Degree Type

Dissertation

Date of Award

2014

Degree Name

Doctor of Philosophy

Department

Ecology, Evolution, and Organismal Biology

Major

Ecology and Evolutionary Biology

First Advisor

Diane M. Debinski

Abstract

Biodiversity is declining globally and one of the primary drivers is agricultural intensification. Conservation and restoration of biodiversity in agricultural ecosystems is going to rely on the enhancement of uncultivated land such as grasslands. The majority of grasslands within agricultural ecosystems have been degraded and now consist of a mix of native and exotic plant species. These altered grasslands have been categorized as novel grasslands because they are composed of plant species from around the globe that have little history of evolutionary interaction. Further research is needed to understand the utility of these novel grasslands for the conservation and restoration of wildlife in agro-ecosystems. This dissertation provides results from studies on butterfly and other insect groups, as well as floral resources, in grasslands typical of agro-ecosystems in the tallgrass prairie ecoregion. We report: 1) the diversity of one group of insects (based on either species richness or composition) did not predict any of the other insect taxa (ants, butterflies, or leaf beetles) in grasslands representing a spectrum in vegetation quality with different management regimes, but insect species composition correlated with composition of vegetation for the two phytophagous insect groups (butterflies and leaf beetles), 2) over seven years of fire and grazing treatments on novel grasslands the butterfly communities became more similar to native prairies, as did the composition of plant functional groups, indicating that restoration of historic ecological processes to novel grasslands may lead to butterfly communities and plant functional group compositions that better mimic historical systems, 3) a treatment employing heterogeneous application of fire and grazing (patch-burn grazing) did result in increased habitat heterogeneity (compared to a treatment that employed a homogenous fire and grazing regime), but did not translate to greater diversity of butterflies, and 4) novel grasslands, reconstructed prairies, and native prairies differed in their seasonal floral resource availability in a variety of ways. This research highlights the importance of considering the potential worth, and need for further research of, novel grasslands for the conservation and restoration of biodiversity in agro-ecosystems.

Copyright Owner

John Thomas Delaney

Language

en

File Format

application/pdf

File Size

141 pages

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