The Mizoram-Manipur-Kachin rain forests is a subtropical moist broadleaf forest ecoregion which occupies the lower hillsides of the mountainous border region joining India, Bangladesh, and Burma (Myanmar). The ecoregion covers an area of 135,600 square kilometres (52,400 sq mi). Located where the biotas of the Indian Subcontinent and Indochina meet, and in the transition between subtropical and tropical regions of Asia, the Mizoram-Manipur-Kachin rain forests are home to great biodiversity. The WWF rates the ecoregion as "Globally Outstanding" in biological distinctiveness.
The ecoregion is characterised by semi-evergreen rain forest, covering the lower elevations of the Chin Hills-Arakan Yoma in Burma's Arakan State and India's Manipur state and the adjacent Chittagong Hills of Bangladesh, then extending northwards along the Naga Hills and Mizo Hills to cover most of India's Nagaland and Mizoram states, and eastwards across Burma's Sagaing Division and Kachin State to the Burma-China border.
The Burmesian coastal rain forests occupy the coastal lowlands of Burma to the south and southwest. To the west, the ecoregion borders the Meghalaya subtropical forests in southeastern Assam, and the Brahmaputra Valley semi-evergreen forests in the Assamese lowlands. The Mizoram-Manipur-Kachin rain forests extend up to the 1,000 metres (3,300 feet) elevation of the Chin Hills-Arakan Yoma range, and the Chin Hills-Arakan Yoma montane forests occupy the portion of the range above 1,000 metres (3,300 feet). As the Mizoram-Manipur-Kachin forests extend east across Burma, they are bounded by the Irrawaddy moist deciduous forests of the Irrawaddy River basin to the south, and by the higher-elevation Northern Triangle subtropical forests to the north and the Northern Indochina subtropical forests to the east. The Northeast India-Burma pine forests occupy the higher elevations of the Naga Hills along the Nagaland-Burma border, and are surrounded by the Mizoram-Manipur-Kachin rain forests on the west, south and east.
The climate of the region is tropical and humid, although somewhat cooler than the adjacent lowlands. Rainfall comes mostly from the monsoon winds from the Bay of Bengal, and parts of the ecoregion can receive up to 2,000 millimetres (79 in) of rain per year.
The predominant plant community is semi-evergreen rain forest, which covers the vast majority of the ecoregion's intact area, a total of 36% of the ecoregion. Other plant communities include tropical wet evergreen forest (5% of the ecoregion's total area), tropical moist deciduous forest (2%), montane wet temperate forest (2%), and subtropical montane forest (1%). 19% of the ecoregion's area has been cleared, primarily for agriculture and grazing, and 34% of the ecoregion consists of degraded areas.
The semi-evergreen rain forest is dominated by trees of the dipterocarp family, including Dipterocarpus alatus, D. turbinatus, D. griffithii, Parashorea stellata, Hopea odorata, Shorea burmanica, and Anisoptera scaphula. Trees of other families include Swintonia floribunda, Eugenia grandis, Xylia xylocarpa, Gmelina arborea, Bombax insignis, Bombax ceiba, Albizia procera, and Castanopsis spp.
The ecoregion is home to 149 known species of mammals. This includes two near-endemic species, a bat Pipistrellus joffrei, and a murid rodent Hadromys humei. The ecoregion is home to several endangered and threatened mammal species, including the tiger (Panthera tigris), clouded leopard (Pardofelis nebulosa), Asian elephant (Elephas maximus), Eld's deer (Cervus eldii), gaur (Bos gaurus), Himalayan goral (Nemorhaedus goral), red panda (Ailurus fulgens), smooth-coated otter (Lutrogale perspicillata), Indian civet (Viverra zibetha), back-striped weasel (Mustela strigidorsa), Assamese macaque (Macaca assamensis), bear macaque (Macaca arctoides), southern pig-tailed macaque (Macaca nemestrina), capped leaf monkey (Semnopithecus pileatus), and hoolock gibbon (Hylobates hoolock).
The ecoregion harbours 580 bird species, of which 6 are near-endemics: Manipur bush quail (Perdicula manipurensis), striped laughingthrush (Garrulax virgatus), brown-capped laughingthrush (Garrulax austeni), marsh babbler (Pellorneum palustre), tawny-breasted wren-babbler (Spelaeornis longicaudatus), and wedge-billed wren-babbler (Sphenocichla humei).