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

Master of Science, University of Toledo, 2013, Biology (Ecology)

Coastal areas are increasingly habited by humans because of their attractiveness for recreation, aesthetics, and industrial purposes. Artificial structures, such as riprap, are used to prevent erosion but also have been shown to reduce biodiversity. The goal of my study was to examine the relationship between riprap altered shorelines, sediment composition, organic matter and invertebrate communities in areas that had shoreline vegetation and those that had not. Using broad taxonomic groups, we found that overall invertebrate diversity was 30% greater in areas adjacent to shorelines with added vegetation. The most abundant taxon, the oligochaetes, showed opposite trends with abundance increasing at least 50% at non-vegetated sites. The relationship between sediment composition and shoreline type was found to be the most significant driver of invertebrate community changes, with the ratio of silt to sand being seven times greater in the absence of vegetation, and diversity having a positive response to this increase. In the western basin of Lake Erie, where most shorelines have riprap alterations, adding vegetation should be considered as a useful management technique.

Committee: Christine Mayer Dr. (Advisor); Thomas Bridgeman Dr. (Advisor); Jonathan Bossenbroek Dr. (Committee Member); Kenneth Krieger Dr. (Committee Member) Subjects: Aquatic Sciences; Ecology; Environmental Science; Limnology

Doctor of Philosophy (PhD), Ohio University, 2001, Plant Biology (Arts and Sciences)

Understory herbaceous vegetation is a vital component of eastern deciduous forests, typically comprising the largest proportion of forest diversity. Understory composition is often correlated with microenvironmental and site conditions such as topography, light availability, and edaphic conditions and provides important indications of site quality, overstory regeneration patterns, and ecosystem health. To better understand understory dynamics and disturbance response, this study examined herbaceous vegetation in managed and mature mixed-mesophytic forests of southeastern Ohio. Specific objectives were to examine: (1) spatial and temporal variability of understory vegetation in an old-growth mixed-mesophytic forest; (2) herb layer dynamics relative to site quality in recently logged and mature oak forests; (3) the relationship of understory vegetation to seasonal soil nitrogen availability in logged and mature stands; (4) the role of the seed bank in post-harvest forest succession; and (5) effects of post-harvest light and soil physical properties on understory forest herbs. Sampling season, topographic aspect, and spatial scale (micro- vs. meso-scale) strongly influenced old-growth understory composition and diversity. In recently clearcut and mature forests, age, sampling season, aspect, and fertility significantly influenced understory composition. Soil C:N ratio was a strong predictor of understory richness in mature forests but weakly related in clearcuts. Seed bank composition differed markedly from aboveground vegetation, but both showed strong topographic and disturbance responses. Experimental treatments simulating post-harvest light and soil compaction conditions caused reduced growth in most study species while patchy, intermediate light levels mimicking mature forest understories often enhanced growth. Results suggest that: (1) forest understories may be frequently undersampled, with sample size, area, and season critical considerations for diversity asse (open full item for complete abstract)

Committee: Brian McCarthy (Advisor) Subjects: Biology, Botany

Master of Science (MS), Ohio University, 2012, Environmental Studies (Arts and Sciences)

Ecoinformatics is considered a sub-discipline of bioinformatics and its goal is to create and expand software tools to manage, manipulate, store and distribute ecological information. Applications developed in ecoinformatics are quite practical in ecological data analysis, particularly in vegetation ecology. Vegetation ecologists are familiar with the challenges of analyzing large data sets, so ecoinformatics is a good tool to improve the problem-solving process. It is possible to automate much of the data analysis step and introduce higher levels of quality control. Software programs like R and Kepler are quite suitable for these purposes. Both are open source computer applications and may be used either alone or in an integrated manner. R is used by many biologists for statistical analysis, while Kepler is designed to automate the dataflow process. Both are userfriendly, and may be easily interfaced. These software applications have been used for certain types of diversity and community data managing projects. Here I present an example of models developed for specific types of data analysis in vegetation ecology. In order to use the model developed for this project, one needs only supply a standard data set in spreadsheet format as input. The application automatically generates output with general necessary abundance estimates. Two models were developed for different types of plant community data. I expect a broad range for future applications of these models in both research and teaching.

Committee: Brian McCarthy (Advisor) Subjects: Bioinformatics; Ecology; Environmental Studies