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

溯河产卵的鲑鱼是太平洋西北部的生命线，其经济、社会和文化价值都建立在鲑鱼的基础上。通常情况下，每年有大量的有机物质通过鲑鱼迁徙从海洋运输到河流中。目前，鲑鱼种群已经下降，立法者，资源管理者和科学界开始询问鲑鱼尸体在溪流生态系统中扮演什么角色。 PI将通过追踪在鲑鱼尸体添加之前，期间和之后添加到阿拉斯加河流中的重氮同位素（15N）的流动来解决这一关键的知识缺口。这将量化的脉冲海洋衍生营养素（MDN）如何改变流N循环速率从食物网和全流的角度来看。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，通过以一种新的方式使用15N示踪技术，将有助于澄清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.