Theses Doctoral

The Causes and Consequences of Community Disassembly in Human Modified Tropical Forest: Scarabaeine Dung Beetles as a Model System

Nichols, Elizabeth Stevens

A central aim of conservation science is improving our understanding how different human activities influence the persistence of native biota and associated ecological and evolutionary processes. Meeting this applied biodiversity research challenge requires that we understand (i) patterns in biological responses to anthropogenic environmental change, (ii) what biological mechanisms influence that response, (iii) how the loss of biological diversity will impact important ecological processes, and (iv) how this information can be translated into effective and practical information useful for decision makers. Increasingly, this final translational step is met through the use of ecological indicator assemblages - suites of species whose presence and abundance in a given area provide a useful gauge for measuring and interpreting changing environmental conditions. This thesis aims to improve our understanding of the patterns, causes and consequences of community disassembly for tropical forest insect species. To do this, I have combined systematic literature reviews and empirical approaches to understand how two widespread anthropogenic drivers of environmental change in tropical forest (i.e. land-use change and degradation) influence the community disassembly of Scarabaeine dung beetles in tropical forest, at a variety of spatial scales. I outline the potential for tropical forest defaunation to negatively impact dung beetle communities, summarize the contributions of dung beetles to a range of key ecological processes, provide empirical data demonstrating how dung beetles can serve as a model system to understand terrestrial trophic cascades, discuss the ability of species traits to explain population trends in observed dung beetle community disassembly, and conclude by demonstrating how these various lines of evidence linking dung beetle species with environmental condition strengthen their potential utility as ecological indicator taxa in applied conservation science.


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More About This Work

Academic Units
Ecology, Evolution, and Environmental Biology
Thesis Advisors
Uriarte, Maria
Ph.D., Columbia University
Published Here
February 17, 2012