SGER: Linking Marine-dDerived Nutrients To Stream Ecosystem Function Using a 15N Tracer Addition Combined with an Experimental Salmon Carcass Addition.

摘要：溯河鲑鱼是太平洋西北地区的命脉，是相当大的经济、社会和文化价值的基础。通常情况下，每年都有大量的有机物质通过鲑鱼迁徙从海洋输送到溪流中。目前，鲑鱼的数量已经下降，立法者、资源管理者和科学界开始问鲑鱼尸体在河流生态系统中扮演什么角色。PIs将通过追踪添加到阿拉斯加河流中的重氮同位素（15N）在添加鲑鱼胴体之前，期间和之后的流动来解决这一关键的知识差距。这将从食物网和整个河流的角度量化海洋来源营养物质（MDN）的脉冲如何改变河流氮循环的速率。这项研究建立在美国农业部资助的一项正在进行的研究的基础上，该研究以一种新颖的方式使用15N示踪技术，将有助于阐明MDN在河流生态系统中的作用。

AbstractTank0120845Anadromous salmon are the life-blood of the Pacific Northwest, on which are based considerable economic, social, and cultural values. Normally, a massive quantity of organic material is transported from the ocean to streams annually via salmon migration. Presently, salmon stocks have declined, and lawmakers, resource managers, and the scientific community are beginning to ask what role salmon carcasses play in stream ecosystems. The PIs will address this critical knowledge gap by tracing the flow of the heavy isotope of nitrogen (15N) added to an Alaskan stream before, during, and after a salmon carcass addition. This will quantify how the pulse of marine derived nutrients (MDN) alters rates of stream N cycling from both a food web and whole-stream perspective. This research builds on the insight gained from an ongoing USDA-funded study by using the 15N tracer technique in a novel way and will help to clarify the role MDN plays in stream ecosystems.