RODENTS & PLANTED FORESTS

By Roslina Ragai - Conservation Department, Grand Perfect S/B, Bintulu, Sarawak.

Anthropogenic activities foster fragmentation and other such modifications of natural habitats can create serious threats to biodiversity. Nevertheless some types of patchy forest remnants within tree plantations can help to maintain certain types of wildlife, such as rodents. Rodents, the Order containing squirrels, rats and porcupines, are distributed widely in natural forest, artificial forests or plantations and near human settlements. Some are pest to crops but others play important roles in forest ecosystems. Their importance in carbon and energy fluxes in the tropical systems is widely accepted. Rodents compose a major food resource to a number of birds e.g. raptors, owls, snakes, felids and other carnivores. Moreover, they enhance the decomposition of plant matter in natural ecosystems.

The Planted Forest Zone (PFZ), located in the Bintulu Division of Sarawak, is an area established for the development of a large Acacia plantation by the Forest Department of Sarawak. Almost 55,000 ha of PFZ have already been planted with Acacia mangium, an exotic tree species that can produce industrial wood for pulp and papers within about seven years.

Since January 2005, small mammal surveys have been underway in collaboration with local and international partners in several areas of the PFZ. Acacia compartments, secondary forests and the less disturbed forests of two conservation areas (Bukit Sarang and Binyo-Penyilam Conservation Areas), conservation corridor (Bukit Mina Conservation Corridor) have been surveyed, along with forest remnants in planted Acacia blocks. However, only a relatively small area of the PFZ has actually been covered so far. Undoubtedly, many more interesting small mammal species are likely to be encountered.

The latest species observed was ranee mouse, Haeromys margarettae in Binyo-Penyilam Conservation Area (BPCA), found in a very unique habitat, mixed peat swamp and kerangas forest. Other interesting species of rodents discovered in PFZ areas are the three-striped ground squirrel, Lariscus insignis, horse-tailed squirrel, Sundasciurus hippurus, grey tree rat, Lenothrix canus and the thick-spined porcupine, Thecurus crassispinis.

A full understanding of small mammal distribution and ecology is still a long journey for us, both in natural forest as well as in the many man-made habitat mosaics which we are creating as Sarawak develops. Fortunately, it seems that a regenerating plantation forest can play an important role to provide a suitable habitat for some of the more adaptable species of small mammals. Even so, we must ensure the right policy, planning and management decisions are made for the long-term survival of these wonderful creatures.

Acknowledgements

I would like to thank the Conservation Department of Grand Perfect Sdn Bhd for their support and assistance in making the field work possible in PFZ. Special thanks to Mr. Rob Stuebing, Belden Giman, Nyegang Megom, Dr. Han Kwai Hin, Ch’ien C. Lee and for those who involved in this project.

References

Giman, B., Stuebing, R., Megum, N., Mcshea, W. J. and Steward, C. M. 2005. A camera trapping survey for mammals in a mixed use planted forest in Sarawak. Raffles Bulletin of Zoology.

Han, K. H. 2005. Field report on inventory study of small mammals and plants in Samarakan Nursery, Bintulu Planted Forest Area, Ulu Tatau from May 10 through 20, 2005. Grand Perfect Sdn. Bhd., unpublished report.

Wilson, D. E. and Helgen, K. M. 2005. Small mammal survey of Bukit Sarang and Samarakan. Grand Perfect Sdn. Bhd., unpublished report.