Dissertation Research: The influence of metacommunity size and habitat destruction on the scaling of species diversity

Washington University, Saint Louis MO

Investigators

Abstract

Habitat destruction is a leading cause of species extinctions, and thus a serious conservation concern. The amount of remaining suitable habitat within a landscape, as well as the isolation of these habitat patches from one another, can have profound effects on biodiversity across a landscape. This research strives to predict how habitat destruction will alter landscape biodiversity through its effects on patch area and isolation, as well as the consequent influence on the resilience of biodiversity following habitat disturbance. Simulation modeling provides two opposing predictions for the effect of habitat destruction on landscape biodiversity. Depending on how habitat destruction alters species' immigration and extinction rates, habitat destruction can have either more severe or less severe effects on biodiversity than expected from a random-extinction model based upon the pre-destruction habitat area. Freshwater ecosystems are subject to both habitat destruction (e.g. draining of wetlands) and disturbances (e.g. contaminants), which can interact to alter patterns of their biodiversity, and are the focus of the empirical part of this study. Preliminary results from surveys of pond amphibian and invertebrate biodiversity indicate that habitat destruction will have more severe effects on biodiversity loss than expected by a random extinction model. To identify a biological mechanism behind this pattern, an experiment using artificial ponds will examine how habitat destruction can alter species immigration and extinction rates and influence the severity of landscape biodiversity loss. A second experiment will investigate how habitat destruction can affect the recovery of aquatic biodiversity following a habitat disturbance. This project provides many opportunities to incorporate outreach to the general public, as well as to provide young scientists with genuine research experiences. Thus far, 6 undergraduate and 6 high school student interns have had hands-on field research experiences as part of this project. In addition to gaining experience in the field, students learn how to disseminate what they have learned to others. Undergraduate students have opportunities to a write senior honors thesis, while high school students act as science outreach ambassadors to their communities through formal and informal settings.