Woody Biomass Stocks and Fluxes in the Barro Colorado Island 50-ha Plot

Tropical forest biomass is a globally important carbon stock with an uncertain future under climate change. Our understanding of tropical forest aboveground biomass stocks and fluxes has been advanced by studies on the Barro Colorado Island (BCI) 50-ha forest plot, where all trees larger than 1 cm in diameter have been measured approximately every five years since 1982. BCI studies introduced new methods for estimating biomass stocks as well as fluxes associated with tree growth and mortality and for quantifying associated uncertainty. Aboveground biomass stocks and fluxes on the BCI plot exhibited strong spatial variation in relation to gap dynamics and weak systematic variation among topographically defined habitats. Biomass fluxes varied strongly among census intervals, but there was no directional trend in biomass stocks. Compared with plot studies in other Latin American tropical forests, BCI is close to the median in stocks and woody productivity and in the 23rd percentile for net flux.