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

这组科学家提出了一项控制陆地向河流提供溶解有机碳的机制的研究，强调了浓度和对生物利用的敏感性的测量。提出的研究重点是东部落叶生物群系的源头溪流。研究目标包括测量：(1)陆源溶解有机碳进入河流的来源，如地下水、土壤水和湿地；(2)这些陆源的生物效用和分子组成；(3)河岸附近和河床以下生物活动对蒸汽水中溶解有机碳浓度的影响。有机碳动力学是河流生态系统研究的核心，因为它将能量流动和养分循环联系起来。溶解的有机碳可以贡献30%到75%的总能量输入到河流生态系统。尽管在过去的二十年里取得了许多进展，但对于有多少溶解的有机碳实际进入溪流和河流，以及随之而来的，有多少在生态系统中被利用，人们仍然知之甚少。

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.