Sungai Serudong Forest Reserve

Sungai Serudong is a class I Protection Forest. It is located in the southeastern Sabah bordering Kalimantan, Indonesia. The FR is accessible through road networks or sea-based transportation (i.e. boats).

Latitude/Longitude:   4° 23.259’N-4° 9.617’N, 117° 14.290’E- 117° 31.816’E

Serudong District Forestry Office is the only infrastructure found within the reserve.

Creations – The FR was gazetted as class I reserve, covering an area of 7,930 ha in 1992. It was formerly gazetted under Kalabakan FR (class II).

Management responsibility – Serudong District Forestry Office.

Boundary matters – The boundary has not been demarcated.

Management plan – None.

Current Use – Protection.

Settlements and other buildings approximately 2 km from the boundary:

• Kem Ramd Sri Saleha
• Kg. Poirgon
• Kg. Batu15 (Abandoned)
• Kg. Serudong Laut

Topography

Figure 1: Topography and drainange map of Sungai Serudong FR

Hydrology 

Major river: Serudong river

Soils

The Lokan, Kretam, Maliau, Brantian and small patches of Weston associations are found in this reserve.

Meteorological data

See Kalabakan rainfall data.

There are two major forest ecosystems in Sungai Serudong FR: lowland mixed dipterocarp and lowland mixed dipterocarp-kerangas. The sporadic distribution of late secondary forests is observed in the matrix of the advanced growth forest of the former two major forest ecosystems. Past timber extraction activities have altered the vegetation into various regenerative stages. 

The forested areas of Sungai Serudong FR are essential for the ecological corridor between the mangrove ecosystems, both Tawau FR (Class I) and Tawau FR (Class V) with the inland forest ecosystems. Hence, the whole reserve is a critical high conservation value ecosystem permitting the exchange and migration of fauna and flora.

Flora

A total of 259 plant taxa were recorded from the forest reserves. Of the total recorded taxa, 60 are endemic to Borneo. The ten most speciose families in decreasing order are the Dipterocarpaceae (59), Euphorbiaceae (20), Malvaceae (14), Moraceae (10), Myristicaceae (9), Annonaceae (8), Achariaceae (7), Ebenaceae (7), Meliaceae (7) and Pentaphyllacaceae (7).

Threatened species under IUCN Red List:

• • 30 Species

Taxa under Wildlife Conservation Enactment 1997: –

Schedule 2, part II – (i) Ginger (ii) Agarwood (iii) Arenga

Species listed under Appendix II CITES: 

• • 1 Species

Prohibited Species Under Sabah Forest Enactment 1968: 

• • 27 species (mostly fruit trees and threatened tree species)

Three high conservation value plant species, namely Cotylelobium lanceolatum, D. crinitus and Hopea tenuinervula were selected as key conservation targets for monitoring biodiversity integrity in reserves.

Avian

Sixty-nine species from 36 families were recorded from this FR. The four most specious families are Pycnonotidae (7), Columbidae (6), Nectariniidae (5), Pellorneidea (5), and Bucerotidae (4).

Threatened species under IUCN Red List recorded from this FR include the Helmeted Hornbill (CR), Black Hornbill (VU), Great Argus (VU), Grey-cheeked Bulbul (VU), Large Green-pigeon (VU) and Rhinoceros Hornbill (VU).

Insect

Sixty nocturnal species were recorded from the FR. At least five Bornean endemic species were recorded from the reserve. The endemics include three moth species, a beetle and a stick insect.

• • Butterfly – 11 species; Interesting species: Trogonoptera brookiana (Rajah Brooke) and Troides amphrysus (Golden Birdwing).
  • Moth – 24 species; Endemics: Aethalida borneana, Amata macroflavifer and Amata Prepuncta.
  • Beetle – 5 species; Endemic: Chalcosoma moellenkampi
  • Dragonfly & damselfly –  8 species; Interesting species: Green damselfly
  • Other insects – 12 species; Interesting species: Megapomponia merula (biggest Cicada recorded in Sabah)

Mammals

A total of 15 mammals from 10 families were recorded from this FR.

• • Helarctos malayanus (VU)*
  • Prionailurus bengalensis (LC)**
  • Paradoxurus hermaphroditus (LC)**
  • Sus barbatus (VU)***
  • Tragulus napu (LC)***
  • Rusa unicolor (VU)***
  • Muntiacus muntjac (LC)***
  • Macaca nemestrina (VU)**
  • Nasalis larvatus (EN)*
  • Hylobates muelleri (EN)**
  • Macaca fascicularis (LC)**
  • Trachypithecus cristatus (NT)**
  • Callosciurus notatus (LC)
  • Callosciurus prevostii (LC)
  • Sundasciurus hippurus (NT)
  • Hystrix brachyura (LC)***
  • Echinosorex gymnura (LC)
  • Tupaia tana (LC)
  • Tupaia longipes (LC)
  • Tupaia gracilis (LC)

Wildlife Conservation Enactment 1997: Schedule 1*; Schedule 2**; Schedule 3***

• Multidisciplinary studies were conducted during the Heart of Borneo Expedition (HoB) by the Sabah Forestry Department in Sungai Serudong FR.

Forest fires – Being surrounded by oil palm plantations increases the risk of forest fire exposure.

Poaching – Accessibility to the forest reserve could be the main factor of poaching activities.

The reserve is a critical ecological corridor linking the mangrove ecosystem in Tawau to inland forest ecosystems. Furthermore, the transboundary wildlife corridor, especially Sabah’s pygmy elephant between Sabah and Kalimantan.