Location and General Description
This ecoregion is made up of the montane moist forests in peninsular Malaysia and southernmost Thailand. There are no clear seasons in peninsular Malaysia, and rainfall is plentiful year-round. Two monsoons inundate the region. From October to March a northeastern monsoon brings extra rain to the eastern side of peninsular Malaysia. The southwest monsoon, which is more powerful, bathes the western side of peninsular Malaysia with rain from April to August. Based on the Köppen climate zone system, this ecoregion falls in the tropical wet climate zone (National Geographic Society 1999).
This ecoregion contains several distinct montane habitat blocks. The most extensive is the Main Range, which encompasses Malaysia's largest remaining area of pristine montane rain forest, reaching about 2,180 m around Cameron Highlands. Together with the Main Range, Fraser's Hill and Genting Highlands are botanically well known, but many other areas remain to be explored. On the east of the peninsula the outlying peak of Mt. Tahan, 2,187 m, in Taman Negara National Park has various endemic plants and a slightly impoverished fauna. Other key sites are the Taiping hills (Bukit Larut, Gunung Bubu) and Gunung Benom.
In the lower elevations of montane forest (about 1,000-1,200 m) the dominance of dipterocarp species ends. These are replaced with highly speciose oak (Quercus and Lithocarpus spp.) and chestnut (Castanopsis spp.) forests. Myrtaceae are also important in the lower montane forests. Common genera also include Agathis spp., Dacrydium spp., Baeckea spp., Leptospermum spp., Podocarpus spp., and Styphelia spp. (Payne and Cubitt 1990). Three major and parallel changes occur in montane forests with increasing altitude. First, there is a decrease in forest height. Montane forest do not have giant emergent trees, and their overall height is much lower. Malaysia's tallest tree species, Koompassia excelsa (known as tualang), does not occur in the montane region. The canopy typically is 10-20 m high. Second, the size and shape of the leaves change. Trees with buttress usually are absent. Lowland forests are dominated by tree species with medium-large leaves. Montane forests are dominated by slender trees with small leaves and a flattish crown surface. Rhododendrons are characteristic of upper montane flora. Rhododendrons are found on acidic and peat soils and have adapted to the harsh upper montane environments (MacKinnon 1997). The third difference is the increased presence of epiphytes. Orchids, ferns, moss, lichen, and liverworts are more abundant in montane forests than in lowland rain forests (MacKinnon 1997). Orchids are found at all levels of the forest but are common epiphytes in the upper montane forests. For growth, orchids need light and moisture as well as a mycorrhiza relationship with a tree or other plant to derive their nutrients. The well-lit and moist conditions of the moss forest in the upper montane zone provide ideal growing conditions for many orchid species (Lamb and Chan 1978).
The noticeable differences in vegetation structure and species composition also affect faunal communities found in montane forests. Few of them are intrinsically montane, but montane forest provides an important habitat reservoir and connecting links between forest patches. There is a single endemic mammal, the rodent Maxomys inas (table 1). Other primarily montane species include the gymnure (Hylomys suillus), siamang (Symphalangus syndactylus), and red-cheeked squirrel (Dremomys rufigenys). Numerous other mammal species that were once common in the lowland rain forest are now finding their last remaining refuges in the montane region. Many of these species are wide-ranging or top carnivore species.
Table 1. Endemic and Near-Endemic Mammal Species.
Muridae Maxomys inas*
An asterisk signifies that the species' range is limited to this ecoregion.
The tiger (Panthera tigris) is peninsular Malaysia's largest predator. The exact number of remaining tigers in peninsular Malaysia is not known, but estimates range from 300 to 650 over the past decade. Taman Negara remains one of the last refuges for the tiger. As Malaysia's tiger population drifts toward extinction, montane reserves may provide some of the best places for conservation (Rabinowitz 1999). There is one Level I TCUs in peninsular Malaysia that overlaps this ecoregion and extends into the lowlands (Dinerstein et al. 1997).
Peninsular Malaysia is also home to the world's smallest rhinoceros, the two-horned Sumatran rhinoceros (Didermocerus sumatrensis). It once ranged through much of southeast Asia, but today the entire population numbers about 500 individuals distributed in isolated populations from peninsular Malaysia to Sumatra and Borneo (McClung 1997). The Malayan tapir (Tapirus indicus) is another endangered species. It is the largest of the four living tapir species and the only Old World representative. The population of the Malayan tapir has been drastically reduced, but they hang on in protected areas. Tapirs can be seen in the Ampang Forest Reserve, and the largest surviving population probably occurs around Taman Negara National Park (McClung 1997; Payne and Cubitt 1990).
Peninsular Malaysia's largest land animal, the Asian elephant (Elephas maximus), is also one of the most endangered. They range over vast tracts of land throughout peninsular Malaysia in search of food, and as habitat is destroyed the population has become fragmented and poached. The estimated population has ranged from 600 to 6,000 individuals, demonstrating the poor knowledge of the actual status of this species in peninsular Malaysia (Sukumar 1989). The second-largest mammal in these forests is the wild cattle, the gaur (Bos gaurus), or seladang as it is known in Malaysia. Widespread poaching and habitat loss have decimated gaur populations outside protected areas (Payne and Cubitt 1990).
Numerous other mammal species live in these forests. Nearly one-half of Malaysia's mammal species are bats. The forests also teem with squirrels, deer, otter, civet, and primate species. They include the rare sun bear (Ursus malayanus) and clouded leopard (Pardofelis nebulosa).
More than 250 bird species are known to live in this ecoregion, including five near-endemic species (table 2). More than seventy-five birds are montane specialists, and BirdLife International considers two of these species threatened: the mountain peacock-pheasant (Polyplectron inopinatum) and the crested argus (Rheinardia ocellata). The ecoregion also overlaps with the peninsular Malaysian portion of the Sumatra and peninsular Malaysia EBA (158) (Stattersfield et al. 1998). Eight restricted-range bird species live in this ecoregion.
Table 2. Endemic and Near-Endemic Bird Species.
Family Common Name Species
Phasianidae Mountain peacock-pheasant Polyplectron inopinatum
Phasianidae Crested argus Rheinardia ocellata
Turdidae Malayan whistling-thrush Myiophonus robinsoni
Muscicapidae Rufous-vented niltava Niltava sumatrana
Timaliidae Marbled wren-babbler Napothera marmorata
An asterisk signifies that the species' range is limited to this ecoregion.
Most of peninsular Malaysia's remaining forests are limited to the high, steep areas of this ecoregion. Approximately two-thirds of these forests remain intact, mainly in two large blocks of primary forest that cover the Main Range (the Titi Wangsa Mountains) and the East Coast Range in the states of Kelantan and Terengganu (IUCN 1991). Taman Negara National Park in peninsular Malaysia is one of the largest protected areas in southeast Asia. However, this park harbors only about 3 percent of the endemic tree species and about 30 percent of the palm species known in peninsular Malaysia (Soepadmo 1995). On paper there are four protected areas that cover 5,120 km2 (30 percent) of the ecoregion area (table 3). However, Belum is still only a proposed nature reserve. Furthermore, in 1996 Malaysia's Department of Wildlife and National Parks discovered that the Cameron Highlands Wildlife Reserve had been degazetted in 1962.
Table 3. WCMC (1997) Protected Areas That Overlap with the Ecoregion.
Protected Area Area (km2) IUCN Category
Belum 2,120 PRO
Cameron Highlands 680 IV
Krau 640 VIII
Taman Negara [IM0146] 1,680 II
Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.
Types and Severity of Threats
Despite the rugged terrain of this ecoregion, logging is intensive on the lower slopes. Resort development has also caused environmental degradation in some popular montane areas (WWF and IUCN 1995). A new road is planned in the Main Range, where it would cause extensive damage to this sensitive habitat (IUCN 1991).
Justification of Ecoregion Delineation
The tropical montane evergreen moist forests above 1,000 m were placed in the Peninsular Malaysian Montane Rain Forests [IM0144]. The lowland rain forests (below 1,000 m) approximates the spatial extent of MacKinnon's (1997) subunit 07a. A DEM was used to derive the 1,000-m contour to delineate this ecoregion's boundary. Therefore, we created three ecoregions within MacKinnon's Malay Peninsular subunit (07a) and Udvardy's Malayan rain forests biogeographic province. We also extracted the large areas of peat swamp forests along the coast of peninsular Malaysia into the Peninsular Malaysian Peat Swamp Forests [IM0145]. Thus, we created three ecoregions within MacKinnon's Malay Peninsular subunit (07a) and Udvardy's Malayan rain forests biogeographic province.
References for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.
Indo-Pacific Reference List
Prepared by: Colby Loucks