UNDERSTANDING THE ECOLOGICAL 

 VALUES OF WETLANDS 



Joseph S. Larson 



WHAT ARE WETLANDS? 



Wetland? In 1970 the term meant little to the real estate developer, lawyer or 

 engineer. Only to wildlife biologists and in certain New England states did the term 

 wetland ha\e a more significant general meaning. Of course, most people had some 

 idea of what marshes, flats, swamps and bogs were. Pocosins, sloughs, hammocks 

 and bays were familiar in certain parts of the nation. Fens and carrs were known to 

 special groups of ecologists. All of these(plus other places known by other names) are 

 today recognized as various kinds of wetlands. 



Wildlife biologists were early users of the term because areas on the landscape that 

 are dominated b\ water and water tolerant plants provide essential habitat to fur- 

 bearing mammals, migratory ducks, geese and swans as well as many other wading, 

 water and shore birds. If these species were to survive in the face of human 

 development, wildlife professionals had to preserve all sorts of wet habitat that was 

 conveniently lumped under the name wetland. In short, wetlands are areas on the 

 landscape where water is present at. near or above the surface of the land long enough 

 to be the primary factor dictating what kinds of plants will grow there and what 

 special types of soil are formed (Figures 1 and 2).' 



Wetlands are where you find trees, shrubs, grasses, rushes, reeds or herbaceous 

 plants that are adapted in some physical way or have developed physiological 

 processes that permit them to grow where water is the dominant element year-round 

 or during a portion of the growing season. The soils on these wetland sites also reflect 

 the influence of water. Many of them are mucks or peats that contain organic matter 

 from the wetland plants. Some have particular physical, chemical or color 

 characteristics that develop due to continuous or long periods of water saturation. 

 Some wetlands, like rocky coastal shores, may have clinging plants and no soil. 

 Others, such as beaches, bars and flats, have no \egetation and technically no "soil." 

 but rather a sand, gravel or silt base. 



A DECADE OF CHANGE IN ATTITUDES TOWARD WETLANDS 



Wetlands, let alone swamps, just were not fit subject for polite dinner table 

 conversation 10 years ago. In a Maryland farmhouse, a Texas ranch or a Florida 

 bungalow, the word bog or swamp was usually linked to mosquitoes, malodorous 

 vapors, dangerous reptiles or desperate men driven from comfortable and "proper" 

 society. A good swamp was a drained or filled swamp. To most people, wetland 

 translated to wasteland. During the late 1960s and even more so during the 1970s, 

 however, wetlands took on a different (and sometimes controversial) public image. 



The Author: Dr. Josephs. Larson received theB.S. and M.S. degrees from the University of Massachusetts 

 and the Ph,|) (lom Virginia Poivtechnic InNlitiile. He in Chairman ol the Department ol Forestr\ and 

 Wildlile Management at the Dniversity o( Massachusetts. Amherst and Executne Chairman ol the National 

 Wetlands Technical Council. 



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