Third Wednesday: Amy Rosemond | Reading the Leaves
On Wednesday, February 21, Dr. Amy Rosemond from the Odum School of Ecology gave a brief overview of her research on detritus in headwater streams. She stressed the importance of leaf litter and wood as a basal food resource in headwater stream systems and how the breakdown of these terrestrial inputs by microbes and stream invertebrates is influenced by dissolved nutrients and temperature. As humans alter the environment surrounding streams, they tend to increase the concentrations of dissolved Nitrogen and Phosphorous, which increases the rate of leaf litter breakdown. These effects are most pronounced for low-quality leaves and coarse woody debris. This has implications for downstream stream segments, as less material is transported to downstream consumers, and for headwaters, as the wood that provides habitat structure as well as food disappears more quickly. These effects are predictable and can be used by managers to assess ecological function in streams. Dr. Rosemond’s group is currently working on a similar set of experiments to test the effects of elevated stream temperature on leaf breakdown rates.