What drives long-term variations in carbon flux and balance in a tropical rainforest in French Guiana?

This study highlights that, over the long-term, carbon fluxes and balance in such tropical rainforest ecosystems are largely controlled by both radiation and water limitation. Even though variations in Rg have a greater impact on these fluxes, water limitation during seasonal droughts is enough to reduce ecosystem productivity, respiration and carbon uptake. The reduced precipitation expected in tropical rainforest areas under future climatic conditions will therefore strongly influence carbon fluxes and carbon uptake. This study also highlights the importance for land surface or dynamic global vegetation models to consider the main drivers of carbon fluxes and balance separately for dry and wet seasons.