Ecosystem rehabilitation and forest regeneration in the humid tropics: Case studies and management insights

Abstract

The highest rates of land use change in the world are found in the tropics. For the period 1981–1990, some 17 million hectares of forest have been converted to other uses each year, of which about half are found in the moist tropical zone. By the year 2050, half of the surface covered by tropical forests in 1990 may have been converted. In the years ahead, a greater proportion of tropical lands may be expected to support secondary forest, degraded zones and other human-impacted areas.

Some issues and approaches in ecosystem rehabilitation have been described as part of the process of elaborating one of the four new research orientations within UNESCO’s Man and the Biosphere Programme (MAB), in an overview of tropical secondary forests, in several recent synthesis reports on the effects of disturbance on tropical forest ecosystems, and in findings of field projects in such countries as China, Papua New Guinea and Thailand. These various studies suggest that mechanized land clearing and logging using bulldozers that are handled insensitively is a principal course of massive disturbance, soil compaction, increased runoff and damage to residual stands.

Socio-economic perspectives and dimensions are vital to the success of rehabilitation schemes, the ingredients and strategies of which may differ in detail from case to case. However, broad guidelines can be set which suggest that tropical ecosystems can and do recover from intensive and sometimes catastrophic human activities.