Defense Date
2024
Document Type
Thesis
Degree Name
Master of Science
Department
Biology
First Advisor
Dr. Julie Zinnert
Abstract
Coastal dunes are natural barriers between land and sea and are imperative to the protection and preservation of inland ecosystems and human infrastructure. However, due to global warming, seal level rise, and coastal development, coastal dunes are under constant threat of destruction. Restoration efforts have been implemented to rebuild the protective function of dunes through the planting of dune building grasses. Dune grasses build and maintain these vital sand dunes. However, little is known about facilitative and competitive relationships among the grasses. In order to maximize restoration efforts, research is needed to better understand the biotic interactions among restorative grass plantings. Our objective was to help fill this knowledge gap by quantifying the facilitative and competitive interactions of four common dune building grasses along the coast of the eastern United States in both polyculture and monoculture communities. To do so we designed plantings of common dune grasses, Ammophila breviligulata, Panicum amarum, Spartina patens, and Uniola paniculata, within polyculture plots to facilitate interspecies interactions and monoculture plots to allow intraspecies interactions along the coast of Hog Island, a Virginia barrier island along the Delmarva peninsula. We also designed a mirror planting of the same four grasses in a mesocosm. The mesocosm planting design included the same polyculture and monoculture combinations of grasses growing within plots. However, each planting design was grown in both pots that allowed root interaction and pots that excluded root interaction though root compartmentalizing. We found that while many of the species were unaffected by planting designs, Panicum amarum had the highest yield in polyculture planting designs where interspecies below ground root interactions were allowed, indicating greater facilitation in polyculture plantings. With the current practice of planting dune grasses in monoculture communities, this research will provide coastal managers with planting designs that maximize the success rate of dune grass establishment and success.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
12-12-2024