Date of Award

10-5-2016

Document Type

Thesis and Dissertation

Degree Name

Master of Science (MS)

Department

School of Biological Sciences

First Advisor

Victoria A. Borowicz

Abstract

Invasion ecology aims to study mechanisms by which invasive species are able to enter, establish, and spread within an ecosystem. This study analyzed Darwin’s naturalization and the biotic resistance hypotheses as the most likely explanations for invasion by an exotic legume, Lespedeza cuneata, into a tallgrass prairie. Darwin’s naturalization hypothesis posits that exotic species are less able to establish in communities that have related species, because similarity in morphology and function promotes intense competition for resources. The biotic resistance hypothesis states that competitors, herbivores, and pathogens already present in the community limit the colonization, naturalization, and persistence of invaders, therefore impeding invasion. Phenological and morphological data, photosynthetically-active radiation (PAR) measurements, Daubenmire cover, and biomass were recorded to test these hypotheses. As predicted by Darwin’s naturalization hypothesis, L. cuneata mass and the mass of other legumes were negatively associated. In addition, phenological differences between L. cuneata and the other legumes on the study site further support Darwin’s naturalization hypothesis. In order to inform conservation management, it is essential to identify mechanisms by which invasion occurs, such as was done in this study.

Comments

Imported from ProQuest Walder_ilstu_0092N_10849.pdf

DOI

http://doi.org/10.30707/ETD2016.Walder.M

Page Count

39

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