Dissertation Research: The Effects of Phenotypic Variation on Food Web Architecture and Ecosystem Fluxes: A Dual Tracer Isotope Approach

本研究的主要目标是确定单个物种内部的变化如何影响河流食物网中能量和物质的转移。拟议的研究将使用一个进化研究的模型系统，特立尼达孔雀鱼（Poecilia reticulata），来确定一个物种的两种表型如何影响溪流中的生态系统过程。特立尼达岛上的溪流发生在平行的流域，与当地适应的孔雀鱼种群有着相似的环境梯度。在以前的研究中已经建立了两种表型：来自有捕食者的溪流的孔雀鱼，以及来自没有捕食者的溪流的孔雀鱼。这两种孔雀鱼的表型可能会以独特的方式影响生态系统，因为它们的进食方式和食物不同。本研究使用重复实验来检验孔雀鱼表型和资源可用性如何影响生态系统。对物种内变异如何影响生态过程的更好理解将为生态和进化过程之间的相互作用提供更多的见解，这可能是广泛和重要的。许多人都熟悉孔雀鱼，因为它们在水族馆贸易中的重要作用，使它们成为交流进化生态学科学研究的一个容易接近的系统。这项工作还将为土地利用变化如何改变河流生态系统的研究提供信息。

The primary goal of this study is to determine how variation within a single species can influence the transfer of energy and materials in stream food webs. The proposed research will use a model system for evolutionary studies, the Trinidadian guppy (Poecilia reticulata), to determine how two phenotypes of a single species can influence ecosystem processes in streams. Streams on the island of Trinidad occur in parallel watersheds that have similar environmental gradients with locally adapted populations of guppies. Two phenotypes have been established in previous studies: guppies from streams with predators, and guppies from streams without predators. These two guppy phenotypes are likely to influence the ecosystem in unique ways because of differences in how they feed and what they eat. This study uses a replicated experiment to examine how both guppy phenotype and resource availability influence ecosystems.A better understanding of how within-species variation affects ecological processes will provide additional insight into interactions between ecological and evolutionary processes, which may be widespread and significant. Many people are familiar with guppies because of their prominent role in the aquarium trade, making them an accessible system to communicate scientific research about evolutionary ecology. This work will also inform studies of how land use change alters stream ecosystems.