- Hot spots are the richest and most threatened reservoirs of plant and animal life of the earth. They have maximum number of endemic species.
- 25 terrestrial hot spots have been identified for the conservation of biodiversity. They occupy 1.4% of the earth’s surface and 20% of worlds the human population lives in these areas. Western Ghats and Eastern Himalayas (Includes some parts of Indo-Burma or Purvanchal Hills) are two hot spots of India.
To qualify as a hot spot, a region must meet two strict criteria:
- Species endemism: the region must contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics, and
- Degree of threat: the region has to have lost at least 70% of its original habitat.
- Each biodiversity hot spot represents a remarkable universe of extraordinary floral and faunal endemism struggling to survive in rapidly shrinking ecosystems.
- Over 50 percent of the world’s plant species and 42 percent of all terrestrial vertebrate species are endemic to the 34 biodiversity hot spots.
- Some hot spots are much richer than others in terms of their numbers of endemics. Five key factors have been taken into consideration and those biodiversity hot spot that tops the list with respect to these five factors are considered as hottest hot spots.
Biodiversity Hotspots Across the World
The eight hottest hot spots in terms of the above five factors are:
- Sundaland [South East Asia]
- Brazil’s Atlantic Forest
- Western Ghats and Sri Lanka
- Eastern Arc and Coastal Forests of Tanzania/Kenya
Indian Biodiversity Hot Spots
There are 3 biodiversity hot spots present in India. They are:
- The Eastern Himalayas [Arunachal Pradesh, Bhutan, Eastern Nepal]
- Indo-Burma and [Purvanchal Hills, Arakan Yoma, Eastern Bangladesh]
- The Western Ghats and Sri Lanka
- 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.
- Since this hotspot is spread over such a large area and across several major landforms, there is a wide diversity of climate and habitat patterns in this region.
Biodiversity of Indo-Burma Region
- Much of this region has been deteriorating rapidly in the past few decades.
- This region is home to several primate species such as monkeys, langurs and gibbons with populations numbering only in the hundreds.
- Many of the species, especially some freshwater turtle species, are endemic.
- Almost 1,300 bird species exist in this region including the threatened white-eared night-heron [Endangered], the grey-crowned crocias [Endangered], and the orange-necked partridge [Near Threatened].
- It is estimated that there are about 13,500 plant species in this hotspot, with over half of them endemic. Ginger, for example, is native to this region.
The Eastern Himalayas
- The Eastern Himalayas is the region encompassing Bhutan, northeastern India, and southern, central, and eastern Nepal.
- The abrupt rise of the Himalayan Mountains from less than 500 meters to more than 8,000 meters results in a diversity of ecosystems that range from alluvial grasslands and subtropical broad leaf forests along the foothills to temperate broad leaf forests in the mid hills, mixed conifer and conifer forests in the higher hills, and alpine meadows above the tree line.
Biodiversity of the Eastern Himalayas
- The Eastern Himalayan hotspot has nearly 163 globally threatened species (both flora and fauna) including the One-horned Rhinoceros [Vulnerable], the Wild Asian Water buffalo [Endangered].
- 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.
- A few threatened endemic bird species such as the Himalayan Quail, Cheer pheasant, Western tragopan are found here, along with some of Asia’s largest and most endangered birds such as the Himalayan vulture and White-bellied heron.
- Mammals like the Golden langur, The Himalayan tahr, the pygmy hog, Lang-urs, Asiatic wild dogs, sloth bears, Gaurs, Muntjac, Sambar, Snow leopard, Black bear, Blue sheep, Takin, the Gangetic dolphin, wild water buffalo, swamp deer call the Himalayan ranged their home.
Western Ghats and Sri Lanka
- Western Ghats, also known as the “Sahyadri Hills” encompasses the mountain forests in the southwestern parts of India and highlands of southwestern Sri Lanka.
- The entire extent of hotspot was originally about 1,82,500 square kms, but due to tremendous population pressure, now only 12,445 square Km or 6.8% is in pristine condition.
- The wide variation of rainfall patterns in the Western Ghats, coupled with the region’s complex geography, produces a great variety of vegetation types.
- These include scrub forests in the low-lying rainshadow areas and the plains, deciduous and tropical rainforests up to about 1,500 meters, and a unique mosaic of montane forests and rolling grasslands above 1,500 meters.
- In Sri Lanka diversity includes dry evergreen forests to dipterocarpus dominated rainforests to tropical montane cloud forest.
- The important populations include Asian elephant, Niligiri tahr, Indian tigers, lion tailed macaque [All Endangered], Indian Giant squirrel [Least Concern], etc.