Central Indochina dry forests explained

Central Indochina dry forests
Map:Ecoregion IM0202.svg
Biogeographic Realm:Indomalayan
Biome:tropical and subtropical dry broadleaf forests
Area:444000
Country:Cambodia
Country1:Laos
Country2:Thailand
Country3:Vietnam
Country4:Myanmar
Border:Cardamom Mountains rain forests
Border1:Chao Phraya freshwater swamp forests
Border2:Chao Phraya lowland moist deciduous forests
Border3:Kayah-Karen montane rain forests
Border4:Luang Prabang montane rain forests
Border5:Northern Annamites rain forests
Border6:Northern Khorat Plateau moist deciduous forests
Border7:Northern Thailand-Laos moist deciduous forests
Border8:Southeastern Indochina dry evergreen forests
Border9:Southern Annamites montane rain forests
Border10:Tonle Sap freshwater swamp forests
Border11:Tonle Sap-Mekong peat swamp forests
Conservation:vulnerable

The Central Indochina dry forests are a large tropical and subtropical dry broadleaf forests ecoregion in Southeast Asia.

Location and description

The ecoregion consists of an area of plateau and low river basin in Cambodia, Thailand, Laos, Vietnam and Myanmar and includes:

These are the drier areas of Indochina with 1,000-1,500 mm rainfall per year and a long dry season when regular fires occur in the undergrowth, some set intentionally to clear the forest or drive out wildlife for hunters.

Great swathes of this ecoregion are densely populated and are used for agriculture or urban development, especially in Thailand.

Flora

While some large areas do remain in northeastern Cambodia, much of the original deciduous dipterocarp forest has presently been cleared, especially in Thailand, Laos, and Vietnam. The remaining woodlands consist of a variety of types of habitats and consequently a wide range of trees and undergrowth plants.

Fauna

The remaining forests are home to some large mammals including Asian elephants (Elephas maximus), wild water buffalo (Bubalus arnee), Eld's deer (Cervus eldii) and three species of wild cattle the gaur (Bos gaurus), the banteng (Bos javanicus) and the kouprey (Bos sauveli). Large herds of these grazing animals were once widespread across the region and were preyed upon by tigers (Panthera tigris), clouded leopard (Felis nebulosa), leopards (Panthera pardus) and dhole (wild dogs) (Cuon alpinus). Both loss of habitat and hunting have seriously reduced numbers of all these animals many of which are endangered with the kouprey very rare and other species such as the Javan rhinoceros (Rhinoceros sondaicus), Sumatran rhinoceros (Dicerorhinus sumatrensis) and Schomburgk's deer (Cervus duvaucelli schomburgki) now extinct in the region.

Other mammals of the region include the pileated gibbon, two leaf monkeys (the silvery lutung and Phayre's leaf monkey), and the sun bear while there are two endemic species, both are vesper bats - the Szechwan myotis (Myotis altarium) and the Chinese pipistrelle (Pipistrellus pulveratus).

There are 500 species of bird in the region including the critically endangered and possibly extinct white-eyed river martin (Pseudochelidon sirintarae), the endemic grey-faced tit-babbler (Macronous kelleyi) and the endangered or threatened Bengal florican (Eupodotis bengalensis), greater adjutant (Leptoptilos dubius) and white-shouldered ibis (Pseudibis davisoni). Other birds of the remaining woodlands of the area include the silver pheasant (Lophura nycthemera), Siamese fireback (Lophura diardi), Mrs. Hume's pheasant (Syrmaticus humiae), grey peacock-pheasant (Polyplectron bicalcaratum), sarus crane (Grus antigone), great hornbill (Buceros bicornis), Austen's brown hornbill (Anorrhinus austeni), and wreathed hornbill (Aceros undulatus).

The reptile and amphibian populations require further study but most likely include endemic species such as a critically endangered Cantor's giant soft-shelled turtle (Pelochelys cantorii), two geckos (the dtella, Gehyra lacerata and the sandstone gecko, Gekko petricolus) and the Korat supple skink (Lygosoma koratense).

Threats and preservation

Active preservation is required to keep large tracts of the remaining habitat intact and connected rather than being broken into small patches. This is particularly important for the survival of the remaining tiger populations in the wild. About 6% of the area is protected with the largest areas including Kulen Promtep Wildlife Sanctuary, Lomphat Wildlife Sanctuary and Phnom Prich in Cambodia and Xe Piane National Biodiversity Conservation Area in Laos.

See also