Eastern Himalayan broadleaf forests


The Eastern Himalayan broadleaf forests is a temperate broadleaf forest ecoregion found in the middle elevations of the eastern Himalayas, including parts of Nepal, India, and Bhutan. These forests have an outstanding richness of wildlife.

Setting

This ecoregion covers an area of and constitutes a band of temperate broadleaf forests lying on steep mountain slopes of the Himalayas between approximately. It extends from the Kali Gandaki River in Nepal across Sikkim and West Bengal in India, Bhutan, and the Indian state of Arunachal Pradesh.
The temperate broadleaf forests transition into the Himalayan subtropical pine forests and the Himalayan subtropical broadleaf forests at lower elevations, and into the Eastern Himalayan subalpine conifer forests at higher elevations. This area receives over 2000 mm of rainfall per year, mostly falling from May to September during the monsoon.

Flora

The Eastern Himalayan broadleaf forests are diverse and species-rich, with a great diversity and many endemic species including plants of Indomalayan, Indochinese, Himalayan, Eastern Asiatic and even Gondwanan origin.
The ecoregion has two broad forest types: evergreen and deciduous. Evergreen forests are characterized by oaks , chiefly Quercus lamellosa, together with Lithocarpus pachyphylla, Rhododendron arboreum, Rhododendron falconeri, Rhododendron thomsonii, Magnolia doltsopa, Magnolia cathcartii, Exbucklandia populnea, Symplocos cochinchinensis, Magnolia spp., Cinnamomum spp., and Machilus spp. The many rhododendron species include more than fifty in Sikkim and another sixty in Bhutan.
In the deciduous forests meanwhile the predominant tree species are Himalayan maple, Juglans regia, Alnus nepalensis, Betula alnoides, Betula utilis, and Echinocarpus dasycarpus.
Finally in Eastern Nepal there are wetter areas dominated by a mixture of Magnolia campbellii, Acer campbellii and Osmanthus suavis'' along with Himalayan hazel.

Fauna

The forests are home to over 500 species of bird some of which migrate to the higher Himalayas in the hot summer. There are twelve near-endemic bird species as well as the strictly endemic rufous-throated wren-babbler. A number of bird species especially pheasant, tragopan and hornbill are easily threatened by changes to their habitat and those found here include the globally threatened rufous-necked hornbill, Sclater's monal, white-bellied heron, Blyth's tragopan and Ward's trogon.
There are four endemic or near-endemic mammals including Gee's golden langur which is found north of the Brahmaputra River between the Sankosh and Manas Rivers. Other endemic mammals are Hodgson's giant flying squirrel, Namdapha flying squirrel and Brahma white-bellied rat, while endangered species found here include a population of Bengal tigers adapted to higher mountain slopes and having a high conservation priority. Other endangered species include takin and Himalayan serow as well as the vulnerable Mandelli's mouse-eared bat, Assam macaque, stump-tailed macaque, dhole, back-striped weasel, clouded leopard, and Irrawaddy squirrel. The area also includes patches of fir forest with a bamboo undergrowth that are home to the endangered red panda.

Conservation

Most of the forest is intact as these are steep inaccessible slopes, although the Quercus lanata forests of the lower elevations are vulnerable to clearance, while the upper slopes are liable to be used for livestock grazing, especially in more densely populated Nepal. Protected areas include Namdapha National Park and Mehao Wildlife Sanctuary in Arunachal Pradesh, Makalu Barun National Park in Nepal, and parts of Thrumshingla, Jigme Dorji, and Jigme Singye Wangchuck National Parks and Kulong Chu Wildlife Sanctuary in Bhutan. There are plans to create corridors of protection linking some of these areas in Bhutan and in India. The area around Namdapha National Park has been increasingly settled by Chakma refugees from Bangladesh. Another threat is the plan to build a dam on the Dihing River. One area of importance that is currently unprotected is Mount Phulchowki in the Kathmandu valley.

Protected areas

In 1997, 15 protected areas were identified in this ecoregion, with a combined area of approximately that includes 7% of the ecoregion's area: