The impact of man on a tropical forest in Indonesia

Initial work within the Man and Biosphere project in East Kalimantan has dealt with the environmental effects of different kinds of land use, entailing study of floristic, faunistic, and soil changes in logged-over forest, secondary forest and dry-land farm, as well as socio-economic conditions in the neighboring settlements of transmigrants. In logged-over forest, 41 percent of residual trees are damaged; fewer tree species are present than in primary forest; 30 percent of the ground is bare; the soil is compacted, with slow infiltration rates, and is subject to erosion. Burnt and unburnt plots of clear-cut primary forest are completely covered by pioneer tree species within six months; both seedlings and resprouts play an important role in recovery. Growth is better in the burnt plot. A similar situation is observed in six-month-old abandoned dry-land farm. Owing to unfavorable farming conditions, the people in the neighboring settlements turn to collecting forest products to supplement their income. Refs.