Project Number: 6206-11220-004-03
Project Type: Specific Cooperative Agreement

Start Date: Jan 01, 2005
End Date: Dec 31, 2009

Objective:
Document carbon dioxide source/sink relationships on grasslands representative of the various North American climatic regimes, the impacts of land use decisions and management practices on major carbon pools and fluxes, and the role of rangelands in the global carbon balance, as influenced by land use decisions and rangeland management practices.

Approach:
Rate and direction of carbon dioxide fluxes will be continuously monitored above grasslands and shrublands on sites at several ARS locations in the central and western U.S., using pop-on chambers and Bowen ratio/energy balance equipment fitted with infrared gas analyses. Within locations, comparisons will be made on grassland sites with and without shrubs, on grazed and ungrazed sites, or on sites dominated by native or introduced forage species. Carbon dioxide flux measurements will be interpreted in light of concomitant analyses of soil and vegetation carbon dynamics, meteorological monitoring, and changes in the surface energy balance.