Wetlands are the largest natural sources of the potent greenhouse gas methane. Production of methane in wetlands can be fueled by a range of carbon substrates, including organic matter recently derived from plant material and organic matter that has been stored in the soil for many years. The relative contributions of old and young carbon substrates to methane emissions are not well constrained but may impact whether wetland ecosystems accelerate or mitigate future climate changes. This project will use field measurements and controlled laboratory experiments to determine seasonal changes in the carbon sources that fuel methane production in a wetland in the Sacramento Delta, California; formerly the largest region of freshwater wetlands in the western United States. The study site is characteristic of highly seasonal temperate wetlands. Natural gradients will be used to explore ecological and meteorological drivers of methane dynamics.
This research will provide rare and valuable data on seasonal variation of carbon sources for methane production in a wetland environment. The work will also take place in the broader context of wetland restoration in the Sacramento-San Joaquin Delta, California, where 150 years of land drainage has led to extreme land subsidence, very large greenhouse gas emissions, and a range of other hydrological and ecological issues. Public and private agencies will be engaged to translate the scientific results of this project into information for public stakeholders and agencies concerned with the future of the Delta. A specific outcome of collaboration will be to provide assistance with the development of a wetland restoration protocols to quantify and minimize methane emissions in delta ecosystems.
