Dissolved organic carbon dynamics are driven by water temperature, primary production, and anoxia over 5 years of whole-ecosystem experiments in a eutrophic reservoir
Year: 2026
Type: article
Abstract: Lakes and reservoirs play a key role in the global carbon cycle, representing important carbon sinks and sources within the terrestrial landscape under different environmental conditions. Changes in climate and land use have led to increased air and surface water temperatures; increased occurrence and duration of hypolimnetic anoxia; and altered hydrology and nutrient loading, which have the potential to affect how these freshwater ecosystems receive and process carbon. To assess how interacting environmental drivers influence carbon cycling in lakes and reservoirs, we used a 5-year whole-ecosystem experiment to investigate the effects of variable catchment, meteorology, and in-lake drivers on epilimnetic and hypolimnetic dissolved organic carbon in a small reservoir. Using a combination of whole-ecosystem models and time-series analyses, we found that primary production and other internal sources contributed a mean of 29% (range: 7–49%) of the dissolved organic carbon in the reservoir’s epilimnion over the 5-year period. We also found that sinking epilimnetic primary production, dissolved organic carbon from the sediments, and other factors were likely important sources of hypolimnetic dissolved organic carbon, especially during periods of anoxia. Both the epilimnion and hypolimnion were found to be intermittent sinks, yet net sources, of dissolved organic carbon. Overall, water temperature was identified as the most important environmental predictor for water-column dissolved organic carbon, with higher concentrations observed under seasonally elevated temperatures during the late summer and early fall. Our results suggest that lakes and reservoirs may become larger sources of dissolved organic carbon to downstream ecosystems in a warmer, more anoxic future.
Source: Aquatic Sciences
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,190
Funders: National Science Foundation, Western Virginia Water Authority, Directorate for Biological Sciences, Directorate for Computer and Information Science and Engineering, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Institute for Critical Technologies and Applied Science, Virginia Tech, Institute for Critical Technology and Applied Science, Division of Biological Infrastructure
Awards: G1158593323, LTREB: Integrating real-time open data pipelines and forecasting to quantify ecosystem predictability at day to decadal scales, Collaborative Research: Consequences of changing oxygen availability for carbon cycling in freshwater ecosystems, Collaborative Research: MRA: Advancing process understanding of lake water quality to macrosystem scales with knowledge-guided machine learning, G6410347091, Collaborative Research: CIBR: Cyberinfrastructure Enabling End-to-End Workflows for Aquatic Ecosystem Forecasting, MSA: Macrosystems EDDIE: An undergraduate training program in macrosystems science and ecological forecasting, G6991793976, Collaborative Research: MRA: Advancing process understanding of lake water quality to macrosystem scales with knowledge-guided machine learning, SCC-IRG Track 2: Resilient Water Systems: Integrating Environmental Sensor Networks and Real-Time Forecasting to Adaptively Manage Drinking Water Quality and Build Social Trust
OpenAlex ID: W7122369220