Encyclopedia of Earth

Western Java montane rain forests

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Western Java, Indonesia (Photograph by © WWF-Canon/Tom MOSS)

The Western Java Montane Rain Forests 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.

caption Source: WWF

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. 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.

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). Semi-evergreen rain forest differs from evergreen rain forest by being slightly more seasonal, with two to four dry months each year.

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 meters (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.

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.

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. 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.

 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 Endemic Bird Area (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).

 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 square kilometers (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

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

 

Types and Severity of Threats

caption Western Java, Indonesia (Photograph by © WWF/Tom MOSS

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.

Justification of Ecoregion Delineation

MacKinnon 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. There are also floristic differences between the lowland and montane vegetation in Java and Bali. Therefore, using MacKinnon's subunit boundary, we delineated the Western Java Rain Forests to represent the moister evergreen forests to the west and the Eastern Java-Bali Rain Forests 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 and Borneo Montane Rain Forests-using the 1,000-m elevation contour of a Digital Elevation Model (DEM).

Additional information on this ecoregion

 

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

 

 

 

 

Glossary

Citation

Fund, W. (2014). Western Java montane rain forests. Retrieved from http://www.eoearth.org/view/article/51cbef397896bb431f69d360

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