Integrated Belowground Greenhouse Gas Flux Measurements and Modeling

collage-2016-04-12Our main objective is to improve understanding of and modeling capacity for interactions of belowground temperature, moisture, and substrate supply that controls the net soil emissions of the three most important anthropogenic GHGs: CO2, CH4, and N2O.

We are working on a novel integration of measurement and modeling of CO2, CH4, and N2O, three key greenhouse gases (GHGs), in upland and wetland soils at the Howland Forest AmeriFlux site in central  Maine. We are integrating subsurface soil process measurements with surface chamber fluxes and landscape-scale fluxes, leveraging ongoing eddy covariance and chamber measurements and allowing the scaling-up of process-based models and soil-flux measurements to the ecosystem scale. In order to do this, we are merging two relatively parsimonious models: (1) the DAMM soil enzymatic kinetics model (Dual Arrhenius and Michaelis-Menten) and (2) the ecosystem flux model FöBAAR (Forest Biomass, Assimilation, Allocation and Respiration). We are using our observations of soil and ecosystem fluxes of multiple GHGs to develop and validate the merged model, as well as to quantify the uncertainties. This modeling framework will have applicability to a wide range of sites, and its parsimonious modular structure will allow incorporation into Earth system models.