Carbon pools recover more quickly than plant biodiversity in tropical secondary forests

Although increasing efforts are being made to restore tropical forests, little information is available regarding the timescales required for carbon and plant biodiversity to recover to the values associated with undisturbed forests. To address this knowledge gap, we carried out a meta-analysis comparing data from >600 secondary tropical forest sites with nearby undisturbed reference forests. Above-ground biomass approached equivalence to reference values within 80 years since last disturbance, whereas below-ground biomass took longer to recover. Soil carbon content showed little relationship with time since disturbance. Tree species richness recovered after about 50 years. In contrast, epiphyte richness did not reach equivalence to undisturbed forests. The proportion of undisturbed forest tree and epiphyte species found in secondary forests was low and changed little over time. Our results indicate that carbon pools and biodiversity show different recovery rates under passive, secondary succession, and that colonisation by undisturbed forest plant species is slow. Initiatives such as the Convention on Biological Diversity and REDD+ should therefore encourage active management to help achieve their aims of restoring both carbon and biodiversity in tropical forests.