Source or sink? Integrating biogeochemical, trophic and landscape processes to model lake carbon budgets under environmental change.

IAN MCCULLOUGH; KAITLIN FARRELL; ANA MORALES-WILLIAMS; DEREK ROBERTS; FACUNDO SCORDO; ZUTAO OUYANG; HILARY DUGAN; PAUL HANSON; SARAH BARTLETT; SAMANTHA BURKE; JONATHAN DOUBEK; FLORA E. KRIVAK-TETLEY; NICHOLAS SKAFF; JAMIE SUMMERS; GRACE HONG; KATHLEEN WEATHERS

Chuncheon

Workshop; GLEON 17 Chuncheon, South Korea; 2015

Global Lake Ecological Observatory Network - Korean Society of Limnology - Kangwon Nation University - National Institute of Ecology - National Institute of Environmental Reserch - Korean Environment Corporation - National Science Foundation

In the era of anthropogenic climate change, the importance of carbon accounting has never been greater. Whereas attempts to assess global carbon budgets have focused on the roles of land and ocean, relatively little research has been devoted to the role of lakes. Lakes process more carbon per unit of surface area than land and most of this carbon is terrestrially derived, but it is still an open question as to whether lakes are net sources or sinks of carbon. We combine principles of limnology, ecosystem ecology and landscape ecology in an integrated process-based model to estimate lake carbon budgets and the conditions that make lakes carbon sources vs. sinks. Our research questions are 1) how do lake carbon budgets vary along environmental gradients?, 2) how do lake carbon budgets vary seasonally relative to annual and long-term trends, 3) what is the role of parameter uncertainty in modeling lake carbon budgets and 4) what is the role of lakes in global carbon budgets? We developed our approach using empirical data from Trout Lake, Wisconsin, USA, but will expand to other lakes and regions in future work. The model is subdivided into three main subprocesses: surface flow and groundwater, net primary productivity, and sedimentation. The integration of these subprocesses subsequently produces overall lake budgets for dissolved and particulate organic carbon at daily intervals.