Tuesday, 22 April 2014 09:54



A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans. To qualify as a biodiversity hotspot on Myers 2000 edition of the hotspot-map, a region must meet two strict criteria:

1. It must contain at least 0.5% or 1,500 species of vascular plants as endemics, and

2. It has to have lost at least 70% of its primary vegetation.

Three regions that satisfy these criteria in India are described below:

a) The Western Ghats and Sri Lanka

The Western Ghats are a chain of hills that run along the western edge of peninsular India. Their proximity to the ocean and through orographic effect, they receive high rainfall. These regions have moist deciduous forest and rain forest. The region shows high species diversity as well as high levels of endemism. Nearly 77% of the amphibians and 62% of the reptile species found here are found nowhere else.

The area is extraordinarily rich in biodiversity. Although the total area is less than 6 percent of the land area of India, the Western Ghats contains more than 30 percent of all plant, fish, bird, and mammal species found in India. Like other hotspots, the Western Ghats has a high proportion of endemic species. The region also has a spectacular assemblage of large mammals and is home to several nationally significant wildlife sanctuaries, tiger reserves, and national parks. The Western Ghats contains numerous medicinal plants and important genetic resources such as the wild relatives of grains (rice, barley, Eleucine coracana), fruits (mango, garcinias,banana, jackfruit), and spices (black pepper,cinnamon, cardamom, and nutmeg).

In addition to rich biodiversity, the Western Ghats is home to diverse social, religious, and linguistic groups. The high cultural diversity of rituals, customs, and lifestyles has led to the establishment of several religious institutions that strongly influence public opinion and the political decision-making process.

Conservation challenges lie in engaging these heterogeneous social groups and involving them in community efforts aimed at biodiversity conservation and consolidation of fragmented habitats in the hotspot.

b) The Eastern Himalayas

The Northeast India, (22-30 degree N and 89-97 degree E) spread over 2,62,379 sq.km., represents the transition zone between the Indian, Indo-Malayan and Indo-Chinese bio-geographic regions and a meeting place of the Himalayan Mountains and Peninsular India. The region is made up of eight states: Arunachal Pradesh, Assam, Meghalaya, Manipur, Mizoram, Nagaland, Sikkim and Tripura and is endowed with a wide range of physiography and eco-climatic conditions.

The Eastern Himalayas region, with diverse climatic conditions and complex topography, has different types of forest and vegetation. Broadly, vegetation types in the EH can be categorised into a) tropical, b) sub-tropical, c) warm temperate, d) cool temperate, e) sub-alpine and f) alpine types.

It has nearly 163 globally threatened species including the One-horned Rhinoceros (Rhinoceros unicornis), the Wild Asian Water buffalo (Bubalus bubalis (Arnee)) and in all 45 mammals, 50 birds, 17 reptiles, 12 amphibians, 3 invertebrate and 36 plant species  The Relict Dragonfly (Epiophlebia laidlawi) is an endangered species found here with the only other species in the genus being found in Japan. The region is also home to the Himalayan Newt (Tylototriton verrucosus), the only salamander species found within Indian limits. There are an estimated 10,000 species of plants in the Himalayas, of which one-third are endemic and found nowhere else in the world.

c) Indo-Burma

The Indo-Burma region encompasses several countries. It is spread out from Eastern Bangladesh to Malaysia and includes North-Eastern India south of Brahmaputra river, Myanmar, the southern part of China's Yunnan province, Lao People’s Democratic Republic, Cambodia, Vietnam and Thailand. The Indo-Burma region is spread over 2 million sq. km of tropical Asia.

Much of Indo-Burma is characterized by distinct seasonal weather patterns. During the northern winter months, dry, cool winds blow from the stable continental Asian high-pressure system, resulting in a dry period under clear skies across much of the south, center, and west of the hotspot (the dry, northeast monsoon). As the continental system weakens in spring, the wind direction reverses and air masses forming the southwest monsoon pick up moisture from the seas to the southwest and bring abundant rains as they rise over the hills and mountains.  A wide diversity of ecosystems is represented in this hotspot, including mixed wet evergreen, dry evergreen, deciduous, and montane forests. There are also patches of shrub lands and woodlands on karst limestone outcrops and, in some coastal areas, scattered heath forests. In addition, a wide variety of distinctive, localized vegetation formations occur in Indo-Burma, including lowland floodplain swamps, mangroves, and seasonally inundated grasslands.


Last Updated on Wednesday, 23 April 2014 07:02