This project aims to improve understanding of atmospheric and hydrologic carbon fluxes in a restored tidal salt marsh in the South San Francisco Bay. I will use soil chambers to measure how much carbon dioxide and methane is taken in and emitted from the marsh. The project will also examine how spatial variability in marsh surface cover impact these exchanges. Shahan will use the data collected in this study to create a biogeochemical model that estimates the carbon budgets of wetlands in the Bay-Delta. A complete carbon budget will illuminate relationships between carbon fluxes and environmental variables. This information can support more informed management of wetlands, as well as allow researchers and decision makers to more effectively plan wetland restoration to be effective in managing carbon fluxes in the face of possible impacts due to climate change.
On-going subsidence of organic soils threatens the physical structure of the Delta, its central role in the state’s water system, many diverse species that depend on it, and threatens future agricultural production. Knowledge of baseline emissions and subsidence rates is important for developing alternative land use scenarios for maximizing benefits for sequestering carbon, reducing or reversing subsidence, providing income for landowners via the carbon market, and reducing flood risk. This project will gather, process, and analyze recent data in the Delta for land-surface elevation changes, greenhouse gas fluxes measured by eddy covariance and gas chambers, soil organic matter content, depth-to-groundwater, and soil organic thickness. These data will be used to update and calibrate the SUBCALC model and refine model inputs to improve the model’s ability to simulate subsidence and CO2 emissions. Collaboration with the Jet Propulsion Laboratory and UC Berkeley will allow use of CO2 flux and InSAR data to calibrate and validate the SUBCALC model. The Delta Conservancy is another partner assisting with assessment of modeling for land-use conversion planning. TNC and Metropolitan Water District are partners to assist with use of SUBCALC for engagement of the carbon market and collaborate with the Suisun RCD to improve estimates of subsidence and CO2 emissions.
