Native, vegetated wetlands in East Tennessee : priorities for preservation

Although wetlands perform processes beneficial to society, wetlands continue to be converted for other land uses. In East Tennessee many ecologically important wetlands remain in private ownership. Information concerning the numbers and types of wetlands, their functions in the landscape, and the environmental impacts to which they are subjected is needed by state agencies in order to make informed decisions concerning the relative importance of a site and appropriate conservation measures. National Wetland Inventory maps, soil surveys, and the Biological Conservation Database were used to locate wetlands in the Blue Ridge, the Ridge and Valley, and the Cumberland Plateau Provinces of East Tennessee. Field investigations were conducted at selected sites for identification, verification of information, and to assess environmental impacts. Based on NWI data, the largest extant wetlands in East Tennessee are anthropogenic in origin; they are related to raised water tables associated with reservoirs. The most frequent types of wetlands in East Tennessee are ponds, many of which are the result of human activity (i.e., farm ponds, mine scars, quarries, dams, etc.). Both ponds and wetlands associated with reservoirs were excluded from this study. Forested, scrub-shrub, and emergent wetlands are less frequent, most are only temporarily flooded, and of the wetter sites (seasonally and semipermanently flooded) most are under two hectares in size. A four hectare size was selected as the threshold for evaluation based on considerations of site quality and viability. Sites meeting this threshold are significant and rare simply due to their comparatively large size in a region where even smaller wetlands are more the norm. Records in the Biological Conservation Database (Natural Heritage Program) indicate that even extremely small sites (< 0.1 hectare) may be important to the maintenance of certain rare, threatened and endangered species in Tenessee, as well as rare biological communities. In this study, of the 19 wetlands identified as deserving protection, 17 are 40 hectares or less, 12 are 12 hectares or less, and 5 are 6 hectares or less. Wetlands were evaluated and prioritized using several ranking methods; results of the methods were compared. Although ranking methods were tested on selected sites, the use of these methods and the results obtained in no way indicates that any of these sites are unworthy of protection.