[Table of Contents]

Sustainability of Forests


Secondary Forests


Secondary forests, which regenerate on native forest that has been cleared for ranching or agriculture, are an important focus of CIFOR research because of growing evidence that they help counter the loss of primary forest. Studies have demonstrated that secondary forests can be managed to provide many of the products that small-farmer households traditionally obtained from primary forests, while providing some of the environmental benefits of primary forests. The findings are leading to an interest in efforts to use policy and technological interventions to augment the value of secondary forests to farmers, thereby inducing them to maintain the amount of area devoted to secondary forests and delay its re-conversion to other uses.

Most of the research in this area has been done in several South American countries, under the direction of Drs. Joyotee Smith and CÚsar Sabogal. Secondary forests cover an estimated 165 million hectares of land in Latin America. The work is supported by funding from the Inter American Development Bank and the Spanish Agency for International Cooperation and includes major involvement by the Tropical Agricultural Center for Research and Higher Education (CATIE).

In 1998, the programme reported encouraging findings from a study in Amazonian Peru that contrasts with generally bleak scenarios about tropical deforestation. Results showed that substantial amounts of secondary forest existed in the area studied even several decades after colonist settlement began. The implications are important because they suggest that deforestation related to slash-and-burn agriculture may be considerably less than commonly believed.

The researchers found that regeneration of secondary forests on previously cleared land appeared to mitigate the impacts of residual primary forest loss. As a result of secondary forest growth, more than a third of the farms in the area studied remained under forest cover after three or four decades of frontier development.

This and related research in Brazil and Nicaragua is part of a broader effort to better understand the dynamics of secondary forests – that is, how their role changes as colonist frontiers develop. The study sites in the three countries were selected to represent different stages of frontier development, with biophysical and socioeconomic research now ongoing. One objective of the project is to develop bio-economic models for analysing how changes in various factors affect the profitability of forest-based small farmers and related decisions about land use.

Other initiatives in this research programme include studies to evaluate the use of silvicultural interventions to enhance the productivity of timber species on young secondary forests. Following a pilot study in Costa Rica, experiments are being carried out in Peru and Nicaragua. CIFOR also is working to compile a book that will provide a comparative review of logged-over and second-growth forests in three regions of the world and aspects related to sustainable management of them.