In the species-rich tropical forests, the most appropriate form of management is to rely on natural regeneration to provide the future crop through selective felling of the mature crop. Following the Selective Management System (SMS), as practiced in Peninsular Malaysia, advanced growth of 30-45 cm diameter at breast height (dbh) is expected to produce the next harvest. Therefore it is important to note that residual stands must be adequate in quantity and of a specific quality to ensure a future yield that is both economical and sustainable in the long term.
An understanding of the distribution, regeneration status and growth potential of logged-over forests is important in ensuring the sustainable production of timber. An assessment of the residual stocking and development status of logged-over forest was carried out by examining the data obtained from growth plots that have been established in the State of Negeri Sembilan since 1992. Based on the enumeration of data obtained from these plots, the results of the analysis are discussed with particular reference to their implications on future production.
The growth plots in the State of Negeri Sembilan were randomly distributed in two (2) forest districts namely East Negeri Sembilan Forest District and West Negeri Sembilan Forest District. In each District, a total of three (3) Growth Plots of were established. These plots were established based on the following characteristics, namely;
- located in the Permanent Reserve Forest,
- number of years after logging to sufficiently represent the different stages of forest development after logging and
- available information on Pre-Felling Inventory and Post-Felling Inventory for the purpose of stocking and species comparison. The size of each plot is one (1) hectare with 25 sub-plots of 20m x 20m and 9 sub-plots of 10m x 10m. In the 20m x 20m sub-plots all trees 10cm dbh and above were measured while in the 10m x 10m sub-plots all trees 5cm-10cm dbh were measured. (Forestry Department Peninsular Malaysia 1992). The background information of the Growth Plots in the State of Negeri Sembilan is shown in table 1.
The first enumerations were made in 1992 and here since being re-measured seven times. The years 2004 was used as the reference year in the relation to the year that the compartment was logged. The definitions of original forest in terms of good, moderate and poor were based on the Second National Forest Inventory 1981-1982. (Forest Department Peninsular Malaysia 1987)