Borneo Lowland & Montane Forests - A Global Ecoregion | WWF

Borneo Lowland & Montane Forests - A Global Ecoregion

Tree roots covered with moss, Kayan Mentarang National Park, Kalimantan (Borneo), Indonesia.

About the Area

This Global ecoregion is made up of 2 terrestrial ecoregions: Borneo lowland rain forests; Borneo montane rain forests.

It comprises of a great variety of habitats including large areas of karst (barren limestone plateaus with caves, sinkholes, and gullies), and a high-altitude swamp forest.

These and other unusual habitats are part of the reason that so many unique species of plants and animals (23 of the 39 mammals endemic to Borneo) have evolved in this region.

Borneo's highest point is Mount Kinabalu in Sabah, Malaysia, with an elevation of 4,095 m (13,435 ft) above sea level. This makes it the world's 6th highest island.

422 new plant species have been discovered in Borneo in the last 25 years, and many other species are waiting to be found and studied, some of which potentially hold important medical properties. However, WWF is concerned that all these promising discoveries could eventually be lost if the disappearing rainforests at the heart of Borneo are not adequately protected.

540,000 sq. km (210,000 sq. miles)

Habitat type:
Tropical and Subtropical Moist Broadleaf Forests

Geographic Location:
An island shared by three countries: Brunei, Indonesia, and Malaysia

Conservation Status:

Local Species

There are about 15,000 species of flowering plants with 3,000 species of trees (267 species are dipterocarps), 221 species of terrestrial mammals and 420 species of resident birds found here.

The forests support a rich variety of flora such as:
  • Asia's most characteristic tree family, the dipterocarpaceae.
  • Unique species of orchids, ferns, lichens, vines and rhododendrons.
  • Species of rafflesia - the parasitic genus lacking true leaves, stems or roots.
  • Carnivorous pitcher plants that trap insects and absorb the proteins from them.
Mammals include the endangered orange-brown orangutan (Pongo pygmaeus), Sumatran rhinoceros (Dicerorhinus sumatrensis), leopard cat (Cynocephalus variegatus), proboscis monkey (Nasalis larvatus), Bornean tarsier (Tarsius bancamus), and the Bornean black-banded squirrel.

A number of birds are endemic to this ecoregion, including the mountain serpent-eagle (Spilornis kinabaluensis), Whitehead's trogon (Harpactes whiteheadi), eyebrowed jungle-flycatcher (Rhinomyias gularis), Bornean whistler (Pachycephala hypoxantha), and the golden-naped barbet (Megalaima pulcherrima).

Featured Species

The most distinctive trait of Proboscis monkey (Nasalis larvatus) is the male's large protruding nose. Whilst the purpose of this large nose is unknown, it is thought that females are most attracted to males with the biggest noses.

The average body mass for an adult male proboscis monkey is between 16 and 22 kg, with females slightly smaller at 7-12 kg. This is a sexually dimorphic species, especially in body size. The proboscis monkey has interdigital webbing that makes it an excellent swimmer. Its favorite foods are fruits, seeds and young leaves. It also eats invertebrates including mosquitoes, caterpillars, and insect larvae. This is a diurnal and semi-terrestrial species. This species always sleeps near rivers, 0 to 15 meters from the river's edge.

The proboscis monkey moves through the forest and on land quadrupedally. This species avoids areas with heavy deforestation, such as agricultural land. The group sizes range from 3 to 32 individuals.

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Damaging human activities such as commercial and illegal logging, large-scale agriculture for oil palm or tea, mining, dam construction, shifting cultivation, illegal collection of species, and infrastructure development have meant that well over half of the lowland forests are now gone, with large fires burning away the remaining tracts.

If the current deforestation trend continues, Borneo's lowland forests, and their biodiversity, will be gone within a decade. Borneo's mountain forests have more protection and are not as economically attractive, so they still remain in good shape. However, it will only be a matter of time before they too face similar threats.
Predictions don't have to come true. But Borneo's tropical rainforests are still being lost to ... 
	© WWF-Germany
Predictions don't have to come true. But Borneo's tropical rainforests are still being lost to fires, illegal logging - and to oil palm plantations. Click on the map to find out about the problems and what WWF is doing with the "Heart of Borneo" initiative.
© WWF-Germany

WWF’s work

WWF's Heart of Borneo initiative aims to assist Brunei, Indonesia and Malaysia to conserve a total of 220,000km2 of equatorial rainforest. Conservation of the rainforest will be enabled through a network of protected areas and sustainably-managed forest, and through international cooperation led by the governments and supported by a global effort.

The 3 Bornean governments – Brunei Darussalam, Indonesia and Malaysia – officially launched the initiative and declared their commitment to support it on 27 March 2006, during the 8th Conference of Parties Convention of Biological Diversity, held in Curitiba, Brazil.

The Heart of Borneo is also a flagship programme of the 5-year action plan of BIMP-EAGA (Brunei Indonesia Malaysia Philippines - East ASEAN Growth Area). This plan is endorsed by the heads of government of all 4 countries.

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