Binsuluk Forest Reserve

Binsuluk FR is situated about 10 km north of Beaufort town in the Klias Peninsula. The southeast tip of the FR is close to the KK-Beaufort Highway. The Membakut-Kuala Penyu road runs close to northern part of the FR, almost to its boundary a few kilometres from Kuala Penyu. The FR is also accessible by small boats through the many small rivers in the peat swamp.

None.

Creation—Binsuluk FR was gazetted in 1984 as a Class I FR. Prior to 1984, it was state land. It was proposed as a FR in 1978. According to a map of the then proposed Sg. Binsuluk FR drawn in Oct 1978, an area of about 8,195 ha in the drier central portion of the FR was logged-over. The map also showed an area of about 3,723 ha in the north-west under special licence to Sabah Match Factory Sdn. Bhd.

Management responsibility—Beaufort District Forestry Office.

Boundary matters—Demarcated.

Management plan—None.

Current use—None.

In the north of the FR are fishing villages, the main ones being Kg Kuala Binsuluk and Kg Lumahat Laut. In the northwest lies Kuala Penyu town. Membakut lies in the east and Beaufort in the south.

Some established villages east of the FR are Kg. Madang Pimping, Kg. Pimping, Kg. Brunei, Kg. Tandul, Kg. Bandau, Kg. Dindong, Kg. Dungau, Kg. Pisau, Kg Mawao and Kg. Lumat.

In the west ar Kg. Kandu, Kg. Kabitang, Kg. Takuli, Kg. Malabau, Kg. Palagau, Kg. Sarutuk, Kg. Kota Klias, Kg. Japar and Kg. Singkorap.

The Papar-Beaufort Highway is situated east of the FR. On the west is the newly sealed road to Kuala Penyu. Surrounding lands are mainly alienated land belonging to farmers mainly planting pineapple, banana and watermelon.

Topography—Almost the whole FR is on peatswamp with a very flat terrain. A small portion is in the mangrove.

Soils—Predominantly Klias Association. Small patches with Weston Association in the eastern border.

Meteorological data—See data from Mempakul, Mawau Estate & Beaufort Meteorological Stations.

The forest type here is peatswamp forest over soils of the Klias Association. Most of the FR was badly burnt during the long drought of 1997-1998. Of the remaining trees, Dryobalanops rappa is the most dominant canopy tree species. Most of the burnt areas are dominated by small shrubs. The northeast portion of the FR is very degraded.

The Binsuluk FR was very similar to the Klias FR (about 10 km southwest of Beaufort) in terms of species composition, i.e. the dominance of D. rappa, D. stenostachys, S. platycarpa, and G. bancanus. Kapur paya (D. rappa ) appears to be one of the most dominant constituents of the upper canopy. However, it cannot be certain whether Klias FR current vegetation status reflects the original structure of the forest. This is because past logging operations may have removed only commercial species (e.g. Dactylocladus stenostachys, Gonystylus bancanus, and Dryobalonops rappa), during a time when kapur paya was either not highly marketable or difficult to transport (i.e. the kapur logs sink in water).

According to a map of the then proposed Sg. Binsuluk FR drawn in Oct 1978, an area of about 8,195 ha in the drier central portion of the FR was logged-over. The map also showed an area of about 3,723 ha in the north-west under special licence to Sabah Match Factory Sdn. Bhd.

The only large mammals present in the FR are wild boars, sambar deer (payau), macaques (Macaca fasicularis) and perhaps proboscis monkeys (Nasalis larvartus) as this species is present in the tributary of Klias River further south.  Love shaded butterflies eg. Thaumantis odona, are present also.

There are proposals to rehabilitate the forest in the FR. The approved GEF Project, headed by the Sabah Forestry Department, may deal with research on its rehabilitation, possibly paving the way for the rehabilitation of other peatswamp forests in Sabah.

The Silviculture Section of the Forest Research Centre set up 11 yield plots in the southeastern portion of the FR in 1986.

Fire—Fire is a great threat to this FR. About 90% of the FR was burnt during the drought of late 1997 and early 1998.  With the drying of the peat by drought, fire and the irrigation canals, the prospect of future fires are unfortunately possible*. However, the remaining peatswamp forest has a rather intact structure, possibly representative of the burnt areas.

* This  concern became reality in early March 2002 when parts of the FR was burnt after a long dry spell in the West Coast beginning December 2001. In early March 2003, fire broke out in the peat swamps of the Klias Peninsula and it lasted for more than 2 weeks. This FR was also affected.

Drainage—Trees growing in peat swamps are sensitive to changes in the mean water table level. Therefore, drainage of water from peat swamps may have damaging effects on the ecology and hydrology of PSFs. Drainage causes the water table level to drop. This could ultimately result in changes to the floristic composition of the forest, with plants that are more suited to the drier conditions succeeding those of the original wetter conditions. The drier conditions also lend themselves to greater fire risks.

Drainage is usually the result of canals being dug to drain water from adjacent land for agricultural development or for transportation of logs by floating them along the extraction canals. A network of canals are found just outside the FR. This would likely have affected the overall mean water table level of the peat swamp basin. How significant this change may be would be a subject of further investigation. The consequent impact of this change on the quality of the peatswamp forest, namely the forest within the FR, is difficult to predict, and would require long term research and observation. But one can expect a negative influence on the ecosystem integrity of the peatswamp forest. If the canals are close-ended, e.g. they do not drain out to a river, then the negative effects may be mitigated.

Peat subsidence—Another serious consequence of excessive drainage is peat subsidence – peat being the very medium that supports the existence of peatswamp forests. Landuses that involve the extensive drainage of peat soils cause peat to wash away or subside and oxidise, until ultimately the peat deposit is completely depleted. Once depleted, the subsoil of peat areas will be exposed. The underlying subsoils are usually sandy podsolic soils or acidic sulphate clays, both types seriously nutrient-deficient and not likely to support agriculture.

This is a very important area for conservation of peat swamp forest in the Klias Peninsula.  Although this FR is surrounded mainly by settlements and economically may not be so viable for nature tourism, there is still a need to preserve the diversity of flora and fauna within the burnt secondary forest of the Binsuluk peat swamp.