Master of Science (MS), Bowling Green State University, 2017, Geology

Many natural ecosystems are in decline due to anthropogenic disturbance and conversion for human development. Conservation efforts have focused on reserves as the primary location for conservation of native diversity however they are fragmented and embedded in a matrix of potentially inhospitable landscape features. Native ecosystems can also be found in marginal ecosystems, such as riparian buffers, ditches, and field margins, but have been overlooked as contributors to native diversity because thy are small and highly invaded. For my thesis I evaluated the conservation value of marginal ecosystems to support plant diversity compared to reserve areas. I used the point-intercept method to identify species presence along two 10 meter transects in 58 ditches and 26 reserves in northwest Ohio. I characterized diversity with 3 indices: species richness, Shannon diversity index, and rarity weighted richness. I used a Hotelling's t-test to compare diversity between ditches and reserves. I evaluated local and regional land use using a modified Daubenmire frame, the National Land Cover Database, and the National Agricultural Statistics Service's Cropland dataset to calculate cropland variation from 2006-2015. I used Geographically Weighted Regressions and linear regressions to assess the influence of local and regional land use on plant diversity and milkweed (Asclepias spp.) distribution. I found that ditches are similar to reserves in maintaining native diversity and contain native species exclusively found in ditches. Secondly, I found diversity is more influenced by local factors and, despite being different landscape contexts, there is no spatial pattern to diversity. Lastly, I found more area of high quality milkweed habitat exists in ditches than reserves. While there are many native species found in reserves, ditches are also highly invaded and ditches can be thought of as hybrid ecosystems. Although ditches are highly invaded, they are an extensive, highly intercon (open full item for complete abstract)

Committee: Andrew Gregory PhD (Advisor); Enrique Gomezdelcampo PhD (Committee Member); Helen Michaels PhD (Committee Member) Subjects: Biology; Biostatistics; Botany; Conservation; Ecology; Environmental Science; Geology; Geomorphology; Land Use Planning; Plant Biology; Quantum Physics; Wildlife Conservation