Biodiversity is the abbreviation of ‘biological diversity’. It means the varied range of flora and fauna. Biodiversity refers to the variety and abundance of living organisms living in a particular region. The total number of species on the Earth is still not known fully. According to one estimate the number may vary between 10 to 1oo million, and is a product of about 4 billion year. Biodiversity deals with the degree of nature’s variety in the biosphere. The variety and richness of plant and animal species may be examined at the local, regional or global level. The term biological diversity (biodiversity) was coined by R.F. Dasmann in 1968. Biodiversity has great significance for the survival of human beings and the existence of flora and fauna. The main advantages of the biodiversity to human beings are:
- Food, fiber, and medicines are obtained from biodiversity.
- Species of plants and animals are necessary for the functioning of ecosystems. Humans derive enormous aesthetic pleasure from interacting with organisms.
- Extinction of species deprives us of opportunities to study and understand ecological relationships among organisms.
Social Relevance of Biodiversity
Biodiversity has great social, economic and aesthetic importance for human beings. Man gets numerous benefits from the resources of the environment, biodiversity and resources. Some of the benefits from biodiversity are as under:
1. Consumptive value
2. Productive use value
3. Social value
4. Ethical and moral values
5. Aesthetic value
The concept of biodiversity hotspots was developed by the British ecologist Norman Myers. Biodiversity hotspots are the areas with a large percentage of endemic species. The biodiversity hotspots are demarcated on the basis of the following two criteria:
- At least 0.5 percent or 1500 of the worlds’ 300,000 species of plants.
- The region has lost 70 or more than 70 percent of its primary vegetation.
- In the case of marine hotspots, coral reefs, snails, lobster, and fishes are taken into consideration.
- Most of the hotspots are found in the tropical and subtropical areas where the temperature and humidity remain high throughout the year. Species and ecosystems diversity also varies with altitudes above the sea level and depth of oceans.
On the basis of Myers’ definition of the hotspot, the ecologists have identified the following hotspots in the world (Fig.3.1).1.
North and Central America
1. California Floristic Province North America has great diversity in topography and climate. The California region of USA has a Mediterranean type of climate in which most of the rainfall occurs only during the winter season. This biodiversity hotspot stretches over the state of California and adjacent mountainous areas. In the northern parts of this hotspot are the tallest trees of the world like the Douglas Fir and oak. In the Mediterranean, biome is found the numerous plants and animals which may adapt to hot summer and cool winters (Fig.3.).
2. Caribbean Islands Hotspot: The West Indies Islands support exceptionally diverse ecosystems, ranging from montane cloud forest to cactus shrub-lands which have been devastated by deforestation to bring the land under agriculture, grazing and other uses.
3. Madrean Pine-Oak Woodlands of the USA and Mexico Border Along the Mexico border, the summers are hot and dry. The daily range of temperature is significantly high but the nights are generally pleasant. This biodiversity hotspot stretches over the mountain of Mexico, Baja Peninsula (Mexico) and southern states of USA. It is an area of rugged terrain, deep gorges and canyons.
4.The Meso- American Forests Stretching over Central America, it is the third largest hotspot in the world. The endemic species of this region include quetzals, howler monkeys and 17,000 species of plants.
5.Atlantic Forests of Brazil South America has distinct physical and cultural personality. This is ne of the richest biodiversity hotspots in the world. It contains over 20,000 plant species, out of which 40 percent are endemic. Locally the vegetation of this region is called as selves. These are the evergreen forests which keep their leaves all the year round. Each leaf lasts for years, and usually dark and waxy green.
6.Brazil’s Cerrado The Cerrado region of Brazil consists of 21 percent of the country. It covers the greater parts of savanna biome of South America. It contains a large number of endemic species of plants and animals.
7. Chilean Winter Rainfall (Valdivian) Forests This biodiversity hotpot stretches over the Andes mountains. Atacama Desert and low level areas of Chile along the coast of Pacific Ocean. It contains rich endemic species of fauna and flora.
8.Tumbes-Choco- Magdalena It is bordered by two other hotspots, i.e. Meso-America to the north and the tropical Andes to the east. It has great diversity in fauna and flora.
9.Tropical Andes Sprawling over the equatorial Andes Ecuador, Peru and Brazil, it is one of the smallest biodiversity hotspots of the world, but has rich endemic plants and animals.
Europe and Central Asia
10.Caucasus Region Stretching over the mountainous regions of Armenia, Georgia and Azerbaijan, the Caucasus Biodiversity Hotspot contains a large number of endemic plant species. The over-interaction of man in this region has threatened the endemic species of fauna and flora.
11. Iran-Anatolia Region Sprawling over the plateau of Anatolia (Turkey), Kurdistan (northern Iraq) and Elburz Mountain and the central parts of Dasht-e-Kavir ( desert of Iran), this biodiversity hotspot has numerous endemic species of plants and animals. Many of these plants and animals of this region are not found anywhere in the world.
12. The Mediterranean Basin and its Eastern Coastal Region: This biodiversity hotspot contains more than 22,500 endemic plant species and numerous species of animals.
13. Mountains of Central Asia The Plateau of Pamir, Tien Shan, Kun-Lun and Hindukush mountains region has great diversity of the species of fauna and flora.
14. South Africa’s Cape Floristic Hotspot Essentially, it is a shrub-land along the southern parts of South Africa. It has great diversity in endemic plants and animals. Many of these plants and animals are not found anywhere in the world.
15. Coastal Forests of Eastern Africa This is a small tract along the eastern coast of Africa. It is rich in endemic plants.
16.Eastern Afro-Montane The Eastern African-montane hotspot is scattered along the eastern mountains of Africa. It extends from Saudi Arabia and Yemen in the north to Ethiopia, Kenya, Tanzania and Zimbabwe in the south. The climatic and altitudinal diversity has resulted into a number of species of plants and animals.
17.The Guinean Forests of Western Africa The lowland forests of West Africa are the home of more than a quarter of African mammals, including more than 20 species of primates.
18. Horn of Africa Rich in endemic plants and animals, the arid Horn of Africa (Somalia) has a renowned source of biological resources for thousands of years.
19.Madagascar and the India Ocean Islands: Madagascar and its neighbouring island groups have astonishing total of eight plant families, four bird families, and five primate families that live nowhere else in the world.
20.Maputoland -Podoland-Albany Hotspot: This biodiversity hotspot stretches along the east coast of southern Africa, below the Great Escarpment, and is an important centre of plant endemism.
21. Succulent Karoo Stretching in Namibia and south Africa, the Karoo Desert has great diversity in endemic plants and animals.
22. East Melanesian Islands: Stretching to the north of New Guinea in South-East Asia, the Melanesian Biodiversity Hotspot consists of over 16,000 islands. These islands are rich in endemic plants and animals.
23. Himalayan Hotspot(Formerly Eastern Himalayan Hotspot) This Himalayan Hotspot stretches over the Himalayas, covering Pakistan, India, Nepal, Bhutan and the eastern states of India. Most of the highest peaks of the world are located in this region. In the Himalayas, there are atitudinal zonation of ecosystems. The growing population, deforestation, industrialization, urbanization and agricultural encroachment have transformed the ecosystems of the Himalayas substantially. Several species of plants and animals of this hotspot are in the list of endangered or threatened species.
24.Indo-Myanmar (Burma) Hotspot Surrounding more than two million square km of tropical Asia, the Indo-Myanmar Hotspot is still revealing biological treasures. The Indo-Burma Hotspot begins at the evergreen forests in the foothills of Chittagong in Bangladesh and extends through Meghalaya, Manipur, Mizoram, and Nagaland to encompass Myanmar. A wide diversity of ecosystems is found in this hotspot including mixed wet evergreen, dry-evergreen, deciduous and montane forests. There are also tracts of shrub-lands and woodlands on limestone outcrops and in some coastal areas, scattered heath forests. It is also characterized by swamps, mangroves and seasonally inundated grasslands. This hotspot covers about 2,373,000 sq km. The over-interaction of man in this region has threatened the ecosystems of this region.
25.Japan Biodiversity Hotspot The islands that comprise the Japanese Archipelago stretch from the humid subtropics in the south to the boreal zone in the north, resulting in a wide variety of climates and bio-diversity in ecosystems.
26.Mountains of South-West China The province of Yunnan (China) and surrounding mountainous areas have great diversity in endemic plants and animals.
27. New Caledonia A group of islands in the South Pacific Ocean, New Caledonia is the home of more than five endemic plant families.
28. New Zealand Biodiversity Hotspot It is a mountainous archipelago once dominated by temperate rain-forests. New Zealand has great biodiversity in endemic plants and animals.
29. Philippine Biodiversity Hotspot This biodiversity hotspot is spreading over 7000 islands of Philippines. It is identified as one of the richest biodiversity hotspot of the world.
30.Polynesia and Micronesian Islands Complex including Hawaii Based on 4500 islands, this biodiversity hotspot is the epicenter of current global extinction crisis.
31.South-Western Australia: The forests, woodlands, shrub-lands and heath of this hotspot are characterized by high endemism among plants and reptiles.
32. Western Sunda (Indonesia, Malay and Brunei) Stretching over Indonesia, Borneo, Brunei, Celebes, and Malaysia, this biodiversity hotspot is quite rich in endemic plants and animals.
33. Wallace (Eastern Indonesia) The fauna and flora of Wallace are varied that every island in this hotspot needs secure protected areas to preserve endemic plants and animals, and the biodiversity of the region.
34.The Western Ghats of India and the Islands of Sri Lanka: This biodiversity hotspot sprawls over Western Ghats and Sri Lanka. In this region, there is a great diversity in terrain, topography, climate, drainage, soils, and natural vegetation. Its natural vegetation varies from the tropical evergreen forests to deciduous and thorny bushes. The forests of the Western Ghats are adversely affected by the rapid growth of population, industrialization, urbanization and agricultural encroachments. Deforestation in Sri Lanka for the purpose of timber has threatened the biodiversity of this hotspot. It has 15,000 flowering plants, and a large number of endemic amphibians, freshwater fishes and invertebrates.
India – A Mega-Biodiversity Nation
India has great diversity in its geo-climatic conditions. Consequently, there is great diversity in its forests, wetlands, mangroves and marine areas. The richness in fauna and flora makes it as one of the 12 mega-biodiversity countries of the world.
According to the data and information provided by the Ministry of Environment and Forest, India accounts for more than 7 per cent of the total fauna and about 11 per cent of the total flora of the world. India has 350 different mammals, 1200 species of birds, 453 species of reptiles and 45,000 plant species. India has 50,000 known species of insects, including 13,000 butterflies and moths. It is estimated that the number of unknown species of insects could be several times higher.
- Location: India
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