Southeastern Asia: Island of Java in Indonesia

The Western Java Montane Rain Forests [IM0167] are found on one of the most actively volcanic islands in the world. Several mammals and nine bird species are found nowhere else on Earth. Once the home of the extinct Javan tiger (Panthera tigris sundaicus), only a fifth of the original habitat remains in this ecoregion, and these forests are scattered in fragments throughout the mountains.

  • Scientific Code
  • Ecoregion Category
  • Size
    10,200 square miles
  • Status
  • Habitats

Location and General Description
This ecoregion represents the montane forests of west Java. Based on the Köppen climate zone system, this ecoregion falls in the tropical wet climate zone (National Geographic Society 1999). Java probably did not exist before the Miocene (24 m.y.). Truly born of fire, the island of Java is the result of the subduction and remelting of the Australian-Indian Ocean tectonic plate beneath the Eurasian tectonic plate at the Java trench. The melted crust has risen as volcanoes and, along with subsequent sedimentation, created Java. Therefore, the surface geology consists of Tertiary and Quaternary volcanics, alluvial sediments, and areas of uplifted coral limestone. Twenty of the volcanoes on Java and Bali have been active in historic times, and they are among the most active volcanic islands in the world. During previous ice ages, when sea levels were much lower, Java was connected to Sumatra, Borneo, and the rest of the Asian mainland (Whitten et al. 1996).

The main forest types in this ecoregion are evergreen rain forest, semi-evergreen rain forest, and aseasonal montane forest. The evergreen and semi-evergreen rain forests generally are found in the lower portions of the ecoregion. Evergreen rain forests of Java contain Artocarpus elasticus (Moraceae), Dysoxylum caulostachyum (Meliaceae), langsat Lansium domesticum (Meliaceae), and Planchonia valida (Lecythidaceae) (Whitten et al. 1996). Semi-evergreen rain forest differs from evergreen rain forest by being slightly more seasonal, with two to four dry months each year (Whitten et al. 1996).

The transition between lowland and montane forests is a floristic one, and some plant families and genera are found only on one or the other side of this transition. Above 1,000 m, genera begin to include Anemone, Aster, Berberis, Galium, Gaultheria, Lonicera, Primula, Ranunculus, Rhododendron, Veronica, and Viola. Some lowland tree species transition out up to 1,200 m. The most abundant montane tree species in the lower montane zone are Lithocarpus, Quercus, Castanopsis, and laurels (Fagaceae and Lauraceae). Magnoliaceae, Hamamelidaceae, and Pococarpaceae are also well represented. Few emergents, primarily Atingia excelsa and Podocarpus spp., are found in the lower montane zone, but tree ferns are common (Whitten et al. 1996).

In the gradual transition from lower to upper montane forest, which begins at approximately 1,800 m, enormous quantities of Aerobryum moss begin to become prevalent on all surfaces. Dacrycarpus (Podocarpus) continues up from the lower montane. Ericaceae shrubs are very characteristic of the upper montane zone, including Rhododendron, Vaccinium, and Gaultheria. Sub-alpine forest, found above 3,000 m, contains one species-poor layer of trees, including Rhododendron and Vaccinium. Edelweiss (Anaphais javanica) is characteristic of the sub-alpine zone (Whitten et al. 1996).

Biodiversity Features
Overall richness and endemism for this ecoregion are moderate compared with those of other ecoregions in Indo-Malaysia.

The ecoregion harbors sixty-four mammal species, of which fourteen are endemics or near endemics (table 1). Of the latter, the Javan or surili leaf monkey (Presbytis comata) and the Javan gibbon (Hylobates moloch) are the most endangered primates in Indonesia (Whitten et al. 1996). Other ecoregional endemic mammals include the Javan mastiff bat (Otomops formosus), Javan shrew-mouse (Mus vulcani), and the red tree rat (Pithecheir melanurus). The Javan subspecies of the yellow-throated marten (Martes flavigula robinsoni) and leopard on Java (Pantera pardus melas) are also considered endangered (IUCN 2000).

Table 1. Endemic and Near-Endemic Mammal Species.

Family Species
Sorcidae Crocidura orientalis*
Sorcidae Crocidura paradoxura
Pteropodidae Megaerops kusnotoi
Rhinolophidae Rhinolophus canuti
Vespertilionidae Glischropus javanus*
Molossidae Otomops formosus
Cercopithecidae Presbytis comata
Hylobatidae Hylobates moloch
Sciuridae Hylopetes bartelsi*
Muridae Mus vulcani*
Muridae Maxomys bartelsii*
Muridae Pithecheir melanurus*
Muridae Kadarsanomys sodyi*
Muridae Sundamys maxi

An asterisk signifies that the species' range is limited to this ecoregion.

More than 230 bird species are known to occur in the ecoregion, of which 30 are endemic or near endemic (table 2). The ecoregion overlaps with the western portion of the Java and Bali forests EBA. There are thirty-four restricted-range bird species in this EBA, of which thirty are found in this ecoregion. Of these, nine bird species are found nowhere else on Earth and four are threatened, including the endangered Javan hawk-eagle (Spizaetus bartelsi) and the vulnerable volcano swiftlet (Collocalia [Aerodramus] vulcanorum), Javan cochoa (Cochoa azurea), and Javan scops-owl (Otus angelinae) (Stattersfield et al. 1998).

Table 2. Endemic and Near-Endemic Bird Species.

Family Common Name Species
Accipitridae Javan hawk-eagle Spizaetus bartelsi
Phasianidae Chestnut-bellied partridge Arborophila javanica*
Columbidae Green-spectacled pigeon Treron oxyura
Columbidae Pink-headed fruit-dove Ptilinopus porphyreus
Columbidae Dark-backed imperial-pigeon Ducula lacernulata
Strigidae Javan scops-owl Otus angelinae*
Caprimulgidae Salvadori's nightjar Caprimulgus pulchellus
Apodidae Waterfall swift Hydrochous gigas
Apodidae Volcano swiftlet Aerodramus vulcanorum*
Trogonidae Blue-tailed trogon Harpactes reinwardtii
Capitonidae Brown-throated barbet Megalaima corvina*
Capitonidae Flame-fronted barbet Megalaima armillaris
Rhipiduridae Rufous-tailed fantail Rhipidura phoenicura
Rhipiduridae White-bellied fantail Rhipidura euryura
Campephagidae Sunda minivet Pericrocotus miniatus
Muscicapidae Sunda robin Cinclidium diana
Muscicapidae Javan cochoa Cochoa azurea*
Aegithalidae Pygmy tit Psaltria exilis*
Pycnonotidae Sunda bulbul Hypsipetes virescens
Zosteropidae Javan grey-throated white-eye Lophozosterops javanicus
Sylviidae Javan tesia Tesia superciliaris*
Sylviidae Sunda warbler Seicercus grammiceps
Timaliidae Rufous-fronted laughingthrush Garrulax rufifrons
Timaliidae White-bibbed babbler Stachyris thoracica
Timaliidae Crescent-chested babbler Stachyris melanothorax
Timaliidae Grey-cheeked tit-babbler Macronous flavicollis
Timaliidae Javan fulvetta Alcippe pyrrhoptera*
Timaliidae Spotted crocias Crocias albonotatus*
Nectariniidae White-flanked sunbird Aethopyga eximia
Fringillidae Mountain serin Serinus estherae

An asterisk signifies that the species' range is limited to this ecoregion.

Current Status
Only a fifth of the original habitat remains. There are twenty-five protected areas that cover 3,410 km2 (13 percent) of the ecoregion (table 3). Although there are several that are larger than 100 km2, none exceed 500 km2; thus, the protected habitats represent isolated mountains (usually volcanic peaks) that are scattered throughout the mountain chains.

Table 3. WCMC (1997) Protected Areas That Overlap with the Ecoregion.

Protected Area Area (km2) IUCN Category
Gunung Pangasaman [IM0161] 110 ?
Telaga Warna 20 I
Gunung Halimun 480 I
Gunung Gede Pangrango 220 II
Gunung Burangrang 50 I
Gunung Jagat 6 I
Gunung Tilu 90 I
Nusu Gede Pandjalu 8 I
Gunung Sawai 50 IV
Gunung Papandayan 70 V
Gunung Simpang 150 I
Kawah Gunung Tangkuban Perahu 20 V
Gunung Ciremai 160 ?
Waduk Gede/Jati Gede 120 ?
Masigit Kareumbi 130 ?
Gunung Masigit 290 ?
Kawah Kamojang 90 ?
Pegunungan Pembarisan 120 ?
Gunung Liman Wilis 230 ?
Gunung Limbung 200 ?
Gunung Perahu 330 ?
Gunung Slamet 260 ?
Gunung Sumbing 60 ?
Pringombo I, II 6 ?
Tuk Songo 140 V
Total 3,410  

Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.

Types and Severity of Threats
Because of this ecoregion's steep terrain, it is less threatened by human activity than the island's lowlands. Population pressure is becoming more intense. Farmers are continually being forced into steeper lands in the upper watersheds and into more marginal environments. The resulting forest clearing has significant destructive effects on nutrient outflow, total water yield, peak storm flows, and stream sedimentation (IUCN 1991).

Justification of Ecoregion Delineation
MacKinnon (1997) included the islands of Java and Bali in biounit 22 (with three subunits). Western Java is wetter than the eastern half of the island, and the forests are richer in species (Whitten et al. 1996; MacKinnon 1997). There are also floristic differences between the lowland and montane vegetation in Java and Bali (Whitmore 1984; Whitten et al. 1996). Therefore, using MacKinnon's subunit boundary, we delineated the Western Java Rain Forests [IM0168] to represent the moister evergreen forests to the west and the Eastern Java-Bali Rain Forests [IM0113] to represent the drier, less species-rich forests of eastern Java and in Bali. However, we also extracted the montane forests into distinct ecoregions-Western Java Montane Rain Forests [IM0167] and Borneo Montane Rain Forests [IM0103]-using the 1,000-m elevation contour of a DEM (USGS 1996).

References for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.
Indo-Pacific Reference List

Prepared by: John Morrison
Reviewed by:


The Global 200