2006 Volume 15 Issue 2 Pages 189-199
Human impacts on a tropical rain forest were observed through stand structure and dynamics of a rural forest in Sumatra. Species composition has been successively changing through continuous and biased impact by local people under nearly dynamic equilibrium conditions in tree density and basal area. Soft wood species (broad-leaved trees with low stem hardness) with fast growth-rates tended to increase their dominance under higher human impact. Because of the lower bulk density of their stem wood and lower tree height, the stem biomass in a rural forest stand could be estimated at only a half of that of a mature forest even under the same basal area conditions. Turnover times of basal area in these rural forests were about 15 years and 25 years for open forest stands and closed forest stands, respectively. When we examined the productivity of several rural forest stands in the study area, an optimum curve could be drawn for the relationship between biomass and productivity. We propose a new criterion for the management of secondary forests based on their economical and environmental functions.
