Master of Science, Miami University, 2014, Botany

The objectives of my study were (1) to determine the spatial distribution of four invasive species; Rubus phoenicolasius, Berberis thunbergii, Rosa multiflora, and Lonicera japonica in a mature forest; (2) to investigate the role of propagule rain from a road, logged forest, and floodplain on these distributions, and (3) to explore the role of treefall gaps as a facilitator of invasion. The importance of propagule rain was indicated by higher densities of R. multiflora near the floodplain and R. phoenicolasius and climbing L. japonica near the road. Based on higher frequency and density, gaps are important for the establishment, growth, and reproduction of R. phoenicolasius, growth of R. multiflora and L. japonica, and reproduction of B. thunbergii.

Committee: David Gorchov PhD (Advisor); Thomas Crist PhD (Committee Member); M. Henry H. Stevens PhD (Committee Member); Jing Zhang PhD (Committee Member); Ziying Jiang PhD (Committee Member) Subjects: Botany; Ecology; Geographic Information Science

MS, Kent State University, 2009, College of Arts and Sciences / Department of Biological Sciences

SUMMARY In this study, I examined genetic diversity and levels of population differentiation between eight populations of the invasive plant multiflora rose (Rosa multiflora Thunberg Ex. Murray) located in Portage and Summit Counties, in northeastern Ohio. I used six microsatellite marker loci to determine allelic diversity, percent polymorphic loci, and expected and observed heterozygosity. My results show that multiflora rose populations included have moderate levels of genetic variation. I found a total of twenty five alleles in the six microsatellite loci that were examined. On an average, there were 4.16 alleles per locus, but the average number of alleles per locus observed in each population ranged between 1.66 and 3.33. Effective number of alleles ranged between 1.38 and 2.17, indicating variation in allele frequencies among loci. Average observed heterozygosity (HO = 0.15) was less than expected heterozygosity (HE = 0.43) across all but one population. This trend of heterozygosity deficiency and F statistics results indicate significant level of inbreeding in the studied populations. Most of the loci failed to conform to Hardy-Weinberg expectations in all populations indicating forces of evolution interacting. Analysis of molecular variance revealed significant levels of genetic differentiation between populations. Nei's unbiased estimators of genetic distance range from nearly 0 to 0.59, indicating high genetic differentiation. These findings are then discussed in the light of ecological and historical considerations.

Committee: Oscar Rocha (Advisor); Barbara Andreas (Committee Member); Andrea Case (Committee Member) Subjects: Biology