Incluye 38 referencias bibliográficas en las páginas 119-120

Selective logging and forest conversion into agroforestry systems are widespread at the margins of tropical moist forests in Southeast Asia, typically creating gradients of forest disturbance intensity from the edge to the interior. We studied the effect of increasing forest use on the temporal and spatial variability of fine root mass and fine root production in a sub-montane tropical moist forest in central Sulawesi. We selected four forest types which represent a disturbance gradient from undisturbed forest to selectively logged forest with small or large timber extraction, and to agroforestry plantations under natural shade tree cover. Increasing intensity of forest use led to a significant decrease in fine root biomass and necromass. Even the extraction of only a limited number of small-diameter stems had a significant negative impact on the fine root biomass. Spatial variability of fine root biomass or necromass within the stands did not differ along the disturbance gradient, and neither did the relative seasonal variation in fine root mass. Fine root production was significantly less in the heavily disturbed forest stands than in the undisturbed forest. Fine root biomass and fine root production were strongly correlated with canopy cover and basal area of the stands, whereas soil physical or chemical conditions were of secondary importance. We conclude that mild to moderate disturbances of tropical moist forests have a significant negative effect on total fine root biomass and carbon fluxes associated with root production, whereas spatial and temporal patterns of the fine root system remain largely unaffected.