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

点击翻译按钮获取中文摘要

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.