The effects of the timing and method of logging on forest structure in Peninsular Malaysia

We investigated the effects of immediate, short-term (2.5 years after logging) and long-term (about 50 years after logging) logging on tree species from different diameter size classes in three forest reserves in Peninsular Malaysia. Demographic data on number of trees, species and diameter of all trees above 1 cm diameter at breast height (dbh) were measured from three ecological plots (20 m × 50 m) established at different elevations in each study site. The total reduction in mean basal area for trees ≥1 cm dbh for both logged stands was significantly different ( P < 0.05), i.e. 50.9% in Compartment 118 and 51.8% in Compartment 48. All trees more than 60 cm dbh in Compartment 118 and 75 cm dbh in Compartment 48 were felled in a single selective cutting under selective management system (SMS). The removal of these genetically superior adult trees will affect the genetic quality of the remaining and subsequent regenerating gene pools. The mean basal area and tree density for seedling and sapling class (