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Wetlands at Vassar College |
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The Priscilla Bullitt Collins Trail was not a wetland until the 1960’s. Previously, the area was dry meadow and woodland, with a stream running through its lowlands (history). The area became a wetland by the manipulation of the land upstream of Fonteyne Kill, specifically the expansion of Raymond Avenue and work done around Vassar Lake, which lies on the other side of Raymond Avenue. Thus, the Priscilla Bullitt Collins Trail is a human-made wetland that has only been in existence for less than forty years. Despite it’s short history as a wetland, the 4-acre area is home to native wetland species as well as many common wetland invasives. Its value lies in its ability to educate visitors about wetland habitats. |
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What is a wetland? |
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The scientific enigma and the ever-present problem of assigning names and labels. |
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Wetlands are broadly defined as the interface between aquatic and terrestrial ecosystems. Beyond this, scientists and naturalists have been unable to agree upon a single definition. However, the inability to define wetlands stems from the fact that the habitats generally assigned the label, "wetland" are incredibly diverse. We are familiar with the terms swamp, bog, marsh, fen, mire, peatland, which all fall under the umbrella term, "wetland." These various habitats include coastal salt-water marshes, freshwater swamps, shallow lakes, highland bogs, and lowland regions that may experience periodic flooding. One can get a sense of the complexity in defining a wetland when considering that wetlands occur in temperate and tropical climates, at all altitudes, and within various salinities and soil types. Furthermore, wetlands often experience temporal variation in the quantity of water they retain, as exemplified by alluvial flooding and varying amounts of precipitation. Basically, there have been three very broad attributes that wetlands share:
Although vegetation is more visible, and therefore more commonly used in identifying a wetland, both the substrate and biota together comprise a more accurate determination of a wetland. |
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For an excellent diagram and explanation go to: |
http://www.geocities.com/RainForest/Vines/3317/wetlandgraphic.html |
http://www.epa.gov/region4/water/wetlands/general/faq.html |
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The Functions of wetlands |
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Wetlands are commonly described as "nature’s kidneys". This is due to the vital role that most wetlands play as filters of organic and inorganic matter that would otherwise flow from dry land directly into aquatic habitats. Wetlands stabilize waterflow in streams and rivers by the absorption and retention of excess rainfall into the wetlands, which can prevent flooding. During dry seasons this excess is then released back into the waterways. Wetlands also can filter pollutants out of water passing from dry land to aquatic habitats. Chemicals, pesticides, and heavy metals are bound or broken down in the hydric soils.
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Wetlands and People: How does a wetland function in society? |
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How a wetland functions in society is variable and depends upon the nature of the wetland as well as the values and concerns of the surrounding communities. Wetlands often have an important biological value as a filter of pollutants and waste from natural and human sources. Some communities preserve wetlands on the principle of conserving biodiversity, while others depend on wetlands for their economic value. Many wetlands play a role in purifying drinking water or preventing soil erosion and flooding.
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References for Wetlands:
Environmental Protection Agency: http://www.epa.gov/region4/water/wetlands/general/faq.html The EPA’s site on wetland policy, protection, and conservation. Mitsch, William J. and James G. Gosselink. Wetlands. New York, Van Nostrand reinhold Company Inc. 1986. 537 pp. National Research Council. Wetlands: Characteristics and Boundaries. Washington DC, National Academy Press, 1995. 307 pp.
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