Greenhouse gas emissions of farm and residential ponds along a forest to agricultural land use gradient

Ponds are biogeochemical hotspots with significant emissions of greenhouse gases (carbon dioxide, CO₂; methane; CH₄) to the atmosphere. However, CO₂ and CH₄ emissions are highly variable among ponds, hampering accurate regional greenhouse gas emission estimates. One potential driver of emissions is land use cover, where agricultural runoff may increase emissions relative to ponds in forested catchments. Therefore, we studied 28 farm and residential ponds along a land use gradient from forest dominated to agricultural dominated catchments in upstate New York, USA, twice during summer when emissions should be highest. We measured diffusive CO₂ and CH₄ emissions, short-term ebullitive CH₄ emissions, bottom and surface water CO₂ and CH₄ concentrations, along with a suite of physicochemical parameters. Our preliminary results show higher chlorophyll a, lower diffusive CO₂ emissions, and lower bottom water oxygen content with increasing proportion of agricultural land use in the catchment. Ultimately, our study will identify spatial drivers at the ecosystem and landscape level which will be useful for constraining aquatic greenhouse gas emissions at regional and global scales.

Primary Presenter: Pascal Bodmer, Cornell University (pb577@cornell.edu)

Authors:

Pascal Bodmer, Cornell University  (pb577@cornell.edu)

Kathryn Gannon, Cornell University  (kag326@cornell.edu)

Meredith Holgerson, Cornell University  (meredith.holgerson@cornell.edu)