Biodiversity Hotspot

Biodiversity Hotspots are an essential topic covered under CBSE Class 12 Biology Unit X Ecology and Environment Chapter 15 Biodiversity and Conservation. As per the latest revisions, Unit X Ecology and Environment will carry a total weightage of 12 marks in CBSE Class 12 Board Exams.

Keyterms: Differentiation, genes, plants, animals, biotypes, ecotypes, biodiversity, planet, beetle species

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What is a Biodiversity Hotspot? 

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A biodiversity hotspot is a biogeographic region that features a significant group of biodiversity which, at the same time, is also threatened with destruction. The British biologist Norman Myers coined the term “biodiversity hotspot” in 1988. A region needs to fulfill two criteria to qualify as a hotspot:

1. The region needs to have a high level of endemism (at least 1500 species of vascular plants)
2. The habitat needs to be threatened (must contain 30% or less of the original habitat)

On our Earth, 35 habitats qualify as Hotspots. They were once covering over 15.7 % of the Earth’s land surface. Today, around 86 percent of the hotspots’ habitat has already been destroyed, and thus, the intact remnants of the hotspots now occupy only 2.3%. These Hotspots help the development of half the world’s plant species as endemics — i.e., species found no place else — and nearly 43% of bird, mammal, reptile and amphibian species as endemics.

Biodiversity Hotspots

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Zoological Survey of India

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The Zoological Survey of India, headquartered in Kolkata, is in charge of surveying India's faunal resources. The rich flora and wildlife of India are well-known. India is home to about 500 mammalian species, over 200 avian species, and over 30,000 insect species. India is noted for having the world's richest flora, with over 18000 kinds of blooming plants. It has a diverse climate, morphology, and habitat. 

Wildlife Map

India’s plant species make up about 7% of all plant species on the planet. The Western and Eastern Himalayas, Indus and Ganges, Assam, the Deccan Plateau, Malabar, and the Andaman Islands are the eight main floristic zones in India, which are home to 3000 Indian plant species.

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Major Hotspots in India

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The Himalayas

The Himalayas (overall) include Northeast India, Bhutan, and the central and eastern sections of Nepal, and are considered the world's highest mountains. There are 163 endangered species in this region (NE Himalayas), including the Wild Asian Water Buffalo and One-horned Rhino, as well as 10,000 plant species, 3160 of which are unique. This mountain range spans about 750,000 km².

Indo-Burma Region

The Indo-Burma Region covers a total area of 2,373,000 km². The Big-antlered Muntjac, Annamite Muntjac, Grey-shanked Douc, Annamite Striped Rabbit, Leaf Deer, and Saola are six large animal species that have been identified in this region in the previous 12 years. This hotspot is particularly recognised for its endemic freshwater turtle species, the majority of which are endangered owing to overfishing and habitat degradation. The endangered White-eared Night-heron, Grey-crowned Crocias, and Orange-necked Partridge are among the 1,300 bird species found here.

Major Hotspots

The Western Ghats 

The Western Ghats run along the western edge of peninsular India, encompassing the majority of India's deciduous and rain forests. It is home to at least 325 species of globally vulnerable flora, animals, birds, amphibians, reptiles, and fish, according to UNESCO. The vegetation in this region used to cover 1,90,000 km², but it has now been reduced to 43,000 km². 229 plant species, 31 animal species, 15 bird species, 43 amphibian species, 5 reptile species, and 1 fish species are among the region's globally endangered flora and fauna.

Sundaland

Sundaland is a South-East Asian hotspot that includes Singapore, Thailand, Indonesia, Brunei, and Malaysia. Sundaland was designated as a World Biosphere Reserve by the United Nations in 2013. The diverse terrestrial and marine ecosystems of this region are well-known. Sundaland is one of the world's ecological hotspots, with 25,000 vascular plant species, 15,000 of which are unique to this region.

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Loss Of Biodiversity

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• Our planet's biological riches are quickly dwindling, and the finger of blame is plainly pointed at human actions.
• Human colonisation of the tropical Pacific Islands is thought to have resulted in the loss of over 2,000 native bird species.
• The IUCN Red List (2004) records the extinction of 784 species in the previous 500 years (containing 338 vertebrates, 359 invertebrates, and 87 plants).
• The present rates of species extinction are projected to be 100 to 1,000 times quicker than in pre-human periods, and our actions are accountable for the faster rates.
• Ecologists predict that if current trends continue, over half of the world's species will be extinct within the next 100 years.

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Causes of Biodiversity Losses

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Habitat Loss and Fragmentation

Aside from outright extinction, pollution has harmed numerous ecosystems, putting the existence of many species in jeopardy. When huge ecosystems are split up into small fragments as a result of numerous human activities, mammals and birds that require extensive territories, as well as certain species with migratory tendencies, suffer severe consequences, resulting in population reductions.

Over Exploitation

Humans have always relied on nature for sustenance and shelter, but when "need" becomes "greed," natural resources are exploited. Over-exploitation of a resource causes the depletion and messes up the balance of the ecosystem.

Causes of Biodiversity Losses

Alien Species Invasions

When foreign species are introduced within a habitat, whether accidentally or by design, some of them become invasive and cause the decline or extinction of native species.

Co-extinctions

When a species goes extinct in a habitat, the plant and animal species that are obligately linked with it also go extinct. The dependence of plants and animals on the extinct species abets their own extinction. 

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Conservation of Biodiversity

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Protection and conservation of ecosystems can take place at two levels. Either biodiversity can be preserved at all levels to conserve the ecosystem (in-situ/on-site conservation) or there can be cases where the species is endangered or threatened and urgent measures need to be used to preserve it (ex-situ/off-site conservation).

Conservation of Biodiversity

Ex situ and in situ biodiversity conservation are both possible. In situ conservation protects endangered species in their native environment, protecting the ecosystem as a whole. 34 ‘biodiversity hotspots' have recently been recommended for serious conservation efforts throughout the world. Three of these (Western Ghats-Sri Lanka, Himalaya, and Indo-Burma) cover India's diverse biomes. The 14 biosphere reserves, 90 national parks, > 450 animal sanctuaries, and several holy groves highlight our country's in situ conservation efforts. 

Ex situ conservation procedures include in vitro fertilisation, tissue culture propagation, and cryopreservation of gametes for endangered species at zoological parks and botanical gardens.

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