Input and Metabolism of Ancient Terrestrial Organic C in a Large River: Importance to the Food Web and Net Ecosystem Metabolism

Nina Caraco-9973925初步的14C测量，加上生态系统预算，表明进入哈德逊河的大部分有机碳是数千年前在陆地上产生的，这些物质在河边停留几个月就会代谢。因此，在陆地上抵抗分解数百至数千年的有机化合物，在进入河流后可能会促进今天的新陈代谢。如果这一现象是真实的和普遍的，那么这种现象对河流食物网以及全球范围内的碳储存和新陈代谢都有影响。研究人员建议使用14C分析来：1)确认哈德逊河的这些初步发现；2)通过采样一些主要的哈德逊支流来推断这种古代C的来源，这些支流排出了不同土地用途的分水岭；3)将他们的观测扩大到其他几条河流；以及4)检查哈德逊河中的关键生物，看看古代C是否支持它们的生长。

AbstractNina Caraco- 9973925Preliminary 14C measurements, coupled with ecosystem budgets, suggest that much of the organic C that enters the Hudson River was produced on land thousands of years ago and that this material is metabolized during only a few months of riverine residence. Thus, organic compounds that resisted decomposition for hundreds to thousands of years on land, may be fueling present-day metabolism upon entering the river. If true and general, this phenomenon has implications for both riverine food webs, and for carbon storage and metabolism at the global scale. The Investigators propose to use 14C analyses to: 1) confirm these preliminary findings for the Hudson River; 2) infer the source of this ancient C by sampling some major Hudson tributaries which drain watersheds with different land uses; 3) expand their observations to several other rivers; and 4) examine key organisms in the Hudson to see if ancient C supports their growth.