DISSERTATION RESEARCH: Consequences of habitat fragmentation for biodiversity and invasive species

University Of Texas At Austin, Austin TX

Investigators

Abstract

This project examines both the direct and indirect effects of habitat fragmentation (patchiness) on native plant diversity and the spread of a non-native invasive grass. Fragmentation has been difficult to study because it is usually occurs at the same time as habitat loss. This project takes advantage of the natural patchiness of central Texas savannas and woodlands to study the effects of fragmentation separate from the effects of habitat loss. Theory predicts that both fragmentation and invasive non-native species will reduce species diversity. Some models suggest fragmentation may directly limit the spread of invasive plants with limited dispersal ability, but indirectly facilitate their establishment by reducing diversity. These hypotheses will be tested. The project will combine analysis of aerial photographs, field observations, measurements of seed dispersal, and experimental manipulation of diversity to quantify the relationships among native biodiversity, the presence and spread of an invasive grass, and habitat fragmentation. Fragmentation and the spread of invasive species are two of the leading threats to biological diversity. This research will test theoretical predictions about these processes and provide insights for the management of landscape structure to preserve biodiversity. The grant will support a graduate student and provide research experience for several undergraduate students.