Neotropical secondary forest succession: changes in structural and functional characteristics

In this review we highlight the main biotic and abiotic factors that influence the patterns of Neotropical secondary forest successions, referred as the woody vegetation that regrows after complete forest clearance due to human activities. We focus on both patterns of specie replacement and various processes that occur during succession, and suggest that the sequence of processes may be predictable even if species composition is not. We describe forest recovery with respect to old-growth conditions, which we define as the structure, function, and composition of the original forest before conversion, and we examine this recovery process within the context of type and intensity of past land use. The various phases of the recovery process are described in derail: from factors affecting early colonization, changes in light and soil properties, soil-vegetation feedbacks at initial and later successional stages, biomass accumulation, forest productivity, rates of species accumulation, and species composition. The consensus of these analyses is that the regenerative power of Neotropical forest vegetation is high, if propagule sources are close by and land use intensity before abandonment has not been severe. Nevertheless, the recovery of biophysical properties and vegetation is heavily dependent on the interactions between site-specific factors and land use, which makes it extremely difficult to predict successional trajectories in anthropogenic settings. We attempt, throughout this review, to integrate the structural and functional characteristics of secondary succession as a way to enhance our ability both to predict and manage successional forest ecosystems due to their increasing importance as timber sources, providers of environmental services, and templates for restoration purposes. (C) 2001 Elsevier Science B.V. All rights reserved.