The ORNL DAAC has released a global data set pertaining to fluxes of carbon dioxide and water from vegetation.
"Net Carbon Dioxide and Water Fluxes of Global Terrestrial Ecosystems, 1969-1998" examines the variability of net surface carbon assimilation, net ecosystem surface respiration, and net surface evapotranspiration among and within vegetation types. The data were compiled from scientific papers published between 1969 and 1998.
Visit the FLUXNET project page to access these and other flux data and documentation maintained by the ORNL DAAC.