- Indomalaya ecozone
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The Indomalaya ecozone is one of the eight ecozones that cover the planet's land surface. It extends across most of South and Southeast Asia and into the southern parts of East Asia.
The Indomalaya Ecozone
Also called the Oriental Realm by biogeographers, Indomalaya extends from Afghanistan and Pakistan through the Indian subcontinent and Southeast Asia to lowland southern China, and through Indonesia as far as Java, Bali, and Borneo, east of which lies the Wallace line, the ecozone boundary named after Alfred Russel Wallace which separates Indomalaya from Australasia. Indomalaya also includes the Philippines, lowland Taiwan, and Japan's Ryukyu Islands.
Most of Indomalaya was originally covered by forest, mostly tropical and subtropical moist broadleaf forests, with tropical and subtropical dry broadleaf forests predominant in much of India and parts of Southeast Asia. The tropical moist forests of Indomalaya are dominated by trees of the dipterocarp family (Dipterocarpaceae).
Contents
Major ecological regions
The World Wildlife Fund (WWF) divides Indomalaya into three bioregions, which it defines as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."
Indian Subcontinent
The Indian Subcontinent bioregion covers most of India, Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka. The Hindu Kush, Karakoram, Himalaya, and Patkai ranges bound the bioregion on the northwest, north, and northeast; these ranges were formed by the collision of the northward-drifting Indian subcontinent with Asia beginning 45 million years ago. The Hindu Kush, Karakoram, and Himalaya are a major biogeographic boundary between the subtropical and tropical flora and fauna of the Indian subcontinent and the temperate-climate Palearctic ecozone.
Indochina
The Indochina bioregion includes most of mainland Southeast Asia, including Myanmar, Thailand, Laos, Vietnam, and Cambodia, as well as the subtropical forests of southern China.
Sunda shelf and the Philippines
Main article: SundalandMain article: Ecoregions of the PhilippinesMalesia is a botanical province which straddles the boundary between Indomalaya and Australasia. It includes the Malay Peninsula and the western Indonesian islands (known as Sundaland), the Philippines, the eastern Indonesian islands, and New Guinea. While the Malesia has much in common botanically, the portions east and west of the Wallace Line differ greatly in land animal species; Sundaland shares its fauna with mainland Asia, while terrestrial fauna on the islands east of the Wallace line are derived at least in part from species of Australian origin, such as marsupial mammals and ratite birds.
History
The flora of Indomalaya blends elements from the ancient supercontinents of Laurasia and Gondwana. Gondwanian elements were first introduced by India, which detached from Gondwana approximately 90 MYA, carrying its Gondwana-derived flora and fauna northward, which included cichlid fish and the flowering plant families Crypteroniaceae and possibly Dipterocarpaceae. India collided with Asia 30-45 MYA, and exchanged species. Later, as Australia-New Guinea drifted north, the collision of the Australian and Asian plates pushed up the islands of Wallacea, which were separated from one another by narrow straits, allowing a botanic exchange between Indomalaya and Australasia. Asian rainforest flora, including the dipterocarps, island-hopped across Wallacea to New Guinea, and several Gondwanian plant families, including podocarps and araucarias, moved westward from Australia-New Guinea into western Malesia and Southeast Asia.
Flora and fauna
Two orders of mammals, the colugos (Dermoptera) and treeshrews (Scandentia), are endemic to the ecozone, as are families Craseonycteridae (Kitti's Hog-nosed Bat), Diatomyidae, Platacanthomyidae, Tarsiidae (tarsiers) and Hylobatidae (gibbons). Large mammals characteristic of Indomalaya include the leopard, tigers, water buffalos, Asian Elephant, Indian Rhinoceros, Javan Rhinoceros, Malayan Tapir, orangutans, and gibbons.
Indomalaya has three endemic bird families, the Irenidae (leafbirds and fairy bluebirds), Megalaimidae and Rhabdornithidae (Philippine creepers). Also characteristic are pheasants, pittas, Old World babblers, and flowerpeckers.
See also
Indomalaya terrestrial ecoregions
Borneo lowland rain forests Brunei, Indonesia, Malaysia Borneo montane rain forests Brunei, Indonesia, Malaysia Borneo peat swamp forests Brunei, Indonesia, Malaysia Brahmaputra Valley semi-evergreen forests India Cardamom Mountains rain forests Cambodia, Thailand, Vietnam Chao Phraya freshwater swamp forests Thailand Chao Phraya lowland moist deciduous forests Thailand Chin Hills-Arakan Yoma montane forests Burma, India Christmas and Cocos Islands tropical forests Australia Eastern highlands moist deciduous forests India Eastern Java-Bali montane rain forests Indonesia Eastern Java-Bali rain forests Indonesia Greater Negros-Panay rain forests Philippines Hainan Island monsoon rain forests China Himalayan subtropical broadleaf forests Bhutan, India, Nepal Irrawaddy freshwater swamp forests Burma Irrawaddy moist deciduous forests Burma Jian Nan subtropical evergreen forests China Kayah-Karen montane rain forests Burma, Thailand Lower Gangetic Plains moist deciduous forests Bangladesh, India Luang Prabang montane rain forests Laos Luzon montane rain forests Philippines Luzon rain forests Philippines Malabar Coast moist forests India Maldives-Lakshadweep-Chagos Archipelago tropical moist forests British Indian Ocean Territory, India, Maldives Meghalaya subtropical forests India Mentawai Islands rain forests Indonesia Mindanao montane rain forests Philippines Mindanao-Eastern Visayas rain forests Philippines Mindoro rain forests Philippines Mizoram-Manipur-Kachin rain forests Bangladesh, India, Burma Myanmar coastal rain forests Burma Nansei Islands subtropical evergreen forests Japan Nicobar Islands rain forests India North Western Ghats moist deciduous forests India North Western Ghats montane rain forests India Northern Annamites rain forests Laos, Vietnam Northern Indochina subtropical forests China, Laos, Burma, Thailand, Vietnam Northern Khorat Plateau moist deciduous forests Laos, Thailand Northern Thailand-Laos moist deciduous forests Laos, Thailand Northern Triangle subtropical forests Burma Northern Vietnam lowland rain forests Vietnam Orissa semi-evergreen forests India Palawan rain forests Philippines Peninsular Malaysian montane rain forests Malaysia, Thailand Peninsular Malaysian peat swamp forests Malaysia, Thailand Peninsular Malaysian rain forests Indonesia, Malaysia Red River freshwater swamp forests Vietnam South China Sea Islands disputed between China, Malaysia, Philippines, Taiwan, Vietnam South China-Vietnam subtropical evergreen forests China, Vietnam South Taiwan monsoon rain forests Taiwan South Western Ghats moist deciduous forests India South Western Ghats montane rain forests India Southern Annamites montane rain forests Cambodia, Laos, Vietnam Southwest Borneo freshwater swamp forests Indonesia Sri Lanka lowland rain forests Sri Lanka Sri Lanka montane rain forests Sri Lanka Sulu Archipelago rain forests Philippines Sumatran freshwater swamp forests Indonesia Sumatran lowland rain forests Indonesia Sumatran montane rain forests Indonesia Sumatran peat swamp forests Indonesia Sundaland heath forests Indonesia Sundarbans freshwater swamp forests Bangladesh, India Taiwan subtropical evergreen forests Taiwan Tenasserim-South Thailand semi-evergreen rain forests Malaysia, Burma, Thailand Tonle Sap freshwater swamp forests Cambodia, Vietnam Tonle Sap-Mekong peat swamp forests Cambodia, Vietnam Upper Gangetic Plains moist deciduous forests India Western Java montane rain forests Indonesia Western Java rain forests Indonesia Central Indochina dry forests Cambodia, Laos, Thailand, Vietnam Chota-Nagpur dry deciduous forests India East Deccan dry evergreen forests India Irrawaddy dry forests Burma Kathiarbar-Gir dry deciduous forests India Narmada Valley dry deciduous forests India Northern dry deciduous forests India South Deccan Plateau dry deciduous forests India Southeastern Indochina dry evergreen forests Cambodia, Laos, Thailand Southern Vietnam lowland dry forests Vietnam Sri Lanka dry-zone dry evergreen forests Sri Lanka Indomalaya Tropical and subtropical coniferous forestsBhutan, India, Nepal, Pakistan Luzon tropical pine forests Philippines Northeast India-Myanmar pine forests Burma, India Sumatran tropical pine forests Indonesia Indomalaya Temperate broadleaf and mixed forestsBhutan, India, Nepal Northern Triangle temperate forests Burma Western Himalayan broadleaf forests India, Nepal, Pakistan Western Himalayan subalpine conifer forests India, Nepal, Pakistan Indomalaya Flooded grasslands and savannasIndia, Pakistan Indomalaya Montane grasslands and shrublandsMalaysia Indomalaya Deserts and xeric shrublandsIndia, Sri Lanka Indus Valley desert India, Pakistan Northwestern thorn scrub forests India, Pakistan Thar desert India, Pakistan Indochina mangroves Cambodia, Malaysia, Thailand, Vietnam Indus River Delta-Arabian Sea mangroves Pakistan Myanmar coast mangroves Burma, India, Malaysia, Thailand Sunda Shelf mangroves Brunei, Indonesia, Malaysia Sundarbans mangroves Bangladesh, India Biomes and Ecozones Terrestrial
biomesPolar/montaneTemperate(Sub)tropicalDryWetAquatic
biomesOther biomes Ecozones External links
Media related to Indomalaya at Wikimedia Commons- Map of the ecozones
References
- Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment. Island Press; Washington, DC.
Categories:- Indomalaya
- Biogeography
- Ecozones
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