湖沼学chapter 5 Aquatic plants and wetland.ppt

chapter 5: Wetland and Aquatic plants types of wetlands As a result of regional differences in soil, climate, water chemistry, and other factors, the variety of wetlands is unmatched. Wetlands are found on every continent except Antarctica, stretching from the tropical regions to the barren tundra. Currently, scientists recognize five major wetland systems: marine, estuarine, lacustrine, riverine, and palustrine. These are grouped into two general categories: Coastal (marine and estuarine) and Inland (lacustrine, riverine, and palustrine). COASTAL  Marine(near the ocean) - water levels rise and fall with the daily tides Bays Sounds Coastline Estuarine(coastal wetland where fresh and saltwater mix) Tidal salt marsh Tidal freshwater marshes Mangrove swamps INLAND (accounts for 90% of U.S. wetlands)  Palustrine (standing or very slowly flowing water) Non-tidal marshes Bogs (peatlands) Riverine (flowing water) - see Rivers of Alabama Drainage basins along freshwater rivers, streams, and creeks Swamps Forested swamps Shrub swamps Lacustrine (shallow water) Low-lying areas surrounding lakes, ponds, and reservoirs Wet meadows Palustrine (standing or very slowly flowing water) Non-tidal marshes Bogs (peatlands) Nontidal (inland) marshes are dominated by herbaceous plants and frequently occur in poorly drained depressions, floodplains, and shallow water areas along the edges of lakes and rivers. Major regions of the United States that support inland marshes include the Great Lakes coastal marshes, the prairie pothole region, and the Florida Everglades. Bog –bogs are sometimes referred to as “peatlands” which lack an overlying layer of mineral soil. Peat is accumulated dead plant matter that decomposes very slowly, making the soil and water highly acidic. Moreover, bogs receive most if not all of their water from precipitation (which lacks the nutrients found in groundwater or runoff), further increasing the acidity in the water and soil. Obvious