DISSERTATION RESEARCH: Effects of Climate-Induced Changes in Generalist Predators on the Structure and Function of Arctic Food Webs

Duke University, Durham NC

Investigators

Abstract

With forecasted changes in climate, it is necessary to understand how organismal adaptations to climatic drivers fit into a broader ecological context. Changes in artic ecosystems are of particular significance because this region is experiencing the fastest rate of climate change on the planet. Moreover, the soils of the arctic tundra store large amounts of organic matter that could be released as carbon dioxide and methane through decomposition by the microbial community. Faster rates of decomposition in the Arctic could result in positive feedbacks on global climate change. The composition and activity of the microbial communities that are responsible for decomposition are affected by invertebrates in the soil, which are themselves are regulated by predators such as spiders. In other ecosystems, cascading effects of spider predation have been found to indirectly inhibit decomposition. If this also occurs in the Arctic, spiders could provide an important ecosystem service by slowing the release of carbon from tundra soils. This project uses an experimental manipulation of spider density and temperature to examine how the relationship between spiders and their prey affects rates of microbial decomposition in the arctic tundra. Results will provide new insights into the potential feedbacks between global climate change and local changes in community structure and function. The Co-PI (Amanda Koltz) is dedicated to furthering opportunities in science for students from diverse backgrounds. For this project, she has worked with and trained four undergraduate students, three of which are women, and one of whom is of African American and Native American descent. In Alaska, Koltz has worked with rural and Alaska Native high school students from The Rural Alaska Honors Institute. She will also host a K-12 teacher (PolarTREC Program) in Alaska for the 2012 field season in order to provide the teacher with an opportunity to participate in hands-on field research and help bring arctic science back to the classroom.