The Effects of Stream Flow and Predation on Trophic Interactions Among Juvenile Cyprinid and Centrarchid Fishes Below Beaver Ponds

河流流量的年变化与无脊椎动物丰度的剧烈波动以及幼鱼和鲤科鱼的密度有关。在没有中央蜥蜴捕食的情况下，小鱼抑制了池塘生境中无脊椎动物的丰度，而没有抑制河纹，中央蜥蜴捕食者在进行物种和大小选择性捕食的同时，将幼鱼限制在浅水河纹的避难所。这项研究是对这些发现的合理延伸。实验将量化河狸池下河流流量、中央鱼捕食和幼鱼密度对无脊椎动物资源、幼鱼和中央鱼的同时影响。将测试与以下四个问题相关的假设：1。幼鱼的生长和存活对鱼类密度的变化有多敏感？如果有的话，种间使用无脊椎动物资源对这些鱼类的生长和存活有什么影响？2. 河狸池下水流状态的变化是否会改变幼鲤和中央鱼类资源利用的强度和结果？3. 捕食者对鲤幼鱼和幼鱼资源利用的强度和结果有什么影响？4. 河狸池塘下水流的变化如何影响捕食者-猎物的相互作用以及幼鱼和鲤科鱼类对无脊椎动物资源利用的结果？这项研究将大大提高我们对河流鱼类生长和生存调控的认识。它还将提高我们将水文制度对营养相互作用的影响纳入新兴的北温带水生景观概念模型的能力。

Annual variation in stream flow is associated with dramatic fluctuations in invertebrate abundance and the density of juvenile cyprinid and centrarchid fishes. In the absence of centrarchid predation, small fishes depress invertebrate abundance in pool habitats but not riffles, and centrarchid predators restrict juvenile fishes to shallow riffle refugia while engaging in species- and size-selective predation. This research is a logical extension of these findings. Experiments will quantify the simultaneous influence of stream flow, centrarchid predation, and juvenile fish density on invertebrate resources and juvenile cyprinid and centrarchid fishes below a beaver pond. Hypotheses will be tested related to the following four questions: 1. How sensitive is the growth and survivorship of juvenile cyprinid and centrarchid fishes to changes in fish density and what, if any, effect does interspecific use of invertebrate resources have on the growth and survivorship of these fishes? 2. Do changes in flow regime below beaver ponds shift the intensity and outcome of resource use by juvenile cyprinid and centrarchid fishes? 3. What effect do centrarchid predators have on the intensity and outcome of resource use by juvenile cyprinids and centrarchids? 4. How do changes in flow regime below beaver ponds effect predator-prey interactions and the outcome of invertebrate resource use by juvenile cyprinid and centrarchid fishes? This research will greatly enhance our understanding of the regulation of growth and survival in stream fishes. It will also increase our ability to incorporate the effect of hydrologic regime on trophic interactions into emerging conceptual models of north-temperate aquatic landscapes.