UPE Seminar - Dissertation Defense Seminar | Alice Carter, Duke University | Shifting thermal and metabolic regimes in a low gradient, temperate river network

Rivers transform more than half of the organic inputs they receive from terrestrial systems. The metabolic processes that drive these transformations provide the energetic base to sustain stream food webs, are linked to multiple elemental cycles and result in oxygen depletion and the release of greenhouse gasses to the atmosphere. In this presentation, I characterize the metabolic regime of New Hope Creek, a stream in the Duke Forest, and describe how it has changed from 50 years ago. In this low gradient stream, forest phenology, flow conditions, and local channel geomorphology constrain the ecosystem energetics and linked biogeochemical cycles. New Hope Creek is warmer, and the flow is more variable than it was 50 years ago. As a result, the stream is more heterotrophic and carbon cycles more quickly.