DISSERTATION RESEARCH: The Roles of Evolutionary History and Ecological Interactions in the Maintenance of a High-Diversity Algal Assemblage

University Of Chicago, Chicago IL

Investigators

Abstract

Understanding the ecological, environmental and evolutionary processes that organize species into distinct communities and ecosystems is of growing importance, particularly in the face of increasing human-induced environmental disturbance. How are species organized into communities, and how do communities recover from disturbance? Communities experience many forms of disturbance, including abiotic disturbance such as temperature and physical forces and biotic disturbance such as consumers eating community members. This project explores community responses to disturbances in intertidal seaweed communities in the Northeast Pacific Ocean to understand how communities are assembled in nature, and how they are maintained in the face of disturbance. The intertidal zone is a natural laboratory, where the tidal cycle creates strong temperature, desiccation, herbivore and wave force gradients over a scale of only meters. This project exploits these gradients using field experiments with seaweed communities, data on the evolutionary relatedness of these species, and physiological measurements in the laboratory. The project will measure community changes in number and abundance of species, relatedness of species and functional capabilities of the community, in response to experimentally manipulated environmental and herbivore pressure, to understand how each of these factors contributes to the species we observe and their recovery from disturbance. The project will contribute to a general understanding of the expected response of ecological communities to environmental perturbations such as climate change and species introductions. The primary role of seaweeds at the base of marine food webs makes it important to understand the determinants of their persistence. With much of the world's population living within 100km of a coast, environmental effects on primary producers exacerbated by climate change are an immediate global concern. This project will also contribute to an interactive public exhibit, via the Field Museum of Natural History?s Pritzker Laboratory, including ?Talk to the Scientist Hour.? Further, field research takes place on Makah Tribal Lands, and will contribute to training Makah interns in ecological field studies and physiological lab studies and providing ocean climate data to Tribal biologists in this productive ecosystem.