Ecoregions

Ecoregions of Malaysia

August 26, 2011, 2:56 pm
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Borneo endemic Rafflesia plant in bloom, Mt. Kinabalu, Sabah @ C.Michael Hogan

The ecogegions of Malaysia include a number of distinct types of rainforests, all of which are sustained by the plentiful rainfall of this equatorial region of Southeast Asia. In additon there are Malaysian ecoregions which are termed swamp forests, that are essentially lowland rainforests which have peaty acidic soils and persistent presence of bogs; moreover, there is one ecoregion consisting of montane alpine meadows. On the coastal zone fringes there are other ecosystems which are based on mangrove swamp formations.

Malaysia, a nation in Southeast Asia, is composed of two parts, Peninsular Malaysia bordering Thailand and northern one-third of the island of Borneo (the southern two thirds of the island are part of Indonesia). Ecoregions are areas that: [1] share a preponderance of their species and ecological dynamics; [2] share similar environmental conditions; and, [3] interact ecologically in ways that are critical for their long-term persistence. Scientists at the World Wildlife Fund (WWF), have established a classification system that divides the world in 867 terrestrial ecoregions, 426 freshwater ecoregions and 229 marine ecoregions that reflect the distribution of a broad range of fauna and flora across the entire Earth. 

Borneo Lowland Rainforests

caption Borneo lowland rainforest, Sarawak River Basin. @ C.Michael Hogan

The Borneo lowland rainforest ecoregion is made up of the lowland dipterocarp forests of Borneo. Borneo_lowland_rainforests are the richest in the world and rival the diversity of New Guinea and the Amazon. With 267 Dipterocarpaceae species (155 endemic to Borneo), Borneo is the center of the world's diversity for dipterocarps. These forests are home to the world's smallest squirrel, the 11 centimetre pygmy squirrel, and the endangered orangutan. In northeast Borneo, populations of Sumatran rhinoceros and Asia's largest terrestrial mammal, the Asian elephant, still tenuously survive in the last pockets of forest. These forests contain the parasitic plant Rafflesia arnoldii, which produces the world's largest flower (up to one metre in diameter). These forests are globally outstanding for both bird and plant richness, with more than 380 birds and an estimated 10,000 plant species found within its boundaries. Unfortunately, these forests have been rapidly converted to oil palm plantations or commercially logged at unprecedented rates over the past ten years. In 1997-1998 fires intentionally set to clear the forest for commercial agriculture such as oil palm ravaged Kalimantan. If the current trend of habitat destruction continues, there will be no remaining lowland forests in Borneo by 2010. 

Borneo Montane Rainforests

This Borneo montane rainforest ecoregion represents the montane forests in the central region of the island of Borneo and falls within the boundaries of all three nations with territory in Borneo: Malaysia, Indonesia, and Brunei. Montane forests are much cooler and moister than lowland forests.The Borneo montane rain forests can be likened to montane islands in a sea of lowland dipterocarp forests. This isolation has produced a unique and diverse set of montane species. Of Borneo's endemic bird species, twenty-three (73 percent) are montane. There are more than 150 mammal species in montane forests, making this ecoregion globally outstanding for mammal richness, and it is the most speciose montane rain forest found in the Indo-Pacific region. Despite this wealth of diversity, large tracts of Borneo's montane forests have not been explored to catalog the flora and fauna.

Borneo Peat Swamp Forests

The Borneo Peat Swamp Forest ecoregion is made up of the peat swamp forests along the western coasts of the island of Borneo, within the Malaysian state of Sarawak and Indonesian Kalimantan. Most of the peat swamp forests are associated with coastal areas, but two large areas of peat swamp forests occur around Lake Mahakam and Lake Kapuas. Although peat swamp forests are not as biodiverse as neighboring lowland rain forests, the Borneo Peat Swamp Forests are some of the most speciose peat swamp forests in the region. Peat swamp forests are a key habitat for the endangered Borneo endemic and unique proboscis monkey (Nasalis larvatus). They are also home to the world's most desirable aquarium fish, the arowana (Scleropages formosus).

Kinabalu Montane Alpine Meadows

The Kinabalu montane alpine meadows ecoregion represents the upper montane habitat on Mt. Kinabalu and the Crocker Range and the surrounding upland areas in the Malaysian state of Sabah (Borneo).The Kinabalu Montane Alpine Meadows are unique to the region in that they have been isolated from other mountain chains for millions of years. This is one of only two ecoregions in the Indo-Pacific region to be globally outstanding for both bird and mammal richness and endemism (the other ecoregion is the Eastern Himalayan broadleaf forests). This montane refuge supports a disjunct distribution of Himalayan, Australasian, and Indomalayan species. Although the apex of Mt. Kinabalu is devoid of vegetation, the slopes and surrounding area have an exceedingly rich flora of approximately 4500 species in more than 180 families with 950 genera. This represents one of the richest concentrations of endemic plant species in the world and is the only Asian example of tropical alpine shrublands with high levels of endemism. This ecoregion supports the greatest concentration of wild orchids on Earth, with more than 750 species in more than sixty genera. This number accounts for more than one quarter of all orchid species found in Malesia.

Myanmar Coast Mangroves

The Myanmar coastal mangroves ecoregion is found in the Irrawaddy delta,  The Myanmar coastal mangroves are some of the most degraded or destroyed mangrove systems in the Indo-Pacific. The sedimentation rate of the Irrawaddy River is the fifth highest in the world. This is largely because of the deforestation that has occurred throughout central Myanmar. The mangroves have also been overexploited from forestry, agriculture, aquaculture, and development projects. The wild species have been severely reduced but hang on in isolated pockets.  The mangrove flora consists of three separate regions: the Rakhine mangroves, Irrawaddy mangroves, and Taninthayi mangroves

Peninsular Malaysian Montane Rainforests 

Fraser's Hill, Malaysia (Photograph by <a href='http://www.worldwildlife.org' _fcksavedurl='http://www.worldwildlife.org' class='external text' title='http://www.worldwildlife.org' rel='nofollow'>© WWF-Canon/Mauri Rautkari</a>)

The Peninsular Malaysian montane rainforest ecoregion is made up of the montane moist forests in Peninsular Malaysia and southernmost Thailand.  The Peninsular Malaysian montane rainforests are one of the last refuges for several of Asia's large characteristic species. These forests still support tigers, Asian elephants, gaur, tapirs, Sumatran rhinoceros, and the spectacular and endemic crested argus. Taman Negara Nature Reserve in central peninsular Malaysia is one of the largest reserves in the Indo-Pacific and provides an essential montane refuge and linkage area to the lowland forests.

Peninsular Malaysian Peat Swamp Forests

The Peninsular Malaysian peat swamp forest ecoregion represents the disjunct peat swamp forests in Peninsular Malaysia and southern Thailand.The Peninsular Malaysian peat swamp forests, though not as diverse in species as the surrounding lowland rainforests, are home to many of Malaysia's endangered species. Asian elephants, Sumatran rhinoceros, tigers, clouded leopards, and Malayan tapir all inhabit these rapidly shrinking forests.  The peat swamp forests of peninsular Malaysia have edaphic and vegetative characteristics similar to those in Sumatra and Borneo.

Peninsular Malaysian Rainforests

The Peninsular Malaysian rainforest ecoregion is made up of the lowland moist forests of peninsular Malaysia and the extreme southern part of Thailand.The Peninsular Malaysian rainforests ecoregion, with 195 mammal species, has the second most mammal species in the Indo-Pacific, behind the Borneo Lowland Rain Forests. Yet most of the wide-ranging or top carnivore species lead a tenuous existence in these biologically outstanding forests. The tiger, Asian elephant, Sumatran rhinoceros, Malayan tapir, gaur, and clouded leopard all fall into this category. As in many other tropical forests in this region, habitat loss and poaching are the two primary reasons for the decline in these and other species.

South China Sea Islands

Three archipelagos or island groups are included in the South China Sea Islands terrestrial ecoregion. These are Pratas (Dungsha) (20°42’N, 116°43’ E), Paracel (Xisha) (16° N, 112° E), and Spratly (Nansha), which is the largest archipelago in the South China Sea. The Spratly Islands are scattered between 11°28’ to 4° N and 109°55’ to 117°50’ E.This ecoregion encompasses several hundred islands, atolls, rocks, cays, banks, and reefs in three archipelagos of the South China Sea. Coral reefs are the predominant structure of these islands; the Spratly group contains over 600 coral reefs in total. Little vegetation grows on these islands, which are subject to intense monsoons. They do, however, provide important habitat for many seabirds, as well as green and hawksbill sea turtles. Unfortunately, the South China Sea Islands are still largely a mystery. Scientists have focused their research on the marine environment, while the ecology of the terrestrial environment remains relatively unknown. Ownership of many of the islands in this active commercial fishery and trade route is disputed. Political instability and the increasing industrialisation of neighboring countries has led to serious disruption of native flora and fauna, overexploitation of natural resources and environmental pollution.   While land formations are numerous within this region, the majority of these are rocks, reefs, sandbanks, or other types of partially submerged landforms.

Sunda Shelf Mangroves

The Sunda Shelf Mangrove ecoregion is found on the island of Borneo and the east coast of Sumatra. The Sunda Shelf Mangroves are some of the most biologically diverse mangroves in the world. They are home to the unique proboscis monkey. Like other mangrove forests in the region, they are under intense threats from logging, shrimp farming, and agriculture conversion.   The climate and physical conditions vary widely in this region, giving rise to a high diversity of plant and animal species found in these forests. However, the region generally has high humidity, seasonal wind and precipitation, high temperatures, and high annual rainfall. Tidal fluctuations have large variations over short distances.

Tenasserim-South Thailand Semi-evergreen Rainforests

The Tenasserim South Thailand semi-evergreen rainforest ecoregion encompasses the mountainous, semi-evergreen rain forests of the southern portion of the Tenasserim Range, which separates Thailand and Myanmar, and the numerous small ranges of peninsular Thailand. This ecoregion also includes the extensive lowland plains that lie between the peninsular mountains and until recent decades supported extensive lowland forest. The southern margin of this ecoregion is defined by the Kangar-Pattani floristic boundary, which separates Indochina from the Malesia region.  The Tenasserim-South Thailand semi-evergreen rainforests cover the transition zone from continental dry evergreen forests common in the north to semi-evergreen rainforests to the south. As a consequence, this ecoregion contains some of the highest diversity of both bird and mammal species found in the Indo-Pacific region. The relatively intact hill and montane forests form some of the best remaining habitat essential to the survival of Asian elephants and tigers in the Indo-Pacific region. However, the lowland forests are heavily degraded, and many lowland specialists such as the endemic Gurney's pitta survive in a few isolated reserves.

See Also

Glossary

Citation

(2011). Ecoregions of Malaysia . Retrieved from http://www.eoearth.org/view/article/51cbed827896bb431f692985

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