Phenotypic Plasticity of Native and Invasive Cool-Season Grasses in Response to Frequency of Moisture Availability

<p>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.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Natural Resource Management

Year dc:date.available

2017

Author dc:creator

• Stephens, Ming-Yu

Contributors dc:contributor

• Lora Perkins

• adaptive plasticity
• ecology
• grass
• invasive species
• Botany
• Ecology and Evolutionary Biology

Licence

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/1201

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-2210