The Forest Resource Assessment (FRA) is an essential component of forest management planning that involves the collection of data about forest dynamics at the FMU level. This is conducted through the establishment of sampling unit (SU) in the production area of the FMU as per Forest Department Sarawak “Technical Manual For Forest Resources Assessment (FRA) in Sarawak” (FDS, 2019).  The objective of the FRA is to determine the dynamic, quantity and quality of timber species in the production forest, at pre-determined levels of statistical accuracy and probability, and to provide a quantitative resource database for the determination of the Annual Allowable Cut (AAC) in natural forests.

Field work on the data collection for Forest Resource Assessment (FRA) has commenced in April 2017 and completed in December 2018.  The FRA data has been submitted to Forest Department Sarawak on the 6th March 2019 under the ref no SFM/MM/2019(11) for the formulation of Sustainable Annual Allowable Cut (AAC) using the FORMIND simulation software.

The summary of FRA Results (from 61 SU) as follows;

  • an average of 1,093.6 trees per hectare
  • average DBH equals 13.17 cm
  • average commercial bole height (CBH) and total height (TH) of 7.16 m and 13.00 m, respectively
  • mean stand basal area of living trees is 22.93 m2/ha
  • total volume averages 175.4 m3/ha, out of which 64.2% is commercial species.
  • 2.1% of the trees assessed during the FRA belong to protected tree species.

Permanent Sample Plots (PSP) network is very important to provide dynamic and reliable data on forest stocking and volume over time and under different forest condition concerning the impact of logging. For PSPs establishment at the FMU level, the selection of the PSPs will be made from a sub-sample of the SUs established during the FRA.  The selection of the PSP from the FRA SU was carried out using the Ranked Set Sampling (RSS) Method whereby it has recommended 31 PSP to be established according to the FRA-SU.

Forest zoning is defined as the zoning of an FMU area into various forest functions based on the topography and land use patterns.  It is broadly zone into three key forest function zone namely Production – the total nest area that can be harvested for timber, Protection – to be left untouched during harvesting operation for conservation and protection purposes, and Community use – reserved for local community use such as shifting agriculture (SA) area, fruits orchards, vegetable farm, cultural site etc.  These areas are to be left untouched during timber harvesting operations.