Cava, M.G.B., N.A.L. Pilon, M.C. Ribeiro, G. Durigan
Active restoration strategies have been recommended to recover Neotropical savannas in abandoned lands, but no studies have investigated the trajectories and speeds of spontaneous recovery for these systems. Research into the dynamics of degraded savannas is urgently needed to guide restoration decision making. In this study, the authors analysed the dynamics of secondary savannas in the Brazilian Cerrado by sampling 29 abandoned pastures (time since abandonment ranging from 3 to 25 years) and applying the space‐for‐time substitution method. They modelled the temporal changes in plant community attributes and estimated the time required for these attributes to match those of two reference ecosystems, old‐growth savanna and a forest‐type savanna, which had encroached following fire suppression (encroached savanna). Tree canopy cover, richness and density rapidly increased with time since pasture abandonment. The cover and richness of the ground layer increased at a much slower pace. Up to 25 years after abandonment, secondary savannas continued to lack many (37%) old‐growth savanna species, mostly from the ground layer (82% of grasses absent). This period was also not sufficient for the secondary savannas to become floristically similar to the encroached savannas, which are dominated by shade‐tolerant tree species. Despite the reported high natural regeneration of Neotropical savanna vegetation, abandoned pastures will not spontaneously return to an old‐growth savanna state.
Journal of Applied Ecology