Flora

WWF has identified the entire Eastern Himalayas as a priority Global 200 Ecoregion while Conservation International has upscaled the Eastern Himalaya Hotspot which initially covered the states of Arunachal Pradesh, Sikkim, Darjeeling Hills, Bhutan, and Southern China to the Indo Burma Hotspot (Myers 2000) which now includes all the eight states of North-East India, along with the neighbouring countries of Bhutan, southern China and Myanmar. The richness of the region’s avifauna largely reflects the diversity of habitats associated with a wide altitudinal range. North East India supports some of the highest bird diversities in the orient with about 850 bird species. The Eastern Himalaya and the Assam plains have been identified as an Endemic Bird Area by the Royal Society for Protection of Birds, (ICBP 1992). The global distribution of 24 restricted-range species is limited to the region. The region’s lowland and montane moist-to-wet tropical evergreen forests are considered to be the northernmost limit of true tropical rainforests in the world
The region has been identified by the Indian Council of Agricultural Research (ICAR) as a centre of rice germplasm while the National Bureau of Plant Genetic Resources (NBPGR), India, has highlighted the region as being rich in wild relatives of crop plants. It is the centre of origin of citrus fruits. Two primitive variety of maize, Sikkim Primitive 1 and 2 have been reported from Sikkim (Dhawan, 1964). Although jhum cultivation, a traditional system of agriculture, is often cited as a reason for the loss of forest cover of the region, this primary agricultural economic activity practised by local tribes reflects the usage of 35 varieties of crops. The region is rich in medicinal plants and many other rare and endangered taxa. Its high endemism in both higher plants, vertebrates and avian diversity has qualified it to be a biodiversity ‘hotspot’ and this aspect has been elaborated in details in the subsequent sections. IUCN in 1995 identified Namdapha in Arunachal Pradesh as a centre of plant diversity.
The following figures highlight the biodiersity significance of the region:

• 51 forest types are found in the region broadly classified into six major types — tropical moist deciduous forests, tropical semi evergreen forests, tropical wet evergreen forests, subtropical forests, temperate forests and alpine forests.
• Out of the nine important vegetation types of India, six are found in the North Eastern region.
• These forests harbour 80,000 out of 15,000 species of flowering plants. In floral species richness, the highest diversity is reported from the states of Arunachal Pradesh (5000 species) and Sikkim (4500 species) amongst the North Eastern States.
• According to the Indian Red data book published by the Botanical Survey of India, 10 percent of the flowering plants in the country are endangered. Of the 1500 endangered floral species, 800 are reported from North East India.
• Most of the North Eastern states have more than 60% of their area under forest cover, a minimum suggested coverage for the hill states in the country.
• North East India is a part of Indo-Burma 'hotspot'. The hotspot is the world's second largest, next only to the Mediterranean basin with an area 2,20,60,000 km²among the 25 identified.