ECOREGIONS

Ecoregions are defined as “A relatively large area of land or water that contains a geographically distinct set of natural communities that share a majority of their species, ecological dynamics and environment conditions and function together as a conservation unit at conservation and regional scales.
The WWF identifies the following ecoregions in the North eastern regions:
Brahmaputra Valley semi evergreen forests which lies along the alluvial plains of the
Brahmaputra river. Despite the long history of habitat loss and degradation the ecoregion still harbors an impressive biodiversity in small fragments of habitat that lie scattered throughout. Most of the ecoregion lies within the eastern state of Assam but small sections extend into neighboring states of Arunachal Pradesh and Nagaland and into southern states of Bhutan. The northeastern region represents the area where the northward migrating Deccan Peninsula first made contact with the Eurasian continent during the tertiary period and is a gateway of species exchanges between the Indian and Malayan funas. (Rodgers and Panwar, 1988). The wide Brahmaputra river is a biogeographic barrier for several species. The golden langur (Semnopithecus geei), hispid hare (Caprolagus hispidus) and pygmy hog (Sus salvanius) are limited to north bank of this river, where as hoolock gibbon (Hylobates hoolock) and stump-tailed macaque (Macaca arctoides) are limited to
the south bank. Most of the ecoregion’s original semi evergreen forests have been converted to grasslands by centuries of fire and small patches of semi-evergreen forests remain only along border of the Indian states of Assam and Meghalaya. Biodiversity features of this region harbors India’s largest elephant (Elephas maximus), the world’s largest population of the greater one horned rhinoceros (Rhinoceros unicornis), tigers (Panthera tigris). The ecoregion overlaps with a high priority (level 1 Tiger Conservation Unit) that extends north to include the subtropical and
temperate forests of the Himalayan foothills. – not understood Pygmy hog and hispid hare are confined to the grassland habitats. Other threatened mammals include swamp deer (Cervus duvauceli) , gaur (Bos gaurus), clouded leopard (Pardofelis nebulosa), capped langur (Trachypithecus pileatus) , Asiatic black bear (Ursus thibetanus) and sloth bear (Melursus ursinus). Brahmaputra river also harbours the Gangetic dolphin (Platanista gangetica). The bird fauna is richer with more than 370 species and 2 species are near endemic (Reference required. Otherwise, stick to the statement of this region having 850+ bird species). The ecoregion overlaps with Birdlife International’s EBA, Assam plains which contains three restricted range bird species. Endemic and near endemic bird species include the Manipur bush quail (Perdicula manipurensis) and the Marsh
barbbler (Pellorneum palustre).
The Eastern Himalayan Broadleaved Forests is globally outstanding for both species richness and endemism especially for its flora. It contains several localized areas of floral richness and
endemism- floral hotspots which are especially rich in rhododendrons and oak. . The 125 mammal species known to occur here include four species that are endemic to the region (which are these four species, Reference Reqd). Three of the species are shared with adjacent ecoregions but the Namdapha flying squirrel is a strict endemic whose range distribution is limited to the broadleaved forest. The golden langur is limited to the broadleaved forests to the north of Brahmaputra river. Despite being shared between this ecoregion and the adjacent Himalayan subtropical forests the golden langur has a limited range distribution. Other threatened species include tiger, red panda
(Ailurus fulgens), takin (Budorcas taxicolor), serow (Nemorhedus sumatraensis), Vespertilionid
bats, Assamese macaque (Macaca assamensis), stump-tailed macaque, wild dog (Cuon alpinus), clouded leopard, Irrawady squirell (Callosciurus pygerythrus). Red Panda is reduced to patches of mature fir forests with a bamboo under-storey (Reference req).
The bird assemblage includes several threatened species including rufous-necked hornbill (Aceros nipalensis), Sclater’s monal (Lophophorus impejanus), Blyth’s tragopan (Tragopan blythii), whitebellied heron (Ardea insignis) and Ward’s trogon (Harpactes wardi) and can be considered as indicators of habitat integrity.
The Eastern Himalayan sub-alpine coniferous forests represent the transition from the
forested ecoregions of the Himalayas to treeless alpine meadows. Several Himalayan birds and mammals exhibit altitudinal seasonal migrations and depend on contiguous habitats that permit these movements. The ecoregion represents the belt of the conifer forest between Kali gandaki river in Nepal and into the state of Arunachal Pradesh in India. The ecoregion lies within the ecotone between the Indo Malayan and Palearctic zoogeographic zones. Although not endemic species, the red panda and the Himalayan musk deer (Moschus chrysogaster) are characteristics of mature fir forests represented by the ecoregion. The red pandas usually are limited to Abies-ringal bamboo forests between 3000-4000m where precipitation is high (Reference?). 200 birds species
are known from this region of which 6 are considered endemic to the region . 
Mizoram- Manipur Kachin Rain Forests has the highest bird species richness of all ecoregions within the Indo pacific region. Biological Distinctiveness: Globally outstanding. This large ecoregion represents the semi evergreen sub montane rain forests that extends from the mid ranges of the Arakan Yoma and Chin Hills north into Chittagong Hills of Bangladesh, the Mizo and Naga Hills of the Indo Myanmar border into the northern hills of Myanmar. It divides the Brahmaputra and Irrawady valleys through which Asia’s largest rivers flow. The semi evergreen forests are characterized by several species of the Dipterocarps that includes,Dipterocarpus alatus, D. turbinatus and D. griffithii. The region includes two near endemic species : the bat Pipistrellus joffrei and murid rodent Hadromys humei  
Biological distinctiveness: Regionally outstanding
This ecoregion is one of the only four tropical or subtropical conifer forest ecoregions in the Indo pacific region. Though not rich in biodiversity they contain species unique to these ecosystems. These forests are found in the north- south Burmese-java Arc. The Arc is formed by the parallel folded mountain ranges that culminate in the Himalayas in the north. Moving south are Manipur and the Chin Hills. The outer south western fringe of mountain ranges forming the arc is the Aracan Yomas, the southern continuation of the folded mountains ranges branching of the Himalayas. The uniquness lies in the association of Pinus with the Dipterocarps

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