Dissertation Research: Exploring Mechanisms of a Species Replacement in a Benthic Stream Community

无论是非生物还是生物过程， 在自然群落中， 一个重要的问题 在溪流中，生态学家传统上 强调非生物因素，但越来越多的证据表明， 生物的相互作用构成了湖泊群落。 在俄亥俄州中部 溪流中，小龙虾物种的替代是必然发生的， 提供了一个独特的机会来严格测试那些生物 控制底栖无脊椎动物分布的过程， 丰饶。 将探讨三种可能的机制： 不同的繁殖成功率，不同的竞争力 能力，特别是对鱼类的不同脆弱性 捕食 具体而言，将确定直接和 捕食和竞争的间接影响可以解释这一点 物种更替 实地调查、实验室实验和实地 操纵将澄清如何差异大小，增长， 栖息地利用影响这三种替代机制中的每一种。 由于这种小龙虾替代品的持续性质， 相信这将成为研究生物学的模型系统， 流中的进程。

Whether abiotic or biotic processes are primarily responsible for the patterns within natural communities remains an important question. In streams, ecologists have traditionally emphasized abiotic factors, but increasing evidence suggests that biotic interactions structure lotic communities. In central Ohio streams, a crayfish species replacement is undeniably occurring, providing a unique opportunity to test rigorously those biotic processes controlling benthic invertebrate distribution and abundance. Three potential mechanisms are to be explored: differential reproductive success, differential competitive ability, and particularly differential vulnerability to fish predation. Specifically, it will be determined if the direct and indirect effects of predation and competition can explain this species replacement. Field surveys, lab experiments, and field manipulations will clarify how differential size, growth, and habitat use influence each of these three alternative mechanisms. Because of the ongoing nature of this crayfish replacement, it is believed that this is to be a model system for studying biotic processes in streams.