DISSERTATION RESEARCH: Food webs in stable isotope space: How patch size and connectivity alter food web structure, functional redundancy, and trophic position

食物网结构影响群落稳定性、养分循环和初级生产力。另一方面，空间生态学已经确定了斑块大小和连通性在决定斑块生境中物种的存在和丰度方面所起的主要作用。该项目旨在弥合这些研究项目之间的差距，使用稳定同位素分析来阐明食物网结构如何取决于斑块大小和环境。由于氮和碳的重、轻同位素比值可以衡量物种的营养地位和生物量的最终来源，因此一个群落中所有物种的同位素特征可以提供功能性食物网结构的定量测量。通过对盐沼节肢动物群落的深入研究，本项目将量化斑块大小和连通性对实现的营养位置多样性和冗余度的影响，并确定物种的营养位置本身是否是斑块空间背景的函数。这项资助提供了急需的食物网和空间生态学的综合，利用稳定同位素分析的新应用来了解异质景观中的资源流动。在这样做的过程中，它为女研究生提供了综合培训，以及一个敏感的、经济上重要的生态系统的基本生态知识。

Food web structure influences community stability, nutrient cycling, and primary productivity. Spatial ecology, on the other hand, has identified the primary roles that patch size and connectivity play in determining the presence and abundance of species in patchy habitats. This project aims to bridge the gap between these research programs, using stable isotope analyses to elucidate how food web structure depends on patch size and context. As the ratio of heavy to light isotopes of nitrogen and carbon measure trophic position and the ultimate sources of species' biomass, the isotopic signatures of all species in a community can provide a quantitative measure of functional food web structure. Using a well-studied salt marsh arthropod community, this project will quantify the effects of patch size and connectivity on the diversity and redundancy of realized trophic positions and determine whether species' trophic positions are themselves functions of patch spatial context.This grant provides a much-needed synthesis of food web and spatial ecology that leverages a novel application of stable isotopic analysis to understand resource flow in a heterogeneous landscape. In doing so, it provides integrative training for a female graduate student, as well as basic ecological knowledge of a sensitive, economically important ecosystem.