Source or Sink: Integrating biogeochemical, trophic, and landscape processes to model lake carbon budgets

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

Honolulu

Congreso; ASLO 2017 MOUNTAINS to the SEA; 2017

ASSOCIATION FOR THE SCIENCES OF LIMNOLOGY & OCEANOGRAPHY

Lake ecosystems actively transform, store, and transport carbon. These processes are dynamic and controlled by the interaction of landscape and in-lake fluxes. Despite this, lake carbon budgets are most often described by equilibrium models and mass balance approaches which may not adequately capture ecosystem functions that contribute to variability within and among carbon pools. Climate and land use change are altering how subsidies are processed in aquatic ecosystems. Determining the sensitivity of lakes to these changes will be critical to understanding their role in global carbon budgets as sources or sinks of organic carbon. Utilizing long term data from 5 lakes across environmental gradients in the United States, Canada, and Sweden, we developed a dynamic, process-based model to better understand variability in carbon pools across environmental gradients of land cover, climate, hydrology, and lake morphometry. Preliminary results indicate that the lakes in our study vary in the stability of their carbon budgets, and as net sources or sinks of organic carbon. Ongoing work will allow us to investigate mechanisms driving organic carbon fluxes, and the sensitivity of these fluxes to environmental change with the ultimate goal of better understanding the role of lakes in global carbon cycles.