USGS CAWSC Grant: Modeling Carbon and Greenhouse Gas Dynamics in Sacramento-San Joaquin Delta Wetlands

For the past decade the Carbon Farm pilot program has been monitoring carbon dioxide and methane emissions from its pilot wetland facility on Twitchell Island in the Sacramento-San Joaquin Delta. One goal is the additional understanding of the geochemical processes that result in carbon accretion, land surface accretion, carbon preservation, nitrous oxide and methane emissions with regard to wetland water depth, vegetation, growth phase, season, temperature and other important biogeochemical variables. To facilitate this understanding, seek to implement an explicit model of redox conditions and greenhouse gas production of the pilot wetlands, using our historic monitoring data and other available monitoring data.

In particular, conduct a review, assessment and synthesis of observation data of daily weather, hydrology, wetland plants, and soil for the target “Carbon Farm” at the Twitchell Island pilot wetland site. Further, characterize the two dominant vegetation types with respect to the biophysical properties related to carbon storage and gas exchange. These two sets of information will be used to construct a model that explicitly simulates redox and carbon decomposition in the pilot wetland, as well as predicts carbon dioxide and methane emissions. Validation of the model will be conducted using historic monitoring data.

Specific objectives are:
• In collaboration with USGS CAWSC staff, aggregate existing field data for calibration of Denitification-Decomposition (DNDC) wetland vegetation model.
• Meet with USGS to collect existing methane emission data for model validation.
• Aggregate and format climate data for modeling simulations.
• Prepare a final report focusing on assessment results.