Year of Publication

2014

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Arts and Sciences

Department

Biology

First Advisor

Dr. Scott K. Gleeson

Abstract

Temperate Midwestern oak savannas are considered imperiled ecosystems with < 1 % remaining since the time of European settlement and are identified as critical areas for preservation. Restoration of Midwestern oak savannas is challenging due to the lack of accurate historical data, few intact remnants remaining to study, and lack of restoration ecology studies. A plant trait-based approach was used to evaluate the ability of six C3 and three C4 native bunchgrasses to restore functionality to a remnant savanna–woodland of the Bluegrass Region of Kentucky. The response and effect framework was used to assess the response of the nine native grasses according to the habitat filters of interannual precipitation, inter- vs. intra-specific competition, and simulated grazing. The effect traits associated with plant-soil nitrogen and carbon cycling were also assessed. The response traits of interannual competition and inter- vs. intra-specific competition along with the effect traits plant-soil nitrogen and carbon cycling were measured in a monoculture experiment conducted at Griffith Woods WMA. The simulated grazing or clipping experiment was conducted over three months in a heated greenhouse experiment.

Four of the C3 species were of the genus Elymus which had significant differences in life history traits compared to the other species and made them particularly well adapted to the Bluegrass Savanna-Woodland. The Elymus species were not well adapted to the most intense clipping treatment. For the other two C3 species, C. latifolium would be a better competitor than D. clandestinum under normal conditions. D. clandestinum had the most number of plastic traits and was the only species to exhibit all three grazing strategies. Comparing the C4 species, T. flavus and P. anceps grew well in the monoculture but A. virginicus did not. The life history traits of A. virginicus does not make this species a good candidate for restoration at this site. The three C4 species were well adapted to clipping. The results of this study suggest that the C3 species, particularly the Elymus, are well adapted to the eutrophic mesic conditions of the Bluegrass Savanna-Woodland, and that the C4 species are better adapted to disturbance.

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