- Biodiversity is the totality of genes, species and ecosystems of a region.
- The term biodiversity was coined by W.G. Rosen (1985)
- Edward Wilson (1992) , a sociobio logist, popularised the term biodiversity.
- According to IUCN (2004), globally total number of known plants and animal species are more than 1.5 million.
- India is one of the 17 megadiversity regions of the world
- India shares 8.1 % of total global species diversity.
- India has been divided into 10 biogeographical regions – (i) Trans·Hima layas, (i i) Himalayas, (iii) Desert, (iv) Semi·arid, (v) Western Ghats, (vi) Deccan Peninsula, (vii) Gangetic plain, (viii) North East, (ix) Coasts, (x) Islands.
- The largest biogeographical region is Deccan Peninsula (area 42%) and most biodiversity rich regions are Western Ghats (area 4.0%) and North·East (area 5.2%).
- Amazon rainforest situated in South America has the maximum biodiversity on earth
- Endemic species are confined to particular region g., western ghats are rich in endemic amphibian species.
- Bio-Diversity helps in creating more productive and stable ecosystems which can tolerate various stresses.
- Ecological diversity is the variety of forms in the ecosystem due to diversity of niches, trophic lands, energy flow, food webs.
- The maintenance of biodiversity is important because:
– Biodiversity is essential for stability of an ecosystem.
– Biodiversity serves as source of food and provides source material
for new improved varieties
- Various products of human use can be obtained from rich
biodiversity, e.g., gums, resins, dyes, paper, fibres, etc.
– Various plant species provide different drugs and medicines, e.g.,
quinine from Cinchona, taxol from Taxus, etc.
LOSS OF BIODIVERSITY :
The most serious aspect of the loss of biodiversity is the extinction of species. Extinction is of three types – natural extinction, mass extinction and anthropogenic extinction.
Natural or background extinction is a slow process of replacement of existing species with the better adapted species due to evolution.
Mass extinctions are due to environmental catastrophes.
Anthropogenic extinctions are extinctions due to human activities like settlements, hunting, over exploitation and habitat destruction.
- Conservation Strategies : In-situ conservation & Ex-citu conservation.
- In-situ conservation: conservation and protection of the whole ecosystem and its biodiversity at all levels. It is performed by two methods – Hot spots and Protected Areas.
- Hotspots – The areas characterized by very high levels of species richness, high degree of endemism and accelerated habitat loss due to threat, degradation, fragmentation and exploitation.
- Protected areas are – National Parks, Sanctuaries, Biosphere Reserves.
- Biosphere Reserves are meant for preserving genetic diversity and unique biological communities. Each biosphere reserve has (i) core (ii) buffer and (iii) transition zone.
- Ex-citu conservation: conservation of threatened plants and animals outside their natural habitats and include ottsite collections and gene banks e.g. botanical gardens, zoo, safari .
- Gene banks are a type of biorepository that maintain stocks of viable seeds (seed banks), live growing plants (orchards), tissue culture and frozen germplasm (cryopreservation) with the whole range of genetic variability.
- Man and Biosphere (MAB) Program is an international programme of UNESCO.,started in 1971 and introduced in India in 1986. MAB has studied human environment, impact of human interference and pollution on biotic and abiotic factors and conservation strategies.
- IUCN (International Union of Conservation of Nature and Natural Resources) is now known as World Conservation Union (WCU).lts headquarters are situated at Gland, Switzerland.
- A Red Data Book is maintained at WCU which is a catalogue of taxa facing risk of extinction . It is prepared to Identify and document the number of species facing high-risk of extinction and set conservation priorities and spread awareness of biodiversity threat.
- IUCN established five conservation strategies : Extinct, Endangered,Vulnerable, Rare and insufficiently known species.
- In 2012, IUCN recognized 9 Red List categories of species.
- Convention on International Trades in Endangered Species (CITES), 1975 – To ensure that international trade on wildlife and plant does not threat their survival and to put ban on international trade in wildlife. India signed the convention in 1976.
- UNCED or Earth Summit (Rio De Janerio, Brazil, 1992) promoted Convention on Biological Diversity (CBD) . India signed it on 1994.
- World Summit ( Johannesberg, South Africa, 2002)- 190 countries attending the Summit pledged to significantly reduce the current rate of biodiversity loss at global, regional and local levels by the year
- In India, Central Board of Wildlife , an advisory body , was constituted in 1952. Later it was renamed as Indian Board of Wildlife (IBWL).
- Wildlife Preservation Society of India, Dehradun was founded in 1958.