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

9731718彼得森软底栖息地是海洋生态系统中最普遍的环境之一；然而，与其他类型的海底系统相比，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大部分研究都集中在捕食、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构成底栖生物群落的过程的了解。然而，对于软底群落，我们的知识中存在一个巨大的关键缺口，即幼虫招募后生物体的二次运动或再扩散的作用。通过为处理这一专题而设计的一系列实地和实验室实验，研究将侧重于两个目标：量化和描述选定的海洋底栖大型无脊椎动物，特别是幼体的二次运动，并确定二次运动在构建软底群落和调节其他过程的相互作用方面的作用。研究将集中在三种常见的河口底栖无脊椎动物，它们的传播能力各不相同，包括两个双壳类和一种多齿蠕虫。这项研究将涉及对这些生物体的直接现场检查，并将包括对水动力制度的描述。计划研究栖息地结构、捕食者和密度依赖对二次扩散的交互作用。这一结果将增加对软底栖环境中影响群落结构和功能的因素知之甚少的方面的知识。

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.