Title: Wetlands of the United States : current status and recent trends / by Ralph W. Tiner, Jr. ... [et al.].
Abstract: hierarchy of wetlands and deepwater habitats, showing systems, subsystems, and classes 4 Diagram showing major wetland and deepwater habitat systems 5 Examples of estuarine emergent wetlands 6 Cross-section of a Northeastern salt marsh 7 Examples of estuarine intertidal flats 8 Mangrove-dominated estuarine scrub-shrub wetlands of Florida 9 Examples of palustrine emergent wetlands 10 Generalized vegetation zones of a pothole wetland in relationship to water regime 1 1Examples of palustrine scrub-shrub wetlands 12 Examples of palustrine forested wetlands 13 Wetland habitat utilization by several families of birds 14 Migratory birds using wetlands 15 Waterfowl habitat areas of major national concern 16 Wetlands are important to many other wildlife species 17 Aerial view of Tinicum Marsh near Philadelphia, Pennsylvania 18 Relative productivity of wetland ecosystems in relation to others 19 Simplified food pathways from estuarine wetland vegetation to commercial and recreational fishes 20 Wetland value in reducing flood crests and flow rates after rainstorms 21 Wetland drainage and filling increase the potential for damaging floods ....22 Estuarine-dependent fish, like salmon, provide the majority of the commercial fisheries in the United States 23 Wetlands provide opportunities for recreational fishing 24 Many Americans enjoy watching birds in and around wetlands 25 Relative abundance of wetlands in the U.S. ( 1984) 26 Extent of wetlands in the conterminous U.S. in the mid-1970's 27 Original and remaining acreages of wetlands in the conterminous US 28 Net losses and gains in wetlands of the conterminous U.S. between the mid- 50's and mid-70's IV 29 Causes of recent wetland losses (mid-1950's to mid-1970's) in the conterminous U.S.; losses to agriculture are highlighted 30 Historical losses of wetlands in Iowa and California 31 Rates of coastal wetland loss in the conterminous U.S 32 Filling of estuarine wetlands for residential housing in Long Island, New York, and other coastal areas was particularly heavy in the 1950's and 1960"s i3 The status of wetland filling and diking in San Francisco Bay prior to the mid- I960's 34 Louisiana's coastal marshes are being permanently flooded by Gulf of Mexico waters at an accelerating rate 35 Chesapeake Bay and its major tributaries 36 Chesapeake Bay is one of the more important wintering areas for canvasbacks in North America 37 Channelization of the Kissimmee River directly destroyed many wetlands and facilitated drainage of more than 100,000 acres of wetlands 38 Present extent of wetlands in the Florida Everglades; former wetlands are also shown 39 Prairie pothole wetlands are the Nation's most valuable waterfowl production areas 40 Original extent and distribution of Minnesota's wetlands 41 Present extent and distribution of Minnesota's wetlands 42 Prairie pothole wetlands continue to be drained for agriculture 43 Sandhill cranes on a Platte River roost at sunrise 44 Actual and projected losses in bottomland forested wetlands of the Lower Mississippi Alluvial Plain 45 Bottomland wetlands are being channelized, clearcut and converted to agricultural uses in many areas of the Southeast 46 Most of the Nation's pocosin wetlands occur along the coastal plain of North Carolina 47 Comparison of the extent of natural or only slightly modified pocosins in North Carolina, (a) early I950's and (b) 1980 48 Riparian wetlands along rivers and lakes are important to many forms of wildlife in the West 49 Establishing waterfowl production areas is one way that the Service protects important waterfowl breeding habitat 50 Current status of state wetland protection efforts List of Tables No. Page 1 List of major wetland values 2 Major causes of wetland loss and degradation 3 Examples of wetland losses in various states 4 Examples of recent wetland loss rates VI Executive SummaryThis report identifies the current status of U.S. wetlands and major areas where wetlands are in greatest jeopardy from the national standpoint.It also presents e.xisting regional and national information on wetland trends.The report is divided into six chapters: (1) Introduction.(2) What Is a Wetland?, (3) Major Wetland Types of the United States, (4)Why Are Wetlands Important?. (5) Current Status and Trends of U.S. Wetlands, and (6) The Future of America's Wetlands.Wetlands include the variety of marshes, swamps and bogs that occur throughout the country.They range from red maple swamps and black spruce bogs in the northern states to salt marshes along the coasts to bottomland hardwood forests in the southern statfes to prairie potholes in the Midwest to playa lakes and riparian wetlands in the western states to the wet tundra of Alaska.The Fish and Wildlife Service has developed a scientifically sound wetland definition and classification system to inventory the Nation's wetlands.The bulk of America's wetlands fall into two ecological systems: (I) EstuarineSystem and (2) Palustrine System.The Estuarine System includes salt and brackish tidal marshes, mangrove swamps and intertidal fiats, while the Palustrine System encompasses the vast majority of the country's inland marshes, bogs, and swamps.Wetlands produce many benefits for society besides providing homes for many fish and wildlife species.Some of the more important public values of wetlands include flood control, v/ater quality maintenance, erosion control, timber and other natural products for man's use, and recreation.Approximately 215 million acres of wetlands existed in the conterminous U.S (i.e., lower 48 states) at the time of the Nation's settlement.In the mid-1970's, only 99 million acres remained, leaving just 46% of the original wetland acreage.The U.S. wetland resource for the lower 48 states encompassed 93.7 million acres of palustrine wetlands and 5.2 million acres of estuarine wetlands.Wetlands now cover about 5% of the land surface of the lower 48 states.The total wetland acreage for the lower 48 states amounts to an area roughly the size of California.Between the mid-I950's and the mid-I970's, about 1 1 million acres of wetland were lost, while 2 million acres of new wetland were created.Thus, in that 20-year interval, a net loss of 9 million acres of wetland occurred.This acreage equates to an area about twice the size of New Jersey.Annual wetland losses averaged 458.000 acres; 440,000 acres of palustrine losses and 18,000 acres of estuarine wetland losses.This annual loss equals an area about half the size of Rhode Island.Agricultural development was responsible for 87% of recent national wetland losses.Urban development and other development caused only 8% and 5% of the losses, respectively.The most extensive wetland losses occurred in Louisiana, Mississippi, Arkansas, North Carolina, North Dakota, South Dakota.Nebraska.Florida and Texas.Greatest losses of forested wetlands took place in the lower Mississippi Valley with the conversion of bottomland hardwood forests to farmland.Shrub wetlands were hardest hit in North Carolina where pocosin wetlands are being converted to cropland or pine plantations or mined for peat.Inland marsh drainage for agriculture was most significant in the Prairie Pothole Region of the Dakotas and Minnesota.Nebraska's Sandhills and Rainwater Basin and Florida's Everglades.Between the mid-1950's and mid-1970's, estuarine wetland losses were heaviest in the Gulf states, i.e., Louisiana, Florida, and Texas.Most of Louisiana's coastal marsh losses were attributed to submergence by coastal waters.In other areas, urban development was the major direct man- induced cause of coastal wetland loss.Dredge and fill residential development in coastal areas was most significant in Florida, Texas, New Jersey.New York, and California.The future of the Nation's wetlands depends on the actions of public agencies, private industry, and private groups and individuals.Recent population and agricultural trends point to increased pressure for converting wetlands to other uses, especially cropland.Increased wetland protection efforts by all levels of government and by private parties are needed to halt or slow wetland losses and to enhance the quality of the remaining wetlands.Major protection options are outlined in the report.