Thesis - Open Access
Master of Science (MS)
Department / School
Natural Resource Management
adaptive plasticity, ecology, grass, invasive species
Phenotypic plasticity, the ability of an individual to alter its growth in response to environmental conditions, is an attribute that is considered a likely invader attribute, as it provides the opportunity to expand its ecological niche breadth. Adaptive phenotypic plasticity can affect not only the ability to establish in a new environment, but also the ability to outperform the existing vegetation over time. Bromus inermis (smooth brome) and Poa pratensis (Kentucky bluegrass) are invasive species in tall- and mixed-grass prairie ecosystems. The objectives of this two-part study were to quantify the adaptive plasticity of biomass accumulation and tiller production in B. inermis and P. pratensis in comparison to their native neighbors (Elymus canadensis (Canada wildrye) and Pascopyrum smithii (western wheatgrass)). In part one, I created water availability stress in three different soils. Biomass of each species was compared between high, medium, and low watering frequencies to determine plasticity of native and invasive species in response to moisture variability. In part two, the same study was performed with B. inermis and P. pratensis as target species, grown concurrently with a neighboring native or invasive species, in order to determine the effect of competition on plasticity of invasives in tall- and mixed-grass prairie. In both parts, the conclusion was the same – the difference between invasive and native species is not large as expected. Though there were species-specific differences in plasticity of the 4 species, neither native nor invasive species were more plastic as a group. Plants from both categories proved to be equally competitive. These results suggest that certain native and invasive species may occupy the same ecological niche, and future research should be done to find which native plantings could be utilized to competitively exclude potential invaders.
Library of Congress Subject Headings
Smooth brome -- Effect of water levels on
Kentucky bluegrass -- Effect of water levels on
Western wheatgrass -- Effect of water levels on
Hairy wildrye -- Effect of water levels on
Includes bibliographical references (pages 41-54)
Number of Pages
South Dakota State University
Stephens, Ming-Yu, "Phenotypic Plasticity of Native and Invasive Cool-Season Grasses in Response to Frequency of Moisture Availability" (2017). Electronic Theses and Dissertations. 1201.