Date of Award
Bachelor of Science
Dr. Kristine Grayson
Biodiversity within an ecosystem can be greatly influenced by environmental disturbances, such as fires, flooding, or other extreme events. Studying the effects of these disturbances on species diversity can be complicated though, due to difficulties tracking species-level responses and isolating the effects of disturbances. Model systems in community ecology, such as rock pools, are a beneficial way to scale down the study of disturbances in discrete communities without losing the ability to analyze important influences or interactions. In this study, macroinvertebrates within the James River rock pools were surveyed to investigate seasonal and annual differences in species richness and diversity, as well as changes following a flooding event. Four periods of pre- and post-flood surveys, spring and fall of 2018 and 2019, were used in this study. Flooding events occurred during all periods expect fall of 2019. Season was found to have a significant effect on biodiversity, with a higher average richness and diversity index found in the fall. The fall flooding event in 2018 was found to decrease biodiversity within the pools as expected, whereas biodiversity in the spring was found to stay the same after flooding events, or increase. These results demonstrate that community-level effects due to flooding are context-dependent, due to the complex and dynamic nature of ecological systems. Longer-term studies addressing aspects such as pool composition or spatial location, species assemblage, and even anthropogenic influence are needed to better understand how disturbance events shape the biodiversity within the James River rock pools. By understanding how disturbance shapes ecological communities, we can better asses how future disturbances may alter the biodiversity of an ecosystem. This knowledge is particularly important as the frequency and severity of climatic events and disturbances increases under climate change.
Leber, Meghan, "The Influence of Flooding on Macroinvertebrate Diversity of the James River Rock Pools" (2020). Honors Theses. 1480.