Dissertation Research: Role of a Dominant Grazer in a Headwater Stream Food Web.

提案： DEB-0107427 PI：电源，玛丽E.，和Frances C. McNeely标题：论文研究：一个占主导地位的食草动物在源头流食物网的作用拟议的研究解决了生态学中的一个基本问题：是什么决定了食物网的结构？ 在一般情况下，一套操纵现场实验的目的是量化的控制，草食性物种可以施加流食物网。 操纵的丰度和物候的一个占主导地位的放牧无脊椎动物（Glossosoma），结合稳定同位素分析，将确定是否Glossosoma的存在和密度控制使用藻类和碎屑（替代能源的流）的其他物种的消费者。 由于舌体虫的形态（石壳）相对不易被捕食，它可能会阻止捕食者对食草动物施加控制。 这将被量化的一个共同的捕食者，太平洋大鲵（Dicamptodon tenebrosus）。 拟议中的工作将以严格的方式测试食草动物对食物网结构施加“中间控制”的假设。

Proposal: DEB-0107427PI: Power, Mary E., and Frances C. McNeelyTitle: Dissertation Research: Role of a Dominant Grazer in a Headwater Stream Food WebThe proposed research addresses a fundamental question in ecology: what determines the structure of food webs? In general, a suite of manipulative field experiments is designed to quantify the control that herbivorous species can exert on stream food webs. Manipulations of the abundance and phenology of a dominant grazing invertebrate (Glossosoma), in combination with stable isotope analyses, will determine if the presence and density of Glossosoma control the use of algae and detritus (alternative energy sources in streams) by other species of consumers. Because Glossosoma is relatively invulnerable to predation as a consequence of its morphology (a stone case), it may prevent predator species from exerting controls over herbivores. This will be quantified with regard to a common predator, the Giant Pacific Salamander (Dicamptodon tenebrosus). The proposed work will test in a rigorous manner, the hypothesis that herbivores exert "intermediate control" over the structure of food webs.