Date of Graduation

Fall 2024

Degree

Master of Science in Biology

Department

Biology

Committee Chair

La Toya Kissoon-Charles

Abstract

Ozark streams are extremely diverse ecosystems, despite frequent flood disturbance. Plant communities are frequently altered by bed-moving floods but are extremely resilient. We know that land-use, sediments, and nutrients can impact plant communities, but more can be divulged about how plants alter communities and how environmental variables influence plant community composition in disturbance-prone Ozark streams. To address this, I examined two key aspects of Ozark stream ecosystems: the role of American Water Willow, Justicia americana, in structuring aquatic habitats and the factors influencing gravel bar plant community composition. In the first chapter, I investigated how J. americana, a native macrophyte, functions as an ecosystem engineer within Ozark streams. I identified J. americana’s impact on streambed sediments and macroinvertebrate communities in bedrock-dominant and gravel-dominant streams. In the second chapter I identified relationships between plant communities and gravel bar characteristics (area, elevation, and canopy cover) in two Ozark streams with contrasting nutrients. J. americana patches increase sediment retention and alter macroinvertebrate richness and abundance. Gravel bar plant communities are all weedy and frequently disturbed species and canopy cover was a more powerful variable driving species composition between streams.

Keywords

macrophytes, Ozark streams, disturbance, plant communities, macroinvertebrates, fine sediment, water willow

Subject Categories

Biology | Botany | Plant Biology

Copyright

© Alexis Renea Reifsteck

Open Access

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