HR: 1340h
AN: B33E-1670    [Abstracts]
TI: Modeling Carbon Flux from Inter-Tidal Salt Marshes
AU: * Kathilankal, J C
EM: jck5e@virginia.edu
AF: University of Virginia, Department of Environmental Sciences 291 McCormick Rd, Clark Hall P.O box 400123, Charlottesville, VA 22903, United States
AU: Fuentes, J D
EM: jf6s@virginia.edu
AF: University of Virginia, Department of Environmental Sciences 291 McCormick Rd, Clark Hall P.O box 400123, Charlottesville, VA 22903, United States
AB: Coastal salt marshes have the potential to accumulate carbon at high rates over longer periods of time due to continuous accretion and burial of sediments rich in organic matter, giving soils in coastal wetlands a distinct advantage over many other environments with respect to the sequestration of organic carbon. Even though ecosystem level fluxes of carbon and energy have been studies in great detail from terrestrial (eg. FLUXNET) and oceanic environments (JGOFS - Joint Global Ocean Flux Study), considerable gaps exists in our understanding of ecosystem fluxes of carbon and energy from inter-tidal salt marshes that form the interface between terrestrial and oceanic ecosystems. The present study is based on observations from a flux tower based on eddy covariance methodology, set up in the lagoonal salt marsh in the Eastern shore of Virginia (37.41°N 75.83°W). The prominent vegetation in these mud flats is the salt marsh cod grass (Spartina alterniflora). The results presented include the trends in assimilatory response of the systems to various environmental forcings. The short nature of the vegetation along with a tidal range which can submerge the vegetation during different times of the day provided an interesting scenario for understanding tidal forcings on carbon flux. The study also addresses the development of a biophysical model for simulating the carbon and energy dynamics of the system by incorporating the theories of turbulent transfer (LNF theory) and by solving the energy balance equations within the different layers of the plant canopy. Spartina alterniflora is considered to be the primary sink for atmospheric carbon, and its distribution was modeled as a C4 photosynthetic mechanism. The model incorporates effects of tidal activity which influences the number of layers available for the model to operate and also the source/sink distribution. The study also addresses the possibility of including the air sea CO2 fluxes as a part of source/sink distribution for carbon dioxide for such inter-tidal ecosystems.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0442 Estuarine and nearshore processes (4235)
DE: 0497 Wetlands (1890)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting