Sources and Biological Lability of Terrestrial Dissolved Organic Carbon Entering Streams: Implications for Stream Ecosystem Metabolism

点击翻译按钮获取中文摘要

The researchers propose an examination of the mechanisms that control the terrestrial supply of dissolved organic carbon to streams, emphasizing measurements of concentration and susceptibility to biological utilization. The proposed research focuses on headwater streams in the Eastern Deciduous Biome. Research objectives include measuring: (1) the sources of terrestrially derived dissolved organic carbon entering streams, such as groundwater, soilwater, and wetlands, (2) the biological utility and molecular composition of these terrestrial sources, and (3) the influence of biological activity near the streambanks and below the streambed on the concentrations of dissolved organic carbon in the steamwater. %%% Organic carbon dynamics are central to stream ecosystem studies because they link energy flow and nutrient cycling. Dissolved organic carbon may contribute from 30% to 75% of the total energy input into stream ecosystems. Despite numerous advances during the past two decades, there is still only a poor understanding of how much dissolved organic carbon actually enters streams and rivers, and concomitantly, how much is utilized within the ecosystems.