Biotic Communities of Marsh Systems FreshSaltwater Systems Freshwater

Biotic Communities of Marsh Systems

Fresh/Saltwater Systems Freshwater marsh 0. 5 -5. 0 ppt (between oligohaline zone and non-tidal freshwater) Saltwater marsh 5. 0 -35. 0 ppt or greater depending upon conditions

Comparison Saltwater -lg. Tidal influence -sandy, lower OM -marine and estuarine macrophytes -low species diversity -moderate to high algal production Freshwater -riverine influence -silt and clay, high OM -freshwater macrophytes -high species diversity -very low algal production (<1%pp)

Salt Marsh Ecology Complex systems Shaped by water, sediments, and vegetation Found on low energy coastlines and protected back barriers

United States Salt Marshes

Basic Characteristics Found in inter-tidal zones Fewer species present, occupying broader niches (recent geologic origin) Stressful environment Large gradients present for temperature, salinity, and p. H

Development Tidal sequence provides major source of sediment load Terrestrial runoff provides secondary source Salt tolerant plant species invade and thrive following deposition of sediments

Atchafalaya Delta Region Recent studies prove importance of riverine input Delta receives 1/3 of Miss. River flow Wetland area actually increasing Surrounding areas are in rapid decline due to subsidence and sea level rise

Global Variations North America Gulf Coast West Coast East Coast European Arctic (North and South)

European Salt Marshes Found above low neap tide line Periodic inundation Different physiology due to tidal influence Salicornia, Suaeda maritima, Juncus maritimus

Primary Production -Classical View Spartina alterniflora responsible for majority of production 3300 g/m/yr production Production influenced by tides

Primary Production -Modern Approach Isotopic analysis C 13/c 12 ratio point towards other sources Algae, diatoms Ominvores complicate data

Primary Consumers Trophic relationships begin with algae or Spartina detritus Rich benthic communities develop Bacteria rich detritus more valuable when compared to plant tissue Species of Uca, Callinectes, and Penaeus common in systems

Primary Consumers cont. Deposit Feeders -take in bottom sediments -filter organic particles -oligochaetes, etc. Suspension Feeders -filter organic material and other nutrients out of water column -use siphons, internal filters -American oysters, mussels

Value to Marsh System Macro-consumers provide an essential link in salt marsh energetics Take potentially harmful nutrients out of water column (phosphorus, etc. ) Bioturbation aerates the soil, increasing algal productivity Feces provide new food source for microbial communities

Secondary Consumers Birds, fish, and crabs compose a majority of the species for this trophic level Primary consumers provide valuable food source for juvenile populations May feed on organisms in sediments and water column

Aerobic Zones Occur in top 2 -3 mm of soil High content of oxidized ions (Fe+++, Mn+4, NO 3 -, SO 4 --) Vital source of energy for system Metals later reduced in anaerobic environment

Anaerobic Zone Nitrate 2 pathways Assimilatory nitrate reduction (plant uptake) Dissimilatory nitrate reduction (denitrification) Significant loss of N in salt marsh

Nitrogen Cycling Complex interactions in both aerobic and anaerobic zones Mineralization production of ammonium ion from organic N Pulled upward (gradient change) oxidized by chemoautotrophs Nitrification (nitrosomonas, nitrobacter)

Mg and Fe reduction Follows dentrification Cause of grey/green coloration in soil Forms ferrous oxides which can inhibit nutrient uptake around plant roots

Sulfur reduction Assimilatory S reduction Desulfovibrio OM produced Combines with Fe to reduce H 2 S concentrations in sediments (limits toxicity) PS bacteria (purple sulfur) create OM on surface of the salt marsh

Methanogenesis Occurs in extremely reduced conditions After oxygen, nitrate, sulfate are used up Can be recycled by bacteria during droughts

Conclusions Complex interactions regarding salt marsh energetics Algal growth and diatom formation provide basic primary production Nutrient cycling in anaerobic zones, rich bacterial communities Low species richness due to emphimeral nature and harsh environment

Food Web Interactions

Tidal freshwater Marshes

Definition Tidal freshwater wetlands are a distinctive type of ecosystem located upstream from tidal saline wetlands (salt marshes) and downstream from non-tidal freshwater wetlands

Characteristics Near freshwater conditions 0. 5 ppt average annual salinity (more concen. during periods of drought ) Plant and animal communities dominated by freshwater species A daily lunar tidal fluctuation

Tidal Freshwater Wetlands lies between the oliogohaline zone and nontidal freshwater

Tidal Freshwater Marshes Are characterized by a large diverse group of broadleafed plants, grasses, rushes, shrubs and herbacious plants.

Grasses, rushes, shrubs

Simplifying terminology Odum, et al (1984) identifies similar terminology in literature such as palustrine emergent wetland, freshwater tidal, transition marsh combined with arrow-arum and pickerelweed marsh…simplified to tidal freshwater marsh for convenience and term is more widely used.

Tidal Freshwater Marshes classified as either: System: palustrine Class: emergent wetland Subclass: persistent and non-persistent System : riverine Class: emergent wetland Subclass: non-persistent

Water regimes for either classification: Permanently flooded – tidal Regularly flooded Seasonally flooded – tidal

The system selected depends on the position of the marsh with respect to the river channel High back marshes with persistent vegetation classified as palustrine Fringing low marshes along river edges classified as riverine

Along United States East Coast Most extensive development of freshwater tidal marshes between Southern New England Georgia

Best developed in locations… Major influx of freshwater Daily tidal amplitude of at least 0. 5 m (1. 6 ft. ) A geomorphological structure which constricts & magnifies the tidal wave in the upstream portion of the estuary

In North Carolina estuaries lie behind Outer Banks reduced tidal amplitude Almost all coastal river systems have tidal and freshwater systems Slight tidal change Irregular tides and greatly affected by the wind

North Carolina is unique… Tidal plant communities present typically restricted in size Tidal swamps present Cape Fear River system, one exception One meter tide Extensive areas of typical tidal freshwater marshes

Characteristics of freshwater wetlands by region Florida, tidal freshwater marshes are very restricted in size or very seasonal Gulf, Louisiana – extensive tidal freshwater marshes • Irregular • Low amplitude • Wind driven

Continued Pacific Coast - relatively rare Alaska – extensive California – associated with large river systems, ex. Sacramento Washington and Oregon – associated with Columbia River

Geological History – relatively recent Freshwater coastal marshes expanded rapidly as drowned river systems were inundated and filled with sediment Northern Gulf of Mexico coast, marshes are probably still expanding due to increased runoff associated with land clearing and human activities

Soil and Water Chemistry Coastal Marsh sediments generally organic Sediments are anaerobic except for a thin surface layer Ammonium is present in the winter but reduced to lower levels in the summer due to plant uptake Nitrogen present in organic form Phosphorus levels vary High cation exchange capacity (CEC) Soil p. H generally close to neutral (6. 3 to 7. 0)

Decomposition – 3 Factors Temperature, major factor in decay As temperatures increase, decay increases Oxygen and water availability Plants in anaerobic or dry environments decompose slowly Plant tissue: broadleaf perennials (high concentrations of nitrogen, leaf tissue readily decays) high marsh grasses (low nitrogen concentrations and structural tissue resistant to decay) • Litter tends to accumulate around persistent grasses • Low erosion rates ( and low tidal energy)

Organic Export Losses of organic carbon from marshes occur through respiration Peat forms below root zone Can convert to methane that escapes as a gas Exported in bodies of consumers that feed on the marsh In anaerobic freshwater, little sulfur available, carbon dioxide can be reduced to methane (which is lost to the atmosphere)

General Model of N & P Cycling

Nutrient budgets Appears to be similar to salt water marshes Open systems Long-term sinks, sources or transformers of nutrients Most inputs are inorganic transformed chemically or biologically to organic forms Recycle most nutrients used within the system; imports and exports are a small percentage of the total material cycled

Tidal Wetland Ecosystem

Marsh Vegetation – Brackish to Fresh Marsh cord grass (Spartina cynosuroides) Narrow leaved cat-tail (Typha angustifolia) Coastal cat-tail (Typha domingensis) Marsh fleabane (Pluchea purpurascens) Arrow-arum (Peltandra virginica) Wild rice (Zizania aquatica Swamp rose (Rosa palustris) Mallows (Hibiscus spp. )

Plants indicating Freshwater Wax myrtle (Myrica cerifera) Sedges (Carex spp. ) Jewelweed (Impatiens capensis) Blue flag (Iris versicolor) Broadleaf cat-tail (Typha latifolia) Wild celery (Vallisneria spiralis) Red maple (Acer rubrum) Water tupelo (Nyssa aquatica)

Algae & Microscopic Organisms Algae Green (Chlorophytes) Blue-green (Cyanophytes) Plankton (non to poor swimmers) Protozoans (animal like w/flagella) • dinoflagellates Diatoms (type of phytoplankton; phyto = green) • Building block of food chain Forams (animal like, eat diatoms) Bacteria

Larger Lower Animals Worms Small snails Jellyfish Shrimp (various spp. ) Crab (various spp. ) Sponges Mollusks Bivalve (oyster, bent mussel) Barnacles Sea squirt

Fish and Shellfish Classification Anadromous (spawns in freshwater, lives in saltwater); Semiandromous (spawns in freshwater adults remain in lower estuaries) ex. Striped bass, Herring. Shad, Sturgeon; Catadromous (spawns in saltwater, lives in freshwater) ex. American eel Estuarine-Marine (a few species move into freshwater marshes to spawn) ex. Spot, Croaker, Brown Shrimp, Summer Flounder Estuarine (complete entire lifecycle in estuary, extend range into freshwater marshes) ex. Killifish, Bay Anchovy, Hogchoker Freshwater (spawn and complete lives in freshwater areas) ex. Bluegill, Sunfish, Largemouth Bass

Amphibians and Reptiles Frogs, Toads Diamondback Terrapins American alligator Water snakes ex. Cottonmouth moccasins

Birds – 280 species reported Waterfowl (44 spp. ) Wading birds (15 spp. ) Rails and shorebirds (35 spp. ) Birds of prey (23 spp. ) Gulls, terns, kingfishers and crows (20 spp. ) Arboreal birds (90 spp. ) Ground and shrub birds (53 spp. )

Mammals Muskrat Nutria Meadow mouse, white footed mouse Cottontail Fox Raccoon Otter Opossum Skunk Whitetail deer Manatee Beaver

Freshwater Food Web

Floating Marshes Usually associated with non-tidal systems Marsh substrate composed of a thick organic mat, entwined with living roots that rises and falls with the surrounding water levels Coastal Louisiana tidal marshes has the largest area of floating marshes in US The flora is diverse but dominated by ferns in spring and Panicum hemitomon in summer and fall

Resources Alongi, D. M. 1998. Coastal Ecosystem Processes. Univ. of Minnesota, Minneapolis. pp. 419. Bertness, Mark D. 1999. The Ecology of Atlantic Shorelines, Sinauer Associates, Inc. Pbulishers Sunderland, Massachusetts, pp. 417. Mc. Lusky, D. S. 1981. The Estuarine Ecosystem. John Wiley &Sons, New York. pp. 150. Mitsch, William J. and James G. Gosselink. 1993. Wetlands, 2 d ed. , Van Nostrand Reinhold, New York, pp. 722. Odum, W. E. , T. J. Smith III, J. K. Hoover, C. C. Mc. Ivor. 1984. The Ecology of Tidal Freshwater Marshes of the United States East Coast: A Community Profile, U. S. Fish and Wildlife Service, FWS/OBS-83/17, Washington, D. C. , pp. 177. Pomeroy, L. R. and Weigert, R. G. 1981. The Ecology of a Salt Marsh. Springer-Verlag, New York. pp. 271 Roberts, Mervin F. 1979. The Tidemarsh Guide, E. P. Dutton, a Division of Sequoia-Elsevier, New York, pp. 240.

Resources Shabreck, R. H. 1988. Coastal Marsh Ecosystem and Wildlife Management. Univ. of Minnesota Press. pp. 138 Statler, Richard. 1993. Barrier Island Botany The Southern United States, Wm. C. Brown Dubuque, Iowa, pp. 164. Tiner, Ralph W. Jr. . 1987. A Field Guide to Coastal Wetland Plants of the Northeastern United States, The University of Massachusetts Press, pp. 285. Wharton, Charles H. . 1978. The Natural Environments of Georgia, Geological and Water resources Division and Resource Planning Section, Office of Planning and Research Georgia Department of Natural Resources Atlanta, Georgia, pp. 227. www. epa. gov/owow/wetlands www. excite. com (photo gallery) www. uf. edu ( plant photo gallery) www. h 20. denr. nc. state. gov

Resources http: //agen 521. www. ecn. purdue. edu/AGEN 521/epadir/wetlands/fr eshwtr_marsh. html http: //www. mobilebaynep. com/habitats/fresh. htm http: //www. uncwil. edu/people/hosier