Recovery of Stream Ecosystems from Insecticide Treatment andDrought

点击翻译按钮获取中文摘要

Organic matter and nutrient dynamics in small mountain streams at the Coweeta Hydrologic Laboratory in western North Carolina, will be studied. Two factors controlling these dynamics will be considered - invertebrate consumer (i.e. leafshredding aquatic insects) activity and drought. Leaf-shredding aquatic insects are hypothesized to be major processors of organic matter and nutrients in small streams. This hypothesis will be tested by comparing organic matter and nutrient dynamics in unmanipulated streams with those in streams from which aquatic insects have been removed with insecticides. Part-way through the study period the insecticide treatment will be halted and the relationship between the recovery of the invertebrate consumer community and changes in organic matter and nutrient dynamics in these streams will be followed. Drought conditions have prevailed at the Coweeta Hydrologic Laboratory since 1984, and data have been taken over this period on stream organic matter and nutrient dynamics. Continued studies of these dynamics will further document the small-stream ecosystem responses to drought conditions; and if the hydrologic regime should return to "normal," the studies would document recovery of these systems from drought. This research is important since very little information exists on the effects of drought on organic matter and nutrient dynamics in streams. The studies will be conducted using well-proven laboratory and field techniques. Dr. Wallace and his colleagues, Drs. Webster and Suberkropp, have good research records and the institutional support for the work is of high quality.