Effects of Algae-Grazing Fishes on Biotic Communities and Ecosystem Processes in North Temperate Streams

该项目建立在三年的调查基础上， 食草-藻类相互作用和捕食-食草-藻类相互作用的影响 北温带河流的相互作用， 关于放牧鱼类（Campostoma）对 生物群落和生态系统一级的进程或速率 溪流系统 之前的研究表明 食肉鱼类之间的关系影响了 吃藻类的小鱼，这反过来又对 分布和附着藻类种类。 前人研究 也表明Campostoma的放牧可能有直接的 对占主导地位的欧扎克河藻类类群的影响 基质，维持初级生产力的“草坪”，以及 藻类种类的变化可能会影响一些现象， 固氮、C：N比或细菌植物群。 本研究 通过实验室和现场相结合的测试， 操纵，假设放牧鱼类普遍存在， 温带河流的结构和功能 生态系统 鱼类作为食草动物在很大程度上被忽视， 北温带溪流 本研究将使用实验室 曲口鱼与几种无脊椎动物溪流比较 放牧对系统影响强度分类群 现象。

This project builds on three years of investigation on the effects of grazer-algae interactions and predator-grazer-algae interactions in north temperate streams to ask fundamental questions about the influence of grazing fishes (Campostoma) on biotic communities and ecosystem-level processes or rates in stream systems. The previous research demonstrated a link between predatory fishes that influenced distributions of the algae-grazing minnows, which in turn has strong effects on disribution and kinds of attached algae. The previous research also suggested that grazing by Campostoma could have a direct influence upon the taxa of algae that dominated Ozark stream substrates, maintaining a "lawn" of primary productivity, and changes in kinds of algae could influence phenomena such as nitrogen fixation, C:N ratios, or bacterial flora. This research tests, through a combination of laboratory and field manipulations, the hypothesis that grazing fishes have prevasive effects throughout the structure and function of temperate stream ecosystems. Fish have largely been overlooked as grazers in north temperate streams. The present study will use laboratory stream comparisons of Campostoma to a variety of invertebrate taxa with regard to strength of grazing effects upon system phenomena.