Environmental Impact of Upland Streams on the Okefenokee Swamp

摘要

The Okefenokee Swamp is the largest freshwater wetland in the U.S. The terrestrial upland component and associated upland streams are located primarily in the northwestern portion of the watershed. Low topographic relief, highly leached sandy soils, and predominantly silvicultural land use practices contribute to low flow, low sediment yields, and low nutrient characteristics of this upland surface water. Deep groundwater contributes little or nothing to swamp hydrology. Upland streams contribute 39% of total input to the swamp. The swamp is divided into three drainages, the Suwannee River, the major swamp surface water output, Cypress Creek, and St. Mary's River. The swamp surface water is similar to other blackwater systems having low pH, low ionic strength, high organic carbon, and predominance of organic and reduced forms of nutrients. Channelization of 25% of total upland stream length decreased surface water flow to the swamp by lowering the shallow groundwater table. Water quality parameters were not affected. Higher concentrations and greater variability of cations and nutrients and correlations with physical variables in channelized streams indicate that channelized streams act as little more than conduits for transport of water and nutrients to the swamp. (Copyright (c) 1981 Elizabeth Reid Blood.)