Date on Senior Honors Thesis
8-2021
Document Type
Senior Honors Thesis
Degree Name
B.S.
Department
Biology
Degree Program
College of Arts and Sciences
Author's Keywords
prairie ecology; plant disease; global change
Abstract
The provisioning of ecosystem services in tallgrass prairies is mediated by interactions between the plants, their associated above- and belowground microbiota, and the abiotic environment, but global change alters these interactions through a variety of pathways. This study investigates the interactions between belowground microbiota, foliar pathogens, and their host plants in order to better understand how ecosystem functioning may change in a tallgrass prairie system under an altered watering regime. The project focuses on North American tallgrass prairie ecosystems and asks whether host plant diversity and abundance, soil biota, and water availability interactively affect plant susceptibility to damage by a wide range of aboveground pathogens and herbivores in a large outdoor experimental garden. Surveyed plant communities include monocultures of each of seventeen focal plant species and six-species polycultures containing one or more of the focal species. Each community is planted in either the presence or absence of live soil biota, and plant communities are watered to replicate natural soil moisture conditions in a prairie ecosystem or are subjected to drought conditions. Individual plants were assessed for foliar damage by each of eight different groups of foliar pathogens and herbivores, quantified as percent of the leaf surface damaged. Plants grown in monoculture communities experienced more foliar damage from more diverse sources than plants grown in polyculture communities, suggesting that low diversity plant communities accumulate more foliar pathogens than high diversity plant communities, and that plants in low-diversity communities are more susceptible to damage from foliar pathogens than plants in high-diversity communities. Additionally, host plant community diversity, soil community composition, and water availability interacted to influence foliar pathogen damage but not diversity of damage sources. These interactive effects suggest that the identities of the soil biota, host plants, and foliar pathogens influence the host plant’s susceptibility to foliar infection. Ultimately, our ability to manage ecosystems in a sustainable way which maintains the provisioning of valuable ecosystem services is dependent on a nuanced understanding of the underlying interactions which drive these ecosystems. This study attempts to disentangle the interactions between plants and their associated microbiota under a changing climate in order to provide insight to an understudied facet of tallgrass prairie management.
Recommended Citation
Workman, Aspen J., "Host community diversity interacts with soil biota and water availability to predict foliar pathogen damage and diversity on tallgrass prairie plants." (2021). College of Arts & Sciences Senior Honors Theses. Paper 288.
Retrieved from https://ir.library.louisville.edu/honors/288
Lay Summary
The provisioning of ecosystem services in tallgrass prairies is mediated by interactions between the plants, their associated above- and belowground microbiota, and the abiotic environment, but global change alters these interactions through a variety of pathways. This study investigates the interactions between belowground microbiota, foliar pathogens, and their host plants in order to better understand how ecosystem functioning may change in a tallgrass prairie system under an altered watering regime. The project focuses on North American tallgrass prairie ecosystems and asks whether host plant diversity and abundance, soil biota, and water availability interactively affect plant susceptibility to damage by a wide range of aboveground pathogens and herbivores in a large outdoor experimental garden. Surveyed plant communities include monocultures of each of seventeen focal plant species and six-species polycultures containing one or more of the focal species. Each community is planted in either the presence or absence of live soil biota, and plant communities are watered to replicate natural soil moisture conditions in a prairie ecosystem or are subjected to drought conditions. Individual plants were assessed for foliar damage by each of eight different groups of foliar pathogens and herbivores, quantified as percent of the leaf surface damaged. Plants grown in monoculture communities experienced more foliar damage from more diverse sources than plants grown in polyculture communities, suggesting that low diversity plant communities accumulate more foliar pathogens than high diversity plant communities, and that plants in low-diversity communities are more susceptible to damage from foliar pathogens than plants in high-diversity communities. Additionally, host plant community diversity, soil community composition, and water availability interacted to influence foliar pathogen damage but not diversity of damage sources. These interactive effects suggest that the identities of the soil biota, host plants, and foliar pathogens influence the host plant’s susceptibility to foliar infection. Ultimately, our ability to manage ecosystems in a sustainable way which maintains the provisioning of valuable ecosystem services is dependent on a nuanced understanding of the underlying interactions which drive these ecosystems. This study attempts to disentangle the interactions between plants and their associated microbiota under a changing climate in order to provide insight to an understudied facet of tallgrass prairie management.
