YOGYAKARTA – Orangutan is the only big ape that lives in Sumatera and Kalimantan in Asia. It is now a species that is threatened to extinct due to forest degradation that is caused by conversion of forests into plantation and settlement. ”Loss of habitat, degradation as well as fragmentation are the threats against orangutans in Sumatera and Kalimatan,” said Slamet Rifanjani in his open doctoral examination in Faculty of Forestry of UGM, Thursday (29/1).
His research in the orangutan habitat in the area of Gunung Palung National Park (TNGP), Ketapang, West Kalimantan, showed the reduction of population of the orangutan. The lecturer from Universitas Tanjungpura revealed this is due to the reduction of density of trees caused by logging that is done whether in continuous or fragmented habitat. This affects the availability of feed, including the punak tree (Tetramerista glabra) which is a commercial tree that is prone to be logged.
In the fragmented habitat, the reduction of population is much bigger at 98,08%, or from 2.60 orangutans per km sq becoming 0.05 orangutan per km sq. A research in 2001 showed 4 orangutans per one km sq. The problem has been aggravated by the high rate of human activities.
This resulted in the orangutan to stay on relatively bigger and higher trees that have a big diameter and are mostly found in the degraded and fragmented forests. “The nest of the orangutan has an average diameter of 10-20 cm at a height between 7 – 18.5 meter,” he said.
Seeing the condition, Slamet recommends the National Park and regional government immediately allocate a special forest for the habitat of orangutan. “This habitat needs to be procured with nests, feed, while access by human is limited,” he concluded.