DRYING GRADIENT INFLUENCE ON FRESHWATER INVERTEBRATE DIVERSITY ALONG A CENTRAL KENTUCKY INTERMITTENT STREAM
Seasonal drying and flooding are frequent natural disturbances in Kentucky’s karst streams. The severity of these changes can vary along a single stream which challenges the aquatic organisms. To test macroinvertebrate community responses to stream drying, we studied a central Kentucky stream that had a perennially flowing section and summer drying intermittent section. As the intermittent section dries, water is reduced to isolated stagnant pools that can range from puddles (<1 m2) to large deep pools (>50 m2). In addition to macroinvertebrates, we measured other environmental characteristics (predatory fish presence, water chemistry, and hydrology). As we predicted, the perennial section had greater species diversity, with higher proportions of disturbance-sensitive groups (i.e. EPT). Within the intermittent section, larger pools were more diverse, likely due to higher dissolved oxygen or habitat complexity. Predatory fish were present in all the intermittent pools and may not be a strong influence on the macroinvertebrate communities. Understanding the community dynamics in drying streams may help us determine which aquatic macroinvertebrates may be vulnerable or resilient to more frequent or severe drying disturbances predicted with climate change.
Margaret Finn (Primary Presenter/Author), Centre College, firstname.lastname@example.org;
Cara Barnett ( Co-Presenter/Co-Author), Centre College, email@example.com;
Mark Galatowitsch ( Co-Presenter/Co-Author), Centre College, firstname.lastname@example.org;