Global Biodiversity Hotspots & Endemic Flora-Fauna
Biodiversity hotspots are biogeographical regions characterised by exceptional concentrations of plant and animal endemism experiencing catastrophic loss of natural habitat. Conceptualised by British ecologist Norman Myers in 1988 and formalized by Conservation International, a region must qualify under two strict quantitative criteria to be designated a global biodiversity hotspot: it must contain at least 1,500 species of vascular plants found nowhere else on Earth (high endemism, >0.5% of world total) and must have lost at least 70% of its original primary native vegetation (high threat level). Globally, 36 biodiversity hotspots have been identified, of which India hosts portions of four major hotspots: the Himalayas (spanning Jammu & Kashmir, Himachal, Uttarakhand, Sikkim, and Arunachal), the Western Ghats and Sri Lanka (an unbroken ecological corridor running through Gujarat, Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu), Indo-Burma (encompassing the northeastern states south of the Brahmaputra, Meghalaya, Mizoram, Manipur, Nagaland, and Tripura), and Sundaland (which includes India's Nicobar Islands along with the Sunda shelf). These fragile ecological realms harbor critically endangered endemics like the Lion-tailed Macaque, Nilgiri Tahr, and Sangai deer, protected under the Biological Diversity Act 2002 and monitored by the National Biodiversity Authority (NBA).
Key Concepts & Examination Highlights
- The concept of biodiversity hotspots was first formulated by British ecologist Norman Myers in a landmark paper published in 'The Environmentalist' in 1988.
- To qualify as a global biodiversity hotspot, a region must meet two criteria: contain at least 1,500 endemic vascular plant species and have lost at least 70% of its primary habitat.
- Globally, 36 terrestrial biodiversity hotspots have been identified by Conservation International, covering just 2.5% of Earth's land surface but hosting over 50% of the world's plant species.
- India is home to portions of four global biodiversity hotspots: The Himalayas, Western Ghats, Indo-Burma, and Sundaland.
- The Western Ghats (Sahyadri Range) was recognized as a UNESCO World Heritage Site in 2012, featuring a cluster of 39 individual protected reserves.
- The Western Ghats hotspot hosts the entire global wild population of the endangered Lion-tailed Macaque (Macaca silenus), primarily concentrated in Silent Valley National Park, Kerala.
- The Nilgiri Tahr (Nilgiritragus hylocrius), the only mountain ungulate in southern India, is endemic to the montane shola-grassland ecosystems of the Western Ghats, with its largest population in Eravikulam National Park.
- The Himalayan Biodiversity Hotspot encompasses the entire Indian Himalayan Region, including Jammu & Kashmir, Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh.
- The Indo-Burma Hotspot spans northeastern India south of the Brahmaputra River, covering Meghalaya, Assam, Mizoram, Manipur, Nagaland, and Tripura, together with Myanmar and Thailand.
- The Brow-antlered Deer or Sangai (Rucervus eldii eldii) is strictly endemic to Keibul Lamjao National Park on Loktak Lake in Manipur within the Indo-Burma hotspot.
- The Sundaland Biodiversity Hotspot includes India's Nicobar Islands, alongside Malaysia, Singapore, Brunei, and western Indonesia.
- The Nicobar Megapode (Megapodius nicobariensis), an endangered scrubfowl that incubates its eggs in large sand mounds, is strictly endemic to the Nicobar Islands.
- The Madhav Gadgil Committee (Western Ghats Ecology Expert Panel, 2011) recommended designating the entire Western Ghats as an Ecologically Sensitive Area (ESA) divided into three zones.
- The subsequent K. Kasturirangan High-Level Working Group (2013) recommended demarcating approximately 37% of the Western Ghats geographical area as an Ecologically Sensitive Area.
- India enacted the Biological Diversity Act in 2002 to implement the United Nations Convention on Biological Diversity (CBD) 1992.
- The National Biodiversity Authority (NBA) is a statutory autonomous body established in 2003 under the Biological Diversity Act, headquartered in Chennai, Tamil Nadu.
- Under the Biological Diversity Act 2002, a three-tier institutional structure is established: National Biodiversity Authority (NBA) at national level, State Biodiversity Boards (SBB) at state level, and Biodiversity Management Committees (BMC) at local panchayat/urban level.
- Agasthyamala Biosphere Reserve, located at the southern tip of the Western Ghats, was inscribed into UNESCO's World Network of Biosphere Reserves in 2016.
- The Nilgiri Biosphere Reserve, established in 1986 across Tamil Nadu, Kerala, and Karnataka, was the very first Biosphere Reserve created in India.
- The Shola forests of the Western Ghats are unique tropical montane dwarf cloud forests interspersed with rolling grasslands occurring at elevations above 1,500 metres.
- The Pygmy Hog (Porcula salvania), the world's smallest and rarest wild pig, is endemic to the dense alluvial tall grasslands of the foothills of the Himalayas, primarily in Manas National Park, Assam.
- The Golden Langur (Trachypithecus geei) is an endangered primate restricted to a narrow geographical range along the Indo-Bhutan border between the Sankosh and Manas rivers in Assam.
- The Great Nicobar Biosphere Reserve was added to UNESCO's World Network of Biosphere Reserves in 2013, home to the indigenous Shompen and Nicobarese tribes.
- The National Park with the greatest altitudinal variation in India is Namdapha National Park in Arunachal Pradesh, ranging from 200 metres to over 4,500 metres in the Indo-Burma/Himalaya transition.
- The Purple Frog (Nasikabatrachus sahyadrensis), a living fossil species burrowing underground that emerges for only two weeks a year to breed, is endemic to the Western Ghats of India.
Sample Solved Questions & Concept Explanations
8 Verified Concept QuestionsKeibul Lamjao National Park, the world's only floating national park famous for the endangered Sangai brow-antlered deer, is located on which lake in Manipur?
Which national park in Kerala is famous for preserving the endangered Lion-tailed Macaque in its pristine tropical evergreen rainforests?
Which national park in Idukki, Kerala, is home to the largest surviving population of the endangered Nilgiri Tahr and features mass blooms of the Neelakurinji flower?
Which national park in Kerala, situated in the Western Ghats and draining into the Pambar River, contains the largest tract of sandalwood forest in the state?
Agasthyamalai Biosphere Reserve, added to the UNESCO World Network of Biosphere Reserves in 2016, is situated across the border of which two states?
Dihang-Dibang Biosphere Reserve, located in the Eastern Himalayas and home to the endemic Mishmi Takin and red goral, is situated in which state?
Seshachalam Hills Biosphere Reserve, established in 2010, is famous for the endemic valuable timber species Pterocarpus santalinus (Red Sanders) in which state?
Manas National Park in Assam is globally celebrated as the primary natural refuge for which critically endangered mammal, the world's smallest wild pig?