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













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                                                        @Wetlands Ecology

                                                                         By Pam Mason


                       OBJECTIVES

                           The purpose of this unit is to familiarize yourself                 Wetlands can be vegetated or nonvegetated. The
                       with the fundamental aspects of wetlands ecology. This             plants that vegetate wetlands are called hydrophytes
                       review will touch on the role of wetlands in the ecosys-           meaning water loving. Hydrophytes are adapted to life in
                       tem, what makes a wetland, different wetland types and             the water. Adaptations can be morphological, reproduc-
                       the plants and animals of the wetland.                             tive or physiological. Plants that have adapted to grow in
                           Following completion of the module, you will:                  saline waters are called halophytes meaning salt loving.
                       1) have a basic understanding of the role of wetlands in                Some common terms can be used to describe tidal
                       the ecosystem, 2) be able to recognize wetlands, and 3)            wetlands by their relative position in the landscape. The
                       define/describe hydrophyte, primary production, detritus,          low marsh is the area of the lowest elevation, often vege-
                       secondary production, food web, zonation.                          tated by saltmarsh cordgrass or pickerelweed. The high
                       LECTURE NOTES                                                      marsh is generally above mean high water and is vege-
                                                                                          tated with saltmeadow hay, saltgrass, big cordgrass. The
                       Introduction                                                       marsh-upland ecotone, where the wetlands grade into
                                                                                          the uplands, is often indicated by the growth of shrubs
                           What is a wetland? A wetland is composed of three              like the marsh elder, highwater bush and wax myrtle.
                       fundamental components; Water, plants and soil.
                           The water that makes wetlands wet is referred to as            Ecosystem Functions
                       wetland hydrology. Wetland hydrology can come from                      Primaryproduction and the food web
                       many sources. The water may come from tides or nonti-                   Green plants use the sun's energy to convert inor-
                       dal sources such as rain, streams or groundwater. Tidal            ganic (nonliving) minerals to organic (living) plant tissue.
                       waters can be salt or fresh. In most tidal systems there is        This process is know as photosynthesis. As the first-
                       a gradient from saltwater to freshwater progressing up-            level of production of organic material the process is
                       stream. In general nontidal wetlands are freshwater, al
                       though some are saltwater. This can occur where there is           called primary production.
                       a high amount of dissolved minerals in the water and high               Plant species common to wetlands have high levels
                                                                                          of primary production. Estimates of the primary produc-
                       evaporation rates increase the concentrations (Chapman,
                       1960).                                                             tion of tidal wetlands are as high as 4-6 tons per acre per
                           Wetland soils are hydric soils. When soils are inun-           year. Wetlands productivity rivals or surpasses the most
                       dated with water, anaerobic (without air) conditions usu-          -productive farmlands (Tiner, 1984).
                       ally result. Anaerobic conditions lead to chemical                      Animals that feed directly on plant material are
                       changes in the soils. Hydric soils are generally dark in           called primary consumers. However, few animals eat
                       color.                                                             the vegetation and most of the plant material becomes de-









                  2


                  tritus'. Detritus is partially decomposed plant material.                          2. High rates of primary productivity may lead to
                  Depending on the wetland system, some or most, of the                        high rates of nutrient uptake and subsequent burial
                  material is exported to the estuary.                                         when the plants die.
                        Many types of microorganisms grow on the detri-                              3. The nutrients used by the growing wetlands
                  tus. The tiny plants and animals which populate the de-                      plants are not available to support the development of
                  tritus increase the value of the detritus as food for                        algal blooms (Mitsch & Gosselink, 1986)..
                  estuarine organisms. The d         .etritus is consumed by                         Fish and Wildlife Habitat
                  many animals, including crabs, fish and shellfish.             The                 A great variety of birds, fish, mammals and inver-
                  consumers digest the microorganisms growing on the                           tebrates use   .wetlands for foraging, shelter, nesting,
                  detritus. However, the detritus is only partially broken-
                  down and passes through mostly undigested. The.detri'                        spawning and nursery areas. Some species of plants
                                                                                               and animals can survive only in wetlands such as salt-
                  tus is repopulated with microorganisms and the process                       marsh cordgrass a     .nd muskrats. However, many other
                  is repeated.                                                                 species use wetlands for food or refuge but not as a pri-
                        The higher level consumers in the process are                          mary residence.
                  those that feed on the detrital consumers. Examples of
                                                                                                     Many species of finfish, including most commer-
                  higher level consumers are shorebirds, finfish and mam-                      cial and game fishes use wetlands as habitat. Striped
                  mals including humans.                                                       bass, white perch and herrings ai@e just some of the fa-
                        Water Quality                                                          miliar fishes which-use wetlands. Crustaceans, like the
                        Wetlands occupy a strategic position in the land-                      blue crab and. shrimp also use wetlands. Many species
                  scape between uplands and the aquatic environment.                           of shellfish are found in wetlands or the adjacent shal-
                  Wetlands can intercept upland runoff and filter and trap                     low waters. Oysters, clams and mussels use wetlands
                  pollutants and sediments before they reach the water-                        as habitat.
                  way. Several      wetlands attributes have the potential to                        Shoreline Erosion Control
                  affect the flow of chemicals and sediments.
                                                                                                     Wetlands deter shoreline erosion by reducing wave
                        1. Wetlands vegetation slows water velocity, caus-
                  ing sediments and sorted chemicals to drop out of the                        energy and current velocity. Roots and,rhizomes of
                  water column on to the wetland.                                              wetland plants stabilize the s      .ubstrate, and the stems and
                                                                                               leaves slow the flow of waves and tidal currents. Al-
                                                                                               though lacking vegetation, the natural slope of nonvege-
                  Wetlands Program                             December 1993                   tated wetlands provide a buffer to shoreline erosion.
                  College of William and Mary
                  School of Marine Science                                                     Wave and tidal curr.ent energy is dissipated as the water
                  Virginia Institute of Marine Science                                         spreads out over the flats.
                  Gloucester Point, Virginia 23062                                                   Flood Protection
                  Dr. Carl Hershner, Program Director                                                Wetlands may slow and temporarily store flood wa-
                  Published by: VIMS Publication Center                                        ters. The capacity for flood water storage is influenced
                  "A publication of the Virginia Department of Environmental                   by the tidal stage. Portions.      of the wetlands already
                  Quality's Coastal Resources Management Program pursuant to                   flooded by tidal waters may be unable to assimilate ad-
                  National Oceanic and Atmospheric Administration Award                        ditional flood waters. This is particularly true of low
                  No. NA270ZO312-01. "                                                         marsh areas with daily tidal inundation. The absorption
                                    "This paper isfunded in part by a grant1cooperative
                                    agreementfrom the National Oceanic and                     of flood water by wetlands and the ability of vegetation
                  S                 Atmospheric Administration. The views expressed            to slow flood waters desynchronizes peak flows mini-
                                    herein are those of the author and do not necessarily      mizing downstream flows.
                                    reflect the views of NOAA or any sub-agencies.


                                                Printed on recycled paper.
                  AQ
                    '41
                  " NW04"111-8










                                                                                                                                                                                                                                                                           3


                                                Wetland Types                                                                                                       high marsh is a mixed community of saltgrass and salt-
                                                Generally it is common to group wetlands into cate-                                                                 meadow hay with saltbush along the upland edge. Oyster-
                                        gories according to salinity regimes. Salinity influences                                                                   catchers, egrets, herons, blue crabs, fiddler crabs and
                                        the kinds of plants and animals present in the wetland.                                                                     finfish are common inhabitants of the saline marsh.
                                                 Euhaline (Marine). Marine marshes have waters                                                                               Brackish (Polyhaline and Mesohaline). The
                                        with a salinity close or equal to seawater. The vast expan-                                                                 seawater is gradually diluted by freshwater and the salin-
                                        sive marshes behind the barrier islands on the eastern                                                                      ity ranges from above and below 16 parts per thousand.
                                        shore are saline marshes. Dominant vegetative species in-                                                                   The marshes are found in the lower Chesapeake Bay and
                                        clude saltmarsh cordgrass, saltmeadow hay, saltgrass and                                                                    extending up the major tributaries and creek systems.
                                        highwater bush. Zonation of the vegetation is simple and                                                                    The vegetation is more diverse than the saline mars                                                 'hes.
                                                                                                                                                                    Bulrush, sea lavender and cattails are common in addition
                                        easily observed. Tall form saltmarsh cordgrass grows at
                                        lower elevations adjacent to the marsh creeks,@ short form                                                                  to saltmarsh cordgrass, saltmeadow hay and sattgrass.
                                        saltmarsh cordgrass occurs in the mid-marsh, and the                                                                        Saltmarsh cordgrass grows adjacent to the creeks, salt-
                                                                                                                                                                    grass and saltmeadow hay with sea lavender and black











                                                                       'J                i
                                                                                                                                                                                                                                                EXTREME HIGH TIDE
                                                                                                                       N .........                          . ......    ........  .. .......                        ..........................................................
                                                   UPLAND
                                                                               .MARSH.U LAND                                                                                                                                                    MEAN HIGH TIDE
                                                                                   BORDER                                P ER               ......                                                                 ............................. ............................
                                                                                                                    IIIG I A      'I                                PANNE                                                                       MEAN LOW TIDE
                                                                                                                                            POOL                                                                                         ....                 .....           .......
                                                                                                                                                            LOWER HIGHMARS11                      LOW MARS11              INTERTI
                                                                                                                                                                                                                                   D L                   -------
                                                                                                                                                                                                                              FLAT                              AQUATIC BED








                                            Eelgrass
                                            Widgeon Grass
                                            Smooth Cordgrass
                                            Glassworts
                                            Sea-Blites
                                            Marsh Fleabane
                                            Marsh Orach
                                            Salt Hay Grass
                                            Spike Grass
                                            Perennial Salt Marsh Aster
                                            Black Grass
                                            Hightide Bush
                                            Seaside Goldenrod
                                            Bulrushes
                                            Rose Mallow
                                            Common Reed
                                            Sea Myrtle
                                            Grass-Leaved Goldenrod
                                            Switchgrass
                                            Marsh Pink
                                            Slough Grass

                                        Figure 1. Generalized disiribution of vegetation in a salt marsh. Note increased plant diversity along marsh-upland
                                        border. (Tiner, 1985, 1987)









              4


              needlerush occupy the mid-marsh and the upland edge                  fresh community is much greater than other tidal wet-
              is marked by highwater bush and marsh'elder. Animals                 lands. Fifty species per acre is typical. Just a few of
              found in the brackish marsh include marsh snails, grass-             the commorn plants are; arrow arum, pickerelweed, wild
              hoppers, clapper rails and fiddler crabs.                            rice, rice cutgrass, cattails, and smartweeds. Zonation
                   Oligohaline. These wetlands form the gradient                   is less sharply defined, however a general profile may
              from brackish to tidal freshwater. Located along the                 be described (Odum, 1984). Arrow arum and pickerel-
              Bay, niajorSributaries and creeks, increased freshwater              weed at the lower elevations adjacent the waterway,
              input dilutes the seawater to around 3 parts per thou-               smartweeds, wild rice, big cordgrass and rice cutgrass
              sand. Saltmarsh cordgrass may still be found along the               at higher elevations, cattails near the upland and wax
              waters edge, but many other less saline tolerant species             myrtle and red maple along the upland edge. A large
              are also'found. Big cordgrass, sedges and three       square -       diversity of animals is a consequence of the great vari-
              grow here. Zonation patterns become less pronounced                  ety of plants. Amphibians and reptiles are common, as
              as salinity decreases. Saltmarsh cordgrass is still found            are migrating waterfowl, muskrats, river otters, voles,
              at the lower elevations, big cordgrass, cattails, bulrush            raccoons and many other animals.
              and marsh mallows may all occur at the higher eleva-                      Tidal Swamps. These wetlands are found at the
              tions.                                                               upper end of tidal influence. The presen      ce of trees dif-
                   Tidal Freshwater. The average salinity is 0.5 ppt,              ferentiates tidal swamps from tidal marshes., In many
              or lower, except during drought. These wetlands occur                swamps, the tidal swamp grades almost imperceptibly
              upstream of oligohaline marsh and downstream of non-                 into a nontidal swamp. Trees in tidal swamps generally
              Odal wetlands. The vegetative diversity of the tidal                 grow on hummocks. Trees within tidal range are gener-



                                                                                                                    Figure 2. Food web.








                                                                                                y



                                                                                                       TOP CARNIVORES





                                                                                                                         'Noma
                                                                       microalgae

                                                                                              PS MARY
                                                                                                IN
                                                                                              CONSUMERS
                                                                                                                                              RW
                    PRODUCERS
                                                                                                        AM-0
                                                                                                                     - : <
                                                                                   bacterl         'k
                                                                                   and'    e                                                 MLW
                                                                                   Protozoa
                                                                                         -zooplanklon-
                                                                                                              SECONDARY
                                                                                                              CONSUMERS              V
                                                                              DECOMPOSERS  &
                                                                              DETRITUS FEEDERS
                                       TI-                                                                                        TERTIARY
                                                                                                                                  CONSUMERS





                                  SAND 9 MUDFLAT INFAUNA








                                                                                                                                             5


                      ally smaller and show autumn colors earlier than trees               Communities (Types are after the Virginia
                      above tidal influence. Tree species found in tidal swamps            Wetlands Cuidelines)
                      include- gums, red maple, green ash and bald cypress.
                      Dragonflies and other insects are common. Amphibians                 Type 1. Saltmarsh cordgrass community.
                      and reptiles, including spring peepers, water snakes, bull-          This community is dominated by Spartina alterni-
                      frogs and turtles, are found in tidal swamps. White-tailed      flora. This species is a tall grass reaching 4-6 feet tall
                      deer, red fox and other upland animals wander into the          near the waters edge. There are distinct growth habits of
                      swamps. Beavers, which were once gone from the                  Spartina according to height. There is a tall form, a short
                      Chesapeake Bay region, are once again inhabitants of            form and some have proposed an intermediate height
                      tidal and nontidal swamps.                                      form of the species exists. The tall form is found growing
                                                                                      adjacent to the marsh creeks and the short form grows fur-



                            AVERAGE ANNUAL
                                  SALINITY                                                            MARSH TYPE


                                                                                                                   NON-TIDAL
                                                                                                                 FRESHWATER
                                               0-0-0                                           0-0-0                                 (DURING
                                                                                                                                        LOW
                                                                                                                     11DAL              FLOW
                                           LIMIT OF                                                              FRESHWATER        CONDITIONS)
                                           TIDAL INFLUENCE


                               * 0.5 Ppt  - - - - - - - -                           - - - - - - - - -


                                                                                                                 OUGOHALINE
                                                                                                              I                     E
                               * 5.0 ppt   - - - - - - --                               - - - - - - - -                             S
                                                                                                                                    T
                                                                          T                                      MESOHALINE         U
                                                                                                                                    A
                              < 1&0 Ppt                                                      - - - - - -                            R
                                                                                                                                    Y


                                                         V0,                                                     POLYHALINE
                                                       1A



                              < 30.0 ppt
                                                           -------------- ----                                 J


                                                                          OCEAN


                                                                                                           EUHALINE
                                                                                                           (MARINE)


                      Figure 3. The relationshigbetween marsh type and average annual salinity (values are approximate only). Terminology
                      is based on Cowardin et al. (1979). (Odum et al, 1984)









              6



              ther from the creeks. It has been theorized that the tall           with swirls. The vegetation is found growing from
              form plants receive a "tidal subsidy" from the increased            about mean high water to the limit of spring tides.
              availability of tidal borne nutrients.                                   Primary productivity is around 1-3 tons per acre.
                   Spartina grows from about mean sea level to mean               However, tidal flushing of this community is limited to
              high water which is approximately the-upper two thirds              spring and storm tides so much of the vegetative mate-
              of the tidal range. The location of the community                   rial remains in the marsh and is not available to the ma-
              within the tidal zone results in daily flushing by the              rine community.
              tide.                                                                    The seed heads of the plants provide food for birds
                   The primary productivity of Spartina is very high.             and some birds nest in this community. Invertebrates
              The average production is about 4 tons per acre but                 like the saltmarsh snail (Melampus) are important food
              may be as. high as 10 tons per acre. Tidal action trans-            for waterfowl, seaside sparrows and rice rats.
              pofts the detritus making it readily available to the ma-                The dense growth habit of the vegetation provides
              nne community.                                                      an effective erosion deterrent, however, the position of
                   Tidal fluctuations allow aquatic animals access to             the community at. the higher elevations affords little op-
              the marsh. Adults of small fish species (killifish, ancho-          portunity to guard against shoreline erosion. If the com-
              vie's) and juveniles of many species (striped bass, spot,           monly occurring saltmarsh cordgrass is absent from the
              croaker) use the marsh for protection and a feeding                 lower elevations, this community will deter shoreline
              area. Blue crabs and shrimp also forage and find ref-               erosion. The saltmeadow community is often the older
              uge in the Spartina. The marsh periwinkle, which                    part of the marsh with deep accumulations of marsh
              clings to the'stems of the vegetation, and the ribbed               peat. Flood waters fro -in high tides and upland runoff
                                                                                                                   marsh peat. The salt-
              mussel are important as food for aquatic animals as                 may be absorbed by the deep
              well as bird and small mammals.                                     meadow acts as a trap, filtering the sediments, nutrients
                   The roots and rhizomes of the plant are used as                and toxics carried by the flood waters.
              food by waterfowl. Some birds use the vegetation as                      Type Ill. Black Needlerush Community.
              nesting material including the clapper rail and willet.                  This community is dominated by black needlerush
              Muskrats use the plants in the construction of lodges.              (Juncus roemerianus). This plant usually grows in pure
              Raccoons and other small mammals can use the
                                                                                  stands with saltmarsh cordgrass, saltmeadow hay and
              Spartina community as a foraging area.                              saltgrass occurring at the edges. The'plants have hard
                   The Spartina community is an effective deterrent               cylindrical stems tapering to a sharp tip. The'plants ap-
              to shoreline erosion. The high growing densities, of the            pear leafless,as the leaves form a sheath around the
              vegetation reduce wave. energy. The,peat is very resis-             stem. The species blooms from June to August. Jun-'
              tant to wave energy due to the dense growth of roots                cus grows from about mean high water to somewhat be-
              and rhizomes. The baffling effect of the vegetation                 low spring tides. The community often grows in
              slows the flow of tidal waters and upland runoff. As                pannes, low areas of the marsh where waters accumu-
              the water velocity is reduced, sediments are deposited              late and evaporation increases salinity.
              on the marsh. This.property makes the Spartina com-                      Black needlerush produces about 3-5 tons per year
              munity effective as a trap for sediments from upland                of vegetative material. Due to the rigid natureof the
              runoff.                                                             species, plants decompose slow     'ly and the location of
                   Type 11. Saltmeadow co      mmunity.                           the community in the high marsh limit's the amount of
                   This community is dominated by saltmeadow hay                  material flushed by the tide.
              (Spartina patens) and saitgrass    (Distichlis spicata).. It             It does not appear that any animals feed on Juncus,
              is common to find saltmarsh cordgrass, marsh elder,                 however the dense, stiff vegetation provides cover for
              groundsel tree and other plants growing in this commu-              some species. Clapper rails nest in the vegetation.
              nity. Saltmeadow hay and saltgrass reach about 1-2                       The dense system of roots and rhizomes is resistant
              feet in height. Large expanses appear meadow-like                   to, erosion. The opportunity to provide shoreline ero-









                                                                                                                                                          7


                     sion protection occurs on some sandy shores and low                  on the stems and seeds. The meadow vole nests among
                     sand berms. The vegetation is an effective trap for sedi-            the stems as does the marsh rice rat, often taking over the
                     ment, although not as effective as the densely matted salt-          nest of a marsh wren.
                     meadow community. The absorbent substrate acts to                         As other species of marsh grass, the dense network
                     buffer coastal flooding.                                             of roots and rhizomes binds the marsh substrate providing
                           Type IV. Saltbush Community.                                   a deterrent to shoreline erosion. Growing at higher eleva-
                           This community is comprised.of groundsel tree or               fions in the tidal zone the opportunity to provide shoreline
                     highwater bush (Baccharis halimifolia) and marsh elder               erosion control is limited; however, it may be particularly
                     (Ivafrutescens). Saltmeadow hay, and saltgrass are often             important.for low salinity wetlands where the lower inter-
                     found growing underneath the bushes. Groundsel tree                  tidal zone is occupied by species that die back each fall.
                     reaches about 15 feet in height, the leaves are alternately               Big cordgrass often is associated with the deep marsh
                     arranged on the branches, and it has conspicuous yellow-             peat common at higher elevations in the older portion of
                     white flowers which bloom September through October.                 the marsh. The deep peat increases the capacity for hold-
                     Marsh elder is 3 to 10 feet high, the leaves are opposite            ing flood waters. Where the community is found growing
                     on the branches, and the flowers are small greenish-white            adjacent to the uplands, flood buffering may allow for the
                     appearing from August to October. The bushes grow at                 settling and trapping of upland sediment, nutrients and
                     the upper limit of the marsh (the marsh-upland ecotone).             toxics. The plants are also effective at trapping larger flot-
                           Primary productivity is low, about 2 tons per year,            sam.
                     and little vegetative material reaches the marine environ-                Type V1. Cattail Community.
                     ment. The shrubs provide diversity to the grasses and                     There are two common species of cattails in this com-
                     reeds common to the marsh. Small birds, like the marsh               munity, the narrowleaf cattail (Typha angustifolia) and
                     wren, nest among the branches.                                       the broadleaf cattail (Typha latifolia). The plants may be
                           The growth habit of the shrubs does not serve well as          found growing with other brackish and freshwater plants
                     a sediment trap, but does effectively trap larger flotsam.           including; sedges, bulrushes, smartweeds, arrow arum
                     Often found growing on sand berms in front of small                  and pickerelweed. Both species grow to heights of 4 to 6
                     marshes, the bushes do provide some erosion protection.              feet, have long strap-like leaves with slightly rounded tips
                                                                                          and have the characteristic fruiting head. Both the male
                           Type V. Big Cordgrass Community.                               and female flowers occur together on one flowering
                           Big cordgrass (Spartina cynosuroides) usually
                     grows in monotypic stands. The grass is- very tall, 6 to 12          spike. In the broadleaf cattail the upper (male) spi@e and
                     feet, and has a distinct feathery fruiting head in the fall.         the lower (female) spike are touching, in the narrowleaf
                     The plants are very sturdy and standing dead plants often            there is a space between the spikes.
                     persist through the winter. Big cordgrass grows from just                 Cattails prefer very wet soils and sometimes grow in
                     above mean high water up to thq upland margin. The                   standing water. They prefer low salinity waters. Look
                     plant is most common in brackish and lower salinity                  for cattails along the upland margin where groundwater
                     marshes.                                                             seepage keeps the soils wet and the salinity low. The
                           Levels of primary productivity range from 3 to 6 tons          vegetative material produced by cattails,, about 2 to 4 tons
                     per acre in this community'. Primary productivity rates              per acre, is not readily accessible to the marine environ-
                     are similar to saltmarsh cordgrass and higher than most              ment.
                     other species growing above mean high water. However,                     Some species of birds use cattails as habitat. Marsh
                     the position of the community at the higher elevations re-           wrens and rice rats build nests attached to the plants. The
                                                                                          plant roots are eaten by muskrats.
                     sults in the transport of the vegetative material being lim-
                     ited to high spring, wind and storm tides.                                The cattail community offers little erosion protection
                       -   Various animals use big cordgrass for cover, food or           due to the preferred location adjacent to the uplands and
                     building materials. Muskrats use the material for build-             the shallow root system of the plants. However, both of
                     ing lodges. Geese eat the rhizomes and other birds feed









               8


               these characteristics make the community effective as a               leaves are shed in the fall, individual stems and seed
               sediment trap, particularly from upland runoff.                      -heads often persist through the winter.
                                                                                          Phragmites usually grows above mean high tide,
                    Type V11. Arrow Arum - Pickerel Weed
                    Community.      .                                                particularly in brackish areas. The plants will also-in-
                    The dominant plants of this community are arrow                  vade the drier areas of disturbed sites. Primary produc-
               arum (Peltandra virginica) and pickerelweed (Ponted-                  tivity rates range from 4 to 6 tons per acre, but the
               eria cordata). The plants may grow in association with                relatively high elevation occupied by the community re-
               sedges, smartweeds, cattails and pond lily. Both spe-                 sults in little transport of vegetated material.
               cies have dark green fleshy leaves and grow in clumps                      There is little evidence of wildlife use of this com-
               about 3 feet high. Arrow arum has leaves shaped like                  munity. The vegetation may provide cover for some
                                                                                     birds and small mammals. Where Phragmites invades
               arrowheads, with a prominent midvein. Arrow arum
               blooms from May to July, but the flowers. are concealed               disturbed sites, there may be a detrimental effect on
                                                                                     wildlife use due to the decrease of vegetative species
               in a sheath called a spathe. Pickerelweed has heart-
               shaped leaves with parallel v    .eins.. The plants bloom             which are important to wildlife.
               from May to October and the showy purple flowers are                       The sturdy nature of the grass makes for a good
               borne on flowering spikes up to 4 inches long.                        shoreline erosion deterrent.    Due to the ability to invade
                    Arrow arum and pickerelweed can be found in non-                 dry, disturbed areas, this species is often found growing
                                                                                     on dredge material acting to stabilize the material.
               tidal freshwater wetlands as well as low salinity and
               tidal freshwater wetlands. In tidal waters, the commu-                     Type IX. Yellow Pond Lily Community.
               nity grows from'about mean sea level to about mean                         Yellow pond lily (Nuphar luteum) grows in fresh-
               high tide in low salinity and freshwater marshes. This                water and may be associated with arrow arum and pick-
               is the same landscape position occupied by saltmarsh                  erelweed. The large saucer shaped leaves float on the
               cordgrass in higher saline waters.                                    water surface at high tide. The plants flower from June
                    About 2 to 4 tons per acre of vegetative material is             to September and have a large yellow flower. The
               produced in this community. The organic material is                   leaves and flowers of the 2 to 4 foot tall plants are emer-
               readily available to the marine system. Unlike many                   gent at low tide,
               other common welland plants such as the marsh                              The floating leaves of one plant occupy several
               grasses, these species decompose quickly and com-                     square feet so plant densities are generally low. Pri-
               pletely in the fall.                                                  mary productivity approaches one ion per acre. Vegeta-
                    The soft, unconsolidated intertidal muds are suscep-             tive material enters the marine environment, but the
               tible to erosion. Without a dense network of roots and                contribution is small compared to other marsh species.
               rhizomes, the plants can serve to stabilize the shoreline                  Yellow pond lily is found in river stretches associ-
               only during the year when the leaves can act to baffle                ated with spawning striped bass, white perch and river
               wave energy. Due to the complete        -die back of -the vege-       herring. The plants provide attachment sites for algae
               tation each fall there is -no standing dead material to pro-          and aquatic animals. Wading herons, egrets and other
               tect the shoreline from erosion in the winter. The large              waterbirds forage on the small fish and invertebrates
               leaves of the vegetation can slow tidal waters and                    among the floating leaves. Finfish also forage in the
               waves to allow some sediment deposition.                              yellow pond lily. A resident of freshwater marshes, the
                    Type VI   I[I. Reed Grass Community.                             eastern painted turtle may be found feeding here as
                    This community is dominated by reed grass                        well.
               (Phragmites communis). This grass often grows in                           While lacking stiff stems and leaves, the large
               pure stands, but may be found growing with saltbush                   leaves do provide some baffling of wave energy. By re-
                                                                                     ducing wave action, the community provides some
               and switchgrass. Phragmites is a tall stiff grass reach-
               ing 6 to 10 fe .et in height. The plants bloom in July and            shoreline protection and allows fo     Ir the settling of some
               August and have a large, feathery seed head. After the                water borne sediments.









                                                                                                                                                   9


                          Type X. Saltwort Community.                                     arrow arum, pickerelweed, smartweeds, wild rice and rice
                          There are three species of vegetation commonly                  cutgrass are among the species which may occur in a
                     called saltwort found in Virginia. The three species are:            freshwater mixed community wetland. Because this com-
                     Salicornia virginica, Salicornia biglovii and Salicornia             munity encompasses many vegetative species, each with
                     europa. Saltworts are leafless succulents. with thick                a preferred elevation, the community may be found grow-
                     green, edible stems. S. europa and S. biglovii are dif-              ing from the subtidal zone to the upper limits of wetlands.
                     fusely branched, fleshy annuals. Salicorma virginica is a                Primary productivity of this community depends
                     perennial with woody stems and typically grows in dense              greatly on the species present. An average value is 3 to 5
                     mats, Saltworts grow in saline and higher salinity brack-            tons per acre. The vegetative material produced by interti-
                     ish marshes above mean high tide in pannes and sparsely              dal species is readily available to the marine environment.
                     vegetated areas.                                                         The high diversity of the freshwater mixed wetland
                          Primary productivity is less than 1/2 ton per acre.             provides foraging areas, nursery areas and nesting sites
                     There is some evidence that some ducks eat the stems.                for a myriad of wildlife species. These wetlands occur
                     Wading birds and other marsh birds may forage where                  along river and creek stretches where striped bass, shad
                     -small fish and invertebrates get trapped by the receding            and river herring spawn. The juvenile fish can find shel-
                     tide in Salicorma pannes.                                            ter among the intertidal vegetation. Wildrice, arrow arum
                          The diminutive habit of the leafless plants, the shal-          and smartweeds are consumed by native and migratory
                     low root system and the preferred location of this commu-            waterfowl, sora rails, redwinged blackbirds and upland
                     nity offers little erosion- protection, flood buffering or           birds. Insects, amphibians and reptiles are more common
                     sediment trapping capabilities.                                      than in the brackish and saline marshes.
                          Type X1. Freshwater Mixed Community.                                 The shoreline erosion deterrent of this community is
                          This community type applies to freshwater wetlands              the same as the arrow arum and pickerelweed community
                     with a heterogeneous mix of vegetation and no single spe-            'because these species grow at the lower elevations adja-
                     cies covers more than 50 percent of the site. Bulrushes,             cent to the waterways. However, due to-the presence of
                                                                                          grasses, sedges, rushes and a peaty substrate at the higher

                                                                                                           Figure 4. Marsh to uplands transition in
                                                                                                           a typicalfreshwater marsh.













                                                                                     BIDENS (seasonal)


                                                                        N N-TIVAL
                                                                       DEPRESSION









                       GREENBRIER              BUTTON BUSH                    SEDGES                       SMARTWEED
                       RED MAPLE               TOUCH-ME-NOT                   MARSH MALLOW                 ARROW ARUM
                       POISON IVY              ROYALFER                       TEARTHUMA                    PICKEREL WEED
                       SWEET PEPPERBUSH-       CATTAIL                        810 CORDGRASS                ARROWHEAD
                       SWAMPROSE-              IRONWEED                       .11- 1 -                     YELLOW POND LILY
                                               SOUARESTEM SPIKEFIUS           SEDGES
                                               MARSH FERN                     WILD RICE










              10


              elevations, the freshwater mixed community is effec-                  As this community is most often bordered by salt-
              tive as a sediment trap and assimilator of flood waters          marsh cordgrass, the community provides effective
              (Figure 4).                                                      shoreline erosion control. Likewise, the attributes of
                   Type X11. Brackish Water Mixed Community.                   the commonly, occurring saltmeadow community spe-
                   This community is comprised of various brackish             cies, saltmeadow hay and saltgrass, provide effective
              wetlands species. No single species cover more than              sediment trapping and flood buffering capabilities
              50 percent of the site. This diverse vegetative commu-'          (Figure 5).
              nity may include saltmarsh cordgrass, saltmeadow hay,                 Type X111. Intertidal Beach Community.
              saltgrass, saltbushes, threesquares, big coidgrass, com-              The intertidal beach is nonvegetated. The domi-
              mon reed and cattails: This community may extend                 nant animal species are burrowing invertebrates. Ani-
              from the lower limit of saltmarsh cordgrass, about               mals that live in the substrate are called infauna.
              mean sea level, to the upland margin.                            Wandering species and nonmobile species attached to
                   Primary productivity of the brackish mixed com-             hard substrates are called epifauna. There is some vafi-
              munity ranges from 3 to 5 tons per acre. The detritus of         ability between species commonly found on bay
              the intertidal species is available to the marine food           beaches and those most often associated with ocean
              web.                                                             beaches. On the ocean beach, mole crabs, donax clams
                   As is the case with the freshwater mixed wetlands,          and haustorid amphipods are common. Amphipods are
              a wide diversity of vegetation provides a variety of             also common on bay beaches as are oligochaete worms
              wildlife food and shelter. Many species of waterfowl             and sand fleas. These animals occur in large numbers;
              feed on  the seed heads. Shorebirds and wading birds             in the summer there may be as many as 5000 individu-
              forage for plentiful invertebrates. Fiddler crabs and            als per square meter-
              marsh crabs are common. Raccoons forage for crabs                     Lacking the macrophytes, large plants, of the vege-
              and shellfish. Small mammals such as the meadow                  tated wetlands, primary production is relatively low.
              vole and rice rat, feed on the vegetation and inverte-           The primary producers of the nonvegetated wetlands
              brates. Foxes are attracted by the small mammals,                are microscopic plants including algae and phytoplank-
              marsh birds and invertebrates.


                                                                                            Figure 5. Marsh to uplands transition in
                                                                                            a typical saltwater marsh.










                                                   ---------- TRANSITION ZONE -----------






                                                                                  SALTMARSH BULRUSH
                                                                                  ALOM FRIF"ATER STREAMETS



                                                                                            A...




                      PINE               GROUNDSEL TRE                 MARSH ELDE               BLACK NEEDLERUSH
                      GREENBRIER                                       SEA OXEYE                                  RA
                                         SALTMEADOW HA                                          SPARTINA ALTERNIFLORA
                      RED CEDAR          FOXTAIL GRASS                 SALTMEAD  HAY                         Short form
                      WAX MYRTLE         GREENBRIER                    SALT GRASS                            Tall form
                                         GOLDENROD










                       ton. The production of animals, or secondary production,           population densities are generally higher than sand or
                       is very high.                                                      mud flats and range from 5300 to 8300 individuals per
                            The large numbers of invertebrates are important              square meter.
                       food for shorebirds. At high tide, finfish and blue crabs               Primary production is similar to sand flats. How-
                       also forage for food. The areas above high tide are used           ever, the smaller particle size and high organic matter con-
                       as nesting sites for terns, plovers and skimmers.                  tent, means greater microbial activity. Bacteria and
                            The low slope of the beach makes it a natural wave            fungi, fundamental to the breakdown of detritus, are
                       dissipator. The dissipation of wave energy reduces the             found in higher numbers in sediments containing small
                       potential for shoreline erosion. The beach interacts with          grain size particles. Nutrient cycling activity is greater
                       dunes, offshore bars and adjacent shoreline in the distribu-       than on the sand flat.
                       tion of sand.                                                           Shorebirds and wading birds feed on the invertebrate
                            Type XIV. Sand Flat Community.                                populations of the sand/mud flat. Waterfowl are attracted
                            Sand flats are populated by various surface dwelling          by the mollusks. Blue crabs and fish use the area for for-
                       and burrowing animals. Sandworms, bloodworms, am-                  aging and shelter. This community often borders a vege-
                       phipods and clams are all found on the sand flat. Animal           tated marsh which may increase the role of both
                       densities range from 300 to 3000 individuals per square            'communities as wildlife habitat. The marsh provides
                       meter.                                                             habitat variety and organic material to support nutrient cy-
                            Most of the animals complete their life cycle in one          cling and food webs.
                       or two years. High rates of production and predation re-                Shoreline erosion control is similar to sand flats.
                       sults in a rapid turnover of individuals. High predation                Type XVI. Mud Flat Community.
                       acts as a control on the size of the animals, in general indi-          Mud flat animal populations are dominated by
                       viduals are small.                                                 spionid- worms, mud snails, razor clams and bloodworms.
                            Primary productivity by microscopic plants ranges             These animals are mostly surface dwelling or shallow bur-
                       from 100 to 200 grams per square meter. Primary con-               rowers. The instable, anoxic mud limits the presence of
                       sumers graze on the small plants incorporating the vegeta-         deep burrowers and deters species other than surface detri-
                       tive material into the food web. This community has a              tal feeders. Animal -populations are highly variable. Gen-
                       reduced role in nutrient cycling due to the low percentage         erally lower than sand/mud flats but higher than sand
                       of organics and the large particle size of the sand.               flats, densities range from 50 to 5000 animals per square
                         .  Sand flats are used as foraging areas, by shorebirds,         meter.*
                       finfish and blue crabs. Juvenile blue crabs and finfish                 Of the nonvegetated wetlands, mud flats probably
                       seek shelter in the shallow waters where larger aquatic            have the highest primary productivity. Mud flats interact
                       animals cannot go. Some sand flats support high shellfish          with adjacent vegetated areas in nutrient cycling. The
                       populations.                                                       marshes provide organic material to the animal popula-
                            Like the intertidal beach, the low slope of this co      in-  tions of the mud flats which breakdown and transform the
                       munity acts as a natural dissipator of wave energy reduc-          organic material.
                       ing the potential for shoreline erosion.                                Foraging wildlife are attracted by the invertebrate
                            Type XV. Sand/Mud Mixed Flat Community.                       populations. Waterfowl, wading birds, finfish and blue
                                                                                          crabs all feed on the mud flats.
                            Hard clams, soft clams, mud snails, parchment
                       worms and polychaetes are commonly associated with in-                  Mud flats occur frequently in quiescent areas and
                       tertidal flats composed of sand and mud. The animals-are           have a limited opportunity to control shoreline erosion. -
                       surface dwellers, burrowers and some build permanent               However, the gradual slope of the mud flat acts like the
                       tubes. Variability in particle size allows some overlap of         other nonvegetated wetlands in the dissipation of wave en-
                       species common to sand flats and mud flats. As a result,           ergy-





                                                                            NOAA COAST
                                                                                                         ly


               12
                                                                                                862 P

                   Type XVII..Intertidal Oyster Reef Community.                   The nooks and crannies of the reef offer niches for
                   Oysters are the dominant- animal, but there is great       manyaquatic animals. Small finfish find shelter among
               diversity in the attached and associated organisms.            the shells, larger fish forage on the reef. Blue crabs
               Hard clams, mud crabs, sand w'orms, barnacles and              feed on the reefs extensively. Oystercatchers and other
               sponges are.associated with oyster reefs. When oyster          birds also forage on the reefs.
               reefs are managed by man, the oysters are most com-                The rigid structure of the permanently attached
               mon. In a natural state, fouling organisms are d 'omi-         shells are resistant to erosion and may dissipate wave
               nant. Populations are very variable, but are generally         energy.
               greater than flat communities.


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                   New York.                                                      University Press. College Station, Tx. 310pp.
               Long, S.P. and C.F. Mason. 1983. Saltmarsh ecology.            Tiner, R.W. 1985. Wetlands of New Jersey. U.S. Fish
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               Odum, W.E., T.J. Smith Jr., J:K. Hoover and C.C.                   ing natural treasure. U.S. Fish and Wildlife Serv-
                   McIvor. 1984. The ecology of tidal freshwater                  ice. Newton Comer, MA. 28pp.
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                   83/17. 177pp.                                                  mission, VMRC, Newport News, VA. 57 pp..
               Silberhom, G.M. 1982. Common plants of the Mid-                White, C.P. 1989. Chesapeake Bay: a field guide. Tide-
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