DYNAMICS OF FOREST REGENERATION FOLLOWING LOGGING MANAGEMENT IN A BORNEAN LOWLAND DIPTEROCARP FOREST

Stand dynamics were monitored for 10 years after conventional logging (CL), reduced-impact logging (RIL) and RIL followed by enrichment line planting (LP) and annual slashing (S) (RIL + LP/S) in three 1-ha plots in each of the three sites of a lowland dipterocarp forest in Central Kalimantan. All trees with diameter at breast height (DBH) >10 cm and planted Shorea johorensis were monitored for survival and growth. Natural recruitment poles of commercial Shorea sp. (DBH > 10 cm) were very low in CL site, intermediate in RIL and high (46 +/- 29.5 trees ha(-1)) in RIL + LP/S. Ten years after treatment, 78% of the planted seedlings were still alive. Although LP increased the stock of desirable Shorea sp. relative to RIL, the improvement of light conditions caused by strip cutting and slashing significantly promoted natural regeneration. For sustainable forest production, LP/S are appropriate treatments. From a financial perspective, LP is recommended when reintroducing desirable species. Selection of the appropriate silvicultural treatment will depend on the postlogging state of the forest and the relative cost of LP and S.