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

提案：deb0107427pi: Power， Mary E., and Frances C. mcneely标题：论文研究：优势食草动物在源头流食物网中的作用。提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？一般来说，一套可操作的野外实验被设计用来量化草食性物种对河流食物网的控制。对占优势的食草无脊椎动物（舌虫）的丰度和物候进行控制，结合稳定同位素分析，将确定舌虫的存在和密度是否控制了其他种类的消费者对藻类和碎屑（溪流中的替代能源）的利用。由于舌骨虫的形态（一个石头的例子），它相对来说不容易受到捕食者的伤害，它可能阻止捕食者物种对食草动物施加控制。这将被量化为一种常见的捕食者，太平洋大鲵（Dicamptodon tenebrosus）。拟议的工作将以严格的方式检验草食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.