the presence or
absence of ice.
Hierarchical Structure
Subsystems.
Systems and Su bsys tems Subtidat-The substrate is continuously sub-
merged.
1@tertidaL -The substrate is exposed and flooded
The term SYSTEM refers here to a complex of by tides; includes the associated splash zone.
wetlands and deepwater habitats that share the
influence of similar hydrologic, geomorphologic, chem- Classes. Rock Bottom, Unconsolidated Bottom,
ical, or biological factors. We further subdivide Aquatic Bed, Reef, Rocky Shore, and Unconsolidated
systems into more specific categories called Shore-
SUBSYSTEMS.
.The characteristics of the five 'major systems- Estuarine System
Marine, Estuarine, Riverine, Lacustrine, and Palus- Definition. The Estuarine System (Fig. 3) consists of
trine-have been discussed at length in the scientific deepwater tidal habitats and adjacent tidal wetlands
literature and the concepts are well recognized; how- that are usually semienclosed by land but have open,
ever, there is frequent disagreement as to which attri- partly obstructed, or sporadic access to the open
butes should be used to bound the systems in space. ocean, and in which ocean water is at least occasionally
For example, both the limit of tidal influence and the diluted by freshwater runoff from the land. The salin-
limit of ocean-derived salinity have been proposed for ity may be periodically increased above that of the

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
-AquaticBed
-Reef

Aquatic Bed
-Estuarine - Reef
-Streambed
Intertidal - Rocky Shore
-Unconsolidated Shore
-Emergent Wetland
Scrub- Shrub Wetland
EForested Wetland

- Rock Bottom
E_
14 - Unconsolidated Bottom
E_ - Aquatic Bed
Tidal
- Rocky Shore
- Unconsolidated Shore
- Emergent Wetland

Rock Bottom
Unconsolidated Bottom
-AquaticBed
Lower Perennial
-Rocky Shore
Riverine - Unconsolidated Shore
- Emergent Wetland
Go
al - Rock Bottom
z
-Unconsolidated Bottom
-Upper Perennial Aquatic Bed
E_
-Rocky Shore
-Unconsolidated Shore

Intermittent Streambed

Rock Bottom
Linmetic Unconsolidated Bottom
-Lacustrine LAquatic Bed
Rock Bottom
-Unconsolidated Bottom
Littoral -Aquatic Bed
-Rocky Shore
Unconsolidated Shore
Emergent Wetland

Rock Bottom
-Unconsolidated Bottom
-AquaticBed
Palustrine -Unconsolidated Shore
- Moss-Lichen Wetland
-Emergent Wetland
EScrub-Shrub Wetland
Forested Wetland

Fig. 1. Classification hierarchy of wetlands and deepwater habitats, showing systems, subsystems, and classes. The Palus-
trine System does not include deepwater habitats.

Table 1. Systems, Classes, and Subclasses with Examples ofDominance Types.

System, Class, and Subclass Examples of Dominance Types

Marine
Rock Bottom
Bedrock American lobster (Homarus americanus)
Rubble Encrusting sponge (Hippospongia gossypina)
Unconsolidated Bottom
Cobble-Gravel Brittle star (Amphipholis squamata)
Sand Great Alaskan tellin (Tellina lu tea)
Mud Atlantic deep-sea scallop (Placopec ten magellanicus)
Organic Clam worm (Nereis succinea)
Aquatic Bed
Rooted Vascular Turtle grass (Thalassia testudinum)
Algal Kelp (Macrocystis pyrifera@
Reef
Coral Coral (Porites porites)
Worm Reef worm (Sabellaria cementarium)
Rocky Shore
Bedrock Gooseneck barnacle (Pollicipes polymerus)
Rubble California mussel (Mytilus californianus)
Unconsolidated Shore
Cobble-Gravel Acorn barnacle (Balanus balanoides)
Sand Pismo clam (7Yvela stultorum)
Mud Boring clam (Platyodon cancellatus)
Organic False angel wing (Petricola pholadiformis
Estuarine
Rock Bottom
Bedrock Sea whip (Muricea californica)
Rubble Tunicate (Cnemidocarpa finmarkiensis)
Unconsolidated Bottom
Cobble-Gravel Smooth Washington clam (Saxidomus giganteus)
Sand Sand dollar (Dendras ter excentricus)
Mud Baltic macoma (Macoma balthica)
Organic Soft-shell clam (Mya arenaria)
Aquatic Bed
Algal Rockweed (Fucus vesiculosus)
Rooted Vascular Eelgrass (Zostera marina)
Floating Water hyacinth (Eichhornia crassipes)
Reef
Mollusk Eastern oyster (Crassostrea virginica)
Worm Reef worm (Sabellaria floridensis)
Streambed
Cobble-Gravel Blue mussel (Mytilus edulis)
Sand Red ghost shrimp (Callianassa californiensis)
Mud Mud snail (Nassarius obsoletus@
Organic Ribbed mussel (Modiolus demissus@
Rocky Shore
Bedrock Acorn barnacle (Chthamalus fragilis)
Rubble Plate limpet (Acmaea testudinalis)
Unconsolidated Shore
Cobble-Gravel Blue mussel (Mytilus edulis)
Sand Quahog (Mercenaria mercenaria)
Mud Clam worm (Nereis succinea)
Organic Fiddler crab (Uca pugnax)
Emergent Wetland
Persistent Saltmarsh cordgrass (Spartina alterniflora)
Nonpersistent Samphire (Salicornia europea)
Scrub-Shrub Wetland
Needle-leaved Evergreen Sitka spruce (Picea, sitchensis@
Broad-leaved Evergreen Mangrove (Conocarpus erectus)
Needle-leaved Deciduous Bald cypress (Taxodium distichum)
Broad-leaved Deciduous Marsh elder (Iva frutescens)
Dead None

Table 1. Continued.

System, Class, and Subclass Examples of Dominance Types

Forested Wetland
Needle-leaved Evergreen Sitka spruce (Picea sitchensis)
Broad-leaved Evergreen Red mangrove (Rhizophora mangle)
Needle-leaved Deciduous Bald cypress (Taxodium dis tichum)
Broad-leaved Deciduous Red ash (Fraxinus pennsylvanica)
Dead None
Riverine
Rock Bottom
Bedrock Brook leech (Helobdella stagnalis)
Rubble Water penny (Psephenus herricki)
Unconsolidated Bottom
Cobble-Gravel Mayfly (Baetis sp.)
Sand Freshwater mollusk (Anodonta implicata)
Mud Freshwater mollusk (Anodontoides ferussacianus)
Organic Sewage worm (Tubifex tubifex)
Aquatic Bed
Algal Stonewort (Nitellaflexilis)
Aquatic Moss Moss (Fissidens adiantoides)
Rooted Vascular Riverweed (Podostemum ceratophyllum)
Floating Bladderwort (Utricularia uutgaris)
Streambed
Bedrock Mayfly (Ephemerella deficiens)
Rubble Fingernail clam (Pisidium abditum)
Cobble-Gravel Tadpole snail (Physa gyrina)
Sand Pond snail (Lymnaea cubensis)
Mud Pouch snail (Aplexa hypnorum)
Organic Oligochaete worm (Limnodrilus hoffineis teri@
Vegetated Old witch grass (Panicum capillare)
Rocky Shore
Bedrock Liverwort (Marsupella emarginata)
Rubble Lichen (Dermatocarpon fluviatile@
Unconsolidated Shore
Cobble-Gravel Freshwater mollusk (Elliptio arctata)
Sand Freshwater mollusk (A nodon ta cataracta)
Mud Crayfish (Procambarus simulans)
Organic Harpacticoid copepod (Canthocamptus robertcokeri)
Vegetated Cocklebur (Xanthium strumarium)
Emergent Wetland (Nonpersistent) Horsetail (Equisetum fluviatile@
Lacustrine
Rock Bottom
Bedrock Freshwater sponge (Spongilla lacustris)
Rubble Brook leech (Helobdella, stagnalis)
Unconsolidated Bottom
Cobble-Gravel Freshwater mollusk (Lampsilis ovata)
Sand Fingernail clam (Sphaerium simile)
Mud Fingernail clam (Pisidium ferrugineum)
Organic Sewage worm JTubi/ex tubifex)
Aquatic Bed
Algal Stonewort (Chara crispa)
Aquatic Moss Moss (Fontinalis antipyretica@
Rooted Vascular Widgeon grass (Ruppia maritima)
Floating Duckweed (Lemna minor)
Rocky Shore
Bedrock Caddisfly (Hydropsyche simulans)
Rubble Freshwater mollusk (Pisidium abditum)
Unconsolidated Shore
Cobble-Gravel Leech (Erpobdella punctata)
Sand Freshwater mollusk (Elliptio dariensis)
Mud Pond snail (Lymnaeapalustris)

Table 1. Continued.

System, Class, and Subclass Examples of Dominance Types

Organic Midge larvae (Chironornus spp.)
Vegetated Goosefoot (Chenopodium rubrum)
Emergent Wetland (Nonpersistent) Pickerelweed (Pon tederia cordata)
Palustrine
Rock Bottom
Bedrock Horse sponge (Heteromeyenia latitenta)
Rubble Pond snail (Lymnaea stagnalis)
Unconsolidated Bottom
Cobble-Gravel Freshwater sponge (Eunapius fragilis)
Sand Freshwater mollusk (Elliptio complanata)
Mud Fingernail clam (Pisidium casertanum)
Organic Ohgochaete worm (Limnod7ilus hoffineis teri)
Aquatic Bed
Algal Stonewort (Chara aspera)
Aquatic Moss Moss (Fissidensjulianus)
Rooted Vascular White water lily (Nymphaea odorata)
Floating Water fern (Salvinia rotundifolia)
Unconsolidated Shore
Cobble-Gravel Toad bug (Gelas tocoris oculatus)
Sand Freshwater mollusk (Elliptio dwiensis)
Mud Crayfish (Fallicambarus fodiens)
Organic Back swimmer (Notonecta lunata)
Vegetated Summer cypress (Kochia scopwia)
Moss-Lichen Wetland
Moss Peat moss (Sphagnum fuscum)
Lichen Reindeer moss (Cladonia rangiferina)
Emergent Wetland
Persistent Common cattail (Typha latifolia)
Nonpersistent Arrow-arum (Peltandra virginica)
Scrub-Shrub Wetland
Broad-leaved Deciduous Speckled alder (A Inus rugosa)
Needle-leaved Deciduous Tamarack (Lafix laiicina)
Broad-leaved Evergreen Coastal sweetbells (Leucothoe axillaris)
Needle-leaved Evergreen Atlantic white cedar (Chamaecypwis thyoides)
Dead None
Forested Wetland
Broad-leaved Deciduous Red maple (Acer rubrum)
Needle-leaved Deciduous Bald cypress JTaxodium distichum)
Broad-leaved Evergreen Sweet bay (Magnolia virginiana)
Needle-leaved Evergreen Black spruce (Picea mariana)
Dead None

open ocean by evaporation. Along some low-energy Limits. The Estuarine System extends (1) upstream
coastlines there is appreciable dilution of sea water. and landward to where ocean-derived salts measure
Offshore areas with typical estuarine plants and less than 0.5 '/oo during the period of average annual
animals, such as red mangroves (Rhizophora mangle) low flow; (2) to an imaginary line closing the mouth of a
and eastern oysters (Crassostrea virginica), are also river, bay, or sound; and (3) to the seaward limit of
included in the Estuarine System .4 wetland emergents, shrubs, or trees where they are not
included in (2). The Estuarine System also includes off-
shore areas of continuously diluted sea water.
'The Coastal Zone Management Act of 1972 defines an Description. The Estuarine System includes both es-
estuary as "that part of a river or stream or other body of tuaries and lagoons. It is more strongly influenced by
water having unimpaired connection with the open sea, its association with land than is the Marine System. In
where the sea-water is measurably diluted with freshwater
derived from land drainage." The Act further states that terms of wave action, estuaries are generally consid-
"the term includes estuary-type areas of the Great Lakes." ered to be low-energy systems (Chapman 1977:2).
However, in the present system we do not consider areas of Estuarine water regimes and water chemistry are
the Great Lakes as estuarine. affected by one or more of the following forces: oceanic

Seaward Limit of Marine System IN
UPLAND MARINE

INTERTIDAL SUBTIDAL INTERTIDAL SUBTIDAL
-0-4-

W W W Uj

LU LU
Q 0
_j Cr D 0 _j Cr T
0 0 0 0 0 W
CO X U) 0
Z 0) Z 0 Z W Z
0 0 0 0
V 0 0 0
Z Z Z Z 0
D Z

EHWS

C ELWS
d

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.

tides, precipitation, freshwater runoff from land areas, Riverine System
evaporation, and wind. Estuarine salinities range from Definition. The Riverine System (Fig. 4) includes all
hyperhaline to oligolialine (Table 2). The salinity may wetlands and deepwater habitats contained within a
be variable, as in hyperhaline lagoons (e.g., Laguna channel, with two exceptions: (1) wetlands dominated
Madre, Texas) and most brackish estuaries (e.g., by trees, shrubs, persistent emergents, emergent
Chesapeake Bay, Virginia-Maryland); or it may be mosses, or lichens, and (2) habitats with water con-
relatively stable, as in sheltered euhaline embayrpents taining ocean-derived salts in excess of 0.5'/oo. A
(e.g., Chincoteague Bay, Maryland) or brackish embay- channel is "an open conduit either naturally or arti-
nients with partly obstructed access or small tidal ficially created which periodically or continuously
range (e.g., Pamlico Sound, North Carolina). (For an contains moving water, or which forms a connecting
extended discussion of estuaries and lagoons see Lauff link between two bodies of standing water" (Langbein
1967.) and Iseri 1960:5).
Subsystems. Limits. The Riverine System is bounded on the land-
Subtidal.-The substrate is continuously sub- ward side by upland, by the channel bank (including
77@@
a

merged. natural and man-made levees), or by wetland domi-
Intertidal.-The substrate is exposed and flooded nated by trees, shrubs, persistent emergents,
by tides; includes the associated splash zone. emergent mosses, or lichens. In braided strearns, the
Classes. Rock Bottom, Unconsolidated Bottom, system is bounded by the banks forming the outer
Aquatic Bed, Reef, Strearnbed, Rocky Shore, Uncon- limits of the depression within which the braiding
solidated Shore, Emergent Wetland, Scrub-Shrub occurs.
Wetland, and Forested Wetland. The Riverine System terminates at the downstream

UPLAND ESTUARINE UPLAND ESTUARINE

INTERTIDAL SUBTIDAL INTERTIDAL INTERTIDAL SUBTIDAL

z z
< LU -C LU W
_J _J
< z
LU z C W UJ
LU a a LU 0
:i 0 0 cc
0 CL W UJ _J
a) 0 0 LU 0
z CO Z CO 9) X 0 0
W CC Z 0 Ir z
UJ 0 LU Ir z
CL 0 LU 0 0
LU z
UJ z z
M 2 :3
W LU

EHWS
a @4
ELWS
d d

aIRREGULARLY FLOODED

bREGULARLY FLOODED

cIRREGULARLY 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.

end where the concentration of ocean-derived salts in present stream channel, and it may never, or only occa-
the water exceeds 0.5%. during the period of annual sionally, be flooded.... It is this subsurface water [the
average low flow, or where the channel enters a lake. It ground water] that controls to a great extent the level
terminates at the upstream end where tributary of lake surfaces, the flow of streams, and the extent of
streams originate, or where the channel leaves a lake. swamps and marshes."
Springs discharging into a channel are considered part Subsystems. The Riverine System is divided into
of the Riverine System. four subsystems: the Tidal, the Lower Perennial, the
Description. Water is usually, but not always, Upper Perennial, and the Intermittent. Each is defined
flowing in the Riverine System. Upland islands or in terms of water permanence, gradient, water veloc-
Palustrine wetlands may occur in the channel, but ity, substrate, and the extent of floodplain develop-
they are not included in the Riverine System. Palus- ment. The subsystems have characteristic flora and
trine Forested Wetlands, Emergent Wetlands, fauna (see Illies and Botosaneau 1963; Hynes 1970;
Scrub-Shrub Wetlands, and Moss-Lichen Wetlands Reid and Wood 1976). All four subsystems are not
may occur adjacent to the Riverine System, often on a necessarily present in all rivers, and the order of occur-
floodplain. Many biologists have suggested that all rence may be other than that given below.
@',Obo'@b

the wetlands occurring on the river floodplain should Tidal. -The gradient is low and water velocity fluc-
be a part of the Riverine System because they consider tuates under tidal influence. The streambed is mainly
their presence to be the result of river flooding. mud with occasional patches of sand. Oxygen deficits
However, we concur with Reid and Wood (1976:72,84) may sometimes occur and the fauna is similar to that
who stated, "The floodplain is a flat expanse of land in the Lower Perennial Subsystem. The floodplain is
bordering an old river.... Often the floodplain may typically well developed.
take the form of a very level plain occupied by the Lower Perennial.-The gradient is low and water

UPLAND PALUSTRINE RIVERINE PALUSTRINE UPLAND

z z
Uj C Z
_j W
0 0 C P z
LU Z Uj 2 Uj 0) W W z
0 3: 1.-
_j W < W co
0 0 0 :) In i5
W Go X 0)0 0' Z W W
M W Z ca z z M
0 3: 0 0 9L W LU
IL 0 0 Z (3 iL 0
z z M 0 W 03
W z

$6-
Al I HIGH WATER k
C AVERAGE WATER b
LOW WATER
e

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

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

velocity is slow. There is no tidal influence, and some Classes. Rock Bottom, , Unconsolidated Bottom,
water flows throughout the year. The substrate con- Aquatic Bed, Streambed, Rocky Shore, Uncon-
sists mainly of sand and mud. Oxygen deficits may solidated Shore, and Emergent Wetland (nonper-
sometimes occur, the fauna is composed mostly of sistent).
species that reach their maximum abundance in still
water, and true planktonic organisms are common, Lacustrine System
The gradient is lower than that of the Upper Perennial Definition. The Lacustrine System (Fig. 5) includes
Subsystem and the floodplain is well developed. wetlands and deepwater habitats with all of the fol-
Upper PerenniaL -The gradient is high and velocity lowing characteristics: (1) situated in a topographic
of the water fast. There is no tidal influence and some depression or a dammed river channel; (2) lacking
water flows throughout the year. The substrate trees, shrubs, persistent emergents, emergent mosses
consists of rock, cobbles, or gravel with occasional or lichens with greater than 30% areal coverage; and
patches of sand. The natural dissolved oxygen concen- (3) total area exceeds 8 ha (20 acres). Similar wetland
tration is normally near saturation. The fauna is and deepwater habitats totaling less than 8 ha are also
characteristic of running water, and there are few or no included in the Lacustrine System if an active wave-
formed or bedrock shoreline feature makes up all or
R
@.@H I.G H WATE,
.V'.@
AGE WA E.

W T R
WA @E

planktonic forms. The gradient is high compared with part of the boundary, or if the water depth in the deep-
that of the Lower Perennial Subsystem, and there is est part of the basin exceeds 2 rn. (6.6 feet) at low
very little floodplain development. water. Lacustrine waters may be tidal or nontidal, but
Intermittent.-In this subsystem, the channel con-
tains nontidal flowing water for only part of the year. ocean-derived salinity is always less than 0.5'/oo.
When the water is not flowing, it may remain in iso- Limits. The Lacustrine System is bounded by
lated pools or surface water may be absent. upland or by wetland dominated by trees, shrubs, per-

Table 2. Salinity modifiers used in this classification system.

Approximate
specific
conductance
Coastal modifiersa Inland modifierSb Salinity (parts per thousand) (/AMhos at 25 oQ
Hyperhaline Hypersaline >40 > 60,000
Euhahne Eusaline 30.0-40 45,000-60,000
Mixohaline (brackish) Mixosalinec 0.5-30 800-45,000
Polyhahne 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.
bInland modifiers are used in the Riverine, Lacustrine, and Palustrine systems.
cThe term Brackish should not be used for inland wetlands or deepwater habitats.

sistent emergents, emergent mosses, or lichens. Lacus- est part of basin less than 2 m at low water; and (4)
trine systems formed by damming a river channel are salinity due to ocean-derived salts less than 0.5'/oo.
bounded by a contour approximating the normal spill- Limits. The Palustrine System is bounded by upland
way elevation or normal pool elevation, except where or by any of the other four systems.
Palustrine wetlands extend lakeward of that bound-
ary. Where a river enters a lake, the extension of the Description. The Palustrine System was developed
Lacustrine shoreline forms the Riverine-Lacustrine to group the vegetated wetlands traditionally called
boundary. by such names as marsh, swamp, bog, fen, and prairie,
Description. The Lacustrine System includes perma- which are found throughout the United States. It also
includes the small, shallow, permanent or intermittent
nently flooded lakes and reservoirs (e.g., Lake Supe- water bodies often called ponds. Palustrine wetlands
rior), intermittent lakes (e.g., playa lakes), and tidal may be situated shoreward of lakes, river channels, or
lakes with ocean-derived salinities below 0.50/00 (e-g,, estuaries; on river floodplains; in isolated catchments;
Grand Lake, Louisiana). Typically, there are extensive or on slopes. They may also occur as islands in lakes or
areas of deep water and there is considerable wave rivers. The erosive forces of wind and water are of
action. Islands of Palustrine wetland may lie within minor importance except during severe floods.
the boundaries of the Lacustrine System. The emergent vegetation adjacent to rivers and
Subsystems. lakes is often referred to as "the shore zone" or the
Limnetic.-All deepwater habitats within the "zone of emergent vegetation" (Reid and Wood 1976),
Lacustrine System; many small Lacustrine systems and is generally considered separately from the river
have no Linmetic Subsystem. itself. As an example, Hynes (1970:85) wrote in ref-
Littoral. -All wetland habitats in the Lacustrine erence to riverine habitats, "We will not here consider
System. Extends from the shoreward boundary of the the long list of emergent plants which may occur along
system to a depth of 2 m (6.6 feet) below low water or the banks out of the current, as they do not belong,
to the maximum extent of nonpersistent ernergents, if strictly speaking, to the running water habitat. " There
these grow at depths greater than 2 m. are often great similarities between wetlands lying
Classes. Rock Bottom, Unconsolidated Bottom, adjacent to lakes or rivers and isolated wetlands of the
Aquatic Bed, Rocky Shore, Unconsolidated Shore, and same class in basins without open water.
Emergent Wetland (nonpersistent). Subsystems. None.
Palustrine System Classes. Rock Bottom, Unconsolidated Bottom,
Definition. The Palustrine System (Fig. 6) includes Aquatic Bed, Unconsolidated Shore, Moss-Lichen
all nontidal wetlands dominated by trees, shrubs, per- Wetland, Emergent Wetland, Scrub-Shrub Wetland,
sistent ernergents, emergent mosses or lichens, and all and Forested Wetland.
such wetlands that occur in tidal areas where salinity
due to ocean-derived salts is below 0.5%.. It also in- Classes, Subclasses, and Dominance Types
cludes wetlands lacking such vegetation, but with all
of the following four characteristics: (1) area less than The CLASS is the highest taxonomic unit below the
8 ha (20 acres); (2) active wave-formed or bedrock subsystem level. It describes the general appearance
shoreline features lacking; (3) water depth in the deep- of the habitat in terms of either the dominant life form

UPLAND LACUSTRINE PALUSTRINE UPLAND

LITTORAL LIMNETIC LITTORAL

W Z Z
LU Z
Z
< _j LU W _j W
< P
W M UJ LU Z
LU I'_ <
_j CC _j %J cc
0 0 Co 0
0 cc W I.-
Z Z W < Z 0 < Z W Cr UJ
0 0. n
0 UjZ 0 W
0 a 0 Z LL
Z cr 0
D ccZ W Z
LU

HIGH WATER

AVERAGE WATER-
c C
LOW WATER
e

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

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

of the vegetation or the physiography and composition algae, though frequently more difficult to detect, are
of the substrate-features that can be recognized used to define the class Aquatic Bed. Pioneer species
without the aid of detailed environmental measure- that briefly invade wetlands when conditions are
ments. Vegetation is used at two different levels in the favorable are treated at the subclass level because
classification. The life forms-trees, shrubs, emer- they are transient and often not true wetland species.
gents, emergent mosses, and lichens-are used to Use of life forms at the class level has two major
define classes because they are relatively easy to dis- advantages: (1) extensive biological knowledge is not
tinguish, do not change distribution rapidly, and have required to distinguish between various life forms, and
traditionally been used as criteria for classification of (2) it has been established that various life forms are
wetlands.' Other forms of vegetation, such as sub- easily recognizable on a great variety of remote
merged or floating-leaved rooted vascular plants, free- sensing products (e.g., Radforth 1962; Anderson et al.
floating vascular plants, submergent mosses, and 1976). If vegetation (except pioneer species) covers
30% or more of the substrate, we distinguish classes
on the basis of the life form of the plants that con-
'Our initial attempts to use familiar terms such as marsh, stitute the uppermost layer of vegetation and that
swamp, bog, and meadow at the class level were unsuc- possess an areal coverage 30% or greater. For
cessful primarily because of wide discrepancies in the use of
these terms in various regions of the United States. In an example, an area with 50% areal coverage of trees over
effort to resolve that difficulty, we based the classes on the a shrub layer with a 60% areal coverage would be
fundamental components (life form, water regime, substrate classified as Forested Wetland; an area with 20% areal
type, water chemistry) that give rise to such terms. We coverage of trees over the same (60%) shrub layer
believe that this approach will greatly reduce the misunder. would be classified as Scrub-Shrub Wetland. When
standings and confusion that result from the use of the fa. trees or shrubs alone cover less than 30% of an area
miliar terms. but in combination cover 30% or more, the wetland is

UPLAND PALUSTRINE UPLAND PALUSTRINE UPLAND PALUSTRINE UPLAND
-------------------

Z Z Z
Ui Z <
U, _j F--
a Z 'r a < LU I- Z
M W Z LLI LU Z 0 2 M W W W
Z < 0
_J 0 V)
M LU P W CO P I-
Ir UJ < Z Uj Z
W Z M Z 0 W IL W
Cr L.LJ LLI M 3:: 0 W W
0 LL 0 0. C!)Z (3
0) cc M 0 W
W co Z W Z LU

W Uj W

Seepage Zone

HIGH WATER

b AVERAGE WATER
a TEMPORARILY FLOODED LOW WATER
b SEASONALLY FLOODED e L2 m

c SEMIPERMANENTLY FLOODED

d INTERMITTENTLY EXPOSED

e PERMANENTLY FLOODED

fSATURATED

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

assigned to the class Scrub-Shrub. When trees and and Shores are intertidal. Bottoms, Shores, and
shrubs cover less than 30% of the area but the total Streambeds are further divided at the class level on
cover of vegetation (except pioneer species) is 30% or the basis of the important characteristic of rock versus
greater, the wetland is assigned to the appropriate unconsolidated substrate. Subclasses are based on
class for the predominant life form below the shrub finer distinctions in substrate material unless, as with
layer. Finer differences in life forms are recognized at Streambeds and Shores, the substrate is covered by,
the SUBCLASS level. For example, Forested Wetland is or shaded by, an aerial coverage of pioneering vascular
divided into the subclasses Broad-leaved Deciduous, plants (often nonhydrophytes) of 30% or more; the
Needle-leaved Deciduous, Broad-leaved Evergreen, subclass is then simply vegetated. Further detail as to
Needle-leaved Evergreen, and Dead. Subclasses are the type of vegetation must be obtained at the level of
named on the basis of the predominant life form. dominance type. Reefs are a unique class in which the
If vegetation covers less than 30% of the substrate, substrate itself is composed primarily of living and
the physiography and composition of the substrate are dead animals. Subclasses of Reefs are designated on
the principal characteristics used to distinguish the basis of the type of organism that formed the reef.
classes. The nature of the substrate reflects regional The DOMINANCE TYPE is the taxonomic category
and local variations in geology and the influence of subordinate to subclass. Dominance types are deter-
wind, waves, and currents on erosion and deposition of mined on the basis of dominant plant species (e.g.,
substrate materials. Bottoms, Shores, and Stream- Jeglum et al. 1974), dominant sedentary or sessile
beds are separated on the basis of duration of inun- animal species (e.g., Thorson 1957@, or dominant plant
dation. In the Riverine, Lacustrine, and Palustrine and animal species (e.g., Stephenson and Stephenson
systems, Bottoms are submerged all or most of the 1972). A dominant plant species has traditionally
time, whereas Streambeds and Shores are exposed all meant one that has control over the community
or most of the. time. in the Marine and Estuarine (Weaver and Clements 1938:91), and this plant is also
systems, -Bottoms are subtidal, whereas Streambeds usually the predominant species (Cain and Castro

1959:29). When the subclass is based on life form, we Animals that live on the rocky surface are generally
name the dominance type for the dominant species or firmly attached by hooking or sucking devices,
combination of species (codominants) in the same layer although they may occasionally move about over the
of vegetation used to determine the subclass.' For substrate. Some may be permanently attached by
example, a Needle-leaved Evergreen Forested Wetland cement. A few animals hide in rocky crevices and
with 70% areal cover of black spruce and 30% areal under rocks, some move rapidly enough to avoid being
cover of tamarack (Larix laricina) would be designated swept away, and others burrow into the finer sub-
as a Picea mariana Dominance Type. When the rela- strates between boulders. Plants are also firmly at-
tive abundance of codominant species is nearly equal, tached (e.g., by holdfasts), and in the Riverine System
the dominance type consists of a combination of both plants and animals are commonly streamlined or
species names. For example, an Emergent Wetland flattened in response to high water velocities.
with about equal areal cover of common cattail (Typha Subclasses and Dominance Types.
latifolia) and hardstern bulrush (Scirpus acutus) would Bedrock. -Bottoms in which bedrock covers 75%
be designated as Typha latifolia-Scirpus acutus Domi- or more of the surface.
nance Type. Rubble. -Bottoms with less than 75 % areal cover
When the subclass is based on substrate material, of bedrock, but stones and boulders alone, or in combi-
the dominance type is named for the predominant nation with bedrock, cover 75% or more of the surface.
plant or sedentary or sessile macroinvertebrate Examples of dominance types for these two sub-
species, without regard for life form. In the Marine and classes in the Marine and Estuarine systems are the
Estuarine systems, sponges, alcyonarians, mollusks, encrusting sponges Hippospongia, the tunicate Cnemi-
crustaceans, worms, ascidians, and echinoderms may docarpa, the sea urchin Strongylocentrotus, the sea
all be part of the community represented by the star Pisas ter, the sea whip Muricea, and the American
Macoma balthica Dominance Type. Sometimes it is -lobster, Homarus americanus. Examples of Lacus-
necessary to designate two or more codominant trine, Palustrine, and Riverine dominance types are
species as a dominance type. Thorson (1957) recom- the freshwater sponges Spongilla and Heteromeyenia,
mended guidelines and suggested definitions for estab- the pond snail Lymnaea, the mayfly Ephemerella,
lishing community types and dominants on level various midges of the Chironomidae, the caddisfly
bottoms. Hydropsyche, the leech Helobdella, the riffle beetle
Rock Bottom Psephenus, the chironomid midge Eukiefferiella, the
crayfish Procambarus, and the black fly Simulium.
Definition. The class Rock Bottom includes all Dominance types for rock bottoms in the Marine
wetlands and deepwater habitats with substrates and Estuarine systems were taken primarily from
having an areal cover of stones, boulders, or bedrock Smith (1964) and Ricketts and Calvin (1968), and those
75% or greater and vegetative cover of less than 30%. for rock bottoms in the Lacustrine, Riverine, and
Water regimes are restricted to subtidal, permanently Palustrine Systems from Krecker and Lancaster
flooded, intermittently exposed, and semipermanently (1933), Stehr and Branson (1938), Ward and Whipple
flooded. (1959), Clarke (1973), Hart and Fuller (1974), Ward
Description. The rock substrate of the rocky benthic (1975), Slack et al. (1977), and Pennak (1978).
or bottom zone is one of the most important factors in Unconsolidated Bottom
determining the abundance, variety, and distribution
of organisms. The stability of the bottom allows a rich Definition. The class Unconsolidated Bottom in-
assemblage of plants and animals to develop. Rock cludes all wetland and deepwater habitats with at least
Bottoms are usually high-energy habitats with well- 25% cover of particles smaller than stones, and a vege-
aerated waters. Temperature, salinity, current, and tative cover less than 30%. Water regimes are re-
light penetration are also important factors in deter- stricted to subtidal, permanently flooded, intermit-
mining the composition of the benthic community. tently exposed, and sernipermanently flooded.
Description. Unconsolidated Bottoms are charac-
terized by the lack of large stable surfaces for plant
'Percent areal cover is seldom measured in the application of and animal attachment. They are usually found in
this system, but the term must be defined in terms of area. areas with lower energy than Rock Bottoms, and may
We suggest 2 m, for herbaceous and moss layers, 16 ml for be very unstable. Exposure to wave and current ac-
shrub layers, and 100 ml for tree layers (Mueller-Dombois tion, temperature, salinity, and light penetration
and Ellenberg 1974:74). When percent areal cover is the key determine the composition and distribution of
for establishing boundaries between units of the classifi-
cation, it may occasionally be necessary to measure cover on organisms.
plots, in order to maintain uniformity of ocular estimates Most macroalgae attach to the substrate by means
made in the field or interpretations made from aerial photo- of basal hold-fast cells or discs; in sand and mud, how-
graphs. ever, algae penetrate the substrate and higher plants

can successfully root if wave action and currents are and the sea pansy Renilla. Examples for the Lacus-
not too strong. Most animals in unconsolidated sedi- trine, Palustrine, and Riverine systems are the snail
ments live within the substrate, e.g., Macoma and the Physa, the scud Gammarus, the oligochaete worm
amphipod Melita. Some, such as the polychaete worm Limnodriluls, the mayfly Ephemerella, the freshwater
Chaetopterus, maintain permanent burrows, and mollusks Elliptio and Anodonta, and the fingernail
others may live on the surface, especially in coarse- clam Sphaerium.
grained sediments. Mad. -The unconsolidated particles smaller than
In the Marine and Estuarine systems, Uncon- stones are predominantly silt and clay, although
solidated Bottom communities are relatively stable. coarser sediments or organic material may be inter-
They vary from the Arctic to the tropics, depending mixed. Organisms living in mud must be able to adapt
largely on temperature, and from the open ocean to the to low oxygen concentrations. Examples of dominance
upper end of the estuary, depending on salinity. types for the Marine and Estuarine systems include
Thorson (1957) summarized and described charac- the terebellid worm Amphitrite, the boring clam Platy-
teristic types of level bottom communities in detail. odon, the deep-sea scallop Placopecten, the quahog
In the Riverine System, the substrate type is largely Mercenaria, the macoma Macoma, the echiurid worm
determined by current velocity, and plants and Urechis, the mud snail Nassarius, and the sea cucum-
animals exhibit a high degree of morphologic and beha- ber Thyone. Examples of dominance types for the
vioral adaptation to flowing water. Certain species are Lacustrine, Palustrine, and Riverine systems are the
confined to specific substrates and some are at least sewage worm Tubifex, freshwater mollusks Anodonta,
more abundant in one type of substrate than in others. Anodontoides, and Elliptio, the fingernail clams Pisi-
According to Hynes (1970:208), "The larger the dium and Sphaerium, and the midge Chironomus.
stones, and hence the more complex the substratum, Organic.-The unconsolidated material smaller
the more diverse is the invertebrate fauna." In Lacus- than stones is predominantly organic. The number of
trine and Palustrine systems, there is usually a high species is limited and faunal productivity is very low
correlation, within a given water body, between the (Welch 1952). Examples of dominance types for Estua-
nature of the substrate and the number of species and rine and Marine systems are the soft-shell clam Mya,
individuals. For example, in the profundal bottom of the false angel wing Petricola pholadiformis, the clam
eutrophic lakes where light is absent, oxygen content worm Nereis, and the mud snail Nassarius. Examples
is low, and carbon dioxide concentration is high, the for the Lacustrine, Palustrine, and Riverine systems
sediments are ooze-Eke organic materials and species are the sewage worm Tubifex, the snail Physa, the
diversity is low. Each substrate type typically sup- harpacticoid copepod Canthocamptus, and the oligo-
ports a relatively distinct community of organisms chaete worm Limnodrilus.
(Reid and Wood 1976:262). Dominance types for Unconsolidated Bottoms in the
Subclasses and Dominance Types. Marine and Estuarine systems were taken predomi-
Cobble-Gravel.-The unconsolidated particles nantly from Miner (1950), Smith (1964), Abbott (1968),
smaller than stones are predominantly cobble and and Ricketts and Calvin (1968). Dominance types for
gravel, although finer sediments may be intermixed. unconsolidated bottoms in the Lacustrine, Riverine,
Examples of dominance types for the Marine and and Palustrine systems were taken predominantly
Estuarine systems are the mussels Modiolus and from Krecker and Lancaster (1933), Stehr and Branson
Mytilus, the brittle star Amphipholis, the soft-shell (1938), Johnson (1970), Brinkhurst and Jamieson
clam Mya, and the Venus clam Saxidomus. Examples (1972), Clarke (1973), Hart and Fuller (1974), Ward
for the Lacustrine, Palustrine, and Riverine Systems (1975), and Pennak (1978).
are the midge Diamesa, stonefly-midge Nemoura-Eu- Aquatic Bed
kiefferiella (Slack et al. 1977), chironomid midge-
caddisfly-snail Chironomus-Hydropsyche-Physa Definition. The class Aquatic Bed includes wetlands
(Krecker and Lancaster 1933), the pond snail Lym- and deepwater habitats dominated by plants that
naea, the mayfly Bae tis, the freshwater sponge Eunap- grow principally on or below the surface of the water
ius, the oligochaete worm Lumbriculus, the scud Gam- for most of the growing season in most years. Water
marus, and the freshwater mollusks Anodonta, regimes include subtidal, irregularly exposed, regu-
Elliptio, and Lampsilis. larly flooded, permanently flooded, intermittently
Sand. -The unconsolidated particles smaller than exposed, sernipermanently flooded, and seasonally
stones are predommantly sand, although finer or flooded.
coarser sediments may be intermixed. Examples of Description. Aquatic Beds represent a diverse group
dominance types in the Marine and Estuarine systems of plant communities that require s-irface water for
are the wedge shell Donax, the scallop Pecten, the optimum growth and reproduction. They are best
tellin shell Tellina, the heart urchin Echinocardium, developed in relatively permanent water or under
the lugworm Arenicola, the sand dollar Dendraster, conditions of repeated flooding. The plants are either

attached to the substrate or float freely in the water wrightii), manatee grass (Syringodium ftliformis),
above the bottom or on the surface. widgeon grass (Ruppia maritima), sea grasses (Halo-
phila spp.), and wild celery (Vallisneria americana).
Subclasses and Dominance Types. Five majo Ir vascular species dominate along the tem-
Algal. =Algal beds are widespread and diverse in perate coasts of North America: shoalgrass; surf
the Marine and Estuarine systems, where they occupy
grasses (Phyllospadix scouleri, P. torreyi), widgeon
substrates characterized by a wide range' of sediment grass, and eelgrass (Zostera marina). Eelgrass beds
depths and textures. They occur in both the Subtidal have the most extensive distribution, but they are
and Intertidal subsystems and may grow to depths of limited primarily to the more sheltered estuarine
30 m (98 feet). Coastal Algal beds are most luxuriant environment. In the lower salinity zones of estuaries,
along the rocky shores of the Northeast and West. stands of widgeon grass, pondweed (Potamogeton),
Kelp (Macrocystis) beds are especially well developed
and wild celery often occur, along with naiads (Najas)
on, the rocky substrates of the Pacific Coast. Domi- and water milfoil (Myriophyllum).
nance types such as the rockweeds Fucus and Asco- In the Riverine, Lacustrine, and Palustrine systems,
phyllum and the kelp Laminaria are common along Rooted Vascular aquatic plants occur at all depths
both coasts. In tropical regions, green algae, including within the photic zone. They often occur in sheltered
forms containing calcareous particles, are more areas where there is little water movement (Wetzel
characteristic; Hal 'imeda and Penicillus are common 1975); however, they also occur in the flowing water of
examples. The red alga Laurencia, and the green algae the Riverine System, where they may be streamlined
Caulerpa, Enteromorpha, and Ulva are also common or flattened in response to high water velocities.
Estuarine and Marine dominance types; Entero- Typical inland genera include pondweeds, horned
morpha and Ulva are tolerant of fresh water and flour- pondweeds (Zannichellia), ditch grasses (Ruppia), wild
is.h near the upper end of some estuaries. The stone- celery, and waterweed jElodea). The riverweed (Podo-
wort Chara is also found in estuaries. sternum ceratophyllum) is included in this class despite
Inland, the stoneworts Chara, Nitella, and Tolypella, its lack of truly recognizable roots (Sculthorpe 1967).
are examples of algae that look much like vascular Some of the R .ooted Vascular species are charac-
plants and may grow in similar situations. However, terized by floating leaves. Typical dominants include
meadows of Chara may be f6und in Lacustrine water water lilies (Nymphaea, Nuphar), floating-leaf pond-
as deep as 40 rn (131 feet) (Zhadin and Gerd 1963), weed (Potamogeton natans), and water shield (Bra-
where hydrostatic pressure limits the survival of senia schreberi). Plants such as yellow water lily
vascular submergents (phanaerogams) (Welch 1952), (Nuphar luteum) and water smartweed (Polygonum
Other algae bearing less resemblance to vascular amphibium), which may stand erect above the water
plants are also common. Mats of filamentous algae surface or substrate, may be considered either emer-
may cover the bottom in dense blankets, may rise to gents or Rooted Vascular aquatic plants, depending on
the surface under certain conditions, or may become the life form adopted at a particular site.
stranded on Unconsolidated or Rocky Shores. Floating Vascular.-Beds of floating vascular
Aquatic Moss.-Aquatic mosses are far less plants occur mainly in the Lacustrine, Palustrine, and
abundant than algae or vascular plants. They occur Riverine systems and in the fresher waters of the
primarily in the Riverine System and in permanently Estuarine System. The plants float freely either in the
flooded and intermittently exposed parts of some water or on its surface. Dominant plants that float on
Lacustrine Systems. The most important dominance the surface include the duckweeds (Lemna, Spirodela),
types include genera such as Fissidens, Drepano- water lettuce (Pistia stratiotes), water hyacinth (Eich-
cladus, and Fontinalis. Fontinalis may grow to depths hornia crassipes), water nut (Trapa natans), water
as great as 120 rn (394 feet) (Hutchinson 1975). For fern (Salvinia rotundifolia), and mosquito ferns
simplicity, aquatic liverworts of the genus Marsupella (A,olla). These plants are found primarily in protected
are included in this subclass. portions of slow-flowing rivers and in the Lacustrine
Rooted Vascular. -Rooted Vascular beds include a and Palustrine systems. They are easily moved about
large array of vascular species in the Marine and by wind or water currents and cover a large area of
Estuarine systems. They have been referred to by water in some parts of the country, particularly the
others as temperate grass flats (Phillips 1974); tropical Southeast. Dominance types for beds floating below
marine meadows (Odum 1974); and eelgrass beds, the surface include bladderworts (Utricularia),
turtlegrass beds, and seagrass beds (Akins and Jeffer- coontails JCeratophyllum), and watermeals (Wolffiella)
son 1973; Eleuterius 1973; Phillips 1974).. The greatest (Sculthorpe 1967; Hutchinson 1975).
number of species occur in shallow, clear tropical or Reef
subtropical waters of moderate current strength in the
Caribbean and along the Florida and Gulf coasts. Prin- Definition. The class Reef includes ridge-like or
cipal dominance types in these areas include turtle mound-like structures formed by the colonization and
grass (Thalasia testudinum), shoalgrass (Halodule growth of sedentary invertebrates. Water regimes are

restricted to subtidal, irregularly exposed, regularly System or of the Tidal Subsystem of the Riverine
flooded, and irregularly flooded. System that are completely dewatered at low tide.
Description. Reefs are characterized by their ele- Water regimes are restricted to irregularly exposed,
vation above the surrounding substrate and their regularly flooded, irregularly flooded, seasonally
interference with normal wave flow; they are primarily flooded, temporarily flooded, and intermittently
subtidal, but parts of some Reefs may be intertidal as flooded.
well. Although corals, oysters, and tube worms are the Description. Streambeds vary greatly in substrate
most visible organisms and are mainly responsible for and form depending on the gradient of the channel, the
Reef formation, other mollusks, foraminifera, coralline velocity of the water, and the sediment load. The
algae, and other forms of life also contribute sub- substrate material frequently changes abruptly be-
stantially to Reef growth. Frequently, Reefs contain tween riffles and pools, and complex patterns of bars
far more dead skeletal material and shell fragments may form on the convex side of single channels or be
than living matter. included as islands within the bed of braided streams
Subclasses and Dominance Types. (Crickmay 1974). In mountainous areas the entire
Coral.-Coral Reefs are widely distributed in channel may be cut through bedrock. In most cases
shallow waters of warm seas, in Hawaii, Puerto Rico, streambeds are not vegetated because of the scouring
the Virgin Islands, and southern Florida. They were effect of moving water, but, like Unconsolidated
characterized by Odum (1971) as stable, well-adapted, Shores, they may be colonized by "pioneering" an-
highly diverse, and highly productive ecosystems with nuals or perennials during periods of low flow or they
a great degree of internal symbiosis. Coral Reefs lie may have perennial emergents and shrubs that are too
almost entirely within the Subtidal Subsystem of the scattered to qualify the area for classification as
Marine System, although the upper part of certain Emergent Wetland or Scrub-Shrub Wetland.
reefs may be exposed. Examples of dominance types Subclasses and Dominance Types.
are the corals Porites, Acropora, and Montipora. The Bedrock.-This subclass is characterized by a
distribution of these types reflects primarily their ele- bedrock substrate covering 75% or more of the stream
vation, wave exposure, the age of the Reef, and its channel. It occurs most commonly in the Riverine
exposure to waves. System in high mountain areas or in glaciated areas
Mollusk.-This subclass occurs in both the Inter- where bedrock is exposed. Examples of dominance
tidal and Subtidal subsystems of the Estuarine types are the mollusk Ancylus, the oligochaete worm
System. These Reefs are found on the Pacific, Limnodrilus, the snail Physa, the fingernail clam
Atlantic, and Gulf coasts and in Hawaii and the Carib- Pisidium, and the mayflies Caenis and Ephemerella,
bean. Mollusk Reefs may become extensive, affording Rubble. -This subclass is characterized by stones,
a substrate for sedentary and boring organisms and a boulders, and bedrock that in combination cover more
shelter for many others. Reef mollusks are adapted to than 75% of the channel. Like Bedrock Streambeds,
great variations in water level, salinity, and tempera- Rubble Streambeds are most common in mountainous
ture, and these same factors control their distribution. areas and the dominant organisms are similar to those
Examples of dominance types for this subclass are the of bedrock and are often forms capable of attachment
oysters Ostrea and Crassostrea (Smith 1964; Abbot to rocks in flowing water.
1968; Ricketts and Calvin 1968). Cobble-Gravel.-In this subclass at least 25% of
Worm.-Worm Reefs are constructed by large the substrate is covered by unconsolidated particles
colonies of Sabellariid worms living in individual tubes smaller than stones; cobbles or gravel predominate.
constructed from cemented sand grains. Although The subclass occurs in riffle areas or in the channels of
they do not support as diverse a biota as do Coral and braided streams. Examples of dominance types in the
Mollusk reefs, they provide a distinct habitat which Intermittent Subsystem of the Riverine System are
may cover large areas. Worm Reefs are generally the snail Physa, the oligochaete worm Limnodrilus,
confined to tropical waters, and are most common the mayfly Caenis, the midge Chironomus, and the
along the coasts of Florida, Puerto Rico, and the mosquito Anopheles. Examples of dominance type in
Virgin Islands. They occur in both the Marine and the Estuarine System or Tidal Subsystem of the Riv-
Estuarine systems where the salinity approximates erine System are the mussels Modiolus and My tilus.
that of sea water. The reefworm Sabellaria is an Sand-In this subclass, sand-sized particles
example of a dominance type for this subclass predominate among the particles smaller than stones.
(Ricketts and Calvin 1968). Sand Streambed often contains bars and beaches
Streambed interspersed with Mud Streambed or it may be inter-
spersed with Cobble-Gravel streambed in areas of fast
Definition. The class Streambed includes all wetland flow or heavy sediment load. Examples of dominance
contained within the Intermittent Subsystem of the types in the Riverine System are the scud Gammarus,
Riverine System and all channels of the Estuarine the snails Physa and Lymnaea, and the midge Chiron-

omus; in the Estuarine System the ghost shrimp Subclasses and Dominance Types.
Callianassa is a common dominance type. Bedrock. -These wetlands have bedrock covering
Mud. -In this subclass, the particles smaller than 75% or more of the surface and less than 30% areal
stones are chiefly silt or clay. Mud Streambeds are coverage of macrophytes.
common in and areas where intermittent flow is Rubble. -These wetlands have less than 75% areal
characteristic of streams of low gradient. Such species cover of bedrock, but stones and boulders alone or in
as tamarisk (Tamarix gallica) may occur, but are not combination with bedrock cover 75% or more of the
dense enough to qualify the area for classification as area. The areal coverage of macrophytes is less than
Scrub-Shrub Wetland. Mud Streambeds are also 30%.
common in the Estuarine System and the Tidal Sub- Communities or zones of Marine and Estuarine
system of the Riverine System. Examples of domi- Rocky Shores have been widely studied (Lewis 1964;
nance types for Mud Streambeds include the crayfish Ricketts and Calvin 1968; Stephenson and Stephenson
Procambarus, the pouch snail Aplexa, the fly Tabanus, 1972). Each zone supports a rich assemblage of inver-
the snail Lymnaea, the fingernail clam Sphaerium, and tebrates, and algae or lichens or both. Dominance
(in the Estuarine System) the mud snail Nassarius. types of the Rocky Shores often can be characterized
Organic.-This subclass is characterized by by one or two dominant genera from these zones.
channels formed in peat or muck. Organic Streambeds The uppermost zone (here termed the lit-
are common in the small creeks draining Estuarine torine-lichen zone) is dominated by periwinkles (Lit-
Emergent Wetlands with organic soils. Examples of torina and Nerita) and lichens. This zone frequently
dominance types are the mussel Modiolus in the takes on a dark, or even black appearance, although
Estuarine System and the oligochaete worm Lirnno- abundant lichens may lend a colorful tone. These
drilus in the Riverine System. organisms are rarely submerged, but are kept moist by
Vegetated Streambeds. -These streambeds are sea spray. Frequently this habitat is invaded from the
exposed long enough to be colonized by herbaceous landward side by semimarine genera such as the slater
annuals or seedling herbaceous perennials (pioneer Ligia.
plants). This vegetation, unlike that of Emergent The next lower zone (the balanoid zone) is commonly
Wetlands, is usually killed by rising water levels or dominanted by mollusks, green algae, and barnacles of
sudden flooding. A typical dominance type is Panicurn the balanoid group. The zone appears white. Domi-
capillare. nance types such as the barnacles Balanus, Chtha-
Dominance types for streambeds in the Estuarine malus, and Tetraclita may form an almost pure sheet,
System were taken primarily from Smith (1964), or these animals may be interspersed with mollusks,
Abbott (1968), and Ricketts and Calvin (1968) and tube worms, and algae such as Pelvetia, enteromorpha,
those for streambeds in the Riverine System from and Ulva.
Krecker and Lancaster (1933), Stehr and Branson The transition between the littorine-lichen and
(1938), van der Schalie (1948), Kenk (1949), Cummins balanoid zones is frequently marked by the replace-
et al. (1964), Clarke (1973), and Ward (1975). ment of the periwinkles with limpets such as Acmaea
and Siphonaria. The limpet band approximates the
Rocky Shore upper limit of the regularly flooded intertidal zone.
Definition. The class Rocky Shore includes wetland In the middle and lower intertidal areas, which are
flooded and exposed by tides at least once daily, lie a
environments characterized by bedrock, stones, or number of other communities which can be charac-
boulders which singly or in combination have an areal terized by don-dnant genera. Mytilus and gooseneck
cover of 75% or more and an areal coverage by vege- barnacles (Pollicipes) form communities exposed to
tation of less than 30%. Water regimes are restricted strong wave action. Aquatic Beds dominated by Fucus
to irregularly exposed, regularly flooded, irregularly and Larninaria lie slightly lower, just above those
flooded, seasonally flooded, temporarily flooded, and dominated by coralline algae (Litho thamnion). The
intermittently flooded. Laminaria dominance type approximates the lower
Description. In Marine and Estuarine systems, end of the Intertidal Subsystem; it is generally ex-
Rocky Shores are generally high-energy habitats posed at least once daily. The Lithothamnion domi-
which lie exposed as a result of continuous erosion by nance type forms the transition to the Subtidal Sub-
wind-driven waves or strong currents. The substrate is system and is exposed only irregularly.
stable enough to permit the attachment and growth of In the Palustrine, Riverine, and Lacustrine systems
sessile or sedentary invertebrates and attached algae various species of lichens such as Verrucaria spp. and
or lichens. Rocky Shores usually display a vertical Dermatocarpon fluviatile, as well as blue-green algae,
zonation that is a function of tidal range, wave action, frequently form characteristic zones on Rocky Shores.
and degree of exposure to the sun. In the Lacustrine The distribution of these species depends on the dura-
and Riverine systems, Rocky Shores support sparse tion of flooding or wetting by spray and is similar to
plant and animal communities. the zonation of species in the Marine and Estuarine

systems (Hutchinson 1975). Though less abundant Palustrine, and Riverine systems examples of domi-
than lichens, aquatic liverworts such as Marsupella nance types are the freshwater mollusk Elliptio, the
emarginata var. aquatica or mosses such as Fissidens snails Lymnaea and Physa, the toad bug Gelastocoris,
julianus are found on the rocky shores of lakes and the leech Erpodella, and the springtail Agrenia.
rivers. If aquatic liverworts or mosses cover 30% or Sand. -The unconsolidated particles smaller than
more of the substrate, they should be placed in the stones are predominantly sand which may be either
class Aquatic Bed. Other examples of Rocky Shore calcareous or terrigenous in origin. They are promi-
dominance types 'are the caddisfly Hydr6psyche and nent features of the Marine, Estuarine, Riverine, and
the fingernail clam Pisidium. Lacustrine systems where the substrate material is
exposed to the sorting and washing action of waves.
Unconsolidated Shore Examples of dominance types in the Marine and
Definition. The class Unconsolidated Shore includes Estuarine systems are the wedge shell Donax, the soft-
all, wetland habitats having three characteristics: (1) shell clam Mya, the quahog Merceharia, the olive shell
unconsolidated substrates with less than 75% areal Oliva, the blood worm Euzonds, the beach hopper
cover of stones, boulders, or bedrock; (2) less than 30% Orchestia, the pismo clam Tivela stultorum, the mole
areal cover of vegetation other- than pioneering plan s; crab Emerita, and the lugworm Arenicola. Examples
and (3) any of the following water regimes: irregularly of dornin ance types in the Riverine, Lacustrine, and
exposed, regularly flooded, irregularly flooded, season- Palustrine systems are the copepods Parastenocaris
ally flooded, temporarily flooded, intermittently and Phyllognathopus, the oligochaete worm Pristina;
flooded, saturated, or artificially flooded. Intermittent the freshwater mollusks Anodonta and Elliptio; and
or intertidal channels of the Riverine System or inter- the fingernail clams Pisidium and Sphaerium.
tidal channels of the Estuarine System are classified Mud. -The unconsolidated particles smaller than
as Streambed. stones are predominantly silt and clay. Anaerobic
conditions often exist below the surface. Mud shores
Description. Unconsolidated Shores are charac- have a higher organic content than cobble-gravel or
terized by substrates lacking vegetation except for sand shores. They are typically found in areas of minor
pioneering plants that become established during brief wave- action. They tend to have little slope and are fre-
periods when growing conditions are favorable. quently called flats. Mud Shores support diverse popu-
Erosion and deposition by waves and currents produce lations of tube-dwelling and burrowing invertebrates
a number of landforms such as beaches, bars, and that include worms, clams, and crustaceans (Gray
flats, all of which are included in this class. Uncon- 1974). They are commonly colonized by algae and
solidated Shores are found adjacent to Unconsolidated diatoms which may form a crust or mat.
Bottoms in all systems; in the Palustrine and Lacus- Irregularly flooded Mud Shores in the Estuarine
trine systems, the class may occupy the entire basin. System have been called salt flats, pans, or pannes.
As in Unconsolidated Bottoms, the particle size of the They are typically high in salinity and are usually sur-
substrate and the water regime are the important
factors determining the types of plant and animal com- rounded by, or lie on the landward side of, Emergent
munities present. Different substrates usually support Wetland (Martin et al. 1953, Type 15). In many and
characteristic invertebrate fauna. Faunal distribution areas, Palustrine and Lacustrine Mud Shores are
is controlled by waves, currents, interstitial moisture, crusted or saturated with salt. Martin et al. (1953)
salinity, and grain size (Hedgpeth 1957; Ranwell 1972; called these habitats inland saline flats (Type 9); they
Riedl and McMahan 1974). are also called alkali flats, salt flats, and salt pans.
Mud Shores may also result from removal of vege-
tation by man, animals, or fire, or from the discharge
Subclasses and Dominance Types. of thermal waters or pollutants.
Cobble-Gravel.-The unconsolidated particles Examples of dominance types in the Marine and
smaller than stones are predominantly cobble and Estuarine systems include the fiddler crab Uca, the
gravel that have been transported away from Cob- ghost shrimp Callianassa, the mud snails Nassarius
ble-Gravel shores by waves and currents. Shell and Macoma, the clam worm Nereis, the sea anemone
fragments, sand, and silt often fill the spaces between Cerianthus, and the sea cucumber Thyone. In the
the larger particles. Stones and boulders may be found Lacustrine, Palustrine, and Riverine systems,
scattered on some Cobble-Gravel shores. In areas of examples of dominance types are the fingernail clam
strong wave and current action these shores take the Pisidium, the snails Aplexa and Lymnaea, the crayfish
form of beaches or bars, but occasionally they form Procambarus, the harpacticoid copepods Cantho-
extensive flats. Examples of dominance types in the camptus and Bryocamptus, the fingernail clam
Marine and Estuarine systems are: the acorn barnacle Sphaerium, the freshwater mollusk Elliptio, the shore
Balanus, the limpet Patella, the periwinkle Littorina, bug Saldula, the isopod Asellus, the crayfish Cam-
the rock shell Thais, the mussels Mytilus and Modio- barus, and the mayfly Tortopus.
lus, and the Venus clam Saxidomus. In the Lacustrine, Organic.-The unconsolidated material smaller

than stones is predominantly organic soils of formerly are typical of wet soil in this region (Britton 1957;
vegetated wetlands. In the Marine and Estuarine Drury 1962).
systems, Organic Shores are often dominated by Lichen. -Lichen wetlands are also a northern sub-
microinvertebrates such as foraminifera, and by Nas- class. Reindeer moss (Cladonia rangiferina) forms the
sarius, Littorina, Uca, Modiolus, Mya, Nereis, and the most important dominance type. Pollett and Bridge-
false angel wing Petricola pholadiformis. In the Lacus- water (1973) described areas with mosses and lichens
trine, Palustrine, and Riverine systems, examples of as bogs or fens, the distinction being based on the
dominance types are Canthocamptus, Bryocamptus, availability of nutrients and the particular plant
Chironomus, and the backswimmer Notonecta. species present. The presence of Lichen Wetlands has
Vegetated.-Some nontidal shores are exposed for been noted in the Hudson Bay Lowlands (Sjbrs 1959)
a sufficient period to be colonized by herbaceous an- and in Ontario (Jeglurn et al. 1974).
nuals or seedling herbaceous perennials (pioneer Emergent Wetland
plants). This vegetation, unlike that of Emergent
Wetlands, is usually killed by rising water levels and Definition. The Emergent Wetland class is charac-
may be gone before the beginning of the next growing terized by erect, rooted, herbaceous hydrophytes,
season. Many of the pioneer species are not hydro- excluding mosses and lichens. This vegetation is
pfiytes but are weedy mesophytes that cannot tolerate present for most of the growing season in most years.
wet soil or flooding. Examples of dominance types in These wetlands are usually dominated by perennial
the Palustrine, Riverine, and Lacustrine systems are plants. AN water regimes are included except subtidal
cocklebur (Xanthiurn strummarium) and barnyard and irregularly exposed.
grass (Echinochloa crusgalli), Description. In areas with relatively stable climatic
Dominance types for unconsolidated shores in the conditions, Emergent Wetlands maintain the same
Marine and Estuarine systems were taken primarily appearance year after year. In other areas, such as the
from Smith (1964), Morris (1966), Abott (1968), prairies of the central United States, violent climatic
Ricketts and Calvin (1968), and Gosner (1971). Domi- fluctuations cause them to revert to an open water
nance types for unconsolidated shores in the Lacus- phase in some years (Stewart and Kantrud 1972).
trine, Riverine, and Palustrine systems were taken pri- Emergent Wetlands are found throughoufthe United
marily from Stehr and Branson (1938), Kenk (1949), States and occur in all systems except the Marine.
Ward and Whipple (1959), Cummins et al. (1964), Emergent Wetlands are known by many names, in-
Johnson (1970), Ingram (1971), Clarke (1973), and Hart cluding marsh, meadow, fen, prairie pothole, and
and Fuller (1974). slough. Areas that are dominated by pioneer plants
Moss-Lichen Wetland that become established during periods of low water
are not Emergent Wetlands and should be classified as
Definition. The Moss-Lichen Wetland class includes Vegetated Unconsolidated Shores or Vegetated
areas where mosses or lichens cover substrates other Streambeds.
than rock and where emergents, shrubs, or trees make
up less than 30% of the areal cover. The only water Subclasses and Dominance Types.
regime is saturated. Persistent. -Persistent Emergent Wetlands are
dominated by species that normally remain standing
Description. Mosses and lichens are important com- at least until the beginning of the next growing season.
ponents of the flora in many wetlands, especially in the This subclass is found only in the Estuarine and @alus-
north, but these plants usually form a ground cover trine systems.
under a dominant layer of trees, shrubs, or emergents. Persistent Emergent Wetlands dominated by salt-
In some instances higher plants are uncommon and marsh cordgrass (Spartina alterniflora), saltmeadow
mosses or lichens dominate the flora. Such cordgrass (S. patens), big cordgrass (S. cynosuroides),
Moss-Lichen wetlands are not common, even in the needlerush Wuncus roemerianus), narrow-leaved cat-
northern United States where they occur most fre- tail (Typha angustifolia), and southern wild rice (Zi-
quently. zaniopsis miliacea) are major components of the
Subclasses and Dominance Types. Estuarine Systems of the Atlantic and Gulf coasts of
Moss. -Moss wetlands are most abundant in the the United States. On the Pacific Coast, common
far north. Areas covered with peat mosses (Sphagnum pickleweed (Salicornia virginica), sea blite (Suaeda cali-
spp.) are usually called bogs (Golet and Larson 1974; fornica), arrow grass (Triglochin maritima), and Cali-
Jeglurn et al. 1974; Zoltai et al. 1975), whether Sphag- fornia cordgrass (Spartina foliosa) are common domi-
num or higher plants are dominant. In Alaska, nants.
Drepanocladus and the liverwort Chiloscyphus fragilis Palustrine Persistent Emergent Wetlands contain a
may dominate shallow pools with impermanent water; vast array of grasslike plants such as cattails (Typha
peat moss and other mosses (Campylium stellaturn, spp.), bulrushes (Scirpus spp.), saw grass (Cladium
Aulacomniumpalustre, and Oncophorus wahlenbergii) jamaicense), sedges (Carex spp.); and true grasses such

as reed (Phragmites communis), manna grasses (Gly- sented by young or stunted trees such as tamarack or
ceria spp.), slough grass (Beckmannia syzigachne), and bald cypress (Taxodium distichum).
whitetop (Scolochloa festucacea). There. is also a Broad-leaved Evergreen.-In the Estuarine
variety of broad-leaved persistent emergents such as System, vast wetland acreages are dominated by
purple loosestrife (Lythrum salicaria), dock (Rumex mangroves (Rhizophora mangle, Languncularia race-
mexicanus), waterwillow (Decodon verticillatus), and mosa, Conocarpus erectus, and Avicennia germinans)
many species of smartweeds (Polygonum). that are less than 6 m tall. In the Palustrine System,
Nonpersis tent. -Wetlands in this subclass are the broad-leaved evergreen species are typically found
dominated by plants which fall to the surface of the on organic soils. Northern representatives are labra-
substrate or below the surface of the water at the end dor tea (Ledurn groenlandicum), bog rosemary (An-
of the growing season so that, at certain seasons of the dromeda glaucophylla), bog laurel (Kalmia polifolia),
year, there is no obvious sign of emergent vegetation. and the semi-evergreen leatherleaf (Chamaedaphne
For example, wild rice (Zizania aquatica) does not calyculata). In the south, fetterbush (Lyonia lucida),
become apparent in the North Central States until coastal sweetbells (Leucothoe axillaris), inkberry (Ilex
midsummer and fall, when it may form dense emergent glabra), and the semi-evergreen black ti-ti (Cyrilla
stands. Noripersistent emergents also include species racemiflora) are characteristic broad-leaved evergreen
such as arrow arum (Peltandra virginica), pickerelweed species.
(Pontederia cordata), and arrowheads (Sagittaria spp.). Needle-leaved Evergreen. -The dominant species
Movement of ice in Estuarine, Riverine, and Lacus- in Needle-leaved Evergreen wetlands are young or
trine systems often removes all traces of emergent stunted trees such as black spruce or pond pine (Pinus
vegetation during the winter. Where this occurs, the serotina).
area should be classified as Noripersistent Emergent Dead. -Dead woody plants less than 6 m tall
Wetland. dominate dead scrub-shrub wetlands. These wetlands
are usually produced by a prolonged rise in the water
Scrub-Shrub Wetland table resulting from impoundment of water by land-
Definition. The class 9crub-Shrub Wetland includes slides, man, or beavers. Such wetlands may also result
areas dominated by woody vegetation less than 6 in from various other factors such as fire, salt spray,
(20 feet) tall. The species include true shrubs, young insect infestation, air pollution, and herbicides.
trees, and trees or shrubs that are small or stunted Forested Wetland
because of environmental conditions. All water
regimes except subtidal are included. Definition. The class Forested Wetland is charac-
Description. Scrub-Shrub Wetlands may represent terized by woody vegetation that is 6 m tall or taller.
a successional stage leading to Forested Wetland, or All water regimes are included except subtidal.
they may be relatively stable communities. They occur Description. Forested Wetlands are most common in
only in the Estuarine and Palustrine systems, but are the eastern United States and in those sections of the
one of the most widespread classes in the United West where moisture is relatively abundant, par-
States (Shaw and Fredine 1956). Scrub-Shrub Wet- ticularly along rivers and in the mountains. They occur
lands are known by many names, such as shrub swamp only in the Palustrine and Estuarine systems and
(Shaw and Fredine 1956), shrub carr JCurtis 1959), bog normally possess an overstory of trees, an understory
(Heinselman 1970), and pocosin (Kologiski 1977). For of young trees or shrubs, and a herbaceous layer.
practical reasons we have also included forests com- Forested Wetlands in the Estuarine System, which
posed of young trees less than 6 in tall. include the mangrove forests of Florida, Puerto Rico,
Subclasses and Dominance Types. and the Virgin Islands, are known by such names as
Broad-leaved Deciduous.-In Estuarine System swamps, hammocks, heads, and bottoms. These names
wetlands the predominant deciduous and broad-leaved often .occur in combination with species names or plant
trees or shrubs are plants such as sea-myrtle (Bacchar- associations such as cedar swamp or bottomland
is halimifolia) and marsh elder (Iva frutescens). In the hardwoods.
Palustrine System typical dominance types are alders Subclasses and Dominance Types.
(Alnus spp.), willows (Salix spp.)", buttonbush (Ceph- Broad-leaved Deciduous. -Dominant trees typical
alanthus occidentalis), red osier dogwood (Cornus of Broad-leaved Deciduous wetlands, which are repre-
stolonifera), honeycup (Zenobia pulverulenta), spirea sented throughout the United States, are most
(Spiraea douglasii), bog birch (Betula pumila), and common in the South and East. Common dominants
young trees of species such as red maple (Acer rubrum) are species such as red maple, American elm (Ulmus
or black spruce (Picea mariana). americana), ashes (Fraxinus pennsylvanica and F.
Needle-leaved Deciduous. -This subclass, consist- nigra), black gum (Nyssa sylvatica), tupelo gum (N.
ing of wetlands where trees or shrubs are pre- aquatica), swamp white oak Quercus bicolor), overcup
dominantly deciduous and needle-leaved, is repre- oak Q lyrata), and basket oak Q michauxii).

Wetlands in this subclass generally occur on mineral are described here in only general terms. Water
soils or highly decomposed organic soils. regimes are grouped under tw6 major headings, Tidal
Needle-leaved Deciduous.-The southern repre- and Nontidal.
sentatives of the Needle-leaved Deciduous subclass Tidal water regime modifiers are used for wetlands
include bald cypress and pond cypress (Taxodium and deepwater habitats in the Estuarine and Marine
ascendens), which are noted for their ability to tolerate systems and Nontidal modifiers are used for all
long periods of surface inundation. Tamarack is nontidal parts of the Palustrine, Lacustrine, and Riv-
characteristic of the Boreal Forest Region, where it erine systems. The Tidal Subsystem of the Riverine
occurs as a dominant on organic soils. Relatively few System and tidally influenced parts of the Palustrine
other species are included in this subclass. and Lacustrine systems require careful selection of
Broad-leaved Evergreen.-In the Southeast, water regime modifiers. We designate subtidal and
Broad-leaved Evergreen wetlands reach their greatest irregularly exposed wetlands and deepwater habitats
development. Red bay (Persea borbonia), loblolly bay in the Palustrine, Riverine, and Lacustrine systems as
(Gordonia lasianthus), and sweet bay (Magnolia vir- permanently flooded-tidal rather than subtidal, and
giniana) are prevalent, especially on organic soils. This Palustrine, Riverine and Lacustrine wetlands regu-
subclass also includes red mangrove, black mangrove larly flooded by the tide as regularly flooded. If
(Avicennia germinans), and white mangrove (Lagun- Palustrine, Riverine, and Lacustrine wetlands are only
cularia racemosa), which are adapted to varying levels irregularly flooded by tides, we designate them by the
of salinity. appropriate nontidal water regime modifier with the
Needle-leaved Evergreen. -Black spruce, growing word tidal added, as in seasonally flooded-tidal.
on organic soils, represents a major dominant of the
Needle-leaved Evergreen subclass in the North. Tidal
Though black spruce is common on nutrient-poor soils, The water regimes are largely determined by oceanic
Northern white cedar (ThuJa occidentalis@ dominates tides.
northern wetlands on more nutrient-rich sites. Along
the Atlantic Coast, Atlantic white cedar (Chamae- Subtidal. The substrate is permanently flooded with
cyparis thyoides) is one of the most common domi- tidal water.
nants on organic soils. Pond pine is a common needle- Irregularly Exposed. The land surface is exposed by
leaved evergreen found in the southeast in association tides less often than daily.
with dense stands of broad-leaved evergreen and decid- Regularly Flooded. Tidal water alternately floods
uous shrubs. and exposes the land surface at least once daily.
Dead. -Dead Forested wetlands are dominated by
dead woody vegetation taller than 6 m (20 feet). Like Irregularly Flooded. Tidal water floods the land
Dead Scrub-Shrub Wetlands, they are most common surface less often than daily.
in, or around the edges of, man-made impoundments The periodicity and amplitude of tides vary in dif-
and beaver ponds. The same factors that produce ferent parts of the United States, mainly because of
Dead Scrub-Shrub Wetlands produce Dead Forested differences in latitude and geomorphology. On the
Wetlands. Atlantic Coast, two nearly equal high tides are the rule
(semidiurnal). On the Gulf Coast, there is frequently
Modifiers only one high tide and one low tide each day (diurnal);
and on the Pacific Coast there are usually two unequal
To fully describe wetlands and deepwater habitats, high tides and two unequal low tides (mixed semi-
one must apply certain modifiers at the class level and diurnal).
at lower levels in the classification hierarchy. The Individual tides range in height from about 9.5 m (31
modifiers described below were adapted from existing feet) at. St. John, New Brunswick (U.S. National
classifications or were developed specifically for this Oceanic and Atmospheric Administration 1973) to less
system. than 1 m (3.3 feet) along the Louisiana coast (Chabreck
1972). Tides of only 10 cm (4.0 inches) are not un-
common in Louisiana. Therefore, though no hard and
Water Regime Modifiers fast rules apply, the division between regularly flooded
and irregularly flooded water regimes would probably
Precise description of hydrologic characteristics occur approximately at mean high water on the
requires detailed knowledge of the duration and timing Atlantic Coast, lowest level of the higher high tide on
of surface inundation, both yearly and long-term, as the Pacific Coast, and just above mean tide level of the
well as an understanding of groundwater fluctuations. Gulf Coast. The width of the intertidal zone is deter-
Because such information is seldom available, the mined by the tidal range, the slope of the shoreline,
water regimes that, in part, determine characteristic and the degree of exposure of the site to wind and
wetland and deepwater plant and animal communities waves.

Nontidal from man-made impoundments, nor irrigated pasture-
Though not influenced by oceanic tides, nontidal lands supplied by diversion ditches or artesian wells,
water regimes may be affected by wind or seiches in are included under this modifier.
lakes. Water regimes are defined in terms of the
growing season, which we equate to the frost-free Water Chemistry Modifiers
period (see the U. S. Department of Interior National
Atlas 1970:110-111 for generalized regional delin- The accurate characterization of water chemistry in
eation). The rest of the year is defined as the dormant wetlands and deepwater habitats is difficult, both
season, a time when even extended periods of flooding because of problems in measurement and because
may have little influence on the development of plant values tend to vary with changes in the season,
communities. weather, time of day, and other factors. Yet, very
Permanently Flooded. Water covers the land surface subtle changes in water chemistry, which occur over
throughout the year in all years. Vegetation is short distances, may have a marked influence on the
composed of obligate hydrophytes. types of plants or animals that inhabit an area. A
Intermittently Exposed. Surface water is present description of water chemistry, therefore, must be an
throughout the year except in years of extreme essential part of this classification system.
drought. The two key characteristics employed in this system
are salinity and hydrogen-ion concentration (pH). All
Semipermanently Flooded. Surface water persists habitats are classified according to salinity, and fresh-
throughout the growing season in most years. When water habitats are further subdivided by pH levels.
surface water is absent, the water table is usually at or
very near the land surface. Salinity Modifiers
Seasonally Flooded. Surface water is present for Differences in salinity are reflected in the species
extended periods especially early in the growing composition of plants and animals. Many authors have
season, but is absent by the end of the season in most suggested using biological changes as the basis for
years. When surface water is absent, the water table is subdividing the salinity range between sea water and
often near the land surface. fresh water (Remane and Schlieper 1971). Others have
Saturated. The substrate is saturated to the surface suggested a similar subdivision for salinity in inland
for extended periods during the growing season, but wetlands (Moyle 1946; Bayly 1967; Stewart and
surface water is seldom present. Kantrud 1971). Since the gradation between fresh and
Temporarily Flooded. Surface water is present for hypersaline or hyperhaline waters is continuous, any
brief periods during the growing season, but the water boundary is artificial, and few classification systems
table usually lies well below the soil surface for most of agree completely.
the season. Plants that grow both in uplands and Estuarine and marine waters are a complex solution
wetlands are characteristic of the temporarily flooded of salts dominated by sodium chloride (NaCl). The
regime. term haiine is used to indicate the dominance of ocean
salt. The relative proportions of the various major ions
Intermittently Flooded. The substrate is usually are usually similar to those found in sea water, even if
exposed, but surface water' is present for variable the water is diluted below seawater strength. Dilution
periods without detectable seasonal periodicity. of sea water with fresh water and concentration of sea
Weeks, months, or even years may intervene between water by evaporation result in a wide range of recorded
periods of inundation. The dominant plant com- salinities in both surface water and interstitial (soil)
munities under this regime may change as soil mois- water.
ture conditions change. Some areas exhibiting this We have modified the Venice System, suggested at a
regime do not fall within our definition of wetland "Symposium on the Classification of Brackish
because they do not have hydric soils or support Waters" in 1958, for use in the Marine and Estuarine
hydrophytes. systems (Table 2). The system has been widely used
Artificially Flooded. The amount and duration of during recent years (Macan 1961, 1963; Burbank 1967;
flooding is controlled by means of pumps or siphons in Carriker 1967; Reid and Wood 1976), although there
combination with dikes or dams. The vegetation has been some criticism of its applicability (den
growing on these areas cannot be considered a reliable Hartog 1960; Price and Gunter 1964).
indicator of water regime. Examples of artificially The salinity of inland water is dominated by four
flooded wetlands are some agricultural lands managed major cations, calcium (Ca), magnesium (Mg), sodium
under a rice-soybean rotation, and wildlife manage- (Na), and potassium (K); and three major anions, car-
ment areas where forests, crops, or pioneer plants may bonate (CO.), sulfate (S04), and chloride (CI) (Wetzel
be flooded or dewatered to attract wetland wildlife. 1975). Salinity is governed by the interactions between
Neither wetlands within or resulting from leakage precipitation, surface runoff, groundwater flow, evap-

oration, and sometimes evapotranspiration by plants. Table 3. pR modifiers used in this
The ionic ratios of inland waters usually differ appre- classification system.
ciably from those in the sea, although there are excep- Modifier pH of Water
tions (Bayly 1967). The great chemical diversity of
these waters, the wide variation in physical conditions Acid < 5.5
such as temperature, and often the relative imperma- Circumneutral 5.5-7.4
nence of surface water, make it extremely difficult to Alkaline > 7.4
subdivide the inland salinity range in a meaningful
way. Bayly (1967) attempted a subdivision on the
basis of animal life; Moyle (1945) and Stewart and Soil Modiflers
Kantrud (1971) have suggested two very different divi- Soil is one of the most important physical com-
sions on the basis of plant life. We employ a sub- ponents of wetlands. Through its depth, mineral com-
division that is identical with that used in the Estua- position, organic matter content, moisture regime,
rine and Marine systems (Table 2).
temperature regime, and chemistry, it exercises a
The term saline is used to indicate that any of a strong influence over the types of plants that live on
number of ions may be dominant or codominant. The its surface and the kinds of organisms that dwell
term brackish has been applied to inland waters of within it. In addition, the nature of soil in a wetland,
intermediate salinity (Remane and Schheper 1971; particularly the thickness of organic soil, is of critical
Stewart and Kantrud 1971), but is not universally importance to engineers planning construction of
accepted (see Bayly 1967:84); therefore, mixosaline is highways or buildings, For these and other reasons, it
used here. In some inland wetlands, high soil salinities is essential that soil be considered in the classification
control the invasion or establishment of many plants. of wetlands.
These salinities are expressed in units of specific con- According to the U. S. Soil Conservation Service,
ductance as well as percent salt (Ungar 1974) and they Soil Survey Staff (1975:1-2), soil is limited to terres-
are also covered by the salinity classes in Table 2. trial situations and sliallow waters; however, "areas
pH Modifiers are not considered to have soil if the surface is perma-
nently covered by water deep enough that only float-
Acid waters are, almost by definition, poor in ing plants are present. . . ." Since emergent plants do
calcium and often generally low in other ions, but some not grow beyond a depth of about 2 m in inland
very soft waters may have a neutral pH (Hynes 1970). waters, the waterward limit of soil is virtually equi-
It is difficult to separate the effects of high concen- valent to the waterward limit of wetland, according to
trations of hydrogen ions from low base content, and our definition. Wetlands can then be regarded as
many studies suggest that acidity may never be the having soil in most cases, whereas deepwater habitats
major factor controlling the presence or absence of are never considered to have soil.
particular plants and animals. Nevertheless, some re- The most basic distinction in soil classification in the
searchers have demonstrated a good correlation be- United States is between mineral soil and organic soil
tween pH levels and plant distribution (Sjbrs 1950; (U. S. Soil Conservation Service, Soil Survey Staff
Jeglum 1971). Jeglum (1971) showed that plants can 1975). The Soil Conservation Service recognizes nine
be used to predict the pH of moist peat. orders of mineral soils and one order of organic soils
There seems to be little doubt that, where a peat (Histosols) in their taxonomy. Their classification is
layer isolates plant roots from the underlying mineral hierarchical and permits the description of soils at sev-
substrate, the availability of minerals in the root zone eral levels of detail. For example, suborders of Histo-
strongly influences the types of plants that occupy the sols are recognized according to the degree of decom-
site. For this reason, many authors subdivide fresh- position of the organic matter.
water, organic wetlands into mineral-rich and mineral- We use the modifiers mineral and organic in this
poor categories (Sj6rs 1950; Heinselman 1970; Jeglum classification. Mineral soils and organic soils are dif-
1971; Moore and Bellamy 1974). We have instituted ferentiated on the basis of specific criteria that are
pH modifiers for freshwater wetlands (Table 3) enumerated in soil taxonomy (U. S. Soil Conser-
because pH has been widely used to indicate the dif- vation Service, Soil Survey Staff 1975:13-14, 65).
ference between mineral-rich and mineral-poor sites, These criteria are restated in our Appendix D for ready
and because it is relatively easy to determine. The reference. If a more detailed classification is desired,
ranges presented here are similar to those of Jeglurn the U. S. Soil Conservation Service classification
(1971), except that the upper limit of the circumneutral. system should be used.
level (Jeglum's mesotrophic) was raised to bring it into
agreement with usage of the term in the United States.
The ranges given apply to the pH of water. They were Special Modifiers
converted from Jeglum's moist-peat equivalents by
adding 0.5 pH units. Many wetlands and deepwater habitats are man-

made, and natural ones have been modified to some reasons, there is a need to recognize regional dif-
degree by the activities of man or beavers. Since the ferences. Regionalization is designed to facilitate three
nature of these modifications often greatly influences activities: (1) planning, where it is necessary to study
the character of such habitats, special modifying management problems and potential solutions on a
terms have been included here to emphasize their regional basis; (2) organization and retrieval of data
importance. The following modifiers should be used gathered in a resource inventory; and (3) interpretation
singly or in combination wherever they apply to of inventory data, including differences in indicator
wetlands and deepwater habitats. plants and animals among the regions.
We recommend the classification and map (Fig. 7) of
Excavated Bailey (1976) to fill the need for regionalization. inland.
Lies within a basin or channel excavated by man. Bailey's classification of ecoregions is hierarchical.
The upper four levels are domain (defined as including
Impounded subcontinental areas of related climates), division
Created or modified by a barrier or dam which (defined as including regional climate at the level of
purposefully or unintentionally obstructs the outflow Kbppen's [19311 types), province (defined as including
of water.Both man-made dams and beaver dams are broad vegetational types), and section (defined as
included. including climax vegetation at the level of Kuchler's
[19641 types). On the map, the boundaries between the
Diked different levels are designated by lines of various
widths and the sections are numbered with a four-digit
Created or modified by a man-made barrier or dike code; digits 1 through 4 represent the first four levels
designed to obstruct the inflow of water. in the hierarchy. The reader is referred to Bailey (1976,
1978) for a detailed discussion and description of the
Partly Drained units appearing on his map, reproduced in our Fig. 7.
The water level has been artificially lowered, but the The Bailey system terminates at the ocean, whereas
area is still classified as wetland because soil moisture the present wetland classification includes marine and
is sufficient to support'hydrophytes. Drained areas are estuarine habitats. Many workers have divided marine
not considered wetland if they can no longer support and estuarine realms into series of biogeographic prov-
hydrophytes. inces (e.g., U. S. Senate 1970; Ketchum 1972). These
provinces differ somewhat in detail, but the broader
Farmed concepts are similar. Figure 7 shows the distribution
The soil surface has been mechanically or physical of 10 marine and estuarine provinces that we offer for
ly North America.
altered for production of crops, but hydrophytes will - Arctic Province extends from the southern tip of
become reestablished if farming is discontinued. Newfoundland (Avalon Peninsula), northward around
Artificial Canada to the west coasts of the Arctic Ocean, Bering
Sea, and Baffin and Labrador basins. It is charac-
Refers to substrates classified as Rock Bottom, teried by the southern extension of floating ice, the
Unconsolidated Bottom, Rocky Shore, and Uncon- 4'C summer isotherm, and arctic biota.
solidated Shore that were emplaced by man, using - Acadian Province extends along the northeast
either natural materials such as dredge spoil or syn- Atlantic coast from the Avalon Peninsula to Cape Cod
thetic materials such as discarded automobiles, tires, and is characterized by a well-developed algal flora and
or concrete. Jetties and breakwaters are examples Of boreal biota. The shoreline is heavily indented and fre-
Artificial Rocky Shores. Man-made reefs are an quently rocky. It has a large tidal range and is
example of Artificial Rock Bottoms. strongly influenced by the Labrador Current.
- Virginian Province extends along the middle
Atlantic coast from Cape Cod to Cape Hattaras. The
REGIONALIZATION FOR THE province is transitional between the Acadian and Caro-
CLASSIFICATION SYSTEM linian provinces (which follow). The biota is primarily
temperate, but has some boreal representatives. The
In this classification system, A given taxon has no Labrador Current occasionally extends down to Cape
particular regional alliance; its representatives may be Hattaras and winter temperatures may approach 4 *C.
found in one or many parts of the United States. The tidal range is moderate.
However, regional variations in climate, geology, soils, - Carolinian Province is situated along the south
and vegetation are important in the development of ' Atlantic coast from Cape Hattaras to Cape Kennedy.
different wetland habitats; and management problems It contains extensive marshes and well-developed
often differ greatly in different regions. For these barrier islands. Waters are turbid and productive. The

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211
0
@L 322, 2215

2320
3
32 '3120
222 1f 321 1, 321@1 2521 2512 2312 ,BOUNDARIES OF
314 ((D 2320 LAND ECOREGIONS
M4210 3212 2311 DOMAIN
1210 2522 )311", --
M1210 DIVISION
10.1 PACIF) 6. LOUlSl4N,4,V
NS ULARC 1320 PROVINCE
2523
-------------
M1310 SECTION
4110
600 1220 M'2 10 6 z
K@ 700 BOUNDARIES OF
FJ 10 Km 10 MARINE AND ESTUARINE
PROVINCES

-----------
PROVINCE

Fig. 7. Ecoregions of the United States after Bailey J1976) with the addition of 10 marine and estuarine provinces proposed in
our classification.

aDomains, Divisions, Provinces and Sections used on Bailey's (1976) map and described in detail in Bailey (1978). Highland
ecoregions are designated, M mountain, P plateau, and A altiplano.

1000 Polar 2000 Humid Temperate 3000 Dry
1200 Tund a 2400 Mari e 3100 Steppe
1210 Arctic Tundra 2410 Willamette,Puget Forest M31 10 Rocky Mountain Forest
1220 Bering Tundra M24 10 Pacific Forest (in conterminous U.S.) M31 11 Grand fir-Douglas-fir Forest
M1210 Brooks Range M2411 Sitka Spruce-Cedar-Heml@k Forest M3112 Douglas-fir Forest
1300 Subarctic M2412 Redwood Forest M3113 Ponderom Pine-Dougles-fir Forest
1320 Yukon Forest M2413 Cedar-Hemlock-Douglas-fir Forest 3120 Palouse Grassland
M1310 Alaska Range M2414 California Mixed Evergreen Forest M3120 Upper Gil. Mountains Forest
2000 Humid Temperate M2415 Silver fir-Douglas-fir Forest 3130 Intermountain Sagebrush
2100 Wam Continental M2410 Pacific Forest (in Alaska) 3131 Sagebmsh-Wheatgrass
2110 Laurentian Mixed Forest 3132 Lahontan Saltbush-Greasewood
2111 Spruce-Fir Forest 2500 Prairie 3133 Great Basin Sagebrush
2112 Northern Hardwoods-Fir Forest 2510 Prairie Parkland 3134 Bonneville Saltbush-Greasewood
2113 Nortbem Hardwoods Forest 2511 Oak-Hickory-Bluestem Parkland 3135 Ponderosa Shrub Forest
2114 Northern Hard.oods-Spmce Forest 2512 Oak + Bluestem Parkland P3130 Colorado Plateau
M2110 Columbia Forest 2520 Prairie Brushland P3131 Juniper-Pinyon Woodland +
M21 11 Douglas-fir Forest 2521 Me@quit@Buffalo Grass Sagebrush Saltbush Mosaic
M2112 Cedar-Hemlock-Douglas-fir Forest 2522 Juniper-Oak-Mesquite P3132 Grama-Galleta Steppe + Juniper-
2200 Hot Continental 2523 Me@quite-Acacia . Pinyon Woodland Mosaic
2210 Eastern Deciduous Forest 2530 Tall-Grass Prairie 3140 Mexican Highland Shrub Steppe
2211 Mixed Mesophytic Forest 2531 Bluestern Prairie A3140 Wyoming Basin
2212 Beech-Maple Forest 2532 Wheatgrass-Bluestem-Needlegrass A3141 Wheatgrass-N,edlegrass-Sagebmsh
2213 Maple-Basswood Forest + Oak Savanna 2533 Bluestem-Grama Prairie A3142 Sagebrush-Wheatgrass
2214 Appalachian Oak Forest 2600 Mediterranean (Dry-summer Subtropical) 3200 Desert
2215 Oak-Hickory Forest 2610 California Grassland 3210 Chiltualman Desert
2300 Subtropical M2610 Sierran Forest 3211 Grama-Tobosa
2310 Oute@ Coastal Plain Forest M2620 California Chaparral 3212 Tarbush-Creosote Bush
2311 Beech-Sweetgum-Magnolia-Pine-Oak 3000 Dry 3220 American Desert
2312 Southern Moodplain Forest 3100 Steppe 3221 Creosote Bush
2320 Southeastern Mixed Forest 3110 Great Plains-Sbortgrass Prairie 3222 Creosote Bush-Bur Sage
3111 Grama-Nmdlegrass-Wbeatgr.es 4000 Humid Tropical
3112 Wheatgrass-Needlegrass 4100 Savanna
3113 Grama-Buffalo Grass 4110 Everglades
4200 Rainforest
M4210 Hawaiian Islands

biota is temperate but has seasonal tropical elements. USE OF THE CLASSIFICATION
The Gulf Stream is the primary influence, and winter SYSTEM
temperatures reach a minimum of 10'C; summer tem-
peratures are tropical (in excess of 20'C). The tidal This system was designed for use over an extremely
range is small to moderate. wide geographic area and for use by individuals and
- West Indian Province extends from Cape Kennedy organizations with varied interests and objectives.
to Cedar Key, Florida, and also includes the southern The classification employs 5 system names, 8 sub-
Gulf of Mexico, the Yucatan Peninsula, Central system names, 11 class names, 28 subclass names, and
America, and the Caribbean Islands. The shoreland is an unspecified number of dominance types. It is, of
usually low-lying limestone with calcareous sands and necessity, a complex system when viewed in its en-
marls, except for volcanic islands. The biota is tropical tirety, but use of the system for a specific purpose at a
and includes reef corals and mangroves. Minimum local site should be simple and straightforward. Arti-
winter temperatures are about 20'C and the tidal ficial keys to the systems and classes (Appendix E) are
range is small. furnished to aid the user of the classification, but ref-
- Louisianian Province extends along the northern erence to detailed definitions in the text is also
coast of the Gulf of Mexico from Cedar Key to Port required. The purpose of this section is to illustrate
Aransas, Texas. The characteristics of the province how the system should be used and some of the poten-
are similar to those of the Carolinian, reflecting the tial pitfalls that could lead to its misuse.
past submergence of the Florida Peninsula. The biota Before attempting to apply the system, the user
is primarily temperate and the tidal range is small. should consider four important points:
- Californian Province extends along the Pacific (1) Information about the area to be classified must
coast from Mexico northward to Cape Mendocino. The be available before the system can be applied. This
shoreland is strongly influenced by coastal mountains information may be in the form of historical data,
and the coasts are rocky. Freshwater runoff is limited. aerial photographs, brief on-site inspection, or detailed
In the southern part volcanic sands are present; and intensive studies. The system is designed for use
marshes and swamps are scarce throughout the at varying degrees of detail. There are few areas for
province. The climate is Mediterranean and is influ- which sufficient information is available to allow the
enced by the California Current. The biota is tem- most detailed application of the system. If the level of
perate, and includes well-developed offshore kelp beds- detail provided by the data is not sufficient for the
The tidal range is moderate. needs of the user, additional data gathering is man-
- Columbian Province extends along the, northern datory.
Pacific coast from Cape Mendocino to Vancouver (2) Below the level of class, the system is open-ended
Island. Mountainous shorelands with rocky foreshores and incomplete. We give only examples of the vast
are prevalent. Estuaries are strongly influenced by number of dominance types that occur. The user may
freshwater runoff. The biota is primarily temperate identify additional dominance types and determine
with some boreal components, and there are extensive where these fit into the classification hierarchy.. It is
algal communities. The province is influenced by both also probable that as the system is used the need for
the Aleutian and California currents. The tidal range is additional subclasses will become apparent.
moderate to large. (3) One of the main purposes of the new classification
- Fjord Province extends along the Pacific coast is to ensure uniformity throughout the United States.
from Vancouver Island to the southern tip of the It is important that the user pay particular attention
Aleutian Islands. Precipitous mountains, deep estu- to the definitions in the classification. Any attempt at
aries (some with glaciers), and a heavily indented modification of these definitions will lead to lack of
shoreline subject to winter icing are typical of the uniformity in application.
coast. The biota is boreal to subarctic. The province is
influenced by the Aleutian and Japanese currents, and (4) One of the principal uses of the classification
the tidal range is large. system will be the inventory and mapping of wetlands
- Pacific Insular Province surrounds all the and deepwater habitats. A classification used in
Hawaiian Islands. The coasts have precipitous moun- mapping is scale-specific, both for the minimum size of
tains and wave action is stronger than in most of the units mapped and for the degree of detail attainable. It
other provinces. The biota is largely endemic and com- is necessary for the user to develop a specific set of'
posed of tropical and subtropical forms. The tidal mapping conventions for each application and to
range is small. demonstrate their relationship to the generalized
Use of Bailey's sections for the Riverine, Lacustrine, classification described here. For example, there are a
and Palustrine systems and the provinces defined number of possible mapping conventions for a small
above for the Marine and Estuarine systems provides wetland basin 50 in (164 feet) in diameter with con-
a regional locator for any wetland in the United States. centric rings of vegetation about the deepest zone. At

a scale of 1:500 each zone may be classified and In areas where the dominance types to be expected
mapped; at 1:20,000 it might be necessary to map the under different water regimes and types of water
entire basin as one zone and ignore the peripheral chemistry conditions have not been identified, detailed
bands; and at 1:100,000 the entire wetland basin may regional studies will be required before the classifi-
be smaller than the smallest mappable unit, and such a cation can be applied in detail. In areas where detailed
small-scale map is seldom adequate for a detailed soil maps are available, it is also possible to infer water
inventory and must be supplemented by information regime and water chemistry from soil series (U. S. Soil
gathered by sampling. In other areas, it may be neces. Conservation Service, Soil Survey Staff 1975).
sary to develop mapping conventions for taxa. that Some of the modifiers are an integral part of this
cannot be easily recognized; for instance, Aquatic system and their use is essential; others are used only
Beds in turbid waters may have to be mapped simply for detailed applications or for special cases. Modifiers
as Unconsolidated Bottom. are never used with systems and subsystems;
however, at least one water regime modifier, one water
chemistry modifier, and one soil modifier must be used
Hierarchical Levels and Modifiers at all lower levels in the hierarchy. Use of the modifiers
listed under mixosaline and mixohaline (Table 2) is
We have designed the various levels of the system optional but these finer categories should be used
for specific purposes, and the relative importance of whenever supporting data are available. The user is
each will vary among users. The systems and sub- urged not to rely on single observations of water
systems are most important in applications involving regime or water chemistry. Such measurements give
large regions or the entire country. They serve to misleading results in all but the most stable wetlands.
organize the classes into meaningful assemblages of If a more detailed soil modifier, such as soil order or
information for data storage and retrieval. suborder (U. S. Soil Conservation Service, Soil Survey
The classes and subclasses are the most important Staff 1975) can be obtained, it should be used in place
part of the system for many users and are basic to of the modifiers, mineral and organic. Special modi-
wetland mapping. Most classes should be easily recog- fiers are used where appropriate.
nizable by users in a wide variety of disciplines.
However, the class designations apply to average
conditions over a period of years, and since many
wetlands are dynamic and subject to rapid changes in Relationship to Other
appearance, the placement of a wetland in its proper Wetland Classifications
place will frequently require data that span a period of
years and several seasons in each of those years. There are numerous wetland classifications in use in
The dominance type is most important to users the United States. Here we relate this system to three
interested in detailed regional studies. It may be neces- published classifications that have gained widespread
sary to identify dominance types in order to determine acceptance. It is not possible to equate these systems
which modifying terms are appropriate, because directly for several reasons: (1) The criteria selected for
plants and animals present in an area tend to reflect establishing categories differ; (2) some of the classifi-
environmental conditions over a period of time. Water cations are not applied consistently in different parts
regime can be determined from long-term hydrologic of the country; and (3) the elements classified are not
studies where these are available. The more common the same in various classifications.
procedure will be to estimate this characteristic from The most widely used classification system in the
the dominance types. Several studies have related United States is that of Martin et al. (1953) which was
water regimes to the presence and distribution Of republished in U. S. Fish and Wildlife Service Circular
plants or animals (e.g., Stephenson and Stephenson 39 (Shaw and Fredine 1956). The wetland types are
1972; Stewart and Kantrud 1972; Chapman 1974). based on criteria such as water depth and permanence,
Similarly, we do not intend that salinity measure- water chemistry, life form of vegetation, and dominant
ments be made for all wetlands except where these plant species. in Table 4 we compare some of the major
data are required; often plant species or associations components of our system with the type descriptions
can be used to indicate broad salinity classes. Lists of listed in Circular 39.
halophytes have been prepared for both coastal and In response to the need for more detailed wetland
inland areas (e.g., Duncan 1974; MacDonald and classification in the glaciated Northeast, Golet and
Barbour 1974; Ungar 1974), and a number of floristic Larson (1974) refined the freshwater wetland types of
and ecological studies have described plants that are Circular 39 by writing more detailed descriptions and
indicators of salinity (e.g., Penfound and Hathaway subdividing classes on the basis of finer differences in
1938; Moyle 1945; Kurz and Wagner 1957; Dillon plant life forms. Golet and Larson's classes are
1966; Anderson et al. 1968; Chabreck 1972; Stewart roughly equivalent to Types 1-8 of Circular 39, except
and Kantrud 1972; Ungar 1974). that they restricted Type 1 to river floodplains. The

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.

Classification of wetlands and deepwater habitats

Water
Circular 39 type, and references for examples of typical vegetation Classes Water regimes chemistry
Type I-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 Sernipermanently 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
Sernipermanently
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 JStewart and Kantrud 1972) Unconsolidated Seasonally Flooded Eusaline
Shore Intermittently Hypersaline
Flooded
Temporarily Flooded
Type 10-Inland saline marshes
Inland salt marshes (Ungar 1974) Emergent Wetland Seasonally Flooded Eusaline
Sernipermanently
Flooded
Type 11 -Inland open saline water
Inland saline lake community (Ungar 1974) Unconsolidated Permanently Flooded Eusaline
Bottom Intermittently
Flooded
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) Sernipermanently
Fresh and intermediate marshes JChabreck 1972) Flooded-Tidal

Table 4. Continued.

Classification of wetlands and deepwater habitats

Water
Circular 39 type, and references for examples of typical vegetation Classes Water regimes chemistry

Type 13-Coastal deep fresh marshes
Marsh jAnderson et al. 1968) Emergent Wetland Regularly Flooded Mixohaline
Estuarine bay marshes, estuarine river marshes Sernipermanently 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 jChapman 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 Euhafine
Mixohaline
Type 19-Sounds and bays
Kelp beds, temperate grass flats (Phillips 1974) Unconsolidated Subtidal Euhafine
Tropical marine meadows (Odum 1974) Bottom Irregularly Exposed Mixohaline
Eelgrass beds (Akins and Jefferson 1973; Eleuterius 1973) Aquatic Bed Regularly Flooded
Flat Irregularly Flooded
Type 20-Mangrove swamps
Mangrove swamps (Walsh 1974) Scrub-Shrub Irregularly Exposed Hyperhahne
Mangrove swamp systems (Kuenzler 1974) Wetland Regularly Flooded Euhaline
Mangrove (Chapman 1976) Forested Wetland Irregularly Flooded Mixohaline
Fresh

Golet and Larson system does not recognize the system recognizes seven classes of wetlands which are
coastal (tidal) fresh wetlands of Circular 39 (Types 12- distinguished by the vegetational zone occupying the
14) as a separate category, but classifies these areas in central or deepest part and covering 5 % or more of the
the same manner as nontidal wetlands. In addition to wetland basin. The classes thus reflect the wetland's
devising 24 subclasses, they also created 5 size cate- water regime; for example, temporary ponds (Class II)
gories, 6 site types giving a wetland's hydrologic and are those where the wet-meadow zone occupies the
topographic location; 8 cover types (modified from deepest part of the wetland. Six possible subclasses
Stewart and Kantrud 1971) expressing the distri- were created, based on differences in plant species
bution and relative proportions of cover and water; 3 composition that are correlated with variations in
vegetative interspersion types; and 6 surrounding average salinity of surface water. The third component
habitat types. Since this system is based on the classes of classification in their system is the cover type,
of Martin et al. (1953), Table 4 may also be used to which represents differences in the spatial relation of
compare the Golet and Larson system with the one emergent cover to open water or exposed bottom soil.
described here. Although our system does not include The zones of Stewart and Kantrud's system are
size categories and site types, this information will be readily related to our water regime modifiers (Table 5),
available from the results of the new inventory of and the subclasses are roughly equivalent to our water
wetlands and deepwater habitats of the United States. chemistry modifiers (Fig. 8).
Stewart and Kantrud (1971) devised a new classifi- Wetlands represent only one type of land and the
cation system to better serve the needs of researchers classification of this part separate from the rest is
and wetland managers in the glaciated prairies. Their done for practical rather than for ecological reasons

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

SALINE HYPERSALINE
6QOOO EUSALINE
45,000
POLYSALINE
SUBSALINE 30,000

15,000 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.

(Cowardin 1978). Recently there has been a flurry of Land Classification Series, Journal of Forestry, vol.
interest in a holistic approach to land classification (in 46, no. 10). A number of classifications have been
developed (e.g., Radford 1978) or are under develop-
Table 5. Comparison of the zones of Stewart and ment (e-g., Driscoll et al. 1978). Parts of this wetland
Kantrud's (1971) classification with the water classification can be incorporated into broader hier-
regime modifiers used in the present classification archical. land classifications.
system. A classification system is most easily learned
through use. To illustrate the application of this
Zone Water regime modifier system, we have classified a representative group of
Wetland-low-prairie Non-wetland by our definition wetlands and deepwater habitats of the United States
Wet meadow Temporarily flooded (Plates 1-56; pages 48-103).
Shallow marsh Seasonally flooded
Deep marsh Sernipermanently flooded
Intermittently exposed ACKNOWLEDGMENTS
Intermittent-alkali Intermittently flooded (with saline
or hypersaline water) The breadth and complexity of preparing this
Permanent-open- Permanently flooded (with mixo- classification caused us to solicit help and advice from
water haline water) individuals too numerous to list here. Frequently the
Fen (alkaline bog) Saturated recommendations were in conflict and we take respon-

sibility for the decisions we have made but acknowl- Braun, E. L. 1950. Deciduous forests of eastern North
edge all suggestions including those not accepted. Sev- America. Hafner Publishing Co., New York and London.
eral meetings were crucial in formulating the present 596 pp.
Brinkhurst, R. 0., and B. G. M. Jamieson. 1972. Aquatic
classification and in modifying earlier drafts. We oligochaetes of the world. University of Toronto Press,
thank those who attended the formative meeting at Toronto. 860 pp.
Bay St. Louis, Mississippi, January i975; The Britton, M. E. 1957. Vegetation of the Arctic tundra. Oreg.
National Wetland Classification and Inventor State Univ. Biol. Colloq. 18:26-61.
y Burbank, W. D. 1967. Evolutionary and ecological impli-
Workshop at College Park, Maryland, July 1975; and cations of the zoogeography, physiology and morphology
the review panels assembled at Sapelo Island, Georgia, of Cyanthura (Isopoda). Pages 564-573 in G. H. Lauff, ed.
and at St. Petersburgi Florida. We also thank those Estuaries. Am. Assoc. Adv. Sci. Rubl. 83.
individuals and agencies who responded to distri- Cain, S. A., and G. M. de Oliveira Castro. 1959. Manual of
bution of the operational draft. Special credit is due vegetation analysis. Harper & Brothers, New York. 325 pp.
Carriker, M. R. 1967. Ecology of estuarine benthic inver-
the regional coordinators of the National Wetland tebrates: a perspective. Pages 442-487 in G. H. Lauff, ed.
Inventory and P. B. Reed, who have furnished contin- Estuaries. Am. Assoc. Adv. Sci. Publ. 83.
uing consultation on application of the system. Martel Caspers, H. 1967. Estuaries: analysis of definitions and bio-
Laboratories field-tested the system and furnished logical considerations. Pages 6-8 in G. H. Lauff, ed.
specific criticisms. We were advised by J. Everett on Estuaries. Am. Assoc. Adv. Sci. Publ. 83.
geomorphology, K. K. Young and 0. Carter on soil Chabreck, R. H. 1972. Vegetation, water and soil charac-
teristics of the Louisiana coastal region. La. Agric. Exp.
taxonomy, R. P. Novitzki on hydrology, and R. H. Stn. Bull. 664. 72 pp.
Chabreck on coastal wetland ecology. M. L. Heinsel- Chapman, V. J. 1974. Salt marshes and salt deserts of the
man and R. H. Hofstetter helped with difficult prob- world. 2nd supplemented edition. J. Cramer, Lehre. 392 pp.
lems of peatland ecology and terminology. R. L. Kolo- Chapman, V. J. 1976. Mangrove vegetation. J. Cramer,
giski aided with botanical problems. J. H. Montanari, Leuterhausen. 447 pp.
Chapman, V. J. 1977. Introduction. Pages 1-30 in V. J.
W. 0. Wilen, and the entire National Wetland Inven- Chapman, ed. Wet coastal ecosystems. Ecosystems of the
tory staff furnished encouragement and logistic world 1. Elsevier Scientific Publishing Co., New York.
support. The staff of the Northern Prairie Wildlife Re- Clarke, A. H. 1973. The freshwater mollusks of the Canadian
search Center contributed substantially to completion Interior Basin. Malacologia 13(1-2):1-509.
of the classification. Art work and graphics were pre- Cowardin, L. M. 1978. Wetland classification in the United
pared by J. Rodiek, R. L. Duval, and C. S. Shaiffer. States. J. For. 76(10):666-668.
J. H. Sather worked closely with us and served as Crickmay, C. H. 1974. The work of the river, The MacMillan
Press, Ltd., London. 271 pp.
editor on previous drafts. Cummins, K. W., C. A. Tryon, Jr., and R. T. Hartman,
editors. 1964. Organism- substrate relationships in
streams. Pyrnatuning Lab. Ecol., Univ. Pittsburg Spec.
Publ. 4.145 pp.
Curtis, J. T. 1959. The vegetation of Wisconsin. The Uni-
REFERENCES versity of Wisconsin Press, Madison. 657 pp.
Abbott, R. T. 1968. Seashells of North America. Golden Dansereau, P., and F. Segadas-vianna. 1952. Ecological study
Press, New York. 280 pp. of the peat bogs of eastern North America. 1. Structure and
Akins, G. J., and C. Q. Jefferson. 1973. Coastal wetlands of evolution of vegetation. Can. J. Bot. 30:490-520.
Cregon. Oregon Coastal Conservation arid Development Daubenmire, R. 1968. Plant communities. Harper & Row,
Commission, Florence, Oregon. 159 pp. New York. 300 pp.
Anderson, J. R., E. E. Hardy, J. T. Roach, and R. E. Witman. den Hartog, C. 1960. Comments on the Venice-system for the
1976. A land use and land cover classification system for classification of brackish water. Int. Rev. gesamten Hydro-
use with remote sensor data. U. S. Geol. Surv. Prof. Pap. biol. 45:481-485.
964. 28 pp. Dillon, 0. W. 1966. Gulf coast marsh handbook. U. S. Soil
Anderson, R. R., R. G. Brown, and R. D. Rappleye. 1968. Conservation Service, Alexandra, Louisiana. n.p.
Water quality and plant distribution along the upper Dix, R. L., and F. E. Smeins. 1967. The prairie, meadow, and
Patuxent River, Maryland. Chesapeake Sci. 9:145-156. marsh vegetation of Nelson County, North Dakota. Can. J.
Bailey, R. G. 1976. Ecoregions of the United States. U. S. Bot. 45:21-58.
Forest Service, Ogden, Utah. (Map only; scale 1:7,500,000.) Driscoll, R. S., J. W. Russell, and M. C. Meier. 1978. Recom-
Bailey, R. G. 1978. Ecoregions of the United States. U. S. mended national land classification system for renewable
Forest Service, Intermountain Region, Ogden, Utah. 77 pp. resource assessments. U. S. Forest Service, Rocky Moun-
Bayly, 1. A. E. 1967. The general biological classification of tain Forest and Range Experiment Station, Fort Collins,
aquatic environments with special reference to those of Colorado. (Unpublished manuscript)
Australia. Pages 78-104 in A. H. Weatherley, ed. Aus- Drury, W. H., Jr. 1962. Patterned ground and vegetation on
tralian inland waters and their fauna. Australian National southern Bylot Island, Northwest Territories, Canada.
University Press, Canberra. Harv. Univ. Gray Herb. Contrib. 190. 111 pp.
Black, C. A. 1968. Soil plant relationships. John Wiley & Duncan, W. H. 1974. Vascular halophytes of the Atlantic and
Sons, Inc., New York. 792 pp. Gulf coasts of North America north of Mexico. Pages 23-50
Bormann, F. H., and G. E. Likens. 1969. The watershed-eco- in R. J. Reimold and W. H. Queen, eds. Ecology of halo-
system concept and studies of nutrient cycles. Pages 49-76 phytes. Academic Press, Inc., New York.
in G. M. VanDyne, ed. The ecosystem concept in natural Eleuterius, L. M. 1972. The marshes of Mississippi. Castanea
resource management.'Academic Press, New York. 37:153-168.

Eleuterius, L. M. 1973. The distribution of certain submerged Kurz, H., and K. Wagner. 1957. Tidal marshes of the Gulf and
plants in Mississippi Sound and adjacent waters. Pages Atlantic coasts of northern Florida and Charleston, South
191-197 in J. L. Christmas, ed. Cooperative Gulf of Mexico Carolina. Fla. State Univ. Stud. 24. 168 pp.
estuarine inventory and study. Mississippi Gulf Coast Langbein, W. B., and K. T. Iseri. 1960. General introduction
Research Laboratory, Ocean Springs. and hydrologic definitions manual of hydrology. Part 1.
Golet, F. C., and J. S. Larson. 1974. Classification of fresh- General surface-water techniques. U. S. Geol. Surv. Water-
water wetlands in the glaciated Northeast. U. S. Fish Supply Pap. 1541-A. 29 pp.
Wildl. Serv., Resour. Publ. 116. 56 pp. Lauff, G. H., editor. 1967. Estuaries. Am. Assoc. Adv. Sci.
Gosner, K. L. 1971. Guide to identification of marine and Publ. 83.
estuarine invertebrates: Cape Hattaras to the Bay of Leitch, W. G. 1966. Historical and ecological factors in
Fundy. John Wiley & Song, Inc., New York. 693 pp. wetland inventory. Trans. N. Am. Wildl. Nat. Resour. Conf.
Gray, 1. E. 1974. Worm and clam flats. Pages 204-243 in 31:88-96.
H. T. Odum, B. J. Copeland, and E. A. McMahan, eds. Lewis, J. R. 1964. The ecology of rocky shores. English Uni-
Coastal ecological systems of the United States. Vol. 2. The versities Press Ltd., London. 323 pp.
Conservation Foundation, Washington, D. C. Liu, T. K. 1970. A review of engineering soil classification
Hart, C. W., Jr., and S. L. H. Fuller, editors. 1974. Pollution systems. Pages 361-382 in Special procedures for testing
ecology of freshwater invertebrates. Academic Press, Inc., soil and rock for engineering purposes. Am. Soc. Test.
New York. 389 pp. Mater. Spec. Tech. Publ. 479.630 pp.
Hedgpeth, J. W. 1957. Classification of marine environments. Macan, T. T. 1961. Factors that limit the range of freshwater
Pages 17-28 in J. W. Hedgpeth, ed. Treatise on marine animals. Biol. Rev. 36:151-198.
ecology and paleoecology; Vol. 1-Ecology. Geol. Soc. Am. Macan, T. T. 1963. Freshwater ecology. John Wiley & Sons,
Mem. 67. Inc., New York. 338 pp.
Heinselman, M. L. 1963. Forest sites, bog processes, and MacDonald, K. B., and M. B. Barbour. 1974. Beach and salt
peatland types in the Glacial Lake Agassiz Region, Minne- marsh vegetation of the North American Pacific coast.
sota. Ecol. Monogr. 33(4):327-374. Pages 175-233 in R. J. Reimold and W. H. Queen, eds.
Heinselman, M. L. 1970. Landscape evolution, peatland Ecology of halophytes. Academic Press, Inc., New York.
types, and the environment in the Lake Agassiz Peatlands Martin, A. C., N. Hotchkiss, F. M. Uhler, and W. S. Bourn.
Natural Area, Minnesota. Ecol. Monogr. 40(2):235-261. 1953. Classification of wetlands of the United States. U. S.
Hutchinson, G. E. 1975. A treatise on limnology. Vol. 3. Lim- Fish Wildl. Serv., Spec. Sci. Rep.-Wildl. 20.14 pp.
nological botany. John Wiley & Sons, New York. 660 pp. Millar, J. B. 1976. Wetland classification in western Canada:
Hynes, H. B. N. 1970. The ecology of running waters. Uni- a guide to marshes and shallow open water wetlands in the
versity of Toronto Press, Toronto. 555 pp. grasslands and parklands of the Prairie Provinces. Can.
Illies, J., and L. Botosaneau. 1963. Problems et methodes de Wildl. Serv. Rep. Ser. 37. 38 pp.
la classification et de la zonation ecologique des aux cour- Miner, R. W. 1950. Field book of seashore life. G. P. Put-
antes, considerees surtout du point de vue faunistique. Int. nam's Sons, New York. 888 pp.
Assoc. Theor. Appl. Limnol. Commun. 12. 57 pp. Montanari, J. H., and J. E. Townsend. 1977. Status of the
Ingram, W. M. 1971. Survival of fresh-water mollusks during National Wetlands Inventory. Trans. N. Am. Wildl. Nat.
periods of dryness. Nautilis 54(3):84-87. Resour. Conf. 42:66-72.
Jeglum, J. K. 1971. Plant indicators of pH and water level in Moore, P. D., and D. J. Bellamy. 1974. Peatlands. Springer-
peatlands at Candle Lake, Saskatchewan. Can. J. Bot. Verlag, Inc., New York. 221 pp.
49-.1661-1676. Morris, P. A. 1966. A field guide to shells of the Pacific Coast
Jeglum, J. K., A. N. Boissonneau, and V. G. Haavisto. 1974. and Hawaii. Houghton Mifflin Company, Boston. 297 pp.
Toward a wetland classification for Ontario. Can. For. Moyle, J. B. 1945. Some chemical factors influencing the
Serv. Inf. Rep. O-X-215.54 pp. distribution of aquatic plants in Minnesota. Am. Midl. Nat.
Johnson, R. 1. 1970. The systematics and zoogeography of 34(2):402-420.
the Unionidae (Mollugea: Bivalvia) of the Southern Moyle, J. B. 1946. Some indices of lake productivity. Trans.
Atlantic Slope Region. Harvard Univ. Mus. Comp. Zool. Am. Fish. Soc. 76:322-334.
Bull. 140(6):263-450. Mueller-Dombois, D., and H. Ellenberg. 1974. Aims and
Kenk, R. 1949. The animal life of temporary and permanent methods of vegetation ecology. John Wiley & Sons, New
ponds in southern Michigan. Univ. Mich. Mus. Zool. Misc. York. 547 pp.
Publ. 71. 66 pp. Odurn, E. P. 1971. Fundamentals of ecology. W. B. Saunders
Ketchum, B. H., editor. 1972. The water's edge: critical Co., Philadelphia. 544 pp.
problems of the coastal zone. MIT Press, Cambridge, Odum, H. T. 1974. Tropical marine meadows. Pages 442-487
Mass. 393 pp. in H. T. Odum, B. J. Copeland, and E. A. McMahan, eds.
Kologiski, R. L. 1977. The phytosociology of the Green Coastal ecological systems of the United States. Vol. 1. The
Swamp, North Carolina. N. C. Agric. Exp. Stn. Tech. Bull. Conservation Foundation, Washington, D. C.
-250. 101 pp. Odum, H. T., B. J. Copeland, and E. A. McMahan, editors.
K6ppen, W. 1931. Grundriss der Klimakunde. Walter de 1974. Coastal ecological systems of the United States. The
Gruyter & Co., Berlin. 388 pp. Conservation Foundation, Washington, D. C. 4 Vols.
Krecker, F. H., and L. Y. Lancaster. 1933. Bottom shore Penfound, W. T. 1952. Southern swamps and marshes. Bot.
fauna of western Lake Erie: a population study to a depth Rev. 18:413-436.
of six feet. Ecology 14:79-83. Penfound, W. T., and E. S. Hathaway. 1938. Plant com-
munities in the marshlands of southeastern Louisiana.
Kiichler, A. W. 1964. Potential natural vegetation of the con- Ecol. Monogr. 8:1-56.
terminous United States. Am. Geogr. Soc. Spec. Publ. 36. Pennak, R. W. 1978. Fresh-water invertebrates of the United
116 pp. States. 2nd Edition. John Wiley & Sons, New York. 803 pp.
Kuenzler, E. J. 1974. Mangrove swamp systems. Pages 346- Pestrong, R. 1965. The development of drainage patterns on
371 in H. T. Odum, B. J. Copeland, and E. A. McMahan, tidal marshes. Stanford Univ. Publ. Geol. Sci. 10: 1 -87.
eds. Coastal ecological systerns of the United States. Phillips, R. C. 1974. Temperate grass flats. Pages 244-314 in
Vol. 1. The Conservation Foundation, Washington, D. C. H. T. Odum, B. J. Copeland, and E. A. McMahan, eds.

Coastal ecological systems of the United States. Vol. 2. The Stewart, R. E. 1962. Waterfowl populations in the upper
Conservation Foundation, Washington, D. C. Chesapeake Region, U. S. Fish Wildl. Serv., Spec. Sci.
Pollett, F. C., and P. B. Bridgewater. 1973. Phytosociology of Rep.-Wildl. 65.208 pp.
peatlands in central Newfoundland. Can. J. For. Res. Stewart, R. E., and H. A. Kantrud. 1971. Classification of
30:433-442. natural ponds and lakes in the glaciated prairie region.
Price, J. B., and G. Gunter. 1964. Studies of the chemistry of U. S. Fish. Wildl. Serv., Resour. Publ. 92. 57 pp.
fresh and low salinity waters in Mississippi and the bound. Stewart, R. E., and H. A. Kantrud. 1972. Vegetation of
ary between fresh and brackish water. Int. Rev. gesamten prairie potholes, North Dakota, in relation to quality of
Hydrobiol. 49:629-636. water and other environmental factors. U. S. Geol. Surv.
Radford, A. E. 1978. Natural area classification systems: a Prof. Pap. 585-D. 36 pp.
standardized scheme for basic inventory of species, corn- Thorson, G. 1957. Bottom communities. Pages 461-534 in
munity and habitat diversity. Pages 243-279 in J. W. Hedgpeth, ed. Treatise on marine ecology and paleo-
Proceedings of the National Symposium, Classification, ecology. Geol. Soc. Am. Mem. 67. Vol. 1.
Inventory, and Analysis of Fish and Wildlife Habitat. U. S. Ungar, 1. A. 1974. Inland halophytes of the United States.
Fish and Wildlife Service, Washington, D. C. Pages 235-305 in R. J. Reirnold and W. H. Queen, eds.
Radforth, N. W. 1962. Organic terrain and geomorphology. Ecology of halophytes. Academic Press, New York. 605 pp.
Can. Geogr. 6(3-4):166-171. U. S. Department of Interior. 1970. National atlas of the
Ranwell, D. S. 1972. Ecology of salt marshes and sand dunes. United States. U. S. Geological Survey, Washington, D. C.
Chapman and Hall, London. 258 pp. 417 pp.
Redfield, A. C. 1972. Development of a New England salt U. S. National Oceanic and Atmospheric Administration.
marsh. Ecol. Monogr. 42(2):201-237. 1973. Tide tables-high and low predictions 1974: East
Reid, G. K., and R. D. Wood. 1976. Ecology of inland waters coast of North and South America. U. S. Government
and estuaries. D. Van Nostrand and Co., New York. 485 pp. Printing Office, Washington, D. C. 288 pp.
Remane, A., and C. Schlieper. 1971. Biology of brackish U. S. Senate. 1970. The National Estuarine Pollution Study.
water. Wiley Interscience Division, John Wiley & Sons, Report of the Secretary of Interior to the United States
New York. 372 pp. Congress pursuant to Public Law 89-753, The Clean Water
Ricketts, E. F., and J. Calvin. 1968. Between Pacific tides, Restoration Act of 1966. U. S. Senate Doc. No. 91-58. U. S.
4th ed. Revised by J. W. Hedgpeth. Stanford University Government Printing Office, Washington, D. C. 633 pp.
Press, Stanford, California. 614 pp. U. S. Soil Conservation Service, Soil Survey Staff. 1975. Soil
Riedl, R., and E. A. McMahan. 1974. High energy beaches. Taxonomy: a basic system of soil classification for making
Pages 180-251 in H. T. Odum, B. J. Copeland, and E. A. and interpreting soil surveys. U. S. Soil Conservation
McMahan, eds. Coastal ecological systems of the United Service. Agric. Handb. 436. 754 pp.
States. Vol. 1. The Conservation Foundation, Washington, van der Schalie, H. 1948. The land and freshwater mollusks of
D. C. Puerto Rico. Univ. Mich. Mus. Zool. Misc. Publ. 70.134 pp.
Sculthorpe, C. D. 1967. The biology of aquatic vascular Walsh, G. E. 1974. Mangroves: a review. Pages 51-174 in
plants. Edward Arnold Ltd., London. 610 pp. R. J. Reimold, and W. H. Queen, eds. Ecology of halo-
Shaw, S. P., and C. G. Fredine. 1956. Wetlands of the United phytes. Academic Press, Inc., New York.
States. U. S. Fish Wildl. Serv., Circ. 39. 67 pp. Ward, H. B., and G. C. Whipple. 1959. Freshwater biology.
Sj6rs, H. 1950. On the relation between vegetation and John Wiley and Sons, Inc., New York. 1248 pp.
electrolytes. in north Swedish mire waters. Oikos 2:241-258. Ward, J. V. 1975. Bottom fauna-substrate relationships in a
Sj6rs, H. 19b9. Bogs and fens in the Hudson Bay lowlands. J. northern Colorado trout stream: 1945 and 1974. Ecology
Arctic Inst. Am. 12(l):2-19. 56:1429-1434.
Slack, K. V., J. W. Nauman, and L. J. Tilley. 1977. Benthic Weaver, J. E., and F. E. Clements. 1938. Plant ecology, 2nd
invertebrates in an arctic mountain stream, Brooks Range, ed. McGraw-Hill Book Company, Inc., New York. 601 pp.
Alaska. J. Res. U. S. Geol. Surv. 5:519-527. Weber, C. I., editor. 1973. Biological field and laboratory
Smith, R. 1. 1964. Key to marine invertebrates of the Woods methods for measuring the quality of surface waters and
Hole Region. Contribution No. 11 of the Systematic- effluents. U. S. Environmental Protection Agency, Office
Ecology Program, Marine Biological Laboratory, Woods of Research and Development, Environmental Monitoring
Hole, Massachusetts. 208 pp. Series. EPA 670/4-73-001.
Stegman, J. L. 1976. Overview of current wetland classifi- Welch, P. S. 1952. Limnology, 2nd ed. McGraw-Hill, New
cation and inventories in the United States and Canada: York. 538 pp.
U. S. Fish and Wildlife Service. Pages 102-120 in J. H. Wetzel, R. G. 1975. Limnology. W. B. Saunders Co., Phila-
Sather, ed. National wetland classification and inventory delphia. 658 pp.
workshop proceedings- 1975, University of Maryland.
U. S. Fish and Wildlife Service, Washington, D. C. Zhadin, V. I., and S. V. Gerd. 1963. Fauna and flora of the
Stehr, W. C., and J. W. Branson. 1938. An ecological study of rivers, lakes and reservoirs of the U.S.S.R. Oldbourne
. an intermittent stream. Ecology 19(l):294-354. Press, London. 626 pp.
Stephenson, T. A., and A. Stephenson. 1972. Life between Zoltai, S. C., F. C. Pollett, J. K. Jeglum, and G. D. Adams.
tiderriarks on rocky shores. W. H. Freeman and Co., San 1975. Developing a wetland classification for Canada. Proc,
Francisco. 425 pp. N. Am. For. Soils Conf. 4:497-511.

APPENDIX A

Scientific and Common Names
of Plants

Scientific name Common namea Scientific name Common namea
Acer rubrum L. Red maple C rubrum L. (Goosefoot)
Alisma plantago-aquatica L. (Water plantain) Chiloscyphus spp. (Liverworts)
Alnus spp. Alders C. fragilis (Roth) Schiffn. (Liverwort)
Alnus rugosa (Du Roi) Spreng. Speckled alder Cladium jamaicense Crantz Saw grass
Alopecurus aequalis Sobol. Foxtail Cladonia rangiferina (L.)
Andromeda glaucophylla Link Bog rosemary Wigg. Reindeer moss
Aristida stricta Michx. (Three-awn) Cladophora spp. (Green algae)
Ascophyllum spp. Rockweeds C. glomerata Katzing (Green algae)
Ascophyllum nodosum L. (Rockweed) Colocasia esculenta Shott. Taro
Aulacomnium palustre (Hedw.) Conocarpus erectus L. (Mangrove)
Schwaegr. (Moss) Cornus stolonifera Michx. Red ozier dogwood
Avicennia germinans (L.) Cyperus spp, Nut grasses
Stearn Black mangrove Cyrilla racerniflora L. Black ti-ti
Azolla spp. Mosquito ferns Decodon verticillatus (L.) Ell. Water willow
Baccharis halimifolia L. Sea-myrtle Dermatocarpon aquaticurn
Beckmannia syzigachne (Weiss) A. Zahlbruckner (Lichen)
(Steud.) Fern. Slough grass D. fluviatile (G. Web) (Lichen)
Betula pumila L. Bog birch Desmatodon heimii (Moss)
Brasenia schreberi Gmel. Water shield Distichlis spicata (L.) Greene I Salt grass)
Calamagrostis canadensis D. stricta (Torr.) Rydb. (Salt grass)
(Michx.) Beauv. Bluejoint Drepanocladus spp. (MOSS)
Calopogon spp. Grass pinks D. fluitans (Head w.) Warnet. (Moss)
Campylium stellatum (Hedw.) Echinochloa crusgalli (L.)
C. Jens. (Moss) Beauv. Barnyard grass
Carex spp. Sedges Eichhornia crassipes (Mart.)
C aquatilis WhIent. (Sedge) Solms. Water hyacinth
C. atherodes Spreng. Slough sedge Eleocharis acicularis (L.)
C. lacustris Willd. (Sedge) R & S (Spike rush)
C. lasiocarpa Erhr. (Sedge) E. palustris (L.) R & S (Spike rush)
� lyngbyei Hornem. (Sedge) Elodea spp. Water weeds
� rostrata S. J. Stokes Beaked sedge Empetrum nigrum L. Crowberry
Caulerpa spp. (Green algae) Enteromorpha spp. (Green algae)
Cephalanthus occidentalis L. Buttonbush Equisetum fluviatile L. (Horsetail)
Ceratophyllum spp. Coontails Eriophorum spp. Cotton grasses
C. demersum L. (Coontail) Fissidens spp. (MOSS)
Chamaecyparis thyoides (L.) F. adiantoides Hedew. (Moss)
BSP Atlantic white cedar F julianus (Mont.) Schimper (Moss)
Chamaedaphne calyculata (L.) Fontinalis spp. (Moss)
Moench Leatherleaf F. antipyretica L. (Moss)
Chara spp. (Stonew,orts) Fraxinus nigra Marsh. Black ash
C. crispa Wallman (Stonewort) F. pennsylvanica Marsh. (Red ash)
C aspera Detharding ex Fucus spp. (Rockweeds)
Willdenow (Stonewort) Fucus vesiculosus C. L. And. (Rockweed)
Chenopodium glaucum L. (Goosefoot) Glyceria spp. Manna grasses
Gordonia lasianthus (L.) Ell. Loblolly bay
Habenaria spp. (Orchids)
aGeneral common names that refer to a higher taxon and Halimeda spp. (Green algae)
names for which there is little agreement on common name Halodule wrightii Aschus Shoalgrass
are shown in parentheses. Halophila spp. (Sea grass)

Scientific name Common namea Scientific name Common namea

Hippurus vulgaris L. Mare's tail Phragmites communis Trin. Reed
Ilex glabra (L.) Gray Inkberry Phyllospadix scouleri Hook. (Surfgrass)
L verticillata (L.) Gray Winterberry P. torreyi Wats. (Surfgrass)
Iva frutescens L. Marsh elder Picea mariana (Mill.) BSP Black spruce
Juncus spp. Rushes P. sitchensis (Bong.) Carr. Sitka spruce
J. gerardii Loisel. Black grass Joinus contorta Dougl. Lodgepole pine
J militaris Bigel. Bayonet rush P. palustris Mill. Longleaf pine
J roemerianus Scheele Needlerush P. serotina Michx. Pond pine
Kalmia angustifolia L. Sheep laurel Pistia stratiotes L. Water lettuce
K polifolia Wang. Bog laurel Podostemum ceratophyllum
Kochia scoparia (L.) Schrad. Summer cypress Michx. Riverweed
Laguncularia racemosa (L.) Polygonum spp. Smartweeds
Gaertn. f. White mangrove P. amphibium L. Water smartweed
Laminaria spp. (Kelps) P. coccineum Muhl. Marsh smartweed
Larix laricina (Du Roi) K. Pontederia cordata L. Pickerelweed
Koch Tamarack Potamogeton spp. Pondweeds
Laurencia spp. (Red algae) P. epihydrus Raf. Ribbon-leaf pond-
Ledum groenlandicum Oeder Labrador tea weed
Lemna spp. (Duckweeds) P. gramineus L. (Pondweed)
L. minor L. Common duckweed P. natans L. Floating-leaf pond-
Li@ucothoe axillaris (Lam.) weed
D. Don Coastal sweetbells Potentilla spp. Cinquefoils
Lithothamnion spp. Coralline algae Quercus bicolor Willd. Swamp white oak
Lycopodium alopecuroides L. Foxtail clubmoss Q. lyrata Walt. Overcup oak
Lyonia lucida (Lam.) K. Koch Fetterbush Q. michauxii Nutt. Basket oak
Lythrum salicaria L. Purple loosestrife Ranunculus trichophyllus White water
Macrocystis spp. (Kelps) Chaix crowfoot
M. pyrifera (L.) C. A. Ag. (Kelp) Rhizophora mangle L. Red mangrove
Magnolia virginiana L. Sweet bay Rhododendron maximum L. Great laurel
Marsupella spp. (Liverworts) Rhynchospora spp. Beak rushes
M. emarginata (Ehrenberg) Rubus chamaemorus L. Cloudberry
Dumortier (Liverwort) Rumex maritimus L. Golden dock
Myrica gale L. Sweet gale R. mexicanus Meisn. (Dock)
Myriophyllum spp. Water milfoils Ruppia spp. Ditch grasses
M. exalbescens Fern. (Water milfoil) R. maritima L. Widgeon grass
Naias spp. Naiads Sagittaria spp. Arrowheads
Nelumbo lutea (Willd.) Pers. American lotus Salicornia spp. Glassworts
Nitella spp. (Stoneworts) S. europaea L. Samphire
N. flexilis (L.) Agardh. (Stonewort) S. virginica L. (Common pickle-
N. obtusa T. F. Allen (Stonewort) weed)
Nuphar spp. Yellow water lilies Salix spp. Willows
N. luteum (L.) Sibth. & Smith (Yellow water lily) Salvinia rotundifolia Willd. Water fern
N. variegatum Engelm. (Yellow water lily) Sarcobatus vermiculatus
Nymphaea spp. (Water lilies) (Hook.) Torr. Greasewood
N. odorata Ait. (White water lily) Schizothrix spp. (Blue green algae)
Nymphoides spp. Floating hearts Scirpus spp. Bulrushes
N. aquatica (Walt.) 0. Kuntze (Floating heart) S. acutus Muhl. Hardstem bulrush
Nyssa Aquatica L. Tupelo gum S. americanus Pers. Common three-
N. sylvatica Marsh. Black gum square
Oncophorus wahlenbergii Brid. Moss S. olneyi Gray (Bulrush)
Panicum capillare L. Old witch grass S. paludosus Nels. Alkali bulrush
Peltandra virginica (L.) Kunth Arrow arum Scolochloa festucacea (Willd.)
Pelvetia spp. (Rockweed) Link Whitetop
Penicillus spp. (Green algae) Spartina alterniflora Loisel. Saltmarsh cordgrass
Persea borbonia (L.) Spreng. Red bay S. cynosuroides (L.) Roth Big cordgrass

Scientific name Common namea Scientific name Common name,

S. foliosa Trin. California cordgrass Ova sp. Sea lettuce
S. patens (Ait.) Muhl. Saltmeadow cord- U.1actuca L. (Sea lettuce)
grass Utricularia spp. Bladderworts
Sphagnum spp. Peat mosses U. vulgaris L. (Bladderwort)
S. fuscum (Schimp.) Klinggr. (Peat moss) Vaccinium atrococcum (Gray) Black highbush
Spiraea douglasii Hook. Spiraea Hell. blueberry
Spirodela spp. Big duckweeds V corymbosum L. Highbush blueberry
S. polyrhiza (L.) Schleid. (Big duckweed) Vallisneria spp. Wild celeries
Suaeda californica Wats. (Sea blite) V americana Michx. Wild celery
Syringodium filiformis Kuetz Manatee grass Verrucaria spp. (Lichens)
Tamarix gallica L. Tamarisk Wolffiella spp. Watermeals
Taxodium ascendens Brogn. Pond cypress Woodwardia virginica (L.)
T distichum (L.) Rich. Bald cypress Smith Virginia chain-fern
Thalassia testudinum Koenig Turtle grass Xanthium strumarium L. (Cocklebur)
Thuja occidentalis L. Northern white Xyris spp- Yellow-eyed grasses
cedar X. congdoni Small (Yellow-eyed grass)
Tolypella spp. (Stoneworts)
Trapa natans L, Water nut Zanichellia spp. Horned pondweeds
Triglochin maritima L. Arrow grass Zenobia pulverulenta (Bartr.)
Typha spp. Cattails Pollard Honeycup
T angustifolia L. Narrow-leaved Zizania aquatica L. Wild rice
cattail Zizaniopsis miliacea (Michx.)
T latifolia L. Common cattail Doell & Ascherson Southern wild rice
Ulmus americana L. American elm Zostera marina L. Eelgrass

APPENDIX B

Scientific and Common Names
of Animals

Scientific name Common naMea Scientific name Common namea
Acmaea spp. Limpets Elliptio spp. Freshwater mollusks
A. testudinalis Mull. Plate limpet E. arctata (Conrad) Freshwater mollusk
Acropora spp. Staghorn corals E. complanata (Lightfoot) Freshwater mollusk
Agrenia spp. Springtails E. dariensis (Lea) Freshwater mollusk
Amphipholis spp. Brittle stars Emerita spp. Mole crabs
A. squamata (Delle Chiaje) Brittle star Ephemerella spp. Mayflies
Amphitrite spp. Terebellid worms E. deficiens Morg. Mayfly
Ancylus spp. Freshwater mollusks Erpobdella spp. Leeches
Anodonta spp. Freshwater mollusks E. punctata Leidy Leech
A. cataracta Say Freshwater mollusk Eukiefferiella spp. Midges
A. implicata Say Freshwater mollusk Eunapius spp. Freshwater sponges
Anodontoides spp. Freshwater mollusks E. fragilis (Leidy) Freshwater sponge
A. ferussacianus (Lea) Freshwater mollusk Euzonus spp. Blood worms
Anopheles spp. Mosquitos Gammarus spp. Scuds
Aplexa spp. Pouch snails Gelastocoris spp. Toad bugs
A. hypnorum (L.) Pouch snail G. oculatus Fabr. Toad bug
Arenicola spp, Lugworms Helobdella spp. Leeches
Asellus spp. Isopods H. stagnalis L. Brook leech
Baetis spp. Mayflies Heteromeyenia spp. Horse sponges
Balanus spp. Acorn barnacles H. latitenta (Potts) Horse sponge
B. balanoides L. Acorn barnacle Hippospongia spp. Encrusting sponges
Bryocamptus spp. Harpacticoid cope- H. gossypina (Duch. and
pods Mich.) Encrusting sponge
Caenis spp. Mayflies Homarus americanus
Callianassa spp. Ghost shrimp Milne-Edwards American lobster
C californiensis Dana Red ghost shrimp Hydropsyche spp. Caddisflies
Cambarus spp. Crayfishes H. simulans Ross Caddisfly
Fallicambarus fodiens (Cottle) Crayfish Lampsilis spp. Freshwater mollusks
Canthocamptus spp. Harpacticoid cope- L. ovata (Say) Freshwater mollusk
pods Ligia spp. Slaters
C. robertcokeri M. S. Wilson Harpacticoid cope- Limnodrilus spp. Oligochaete worms
pod L. hoffineisteri Clap. Oligochaete, worm
Cerianthus spp. Sea anemones Littorina spp. Periwinkles
Chaetopterus spp. Polychaete wornis Lumbriculus spp. Oligochaete, worms
Chironomus spp. Midges Lymnaea spp. Pond snails
Chironomidae Midges L. cubensis Pfieffer Pond snail
Chthamalus spp. Acorn barnacles L. palustris (C. F. Miller) Pond snail
C. fragilis Darwin Acorn barnacle L. stagnalis L. Pond snail
Cnemidocarpa spp. Tunicates Macoma spp. Macomas
C. finmarkiensis (Kiaer) Tunicate M. balthica (Linne) Baltic macoma
Crassostrea spp. Oysters Melita spp. Amphipods
C. virginica (Geml.) Eastern oyster Mercenaria spp. Quahogs
Dendraster spp. Sand dollars M. mercenaria (L.) Quahog
D. excentricus (Eschscholtz) Sand dollar Modiolus spp. Mussels
Diamesa spp. Midges M_ demissus (Dill) Ribbed mussel
Donax spp. Wedge shells Montipora spp. Corals
Echinocardium spp. Heart urchins Muricea spp. Sea whips
M. californica Aurivillius Sea whip
amost common names refer only to general groupings. Mya spp. Soft-shell clams

Scientific name Common namea Scientific name Common naMea
M. arenaria (L.) Soft-shell clam Porites spp. Corals
Mytilus spp. Mussels P. porites (Pallas) Coral
M. californianus Conrad California mussel Pristina spp. Oligochaete worms
M. edulis Linne Blue mussel Procambarus spp. Crayfish
Nassarius spp. Mud snails P. simulans (Faxon) Crayfish
N. obsoletus (Say) Mud snail Psephenus spp. Riffle beetles
Nemoura spp. Stone flies P. herricki (DeKay) Water penny
Nereis spp. Clam worms Renilla spp. Sea pansies
N. succinea (Frey and Sabellaria spp. Reef worms
Leuckart) Clam worm S. cementarium Moore Reef worm
Nerita spp. Nerites S. floridensis Hartman Reef worm
Notonecta spp. Back swimmers Saldula spp. Shore bugs
N. lunata Hung Back swimmer Saxidomus spp. Venus clams
Oliva spp. Olive shells S. giganteus (Deshayes) Smooth Washington
Orchestia spp. Beach hoppers clam
Ostrea spp. Oysters
Parastenocaris spp. Copepods Simulium spp. Black flies
Patella spp. Limpets Siphonaria spp. False limpets
Pecten spp. Scallops Sphaerium spp. Fingernail clams
Petricola pholadiformis Lam, False angel wing S. simile Say Fingernail clam
Phyllognathopus viguieri Spongilla spp. Freshwater sponges
Maryek Copepods S. lacustris (L.) Freshwater sponge
Physa spp. Snails Strongylocentrotus spp. Sea urchins
P. gyrina Say Tadpole snail Tabanus spp. Flies
Pisaster spp. Sea stars Tellina spp. Tellin shells
Pisidium spp. Fingernail ' clams T. lutea Wood Great Alaskan tellin
P. abditum Holdeman Fingernail clam Tetraclita spp. Acorn barnacles
P. casertanum (Poli) Fingernail clam Thais spp. Rock shells
P. ferrugineum Prime Fingernail clam Thyone spp. Sea cucumbers
Placopecten spp. Deep-sea scallops Tivela stultorum (Mawe) Pismo clam
P. magellanicus (Gmelin) Atlantic deep-sea Tortopus spp. Mayflies
scallop Tubifex spp. Sewage worms
Platyodon spp. Boring clams T. tubifex (O.F.M.) Sewage worm
P. cancellatus (Conrad) Boring clam Uca spp. Fiddler crabs
Pollicipes spp. Gooseneck barnacles U. pugnax (Smith) Fiddler crab
P. polymerus Sowerby Gooseneck barnacle Urechis spp. Echiurid worms

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 pre- however, individual trees or shrubs may shed their leaves
dominantly of unconsolidated sand, gravel, stones, cobbles, jMueller-Dombois and Ellenberg 1974).
or rubble and 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.
generated by waves and currents and extending from the This is equivalent to extreme higher high water of mixed
water to a distinct break in landform or substrate type semidiurnal tides.
(e.g., a foredune, 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.
ity. The term should not be applied to inland waters (see This is equivalent to extreme lower low water of mixed
page 25). semidiurnal tides.
boulder Rock fragments larger than 60.4 cm (24 inches) in flat A level landform composed of unconsolidated sedi-
diameter. ments-usually mud or sand. Flats may be irregularly
broad-leaved deciduous Woody angiosperms (trees or shrubs) shaped or elongate and continuous with the shore, whereas
with relatively wide, flat leaves that are shed during the bars are generally elongate, parallel to the shore, and sepa-
cold or dry season; e.g., black ash (Fraxinus nigra). rated from 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 JLemnaminor).
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 lily (Nymphaea odorata), floating-leaved pondweed (Pota-
in sufficient quantities to effervesce carbon dioxide visibly mogeton natans). Plants such as yellow water lily JNuphar
when treated with cold 0.1 normal hydrochloric acid. Cal- luteum@ which sometimes have leaves raised above the
careous sands are usually formed of a mixture of fragments surface are considered floating-leaved plants or emergents,
of mollusk shell, echinoderm spines and skeletal material, depending on their growth habit at a particular site.
coral, foraminifera, and algal platelets (e.g., Halimeda). floodplain "a flat expanse of land bordering an old river. .
channel "An open conduit either naturally or artificially (see Reid and Wood 1976:72, 84).
created which periodically or continuously contains moving fresh Term applied to water with salinity less than 0.5 I/oo
water, or which forms a connecting link between two bodies dissolved salts.
of standing water" (Langbein and Iseri 1960:5). gravel A mixture composed primarily of rock fragments
channel bank The sloping land bordering a channel. The bank 2 mm (0.08 inch) to 7.6 cm. (3 inches@ in diameter. Usually
contains much sand.
has steeper slope than the bottom of the channel and is growing season The frost-free period of the year (see U. S.
usually steeper than the land surrounding t .hechannel. Department of Interior, National Atlas 1970:110-111 for
circumneutral Term applied to water with a pH of 5.5 to 7.4. generalized regional delineation).
codominant Two or more species providing about equal areal haline Term used to indicate dominance of ocean salt.
cover which in combination control the environment. herbaceous With the characteristics of an herb; a plant with
cobbles Rock fragments 7.6 cm J3 inches) to 25.4 cm (10 in- no persistent woody stem above ground.
ches) in diameter. histosols Organic soils (see Appendix D).
deciduous stand A plant community where deciduous trees or hydric soil Soil that is wet long enough to periodically
shrubs represent more than 50% of the total areal coverage produce anaerobic conditions, thereby influencing the
of trees or shrubs. growth of plants.
dominant The species controlling the environment. hydrophyte Any plant growing in water or on a substrate
dormant season That portion of the year when frosts occur that is at least periodically deficient in oxygen as a result of
(see U. S. Department of Interior, National Atlas 1970-110- excessive water content (plants typically found in wet
I I I for generalized regional delineation). habitats@.
emergent hydrophytes Erect, rooted, herbaceous angio- hyperhaline Term to characterize waters with salinity greater
sperms that may be temporarily to permanently flooded at than 40 I/oo, due to ocean-derived salts.
the base but do not tolerate prolonged inundation of the hypersaline Term to characterize waters with salinity greater
entire plant; e.g., bulrushes (Scirpus spp.), saltmarsh than 40 I/oo, due to land-derived salts.
cordgrass. macrophytic: algae Algal plants large enough either as indi-
emergent mosses Mosses occurring in wetlands, but gen- viduals or communities to be readily visible without the aid
erally not covered by water. of optical magnification.
eutrophic lake Lakes that have a high concentration of plant mean high water The average height of the high water over
nutrients such as nitrogen and phosphorus. 19 years.

mean higher high tide The average height of the higher of two respiration. This level (the compensation level) usually
unequal daily high tides over 19 years. occurs at the depth of 1% light penetration and forms the
mean low water The average height of the low water over 19 lower boundary of the zone of net metabolic production.
years. pioneer plants Herbaceous annual and seedling perennial
mean lower low water The average height of the lower of two plants that colonize bare areas as a first stage in secondary
unequal daily low tides over 19 years. succession.
mean tide level A plane midway between mean high water polyhatine Term to characterize water with salinity of 18 to
and mean low water. 30 '/oo, due to ocean salts.
mesohaline Term to characterize waters with salinity of 5 to polysaline Term to characterize water with salinity of 18 to
18 '/oo, due to ocean-derived salts. 30 '/oo, due to land-derived salts.
mesophyte Any plant growing where moisture and aeration
conditions lie between extremes. (Plants typically found in saline General term for waters containing various dissolved
habitats with average moisture conditions, not usually dry salts. We restrict the term to inland waters where the
or wet.) ratios of the salts often vary; the term haline is applied to
mesosaline Term to characterize waters with salinity of 5 to coastal waters where the salts are roughly in the same
18 'too, due to land-derived salts. proportion as found in undiluted sea water (see page 25).
mineral soil Soil composed of predominantly mineral rather salinity The total amount of solid material in grams con-
than organic materials (see page 44). tained in I kg of water when all the carbonate has been
mixohaline Term to characterize water with salinity of 0.5 to converted to oxide, the bromine and iodine replaced by
30 010o, due to ocean salts. The term is roughly equivalent to chlorine, and all the organic matter completely oxidized.
the term brackish. sand Composed predominantly of coarse-grained mineral
mixosaline Term to characterize waters with salinity of 0.5 to sediments with diameters larger than 0.074 mm (Black
30 O/oo, due to land-derived salts. 1968) and smaller than 2 mm (Liu 1970; Weber 1973).
mud Wet soft earth composed predominantly of clay and shrub A woody plant which at maturity is usually less than
silt-fine mineral sediments less than 0.074 mm in diam- 6 m (20 feet) tall and generally exhibits several erect,
eter (Black 1968; Liu 1970). spreading, or prostrate stems and has a bushy appearance;
needle-leaved deciduous Woody gymnosperms (trees or e.g., speckled alder (Alnus rugosa) or buttonbush (Cepha-
shrubs) with needle-shaped or scale-like leaves that are lanthus occidentalis).
shed during the cold or dry season; e.g., bald cypress (Taxo- sound A body of water that is usually broad, elongate, and
dium distichum). parallel to the shore between the mainland and one or more
needle-leaved evergreen Woody gymnosperms with green, islands.
needle-shaped, or scale-like leaves that are retained by spring tide The highest high and lowest low tides during the
plants throughout the year; e.g., black spruce (Picea lunar month.
mwiana). stone Rock fragments larger than 25.4 cm (10 inches) but less
nonpersistent emergents Emergent hydrophytes whose than 60.9 cm (24 inches).
leaves and stems break down at the end of the growing submergent plant A vascular or nonvascular hydrophyte,
season so that most above-ground portions of the plants either rooted or nonrooted which lies entirely beneath the
are easily transported by currents, waves, or ice. The water surface, except for flowering parts in some species;
breakdown may result from normal decay or the physical e.g., wild celery JVallisneria americana) or the stoneworts
force of strong waves or ice. At certain seasons of the year (Chara spp.).
there are no visible traces of the plants above the surface of terrigenous Derived from or originating on the land (usually
the water; e.g., wild rice (Zizania aquatica), arrow arurri referring to sediments) as opposed to material or sediments
JPeltandra virginica). produced in the ocean (marine) or as a result of biologic
obligate hydrophytes Species that are found only in activity (biogenous).
wetlands-e.g., cattail (Typha latifolia) as opposed to ubiq- tree A woody plant which at maturity is usually 6 m (20 feet)
uitous species that grow either in wetland or on upland- or more in height and generally has a single trunk, un-
e.g., red maple 0 cer rubrum). branched to about I m above the ground, and a more or less
oligohaline Term to characterize water with salinity of 0.5 to definite crown; e.g., red maple (Acer rubrum), northern
5.0 'too, due to ocean-derived salts. white cedar (Thuja occidentalis).
oligosaline Term to characterize water with salinity of 0.5 to water table The upper surface of a zone of saturation. No
5.0 'too, due to land-derived salts. water table exists where that surface is formed by an
organic soil Soil composed of predominantly organic rather impermeable body (Langbein and Iseri 1960:21).
than mineral material. Equivalent to Histosol (see page 44). woody plant A seed plant (gymnosperm or angiosperm) that
persistent emergent Emergent hydrophytes that normally develops persistent, hard, fibrous tissues, basically xylem;
remain standing at least until the beginning of the next e.g., trees and shrubs.
growing season; e.g., cattails (Typha spp.) or bulrushes xerophyte, xerophytic Any plant growing in a habitat in
(Scirpus SPP.). which an appreciable portion of the rooting medium dries
photic zone The upper water layer down to the depth of effec- to the wilting coefficiept at frequent intervals. (Plants
tive light penetration where photosynthesis balances typically found in very dry habitats.)

APPENDIX D

Criteria for Distinguishing Organic
Soils from Mineral Soils

The criteria for distinguishing organic soils from of the materials. A thick layer of sphagnum has a very
mineral soils in the United States (U. S. Soil Conser- low bulk density and contains less organic matter than a
vation Service, Soil Survey Staff 1975:13-14, 65) are thinner layer of well-decomposed muck. It is much easier
quoted here so that those without ready access to a to measure thickness of layers in the field than it is to
copy of the Soil Taxonomy may employ this infor- determine tons of organic matter per hectare. The defi-
mation in the classification of wetlands: nition of a mineral soil, therefore, is based on thickness
of the horizons or layers, but the limits of thickness
For purposes of taxonomy, it is necessary, first, to must vary with the kinds of materials. The definition
define the limits that distinguish mineral soil material that follows is intended to classify as mineral soils those
from organic soil material and, second, to define the that have no more organic material than the amount per-
minimum part of a soil that should be mineral if the soil mitted in the histic epipedon, which is defined later in
is to be classified as a mineral soil, this chapter.
Nearly all soils contain more than traces of both To determine whether a soil is organic or mineral, the
mineral and organic components in some horizons, but thickness of horizons is measured from the surface of the
most soils are dominantly one or the other. The horizons soil whether that is the surface of a mineral or an organic
that are less than about 20 to 35 percent organic matter horizon, Thus, any 0 horizon at the surface is considered
by weight have properties that are more nearly those of an organic horizon, if it meets the requirements of
mineral than of organic soils. Even with this separation, organic soil material as defined later, and its thickness is
the volume of organic matter at the upper limit exceeds added to that of any other organic horizons to determine
that of the mineral material in the fine-earth fraction. the total thickness of organic soil materials.

MINERAL SOIL MATERIAL DEFINITION OF MINERAL SOILS
Mineral soil material either Mineral soils, in this taxonomy, are soils that meet one
1. Is never saturated with water for more than a few of the following requirements:
days and has < 20 percent organic carbon by weight; or 1. Mineral soil material < 2 rum in diameter (the fine-
2. Is saturated with water for long periods or has been earth fraction) makes up more than half the thickness of
artificially drained, and has the upper 80 cm (31 in.);
a. Less than 18 percent organic carbon by weight if 60 2. The depth to bedrock is < 40 cm and the layer or
percent or more of the mineral fraction is clay; layers of mineral soil directly above the rock either are
b. Less than 12 percent organic carbon by weight if 10 cm, or more thick or have half or more of the thickness
the mineral fraction has no clay; or of the overlying organic soil material; or
c. A proportional content of organic carbon between 3. The depth to bedrock is @@ 40 cm, the mineral soil
12 and 18 percent if the clay content of the mineral material immediately above the bedrock is 10 cm or
fraction is between zero and 60 percent. more thick, and either
Soil material that has more organic carbon than the a. Organic soil material of < 40 cm thick and is
amounts just given is considered to be organic material. decomposed (consisting of hemic or sapric materials as
defined later) or has a bulk density of 0.1 or more; or
DISTINCTION BETWEEN MINERAL SOILS AND b. Organic soil material is < 60 em thick and either is
ORGANIC SOILS undecomposed sphagnum or moss fibers or has a bulk
Most soils are dominantly mineral material, but many density that is < 0. 1.
mineral soils have horizons of organic material. For sim-
plicity in writing definitions of taxa, a distinction be- ORGANIC SOIL MATERIALS
tween what is meant by a mineral soil and an organic soil Organic soil materials and organic soils
is useful. In a mineral soil, the depth of each horizon is 1. Are saturated with water for long periods or are arti-
measured from the top of the first horizon of mineral ficially drained and, excluding live roots, (a) have 18
material. In an organic soil, the depth of each horizon is percent or more organic carbon if the mineral fraction is
measured from the base of the aerial parts of the 60 percent or more clay, (b) have 12 percent or more
growing plants or, if there is no continuous plant cover organic carbon if the mineral fraction has no clay, or (c)
from the surface of the layer of organic materials. To have a proportional content of organic carbon between
apply the definitions of many taxa, therefore, one must 12 and 18 percent if the clay content of the mineral frac-
first decide whether the soil is mineral or organic. tion is between zero and 60 percent; or
If a soil has both organic and mineral horizons, the 2. Are never saturated with water for more than a few
relative thickness of the organic and the mineral soil days and have 20 percent or more organic carbon.
materials must be considered. At some point one must Item 1 in this definition covers materials that have been
decide that the mineral horizons are more important. called peats and mucks. Item 2 is intended to include
This point is arbitrary and depends in part on the nature what has been called litter or 0 horizons. Not all organic

soil materials accumulate in or under water. Leaf litter < 0.1 g per cubic centimeter (6.25 lbs per cubic foot);
may rest on a lithic contact and support a forest. The (2) 40 cm or more if
only soil in this situation is organic in the sense that the Ja) The organic soil material is saturated with
mineral fraction is appreciably less than half the weight water for long periods (> 6 months) or is arti-
and is only a small percentage of the volume of the soil. ficially drained; and
(b) The organic material consists of sapric or
DEFINITION OF ORGANIC SOILS hemic materials or consists of fibric materials that
Organic soils (Histosols) are soils that are less than three-fourths moss fibers by volume
1. Have organic soil materials that extend from the and have a moist bulk density of 0. 1 or more; and
surface to one of the following: b. Have organic soil materials that
a. A depth within 10 cm. or less of a lithic or paralithic (1) Do not have a mineral layer as much as 40 cm
contact, provided the thickness of the organic soil thick either at the surface or whose upper boundary
materials is more than twice that of the mineral soil is within a depth of 40 cm from the surface; and
above the contact; or (2) Do not have mineral layers, taken cumulatively,
b. Any depth if the organic soil material rests on frag- as thick as 40 cm within the upper 80 cm.
mental material (gravel, stones, cobbles) and the inter- It is a general rule that a soil is classed as an organic
stices are filled with organic materials, or rests on a soil (Histosol) either if more than half of the upper
lithic or paralithic contact; or 80 cm (32 in.) [sic] of soil is organic or if organic soil
2. Have organic materials that have an upper boundary material of any thickness rests on rock or on frag-
within 40 cm of the surface and mental material having interstices filled with organic
a. Have one of the following thicknesses: materials.
(1) 60 cm or more if three-fourths or more of the Soils that do not satisfy the criteria for classification
volume is moss fibers or the moist bulk density is as organic soils are mineral soils.

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 0.5 '/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 oceanic tides, or if influenced by oceanic tides, salinity less than 0.51/o..
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 percent of substrate but non-
persistent 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 in (6.6 feet) or more ...................................................... LACUSTRINE
7. No wave-formed or bedrock shoreline feature present and water less than 2 in deep ... PALUSTRINE

Key to the Classes

1. During the growing season of most years, areal cover by vegetation is less than 30%.
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 and Marine Systems) .......... 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 ... ............................................................ ROCKYSHORE
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. 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)

7. Vegetation composed of algae, bryophytes, lichens, or vascular plants that are usually hydrophytic
perennials.
9. Vegetation composed predominantly of nonvascular species.
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. Vegetation herbaceous
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 ..................................... rORESTED WETLAND

'4- 4.

Plate 1. -Classification: SYSTEM Marine, SUBSYSTEM Subtidal, CLASS Rock Bottom, SUBCLASS Bedrock, WATER REGIME Subtidal,
WATER CHEMISTRY Euhaline. (Monroe County, Florida; Date unknown; Photo courtesy of Florida Department of Natural
Resources)

CAI
j
J,
*L

100,
@V"

ilk

e,
4
4W
- I

"It'll

Plate 2. -Classification: SYSTEM Marine, SUBSYSTEM Subtidal, CLASS Reef, SUBCLASS Coral, WATER REGIME Subtidal, WATER
CHEMISTRY Euhaline. This is an underwater photograph showing corals (Acropora and Porites) as well as alcyonarians.
(Monroe County, Florida; Date unknown; Photo courtesy of Florida Department of Natural Resources)

-Z
-C.

.7-

i J

Plate 3. -Classification: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS Rocky Shore and Aquatic Bed, WATER REGIME Regularly
Flooded and Irregularly Flooded, WATER CHEMISTRY Euhaline. In this photo taken at low tide, the dominant organisms are
rockweed @F@cus spp.) and acorn barnacles (Balanus spp.). (Newport County, Rhode Island; July 1977)

Aw
-7-

.n
W'l

4X
7'1

@Z- @-4't
ZAK,

Plate 4-Classification: SYSTEM Marine, SUBSYSTEM Intertidal, CLASS Rocky Shore and Aquatic Bed, SUBCLASS Rubble and
Algal, WATER REGIME Regularly Flooded, WATER CHEMISTRY Euhaline. The dominant organisms are rockweed (Fucus spp.)
and acorn barnacles (Balanus spp.). Most stones are larger than 30.5 cm (12 in.) in diameter. (Washington County, Rhode
Island; July 1977)

or
-V

r
*40 TM
'A
x

Plate 5. -Classification: SYSTEM Marine, SUBSYSTEM intertidal, CLASS Unconsolidated Shore, WATER REGIME Regularly Flooded
and Irregularly Flooded, WATER CHEMISTRY Euhaline. Estuarine system wetland is shown at left of the beach. (Tillamook
County, Oregon; August 1977; Photo courtesy of P. B. Reed)

-@o

7;@t@ _,77
AF,

Plate 6.-Classificdtion: SYSTEM Estuarine, SUBSYSTEM Subtidal, CLASS Unconsolidated Bottom, SUBCLASS Sand, WATER REGIME
Subtidal, WATER CHEMISTRY Mixohahne. An irregularly flooded persistent-emergent wetland dominated by @saltmarsh
cordgrass (Spartina alterniflora@ and saltmeadow grass (Spartina patens) is shown in the right background. (Washington
County, Rhode Island; July 1977)

4'@ - -!!t
p 11, @d!
I jT i

Y'
j!1 j@ 'y@ ';!@'
1, 'p I " , , J:
''x

44-RA R-@ m

law

N'
lip

Plate 7. -Classification: SYSTEM Estuarine, SUBSYSTEM Subtidal, CLASS Aquatic Bed, SUBCLASS Submergent Vascular, WATER
REGIME Subtidal, WATER CHEMISTRY Oligohaline, SOIL Mineral. The dominant plant is water milfoil (Myriophyllum exal-
bescens) and the most common subordinates are pondweeds (Potamogeton spp.@. (Nansemond County, Virginia; July 1973)

';4

V-

4'
j_'

141

Plate 8. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Reef, SUBCLASS Mollusk, WATER REGIME Regularly
Flooded, WATER CHEMISTRY Mixohaline. The dominant animals are oysters (Crassostrea spp.). An individual red mangrove
(Rhizophora mangle) has become established on the reef. (Collier County, Florida; January 1978)

Plate 9. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Rocky Shore and Aquatic Bed, SUBCLASS Rubble and
Algal, WATER REGIME Regularly Flooded and Irregularly Flooded, WATER CHEMISTRY Euhaline, SPECIAL MODIFIER Artificial.
The dominant organisms shown are rockweed (Fucus spp.) and acorn barnacle (Balanus spp.). (Washington County, Rhode
Island; July 1977)

_45; 77

7 -ate.;

4@' 'Z

AMN Em

Plate 10. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIME
Regularly Flooded, WATER CHEMISTRY Polyhaline, SOIL Mineral. The dominant animal is the eastern oyster (Crassostrea
virginica). An emergent wetland dominated by saltmarsh cordgrass (Spartina alterniflora) is shown in the background.
(Accomac County, Virginia; June 1972)

4",
r 7777
@NO W@O-",
7
-*12 W-"7@7w*-

71
R

-V

Alk

_q,
'Iasi&

Plate ll.-Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Unconsolidated Shore and Streambed, SUBCLASS
Mud, WATER REMME Regularly Flooded, WATER CHEMISTRY Mixohaline. (Anchorage County, Alaska; July 1977)

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Plate 12. -Classification: SYSTEm Estuarine, suBsysTEm Intertidal, CLASS Scrub-Shrub, SUBCLASS Broad-leaved Evergreen,
WATER RFGimE Regula@ly Flooded and lrregular@y Flooded, WATER CHEMISTRY Oligobalifie, SOIL Organic. The dominant plant
is red mangrove (Rhizophora @nangle). This wetland i's'par@ 'of the FloHda Everglades. (Dade'County, Florida; December
1975)

Plate 13. -Classification: SYSTEM Estuarine, SUBSYSTEM Inteitidal, CLASS Scrub-Shrub Wetland, SUBCLASS Broad-leaved
Deciduous, WATER REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. The dominant plant is marsh
elder (Iva frutescens). Subordinate species are black grass (Juncus gerardii), salt grass (Distichlis spicata), and saltmeadow
cordgrass (Spartina pateO. This wetland lies toward the landward edge of an estuarine irregularly flooded persistent-
emergent wetland dominated by Spartina alterniflora, Spartina patens, and Distichlis spicata visible at the left and in the
background. (Washington County, Rhode Island; July 1977)

...........

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Plate 14. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, WATER
REGIME Regularly Flooded, WATER CHEMISTRY MiXohaline, SOIL Mineral. The dominant plant is California cordgrass
(Spartina foliosa@. The most common subordinate is glasswort (Salicornia spp.). This wetland borders an irregularly flooded
emergent wetland dominated by Salicornia spp. (San Mateo County, California; August 1976)

A)a"111

Plate 15. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, WATER
REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Dominant plants are reed (Phragmites cornrnunis@
and saltmeadow cordgrass (Spartina patens). Saltmarsh cordgrass (Spartina alterniflora) is a subordinate species.
(Washington County, Rhode Island; July 1977)

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Plate 16. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, WATER
REGIME Irregularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Organic. The dominant plant is bulrush (Scirpus olneyi).
Subordinate species are saltmeadow cordgrass (Spartina patens) and saltmarsh cordgrass (Spartina alterniflora) which
appear as a fringe at the water's edge. (Dorchester County, Maryland; June 1974)

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Plate 17. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, WATER
REGIME Regularly Flooded, WATER CHEMISTRY Mixohaline, SOIL Organic. The dominant plant is the sedge Carex lyngbyei.
The photo was taken at low tide. (Coos County, Oregon; May 1977)

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Plate 18. -Classification: SYSTEM Estuarine, SUBSYSTEM Intertidal, CLASS Emergent Wetland, SUBCLASS Persistent, WATER
REGIME Irregularly Flooded, WATER CHEMISTRY Mixohahne. Dominant plants are sedges (Carex lyngbyei and C aquatilis).
Subordinate plants are bulrush (Scirpus spp.@, mare's tail (Hippurus vulgaris), cinquefoils (Potentilla spp.), and bluejoint
(Calamagrostis canadensis). (Anchorage County, Alaska; July 1977@

------ -- - - - -

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Plate 19. -Classification: SYSTEM Riverine, SUBSYSTEM Tidal, CLASS Unconsolidated Shore, and Emergent Wetland, SUBCLASS
Mud and Nonpersistent, WATER REGIME Regularly Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral. The
emergent wetland on the right is dominated by arrow arum (Peltandra virginica). (Cecil County, Maryland; July 1972)

Plate 20.-Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Aquatic Bed, SUBCLASS Vascular, WATER
REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Organic, SPECIAL MODIFIER Excavated. The
dominant plant is the white water lily Nymphaea odorata. 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)

Plate 21. -Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Emergent Wetland, SUBCLASS Nonpersistent,
WATER REGIME Semipermanently Flooded, WATER CHEMISTR-i Fresh-Circumneutral, SOIL Mineral. Dominant plants are
arrow arum (Peltandra virginica) and pickerelweed (Pontederia cordata). (Hampden County, Massachusetts; July 1970)

"-1111111111"I", ...... ..... .

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Plate 22. -Classification: SYSTEM Riverine, SUBSYSTEM Lower Perennial, CLASS Unconsolidated Shore, SUBCLASS Sand, WATER
REGIME Seasonally Flooded, WATER CHEMISTRY Mixohaline, SOIL Mineral. Young tamarisk (Tamarix gallica) plants are
scattered over the flat area. (Socorro County, New Mexico; April 1978; Photo courtesy of P. B. Reed)

N'
14

27" "i

Plate 23. -Classification: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Rock Bottom, SUBCLASS Bedrock, WATER
REGIME Permanently Flooded, WATER CHEMISTRY Fresh. (Penobscot County, Maine; October 1977; Photo courtesy of R. W.
Tiner)

Ar-_
4-'T. lqy

Plate 24. -Classification: SYSTEM Riverine, SUBSYSTEM Upper Perennial, CLASS Unconsolidated Bottom, SUBCLASS Cob-
ble-GraveI, WATER REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral. (Washington County, Rhode
Island; July 1977)

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Plate 25. -Classification: SYSTEM Riverine, SUBSYSTEM Intermittent, CLASS Streambed, SUBCLASS Sand, WATER REGIME In-
termittently Flooded, WATER CHEMISTRY Mixosaline. This stream flows at 4,200 M3/S (150,000 cfs) each year. (Socorro
County, New Mexico; April 1978@

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Plate 26. -Classification: SYSTEM Lacustrine, SUBSYSTEM Limnetic, CLASS Aquatic Bed, SUBCLASS Vascular, WATER REGIME
Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral. The dominant plant is white water lily (Nymphaea odorata).
Subordinate species are bladderworts (Utricularia spp.). (Washington County, Rhode Island; July 1977)

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Plate 27. -Classification: SYSTEM Lacustrine, SUBSYSTEM Limnetic and Littoral, CLASS Unconsolidated Bottom and Un-
consolidated Shore, SUBCLASS Mud, WATER REGIME Permanently Flooded and Semipermanently Flooded, WATER CHEMISTRY
Fresh, SPECIAL MODIFIER Impounded. The photo shows Foster reservoir at full pool. The semipermanently flooded area is
inundated in this photograph but would be drawn down from October through March. (Linn County, Oregon; July 1975;
Photo courtesy of U. S. Corps of Engineers)

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Plate 28. -Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIME
Seasonally Flooded, WATER CHEMISTRY Hypersaline, SOIL Mineral. (Salt Lake County, Utah; June 1973)

MIn
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444'

Plate 29-Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Emergent Wetland, SUBCLASS Nonpersistent, WATER
REGIME; Sernipermanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral. The dominant plant is bayonet
rush Wuncus militaris). The subordinate species are common threesquare (Scirpus americanus) and pickerelweed (Pontederia
cordata). The photo shows a gravel beach on the landward edge of the wetland. (Washington County, Rhode Island; July
1977)

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211

Plate 30. -Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Emergent Wetland, SUBSYSTEM Nonpersistent, WATER
REGIME Permanently Flooded, WATER CHEMISTRY Fresh, SOIL Unknown. The dominant plant is pickerelweed (Pontedvia
cordata). (Washington County, Maine; June 1978; Photo courtesy of P. B. Reed)

--------------------

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Plate 31. -Classification: SYSTEM Lacustrine, SUBSYSTEM Littoral, CLASS Emergent Wetland, SUBCLASS Nonpersistent, WATER
REGIME Permanently Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral, SPECIAL MODIFIER Impounded. The
dominant plant is American lotus (Nelumbo lutea). Subordinate plants are duckweeds (Lemna spp.) and bald cypress
(Taxodium distichum). (Obion County, Tennessee; September 1975)

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Plate 32. -Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Permanently
Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Mineral, SPECIAL MODIFIER Impounded. This beaver pond is situated
in the San Juan Mountains. (Gunnison County, Colorado; Date unknown; Photo courtesy of R. M. Hopper)
AM

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Plate 33. -Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Semipermanently
Flooded, WATER CHEMISTRY Fresh-Alkahne, SOIL Mineral, SPECIAL MODIFIER Impounded. A sparse stand of water plantain
(Alisma plan tago-aq uatica@ appears along the edge of the impoundment. (Billings County, North Dakota; July 1970; Photo
courtesy of J. Lokemoen)

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Plate 34.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, SUBCLASS Mud, WATER REGIME Sernipermanently
Flooded, WATER CHEMISTRY Mesosaline, SOIL Mineral. The dominant plant is summer cypress (Kochia scoparia). The subordi-
nate plants are golden dock (Rumex mwitimus) and goosefoot (Chenopodium glaucum). This wetland is pictured during
drouth conditions when the bottom is being invaded by pioneer species. (Stutsman County, Aorth Dakota; August 1961;
Photo courtesy of R. E. Stewart)

......... ....

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Plate 35. -Classification: SYSTEM Palustrine, CLASS Aquatic Bed, SUBCLASS Vascular, WATER REGIME Semipermanently
Flooded, WATER CHEMISTRY Oligosaline, SOIL Mineral. The dominant plant is white water crowfoot (Ranunculus tticho-
phyllus). (Stutsman County, North Dakota; August 1966; Photo courtesy of R. E. Stewart)

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Plate 36. -Classification: SYSTEM PalUstrine, CLASS Unconsolidated Shore, SUBCLASS Mud, WATER REGIME Seasonally Flooded
and Intermittently Flooded, WATER CHEMISTRY Mixosaline, SOIL Mineral. The dominant plant is greasewood (Sarcobatus
vermiculatus). Subordinate species are rushes (Juncus spp.) and salt grass (Distichlis stricta). Some areas of the photo are
sernipermanently flooded unconsolidated bottom. Because annual precipitation averages only about 18 cm (7 in.), these
wetlands are heavily dependent on snowpack in the surrounding mountains as a source of water. (Saguache County,
Colorado; Date unknown; Photo courtesy of R. M. Hopper)

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16;

Plate 37.-Classification: SYSTEM Palustrine, CLASSMoss-Lichen Wetland, WATER REGIME Saturated, WATER CHEMISTRY
Fresh-Acid; SOIL Sphagnofibrist. The dominant plant is peat moss (Sphagnum spp.). Subordinate species include reindeer
moss (Cladonia spp.), leatherleaf (Chamaedaphne calyculata), crowberry (Empetrurn nigrum), and cottongrass (Eriophorum
spp.). (Campabello Island International Park Maine-Canada; June 1976)

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Plate 38. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland (Foreground), SUBCLASS Persistent, WATER REGIME
Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Paleudult. The dominant plants are three-awn (Aristida stricta) and beak
rushes (Rhynchospora spp.). Subordinate species include longleaf pine (Pinus palustris), orchid (Habenaria spp), yellow-eyed
grass (Xyris spp.), grass pink (Calopogon spp.), and foxtail clubmoss (Lycopodium alopecuroides). (Brunswick County,
North Carolina; December 1975)

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Plate 39. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Permanently
Flooded, WATER CHEMISTRY Fresh, SOIL Unknown. The dominant plant is common cattail (Typha latifolia). This palustrine
emergent wetland borders a lacustrine system that is still ice covered. Note that the persistent vegetation remains standing.
(Knox County, Maine; April 1978)

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Plate 40. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Sernipermanently
Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Organic. The doniinant plant is saw grass (Cladium jamaicense).
(Dade County, Florida; December 1975)

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Plate 41. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally
Flooded, WATER CHEMISTRY Fresh-Circumneutral, SOIL Organic. The dominant plant is sedge (Carex lasiocarpa). Subordi-
nate plants include sedges (Carex lacust7is and C rostrata), marsh smartweed (Polygonum coccineum), bladderwort (Utri-
cularia vulgaiis), bluejoint (Calamagrostis canadensis), and pondweed (Potamogeton gramineus). (Beltrami County, Min-
nesota; June 1972; Photo courtesy of J. H. Richmann)

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Plate 42. -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 courtesy of H. A. Kantrud)

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Plate 43-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, WATER REGIME Temporarily Flooded, WATER
CHEMISTRY Fresh, SOIL Mineral, SPECIAL MODIFIER Farmed. Dominant species include nut sedge (Cyperus sp.), arrow arum
(Peltandra virginica), and barnyard grass (Echinochloa crusgalli). (Dade County, Florida; January 1978; Photo courtesy of
P. B. Reed)

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Q11

Plate 44. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Sernipermanently
Flooded, WATER CHEMISTRY Mixosaline, SOIL Mineral. Dominant plants are alkali bulrush (Scirpus paludosus) in foreground
and hardstem bulrush (Scirpus acutus) in background. (Stutsman County, North Dakota; August 1962; Photo courtesy of
R. E. Stewart)

Plate 45. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally
Flooded, WATER CHEMISTRY Polysaline, SOIL Mineral. The dominant plant is spike rush (Eleocharis palustiis). Subordinate
plants include marsh smartweed (Polygonum coccineum), slough sedge (Carex atherodes), and foxtail (Alopecurus aequalis).
(Stutsman County, North Dakota; August 1962; Photo courtesy of R. E. Stewart)

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Plate 46.-Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally
Flooded, WATER CHEMISTRY Mixosaline, SOIL Mineral. The dominant plants are sedge (Carex spp.), bulrush JScirpus spp.),
rush (Juncus spp.), and foxtail (Alopecurus aequalis). This wetland is typical of irrigated hay in the West. Water may be
diverted from rivers or may be from artesian wells as in this plate. (Saguache County, Colorado; Date unknown; Photo
courtesy of R. M. Hopper)

L
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V

Plate 47. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally
Flooded Tidal, WATER CHEMISTRY Fresh, SOIL Unknown. Dominant vegetation includes cattail (Typha sp.), grasses
(Gramineae), alder (Alnus sp.), and spiraea (Spiraea sp.). (Knox County, Maine; April 1978; Photo courtesy of P. B. Reed)

7-
J"
4 J -

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Plate 48. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Saturated, WATER
CHEMISTRY Fresh, SOIL Unknown. The dominant plants are sedges (Carex spp.). (Lassen County, California; August 1975)

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Plate 49. -Classification: SYSTEM Palustrine, CLASS Emergent Wetland, SUBCLASS Persistent, WATER REGIME Seasonally
Flooded, WATER CHEMISTRY Fresh, SOIL Mineral, SPECIAL MODIFIER Farmed. The dominant plant is taro (Colocasia esculenta).
(Kauai County, Hawaii; September 1972; Photo courtesy of E. Krider)

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ZTE

Plate 50. -Classification: SYSTEM Palustrine, CLASS Scrub-Shrub, 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
courtesy of D. Peters)

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7

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Plate 51. -Classification: SYSTEM Palustrine, CLASS Scrub-Shrub, SUBCLASS Broad-leaved Evergreen, WATER REGIME
Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Sphagnofibrist. The dominant plants are Labrador tea (Ledum groen-
landicum@, sheep laurel (Kalmia angustifolia), and leatherleaf (Chamaedaphne calyculata). Subordinate species include peat
moss (Sphagnum spp.), crowberry (Empetrum nigrum), cloudberry (Rubus chamaemorus), and black spruce (Picea ma?iana).
(Washington County, Maine; June 1976)

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Plate 52. -Classification: SYSTEM Palustrine, CLASS Scrub-Shrub, SUBCLASS Broad-leaved Evergreen, WATER REGIME
SatUrated, WATER CHEMISTRY Fresh-Acid, SOIL Medisaprist. The dominant plants are black ti-ti (Cyrilla racemiflora) and
honeycup (Zenobia pulverulenta). Subordinate species include leatherleaf (Chamaedaphne calyculata), peat moss (Sphagnum
spp.), highbush blueberry (Vaccinium corymbosum), loblolly bay (Gordonia lasianthus), pond pine @Pinus serotina), and black
highbush blueberry (Vaccinium atrococcum). (Brunswick County, North Carolina; December 1975)

100

Plate 53. -Classification: SYSTEM PaluStrine, CLASS Forested Wetland, SUBCLASS Broad-leaved Deciduous, WATER REGIME
Saturated, WATER CHEMISTRY Fresh-Acid, SOIL Organic. The dominant plant is red maple (Acer rubrum). Subordinate
species include black gum (Nyssa sylvatica@, highbush blueberry (Vaccinium corymbosum), great laurel (Rhododendron
maximum), and winterberry (flex uerticillata). (Washington County, Rhode Island; June 1977)

101

C ,KI! 7
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Plate 54. -Classification: SYSTEM Palustrine, CLASS Aquatic Bed (foreground), Forested Wetland (background), SUBCLASS
Floating (foreground) and Needle-leaved Deciduous (background), WATER REGIME Permanently Flooded, WATER CHEMISTRY
Fresh. The dominant plant in the foreground is water lettuce (Pistia stratiotes) and in the background bald cypress
(Taxodium distichum). The subordinate species is arrowhead (Sagittaria spp.). (Collier County, Florida; January 1978)

102

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Plate 55.-Classification: SYSTEM Palustrine, CLASS Forested Wetland, SUBCLASS Needle-leaved Evergreen, WATER REGIME
Seasonally Flooded, WATER CHEMISTRY Fresh-Acid, SOIL Organic. The dominant plant is Atlantic white cedar (Chamae-
cyparis thyoides). Subordinate plants include highbush blueberry (Vacciniurn corymbosum), peat moss (Sphagnum spp.),
winterberry (Dex verticillata), and red maple (Acer rubrum). Low vegetation in the foreground includes leatherleaf (Chamae-
daphne calyculata) and Virginia chain-fern (Woodwardia virginica). (Washington County, Rhode Island; July 1977)

103

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Plate 56.- 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)

36668 141

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 en-
vironmental and cultural values of our national parks and historical
places, and providing for the enjoyment of life through outdoor recre-
ation. The Department assesses our energy and mineral resources and
works to assure that their development is in the best interests of all our
people. The Department also has a major responsibility for American In-
dian reservation communities and for people who live in island territories
under U.S. administration.

OF th,

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