Figure 1.
The 2001–2010 global carbon and nitrogen cycles of terrestrial ecosystems. The values in parentheses are the changes from the pre-industrial equilibrium fluxes (1860s) owing to land-use, climate and atmospheric CO2 change (blue) and anthropogenic nitrogen additions (red). Carbon fluxes: Pg C yr−1; nitrogen fluxes: Tg N yr−1. NOx, N2O and N2 emissions are from soils only. Ra, Rr and Rh are autotrophic, rhizosphere and heterotrophic respiration, respectively. BNF, biological nitrogen fixation; GPP, gross primary production.