Envis Centre, Ministry of Environment & Forest, Govt. of India
Printed Date: Thursday, December 19, 2024
Biodiversity Hotspot
Biodiversity is not distributed uniformly over the earth. Some areas, particularly along the tropics, are rich in species. Many species in these areas are threatened with extinction. However, the fund for conservation is rather limited and hence it is important to fix priority areas of conservation. In 1988 British ecologist, Norman Myres forwarded a concept called hotspots to identify the most major criteria for designating an area as hotspot are : (i) richness in endemic species, and (ii) impact by human activities. Endemic species are those restricted to certain localized areas of the earth. Evolutionary history has endowed species with ecological characteristics that respond to the environment they inhabit. However, most species are rare and restricted, because their ecological requirements are only met over by a small area and because they are not capable of dispersing great distances to other suitable habitats.
Plant diversity is the biological basis for hotspot designation. To qualify as a hotspot, a region must support 1,500 endemic plant species, 0.5 percent of the global total. Existing primary vegetation is the basis for assessing human impact in a region; to qualify as a hotspot, a region must have lost more than 70 percent of its original habitat. Identification of hotspot would help pin pointing priority areas for conservation.
According to the classification of Norman Myres' there are 25 hotspots scattered in different parts of the world. Even though the 25 biodiversity hotspots together represent 1.4 percent of the earth's land area, they contain 44 percent of all plant species and 35 percent of all terrestrial vertebrate species in the world. Each of these hotspots is under severe pressure due to anthropogenic interventions and has already lost at least 70 percent of its original natural vegetation.
India is part of two hotspots- Indo-Burma (earlier Eastern Himalayas) and Western Ghats and Sri Lanka Of late, conservationists named nine new 'Biodiversity Hotspots', making the total to 34, which also include the Himalayas .
Map showing major hotspots in India
Biodiversity Hotspots in India : Western Ghats (Sahyadri Hills)
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The Western Ghats, also known as the Sahyadri Hills , is a mountain chain running from the north to the South and is isolated by the Arabian Sea to the West, the arid Deccan Plateau to the East, and the Vindhya-Satpura ranges to the North. They have different vegetation types: scrub jungles and grasslands at low altitudes, dry and moist deciduous forests, montane grasslands and shoals, and the precious tropical evergreen and semi evergreen forests. Complex topography, high rainfall and relative inaccessibility have helped the region retain its biodiversity. Of the 15,000 flowering plant species in India , there are an estimated 4,780 species in the Western Ghats region. There is also a great diversity of traditional crop plants and an equal diversity of animal life. A large number of amphibians, freshwater fishes and invertebrate groups are endemic to Western Ghats .
Silent Valley Movement Endemic animals of Western Ghats
Biodiversity Hotspots in India : Indo-Burma ( Eastern Himalayas )
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The area covered by Indo-Burma hotspot can be described as tropical Asia East of the Ganges-Brahmaputhra lowlands, excluding the Malesian region. The Indo-Burma Hotspot begins at the evergreen forests in the foothills of Chittagong in Bangladesh and extends through the Garo and Khasi Hills of Meghalaya in India, then eastwards through Manipur, Mizoram and Nagaland to encompass most of Myanmar (except the extreme northern alpine areas), a part of southern and western Yunnan, China, all of Lao People's Democratic republic (P.D.R), Vietnam and Cambodia, the coastal lowlands of southern China, Hainan island, the vast majority of Thailand, a small fraction of Peninsular Malaysia, and the Andaman Islands of India. As defined, the hotspot covered 2,373,000 squares kilometre.
Biodiversity Conservation Programmes
Biodiversity Conservation Programme
Malabarsanctuary
Fauna statistics: World, India and Kerala
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World
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India
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Kerala
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Fishes
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31000 (1)
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2439 (1)
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196 (2)
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Amphibians
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6184 (3)
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277 (4)
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117 (2)
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Reptiles
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8734 (5)
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408 (3)
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159 (2)
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Birds
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9782 (6)
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1179 (7)
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484 (8)
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Mammals
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5416 (9)
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410 (3)
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145 (2)
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Plant Diversity in Kerala
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The Western Ghats region, wherein the state is situated, is one of the 25 biodiversity hotspots in the whole world. The state contains more than 4,500 species of flowering plants of which above 1,500 taxa are endemic in nature. There is also equally rich fauna belt in the state. The diversity of lower plants and animal groups, and the marine flora and fauna in particular even though not fully known, is remarkably rich in the state. An earlier rough estimate had shown that there are about 10,035 plant species indigenous to the state. The available total floral wealth of the state is given below.
Category
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Kerala
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India
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% to the Indian Flora
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Flowering Plants
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4500
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17500
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25.71
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Gymnosperms
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4
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64
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6.25
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Pteridophytes
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236
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1100
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21.45
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Bryophytes
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350
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2850
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12.28
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Lichens
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520
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2000
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26.00
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Algae
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325
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6500
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5.00
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Fungi
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4800
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14500
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33.10
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Threats to the Biodiversity of Kerala
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1. Encroachments : Kerala is one of the most land hungry State in India with lowest per capita land holding. Organised encroachment of forest land might have started as early as 1950s. Initially the policy of government was to allot forest land for schemes; like ‘grow more food’, ‘arable land’ etc. The direct impact of encroachment is habitat loss, besides the existence of constant threat on the forests by the fringe people. In addition to their involvement directly in the illegal activities they provide shelter for the unscrupulous offenders of the plains who are engaged in all kinds of illegal activities. The policy of the State Government is that all encroachments after 01-01-1977 will be evicted.
2. Cattle grazing :Grazing by cattle in forest, although not rampant as else where in the country, is identified as a threat to biodiversity in Kerala. The grazing not only removes the biomass and compete with wild herbivores, but also spread contagious diseases to wild animals. The trampling leads to soil erosion and changes the physical properties of soil. Intensive grazing will lead to domination of a single or a few species, changing the species composition of natural vegetation. Cattle grazing speeds up the invasion of weeds.
3. Collection of Fire wood:Firewood collection directly poses threat in the form of removal of biomass, which affects microhabitat of flora and fauna, and indirectly leads to extensive fire and other illegal activities. The proximity of settlements to the forests is the main factor, which determines the intensity of firewood collection. The firewood collection leads to degradation of habitats which subsequently alters the species composition and vegetation types. It is roughly estimated that 0.8 million cubic meters of firewood is illegally removed from the forest annually. Along with dead and wind fallen trees, standing trees and poles are also removed as firewood.
4. Man-Animal Conflict:A major problem associated with the conservation of wild animals especially the herbivores like elephants in India is that of crop depredation and man-slaughter. Animals such as elephants, gaur, sambar, wild boar and birds like peacock, cause extensive damage to the crops. This phenomenon has registered significant increase in recent years due to habitat fragmentation and degradation of natural forests and corridors. Almost all the Protected Areas and Non-Protected Areas of Kerala contain a large number of settlements either inside or on the periphery. This leads to degradation of surrounding habitats. The traditional tolerance among the people who live inside the forests or its adjacent areas are fast disappearing and people have become increasingly antagonistic. As a result, the people tend to kill the animals either by poisoning or by other means, like keeping crackers in fruits, etc.. This problem is very severe in northern Kerala where cultivation of paddy is extensive. At present Kerala Forest Department provides compensation for the crop and property damage, human causalities and cattle loss caused by the scheduled animals like elephant, tiger, leopard, gaur, etc. Providing compensation is not a long –term solution. In some areas where conflict is rampant, physical and psychological barriers are being provided. However, these efforts are found to be effective for only a certain period and become ineffective in due course.
5. Poaching:The abundance of wild animals and high demand for their products in the clandestine, market pose threat to wild animals. Hervibvores like gaur, sambar, chital etc are being poached for their meat. A lot of other not so spectacular species of animals ranging from reptiles to birds as well as plants and medicinal herbs are all part of the illegal wildlife trade. The major impact of poaching is species loss and change in their demography apart from extensive fire and other illicit activities.
6. Illegal and unsustainable/unscientific collection of Non-Timber Forest Produce (NTFP):Non-Timber Forest Produce (NTFP) collection is one of the major livelihoods of the local people. The NTFP consist of a variety of products, which are sources of food, fibre, manure, construction materials, cosmetics and cultural products. The users of NTFP range from local individuals to multinational companies. With the development of modern techniques, the number of products and uses based on NTFP has increased by many folds. This market driven utilization became instrumental in their unsustainable exploitation and resulted in degrading the natural vegetation. Studies indicate NTFP collectors are amongst the lowest-income groups in India, often receiving a mere 5-20% of the value for their products (SPWD,1993). About 69% of the forest based employment is related to NTFP.
The forests of Kerala are very rich in NTFP including edible products, medicinal plants, toiletries, tans, dyes, gums, resins, rattan, bamboo, grasses and animal products. Although 500 species of NTFP are available in the forests of Kerala, about 120 items are listed as commercially important by the Kerala Forest Department. But as per record more than 200 species are being collected. Considering its widespread nature and higher prioritization, the threat needs to be tackled immediately to conserve biodiversity.
7. Mining:Even though mining is not a severe threat to the biodiversity of Kerala, Sand mining is prevalent in the central and southern parts of Kerala. It is a threat to the stability of a landscape, which results in land sliding and lowering of water table. The removal of habitat will endanger the survival of riparian species since most of them occupied a very narrow habitat niche. At the same time regulated sand mining would help in keeping the health of the streams and reservoirs. Indiscriminate sand mining in some rivers systems in the state is posing severe threat to the stability of bridges and banks. Transportation of sand through the forests and other related activities pose severe threat to the ecosystem.
8. Mass Tourism and Pilgrimage:Mass Tourism and Pilgrimage are considered to be one of the major and increasing threats to biodiversity conservation. Approximately 13 million people visit forest areas annually either as pilgrims or visitors. Among all the Protected Areas in India, Periyar Tiger Reserve receives a maximum number of tourists. The large influx of people into the forests in short duration makes severe changes to habitat. The major impact of tourism and pilgrimage is littering and over-utilization of resources such as soil erosion, fire, disturbance to wild animals for feeding, ranging etc are also reported due to a large number of pilgrims and unruly behaviour of visitors.
9. Forest Fires:Fire is one of the major threats facing the forests of Kerala. People who are engaged in grazing livestock often burn the area to get fresh shoots for their cattle, during lean season. Apart from this, those who are involved in illicit activities such as ganja cultivation, poaching, tree felling, NTFP collection and very often the ignorant tourists and pilgrims are also responsible for big forest fires.
The effect of fire depends on the type of vegetation, frequency and intensity of fire and season of burning. Fire causes extensive damage in deciduous forests and grasslands due to heavy fuel load. Only some weeds manage to establish a strong foothold even after severe fire with the help of fire resistant adaptations. The direct impacts of fire are change in vegetation composition and physical properties of soil, soil erosion and loss of habitat.
10. Illicit Felling:Tree felling is one of the severe threats to biodiversity conservation in the state. The primary effect of tree felling on bio diversity is the removal of biomass and loss of habitat for many epiphytic and arboreal species. Tree felling leads to soil erosion and change of the soil properties. In some cases people involved in tree falling set fire to the forests. The opening up of canopy due to felling changes the microclimate and invite weeds to colonize and in turn changes the structure of vegetation. Apart from the direct impact of loss in terms of money to the state, the indirect impact of felling is the constant conflict between the administrative staff and the people involved in this illegal activity.
11. Invasive species: These are non indigenous or non-native plants and animals that adversely affect the habitats and bio regions they invade economically, environmentally and ecologically.
Examples of plant invasion in Kerala include Water hyacinth (Eichornia crassipes) and Lantana (Lantana camara). Water hyacinth, a fast-growing plant with populations known to double in as little as 12 days, blocks waterways, limiting boat traffic, swimming and fishing. The weed prevents sunlight and oxygen from reaching the water column and submerged plants. By crowding out native aquatic plants, it dramatically reduces biological diversity in aquatic ecosystems. Listed as one the 100 most dangerous invasive alien species of the world, this aquatic weed native to South America, was introduced to the country as an ornamental plant for cultivation in ponds because of its beautiful, large purple and violet flowers. Today, it invades more than 50 countries in five continents.
Examples of animal invasion in our state include like Tilapia fish (Oreochromis mossambica), Sucker catfish (Plecostomus multiradiatus) and the African Giant Snail (Achatina fulica).
Considering the damage caused to native fish species and biodiversity, Tilapia is termed a ‘biological pollutant’ by the Food and Agriculture Organization. The African Giant Snail (Achatina fulica) a native of East Africa creates serious pest menace in many parts of Kerala in the year 2010. This pest can attack nearly 500 plant species, including those bearing fruits and vegetables and even rubber and coffee.
Protected Areas of Kerala: The Protected areas of Kerala include a wide range of biomes, extending east from the coral reefs, estuaries, salt marshes, mangroves and beaches of the Arabian Sea through the tropical moist broadleaf forests of the Malabar Coast moist forests to the North Western Ghats moist deciduous forests and South Western Ghats moist deciduous forests to South Western Ghats montane rain forests on the western border of Tamilnadu in the Western Ghats.more details...
Biodiversity- IUCN Red List- RET Database