Why minimum diameter cutting alone cannot fit with RIL objectives

Abstract : In tropical forest, logging operations are basically defined by a single and very simple rule: the Minimum Diameter Cutting Limit (MDCL). Because mixed dipterocarp forests exhibit a relatively high density of timber species (10 to 20 trees/ha), the MDCL rule leads to high felling intensities. Field experiments in East Kalimantan showed that under such high felling intensities, RIL techniques are inefficient to reduce damage on forest stand. The long term consequence of high rate of damage is an increase of the rotation cycle (> 80 years) poorly compatible with sustainable forest management principles. In addition to the global effect of logging on forest stand, commercial species face drastic change in their density and structure. Their capability to adapt to the new environmental conditions and to maintain populations in the ecosystem after logging will mainly depend on the following features: original population density, population structure, regeneration strategy, and breeding systems. Based on these ecological features, we propose additional silvicultural rules in complement with the MDCL, to keep logging intensity under an acceptable threshold that can be compatible with sustainable forest management.