Science has attempted to classify and categorize the variability in nature for over a century.This has led to an understanding of its organization into communities of plants and animals.This information has helped in utilizing the earth’s biological wealth for the benefit of humanity and has been integral to the process of ‘development’. This includes better health care,better crops and the use of these life forms as raw material for industrial growth which has led to a higher standard of living for the developed world. However this has also produced the modern consumerist society, which has had a negative effect on the diversity of biological resources upon which it is based. The diversity of life on earth is so great that if we use it sustainably we can go on developing new products from biodiversity for many generations. This can only happen if we manage biodiversity as a precious resource and prevent the extinction of species.
Definition:
‘Biological diversity’ or biodiversity is that part of nature which includes the differences in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally, in a region,in the country and the world, and various types of ecosystems, both terrestrial and aquatic,within a defined area.
What is biodiversity?
Biological diversity deals with the degree of nature’s variety in the biosphere. This variety can be observed at three levels; the genetic variability within a species, the variety of species within a community, and the organisation of species in an area into distinctive plant and animal communities constitutes ecosystem diversity.
Genetic diversity
Each member of any animal or plant species differs widely from other individuals in its genetic makeup because of the large number of combinations possible in the genes that give every individual specific characteristics. Thus, for example,each human being is very different from all others. This genetic variability is essential for a healthy breeding population of a species. If the number of breeding individuals is reduced,the dissimilarity of genetic makeup is reduced and in-breeding occurs. Eventually this can lead to the extinction of the species. The diversity in wild species forms the ‘gene pool’ from which our crops and domestic animals have been developed over thousands of years. Today the variety of nature’s bounty is being further harnessed by using wild relatives of crop plants to create new varieties of more productive crops and to breed better domestic animals. Modern biotechnology manipulates genes for developing better types of medicines and a variety of industrial products.
Species diversity
The number of species of plants and animals that are present in a region constitutes its species diversity. This diversity is seen both in natural ecosystems and in agricultural ecosystems.Some areas are more rich in species than others.Natural undisturbed tropical forests have a much greater species richness than plantations developed by the Forest Department for timber production.A natural forest ecosystem provides a large number of non-wood products that local people depend on such as fruit, fuel wood,fodder, fiber, gum, resin and medicines. Timber plantations do not provide the large variety of goods that are essential for local consumption.In the long-term the economic sustainable returns from non-wood forest products is said to be greater than the returns from felling a forest for its timber. Thus the value of a natural forest,with all its species richness is much greater than a plantation. Modern intensive agricultural ecosystems have a relatively lower diversity of crops than traditional agropastoral farming systems where multiple crops were planted.At present conservation scientists have been able to identify and categorise about 1.8 million species on earth. However, many new species are being identified, especially in the flowering plants and insects. Areas that are rich in species diversity are called ‘hotspots’ of diversity. India is among the world’s 15 nations that are exceptionally rich in species diversity.
Ecosystem diversity
There are a large variety of different ecosystems on earth, which have their own complement of distinctive inter linked species based on the differences in the habitat. Ecosystem diversity can be described for a specific geographical region,or a political entity such as a country, a State or a taluka. Distinctive ecosystems include landscapes such as forests, grasslands, deserts,mountains, etc., as well as aquatic ecosystems such as rivers, lakes, and the sea. Each region also has man-modified areas such as farmland or grazing pastures.An ecosystem is referred to as ‘natural’ when it is relatively undisturbed by human activities, or ‘modified’ when it is changed to other types of uses, such as farmland or urban areas. Ecosystems are most natural in wilderness areas. If natural ecosystems are overused or misused their productivity eventually decreases and they are then said to be degraded. India is exceptionally rich in its ecosystem diversity.
Evolution and the Genesis of Biodiversity:
The origins of life on earth some three and a half billion years ago are obscure. Life was probably initiated as a product of organic reactions in the Earth’s primordial seas. Alternative possibilities such as life beginning in a muddy ooze,or of life having been seeded from outer space have also been suggested. Once life took hold on the planet, it began gradually to diversify.Unicellular unspecialized forms gradually evolved into complex multi-cellular plants and animals.Evolution is related to the ability of living organisms to adapt to changes in their environment.Thus the abiotic changes in nature such as climatic and atmospheric upheavals, repeated glaciations,continental drift and the formation of geographical barriers, segregated different communities of plants and animals and gradually lead to the formation of new species over millions of years. Most species appear to have a life span extending over several million years. Their adaptability to gradual changes in their habitat, and interactions with newly formed species produce groups of inter linked organisms that continue to evolve together. Food chains, prey-predator relationships, parasitism (complete dependence on another species), commensalism (a partnership beneficial to both species), etc. are important examples.
Behavioural patterns of the different species comprising a community of species links them to each other through their breeding biology, feeding patterns, migrations,etc. As ancient species became extinct due to geological upheavals, they left behind empty ‘niches’ in the habitat that stimulated existing species to fill them through the formation of new species. The Earth’s ancient history has seen periods of mega extinctions, which have been followed by periods of formation of new species.Though these repeatedly led to a drastic reduction in the number of species, the diversity of life recuperated each time by gradually increasing the number of species existing on earth. This however took millions of years, as evolution is a very slow process.
Thus when man came on the scene some 2 million years ago,the earth was more rich in species than ever before. During the recent past however, extinctions due to the activities of modern man have begun to take place so rapidly that nature has had no time to evolve new species. The earth is loosing species more rapidly than ever before.The diversity of life at all three organisational levels, genetic, species and ecosystem, is thus being rapidly modified by modern man. This is a great loss to future generations who will follow us.
Biodiversity (complete info.)
Biogeographic Classification Of India
India can be conveniently divided into ten major regions, based on the geography, climate and pattern of vegetation seen and the communities of mammals, birds, reptiles,amphibia,insects and other invertebrates that live in them. Each of these regions contains a variety of ecosystems such as forests, grasslands,lakes, rivers, wetlands, mountains and hills,which have specific plant and animal species.
1. The cold mountainous snow covered Trans Himalayan region of Ladakh.
India’s Biogeographic Zones
1. The cold mountainous snow covered Trans Himalayan region of Ladakh.
Constituting 5.6 percent of the country’s geographical area, this zone includes high altitude cold and arid mountain areas, including cold deserts. An extension of the Tibetan Plateau, this zone has sparse alpine steppe vegetation with many endemic species. It supports some of the biggest populations of wild sheep and goats in the world as well as some rare species of fauna such as Snow Leopard (Uncia uncia).
2. The Himalayan ranges and valleys of Kashmir,Himachal Pradesh, Uttarakhand, Assam and other North Eastern States.
Consisting of the entire Himalayan mountain range, this zone covers 6.4 percent of the total geographical area and has alpine and sub-alpine forests, grassy meadows and moist deciduous forests. It provides diverse habitats for a range of species including endangered ones such as Hangul (Cervus eldi eldi) and Musk Deer (Moschus moschiferus).
3.Semi-Arid
This zone covers 16.6 percent of the country. Although overall semi-arid, this zone also has several lakes and marshlands. The grasses and palatable shrub layer of this zone support the highest wildlife biomass. The endangered Asiatic Lion (Panthera leo persica) is also found in this zone (in the Gir forests of Gujarat).
4. The Gangetic plains.
Flanking the Ganga River and its tributaries, the Gangetic Plain zone extends up to the Himalayan foothills in the north. This flat alluvial zone is topographically fairly homogenous and constitutes 10.8 percent of the country’s geographical area. This zone supports many large and charismatic mammals such as One-horned Rhinoceros (Rhinoceros unicornis), Asian Elephant and Wild Water Buffalo. Other characteristic fauna includes Swamp Deer (Cervus duvauceli), Hog Deer (Axis porcinus) and Hispid Hare (Carprolagus hispidus).
5. The Thar Desert of Rajasthan.
This arid zone falls west of the Aravalli hill range and comprises both the salt and sand deserts of north-western India. Constituting 6.6 percent of the country’s geographical area, this zone also has large expanses of grasslands that support several endangered species such as the Great Indian Bustard (Ardeotis nigriceps).
6. The semi arid grassland region of the Deccan plateau-Gujarat, Maharashtra,Andra Pradesh, Karnataka and Tamil Nadu.
This is the largest zone covering as much as 42 percent of the country. It supports some of the finest forests in India with abundant populations of deer and antelope species such as Chital (Axis axis), Sambar (Cervus unicolor) and Four-horned Antelope (Tetracerus quadricornis). There are small populations of Asian Elephants (Elephas maximus) and Wild Water Buffaloes (Bubalus arnee) as well.
7. The Northeast States of India.
Characterised by diverse habitats and long-term geological stability, the North-East zone covers 5.2 percent of India’s geographical area. Due to its location at the junction of the Indian, Indo-Malayan and Indo-Chinese bio-geographical regions, it is considered a ‘gateway’ for much of India’s flora and fauna. There are significant levels of endemism in all floral and faunal groups.
8. The Western Ghats in Maharashtra,Karnataka and Kerala.
Western Ghats is a mountain range running along the western coast of peninsular India, from Tapti River in the north to Kanyakumari in the south. Constituting 4 percent of the country’s geographical area, this zone supports tropical evergreen forests that are home to approximately 15,000 species of higher plants, of which around 4,000 (27 percent) are endemic. There are several endemic faunal species as well, such as the Nilgiri Langur (Presbytis johnii) and the Lion-tailed Macaque (Macaca silenus).
9. The Andaman and Nicobar Islands.
Although this zone covers only 0.3 percent of the country’s geographical area, it is nonetheless important from the biodiversity perspective. The Andaman and Nicobar Islands have some of India’s finest tropical evergreen moist forests and show high degree of endemism in flora and fauna.
10. The long western and eastern coastal belt with sandy beaches, forests and mangroves.
The coastal zone constitutes 2.5 percent of the geographical area and covers beaches, mangroves, mud flats, coral reefs and marine angiosperm pastures. Sundarbans – shared with Bangladesh – is the largest contiguous mangrove area in the world. The Lakshadweep Islands – having a biodiversity-rich reef lagoon system – are also included in this zone.
Details of Biodiversity Act - 2002
National Biodiversity Authority
National Biodiversity Action Plan
Biodiversity and Governance
