Effects of Consumers on Spatial Heterogeneity in Their Resources in Streams

库珀虽然最近的理论和实证研究表明，空间异质性对种群和社区的动态有着深远的影响，但很少有人研究消费者对其资源的空间异质性的影响。在这项研究中，PI将应用空间统计学分析操纵食草动物，捕食者和营养物质的大型实验，以量化消费者和营养物质对河流中较低营养水平的空间异质性的影响。PI还将量化消费者对资源斑块不同方面的分布反应。该设计结合了预算方法，这样我们就可以确定负责直接捕食者效应（猎物迁移与捕食者消费）的机制，以及多营养级相互作用，这样PI就可以检查不同捕食者（鳟鱼，石蝇）对猎物（无脊椎动物）和猎物资源（藻类）的直接和相互作用。附属调查将确定斑块的规模和重叠的消费者和他们的资源在自然流。这项研究将指导营养链模型的开放系统，包括空间异质性。该研究首次明确使用空间统计来解决消费者对其资源的空间异质性的影响。这种方法将大大扩展我们的理解，自上而下的力量如何影响社区结构和动态的空间明确的背景下。

9407591 Cooper Although recent theoretical and empirical investigations have indicated the profound influence of spatial heterogeneity on the dynamics of populations and communities, there have been few examinations of the effects of consumers on spatial heterogeneity of their resources. In this research, the PI will apply spatial statistics to the analysis of large experiments manipulating grazers, predators, and nutrients to quantify the effects of consumers and nutrients on spatial heterogeneity in lower trophic levels in streams. The PI will also quantify the distributional responses of consumers to different aspects of patchiness in their resources. The design incorporates both a budget approach, so that we can determine the mechanisms responsible for direct predator effects (prey emigration vs predator consumption), and multi-trophic level interactions, so that the PI's can examine the direct and interactive effects of different predators (trout, stoneflies) on their prey (invertebrates) and their prey's resources (algae). Subsidiary investigations will determine scales of patchiness and overlap in consumers and their resources in natural streams. This research will be guided by trophic chain models for open systems that incorporate spatial heterogeneity. %%% The proposed research is the first to explicitly use spatial statistics to address the effects of consumers on the spatial heterogeneity of their resources. This approach will greatly expand our understanding of how top-down forces effect community structure and dynamics within a spatially-explicit context.