The timber resource assessment is designed using stratified samplings points spread across the FMU in areas approved by the Forest Authority. As logging progresses, the present data will be updated accordingly. The output of Annual Allowable Cut (AAC) is the analysis of timber resources in natural forests in the FMU. Timber resource assessment was done with the following objectives:-
- Estimate the mean and total growing stocks by species group;
- Achieve a precision of estimates within 20% sampling error at 95% probability level; and
- To allocate the schedule coupes numbering for the proposed FMU.
Forest Resources and Forest Research
- More than 15 PSPs were established within the FMU area. The objective for the establishment of PSP is to determine the Annual Allowable Cut (AAC) to sustainably manage this FMU area.
The Location of Sampling Plots within the Mengiong – Gaat FMU
- The calculation of AAC was based on the PSP result for growth simulation.
- A repeated simulation runs have been carried out using different harvesting scenarios and their results were analyzed in terms of sustainability with estimated harvesting volume that will be achieved.
- It has a 25-year cutting cycle with an extractable of 9 to 15 trees/ha and an average harvestable gross volume of 30.0370 m3/ha.
- This calculation serves as a temporary indication of sustainable harvestable volume.
- Identification and monitoring of Endangered, Rare and Threatened (ERT) Species and their habitats and dynamism in sustainably well managed forest area.
- Non-Timber Forest Product (NTFP) like palm, bamboo, rattan, wild fruits and edible wild vegetable are present in the proposed FMU.
- Based on 15 PSPs, it has a total of 92 trees for DBHOB 30.0 cm and above with an estimated volume of 104.53 m3/ha, amongst which 77 trees are from DBHOB 30.0 – 49.9 cm with an average gross volume of 61.98 m3/ha whereas 24 trees or 42.552 m3/ha for 45.0 cm and above, and another 15 trees for DBHOB 50.0 cm and above with an estimated volume of 42.54 m3/ha respectively.
- FMU has the total of 15 ERT species of fauna with 21 species consisting of mammals, 2 reptiles and 1 insect.
- Rate of Annual Harvest:
- The average of harvestable yields within the research PSP is 42.91 m3/ha, derived from high density and low density of productivity areas based on fair representation of PSPs.
- The preliminary growth calculation of Mean Annual Increment (MAI) is 0.4 cm/year and 1.7216 m3/ha/year. The basal area is calculated as 26.018 m2/ha.
- Allowable Cutting Area (ACA) is 1,443.64 ha/year.
- AAC is 29,743.3643 m3/year or MPL is 2,478.6136 m3 of production limit for the initial planning of this FMP.
Forest Zoning
- Production area – Mixed Hill Dipterocarp Forests for the production of timber.
- Conservation area – undisturbed and partially disturbed which would serve as reference as continuous in research studies, refuge and breeding sites, as well as timber tree seed production and conservation of genetic diversity.
- Shifting Agriculture Area (areas affected by the local communities used)
Types of Zones and Sizes in Hectares:
| FMU Area | Type of Zones | Area (Ha) |
Percentage (%) |
|
| Yield Control Area | 33,482 | 36.32 | ||
| HCVF | Terrain IV | 134 | 0.15 | |
| Stream Buffer Zones | 244 | 0.27 | ||
| Kerangas | 61 | 0.06 | ||
| Saltlicks | 14 | 0.02 | ||
| HCVF | 66 | 0.07 | ||
| Water-Catchment | 13 | 0.01 | ||
| Shifting Agriculture | 2,077 | 2.25 | ||
| Sub-total | 36,091 | 39.16 | ||
| Salvage Logging | 19,587 | 21.25 | ||
| 100 m Buffer Zone | 5,777 | 6.27 | ||
| Baleh HEP Inundated Zone | 18,802 | 20.40 | ||
| Conservation Area | 11,922 | 12.93 | ||
| Sub-total | 56,088 | 60.85 | ||
| Total Licensed Area | 92,179 | 100 | ||