Collaborative: Assessing Effects of Food Web Structure on Patterns of Productivity and Trophic Transfer in Lake Food Webs

小行星9520214 本研究将探讨上层食物网配置对加州城堡湖浮游生态系统结构、碳流和生产力的影响。这项研究建立在一个完整的湖泊食物网操纵，并增加了价值和重要性的一个发达的长期数据集，强调初级生产力的生物和气候的决定因素。在这个项目中，城堡湖的食物网配置将通过改变虹鳟鱼的放养率来操纵。操作将减少虹鳟鱼，从而增加了丰富的黄金光泽，桡足类，和微食草动物的细菌。通过测量微生物和初级生产率，评估后生动物和鱼类的种群和生长动态，本研究将估计不同食物网配置下食物网的生产模式和碳流。城堡湖食物网的营养结构操作的反应将比较并发动态在一个未受干扰的参考网站，悬崖湖。除了对整个湖泊的操作外，还将进行一系列中、微观实验，以解决决定食物网结构的机制。本研究将在一个定量模拟模型中进行总结和综合。这种定量框架将允许整合从调查跨越各种空间和时间尺度，并将允许解释的微生物和经典的食物网动态的背景下，长期的数据记录的城堡湖生态系统。

9520214 Goldman This research will examine the effect of upper food web configuration on pelagic ecosystem structure, carbon flow, and productivity in Castle Lake, California. This research builds on a whole lake food web manipulation, and augments the value and importance of a well-developed long term data set emphasizing biological and climatic determinants of primary productivity. In this project, food web configuration in Castle Lake will be manipulated by varying the stocking rates of rainbow trout. The manipulation will reduce rainbow trout, thus increasing the abundance of golden shiners, copepods, and micrograzers of bacteria. By measuring rates of microbial and primary production and assessing population and growth dynamics of metazoans and fish, this research will estimate patterns of production and carbon flow through the food web under different food web configurations. The response of the Castle Lake food web to trophic structure manipulation will be compared to concurrent dynamics in an unperturbed reference site, Cliff Lake. In addition to the whole lake manipulation, a series of meso- and microcosm experiments to address mechanisms determining food web structure will be conducted. This research will be summarized and synthesized within a quantitative simulation model. This quantitative framework will allow integration from investigations spanning a variety of spatial and temporal scales, and will allow interpretation of microbial and classic-based food web dynamics within the context of the long-term data record for the Castle Lake ecosystem.