In situ and ex situ conservation

The essentials

In situ (on site) conservation protects species in their natural habitat, so the whole ecosystem is protected. Ex situ (off site) conservation takes threatened plants and animals out of their natural habitat and protects them in special settings.

Biodiversity hotspots: These are regions with very high levels of species richness and high degree of endemism (species confined to that region and not found anywhere else). Initially 25 hotspots were identified; more were added later (NCERT lists 34). Three of these cover India's rich biodiversity regions: the Western Ghats and Sri Lanka, Indo-Burma and the Himalaya. Although all hotspots together cover less than 2 per cent of the earth's land area, they hold a very large share of species, and strict protection of them could reduce ongoing mass extinctions by almost 30 per cent.

Protected areas in India: Ecologically unique and biodiversity-rich regions are legally protected as biosphere reserves, national parks and wildlife sanctuaries.

Sacred groves: India has a history of religious and cultural traditions that emphasise protection of nature. In many cultures, tracts of forest were set aside and all trees and wildlife within were venerated and given total protection. Such sacred groves are found in the Khasi and Jaintia Hills in Meghalaya, the Aravalli Hills of Rajasthan, the Western Ghat regions of Karnataka and Maharashtra, and the Sarguja, Chanda and Bastar areas of Madhya Pradesh. In Meghalaya, sacred groves are the last refuges for many rare and threatened plants.

Ex situ methods:

• Zoological parks, botanical gardens and wildlife safari parks.
• Many animals that have become extinct in the wild continue to be maintained in zoological parks.
• Cryopreservation: gametes of threatened species can be preserved in viable and fertile condition for long periods.
• Eggs can be fertilised in vitro, and plants can be propagated using tissue culture.
• Seed banks preserve seeds of different genetic strains of commercially important plants for long periods.

International efforts: The Earth Summit held in Rio de Janeiro in 1992 called upon all nations to take measures for conservation of biodiversity and sustainable utilisation of its benefits. The World Summit on Sustainable Development in Johannesburg in 2002 saw countries pledge to achieve a significant reduction in the rate of biodiversity loss.

Common mistakes

• National parks and sacred groves are in situ; zoos, seed banks and cryopreservation are ex situ.
• A hotspot needs both high species richness and high endemism.