Forest Harvesting_Sequence of Operations
Sequence of Operations
In the permanent forest estate, the selective felling system, with the sequence of operations is adopted in the harvesting of hill mixed dipterocarp forest (HMDF) and peat swamp forest (PSF). It is aimed at removing selectively, in a single felling operation, the mature and over-mature trees, while means at the same time, leaving behind a residual stand with sufficient number of trees in the intermediate diameter classes to form the next crop.
Because of the multi-layered structure of the forest stands, the system has been designed to safeguard the environment and takes advantage of the timber market demand. In harvesting the mature and over-mature trees, sustainability of the forests is assured.
Some damage to residual stands is caused by tree-felling while the building of road and skid trails in the tropical weather such as of heavy rainfall conditions does affect the soil, causing certain degree of erosion and sedimentation of water in the streams and rivers. These are temporary effects as ground vegetation soon takes over to protect the bare areas.
Annual Coupe
The annual coupe system is a format to control and monitor harvesting activities and yield of harvest. As from September 1992, the yield control incorporates the monthly production quota for each concession in the hill mixed dipertocarp forest. The sequence of operations in the annual coupe system, commonly known as Permit to Enter Coupe (PEC), is shown in the table below. Every operational activity has to be approved before the next operation is executed.
Sequence of Operational Activities in the Annual Coupe System
| Forest Type | Sequence of Operations | Operational Activities |
| HMDF | 1 | Cut, demarcate and survey coupe boundaries. |
| 2 | Prepare topographical work map. | |
| 3 | Align and survey of proposed road on the ground. | |
| 4 | Start road construction as planned in the approved map; demarcate and survey logging block boundaries and carry out tree enumeration. | |
| 5 | Fell and extract timber from approved blocks. | |
| PSF | 1 | Cut rentis for rail lines, and demarcate and survey coupe and block boundaries. |
| 2 | Carry out 100 percent enumeration of annual coupe. | |
| 3 | Construct rail lines. | |
| 4 | Construct "Kuda-Kuda", fell and extract timber |
In order to protect the quality of water supply to the rural communities, harvesting is banned in the hill forests on steep slopes such as those with gradients of 35 degrees and above (60 per cent or more) as well as in forests in the water catchment areas. Lately, helicopter logging using giant helicopters has been introduced to minimise degradation to the environment and to the water quality.
