Dissertation Research: The Influence of Competition and Environmental Heterogeneity on the Movement Patterns of a Benthic Invertebrate

虽然移徙发生在许多社区，理论研究表明它可能对社区动态产生重要影响，但人们对它的理解并不充分。流社区提供了调查迁移的绝佳机会。最近的研究表明，运动可能受到种内和种间竞争的影响，因此它是密度依赖的。然而，这些群落中生物诱导迁移的流行程度尚不清楚。一些理论研究表明，密度依赖的迁移可能对社区动态产生重要影响；但是，没有进行彻底的调查。很明显，不仅需要实证和理论研究来了解河流中密度依赖性迁移的普遍性，而且还需要了解其对群落结构的重要性。将使用实验室和实地实验相结合的方法来量化环境异质性和种内竞争对一种球蝇（Hydropsyche slossonae）迁移的影响。实验室研究将记录过程，实地研究将验证它们在自然群落中的重要性。现有的理论模型将被修改，以纳入密度依赖迁移。通过这种建模工作，将评估这种迁移对社区结构的影响。一个计算机模型也将用于生成特定于流社区的预测。结合实证和理论研究将提供一个独特的机会来了解移民对人口动态的影响。

Although migration occurs in many communities and theoretical studies suggest that it can be an important influence on community dynamics, it is not well understood. Stream communities provide an excellent opportunity to investigate migration. Recent research suggests that movement may be influenced by intraspecific and interspecific competition such that it is density-dependent. However, the prevalence of biotically induced migration in these communities is unknown. A few theoretical studies suggest that density-dependent migration can have important consequences for community dynamics; however, no thorough investigations have been undertaken. It is clear that both empirical and theoretical investigations are needed to understand not only the prevalence of density-dependent migration in streams, but its importance to community structure. A combination of laboratory and field experiments will be used to quantify the effects of environmental heterogeneity and intraspecific competition on the migration of a caddisfly, Hydropsyche slossonae. Laboratory studies will document processes and field studies will verify their importance in natural communities. Existing theoretical models will be modified to incorporate density-dependent migration. Through this modeling effort, the influence of such migration on community structure will be assessed. A computer model to will also be used to generate predictions specific to stream communities. Combining both empirical and theoretical studies will provide a unique opportunity to understand the influence of migration on population dynamics.