Dissertation Research: Terrestrial subsidies to aquatic food webs: new insights from hydrogen isotopes

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Food webs can be supported both by organic matter produced within an ecosystem and by organic matter produced elsewhere. In many lakes, for instance, inputs of terrestrial detritus substantially contribute to available organic matter. Recent research has quantified the extent to which these terrestrial subsidies are incorporated into the food web. However, these studies have been limited to very few lakes, making it difficult to understand the magnitude or drivers or variation in the importance of subsidies. This study seeks to overcome these limitations by testing an emerging new approach for quantifying terrestrial subsidies to aquatic consumers, and applying this approach across a suite of lakes. The investigators will combine laboratory experiments, field experiments, and comparative field surveys in order to refine the hydrogen stable isotope approach and provide new insights into cross-ecosystem subsidies. As ecosystem management embraces landscape scales, measurements of cross-ecosystem flows assume greater importance in environmental assessments. This project will provide new measurements of cross-ecosystem flows while developing a powerful new method for measuring terrestrial-aquatic subsidies.