Importance of Secondary Dispersal in Determining Patterns of Spatial Abundance in Macro-Invertebrate Communities

9731718 Peterson软底栖生物栖息地是海洋生态系统中最普遍存在的环境之一；然而，与其他类型的底栖生物系统相比，我们对决定物种丰度和分布的过程的了解相形见绌。过去对底栖生物系统的研究主要集中在捕食、干扰和竞争对成年底栖生物种群的作用上。最近对幼虫供应和整个招募过程的潜在作用的关注极大地扩展了我们对底栖生物群落结构过程的了解。然而，对于软底群落，在我们的知识中存在一个巨大的，关键的空白，即幼虫招募后生物体的二次运动或再扩散的作用。通过一系列旨在解决这一主题的实地和实验室实验，研究将集中在两个目标上：量化和描述选定的海洋底栖大型无脊椎动物，特别是幼体的次级运动，并确定次级运动在构建软底群落和调解其他过程的相互作用中的作用。研究将集中在三种常见的河口底栖无脊椎动物，它们的扩散能力各不相同，包括两种双壳类动物和一种多角形蠕虫。这项研究将包括直接检查这些生物的原位，并将包括流体力学制度的特征。规划了生境结构、捕食者和密度对二次分散依赖性的相互作用研究。这些结果将增加对软底栖环境中影响群落结构和功能的因素的认识。

9731718 Peterson Soft-bottom benthic habitats represent one of the most ubiquitous environments within the marine ecosystem; however, our knowledge of the processes which determine species abundance and distribution pales in comparison to other types of benthic systems. The majority of past research in benthic systems has focused on the role of predation, disturbance, and competition on adult benthic populations. Recent attention to the potential role of larval supply and the entire recruitment process has greatly expanded our knowledge of the processes which structure benthic communities. Nevertheless, for soft-bottom communities, one large, critical gap exists in our knowledge, the role of secondary movement or redispersal of organisms following larval recruitment. Through a series of field and laboratory experiments designed to address this topic, research will focus on two objectives: to quantify and describe the secondary movement of selected marine benthic macro-invertebrates, particularly juveniles, and to determine the role secondary movement has in structuring soft-bottom communities and mediating interactions of other processes. Research will focus on three common estuarine benthic invertebrates which vary in their dispersal abilities and include two bivalves and one polychate worm. The research will involve direct examination of these organisms in situ and will include a characterization of the hydrodymanic regimes. Research on the interaction of habitat structure, predators and density dependence on secondary dispersion is planned. The results will add knowledge to a poorly understood aspect of the factors which influence community structure and function in soft-bottom benthic environments.