Concepts: Biodiversity conservation

4.1 Why conserve biodiversity

Three kinds of reason are given: narrowly utilitarian, broadly utilitarian and ethical. Narrowly utilitarian reasons are the direct economic gains: food from cereals, pulses and fruits, firewood, fibre, construction material, industrial products such as tannins, lubricants, dyes, resins and perfumes, and medicines. More than 25 per cent of the drugs sold worldwide come from plants, and about 25,000 plant species are used in traditional medicine. Bioprospecting, the search through molecular, genetic and species diversity for economically useful products, is a growing activity for biodiversity-rich nations.

The broadly utilitarian reasons are the ecosystem services nature provides. The Amazon forest is estimated to produce about 20 per cent of the oxygen in the earth's atmosphere through photosynthesis. Pollination, without which plants cannot give fruits or seeds, is another service performed by bees, bumblebees, birds and bats. There are also aesthetic benefits: a walk through thick woods, spring flowers in bloom, a bulbul's song in the morning.

The ethical argument is about what we owe other species. Every species has intrinsic value even if it has no current economic use, and we have a moral duty to pass the biological legacy to future generations in good order.

4.2 In situ conservation

Protecting the whole ecosystem protects biodiversity at every level. This approach is called in situ, meaning on site; saving the entire forest to save the tiger is the standard example. Conservation resources are always short, so conservationists identified biodiversity hotspots for maximum protection: regions with very high species richness and a high degree of endemism, meaning species confined to that region and found nowhere else. The list began with 25 hotspots and nine more were added, making 34. The list was later expanded, and India's richest regions lie within three entries: Western Ghats with Sri Lanka, Indo-Burma, and the Himalaya. Together the hotspots occupy under 2 per cent of the planet's land, yet protecting them strictly could reduce the current mass extinctions by nearly 30 per cent.

Indian law protects rich and unique regions as biosphere reserves, national parks and sanctuaries. The current count is 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries. Indian culture also set aside forest tracts for protection: such sacred groves are found in Meghalaya's Khasi and Jaintia Hills, in the Aravalli Hills of Rajasthan, in the Western Ghats across Karnataka and Maharashtra, and in Madhya Pradesh's Sarguja, Chanda and Bastar areas. Meghalaya's groves are the final refuge for many rare and threatened plants.

4.3 Ex situ conservation

Ex situ conservation, meaning off site, moves threatened animals and plants away from their habitat into a special setting where they receive protection and care. Zoos, botanical gardens and wildlife safari parks all serve this purpose, and some animals now extinct in the wild survive only in zoos. The approach has moved beyond enclosures: cryopreservation keeps gametes viable and fertile for long periods, eggs can be fertilised in vitro, tissue culture propagates plants, and seed banks store seeds of commercially important strains.

In situ and ex situ answer different situations. When an endangered species needs urgent protection from a threat in its own habitat, ex situ is the practical choice; when the aim is to protect an entire ecosystem and its interactions, in situ does the job.

4.4 International agreements

Biodiversity has no political boundaries, so conserving it is a shared responsibility. The Convention on Biological Diversity, known as the Earth Summit, was held in Rio de Janeiro in 1992 and called on nations to conserve biodiversity and use its benefits sustainably. In 2002 the World Summit on Sustainable Development at Johannesburg, South Africa, saw 190 countries pledge to reduce the rate of biodiversity loss significantly by 2010 at global, regional and local levels.

4.5 Where the two approaches meet

In practice in situ and ex situ are used together. A species saved in a zoo can be reintroduced once its habitat is protected again, and seed from a seed bank can restore a population whose wild site has been lost. The two approaches also fail together: ex situ collections lose genetic variation over generations in captivity, and in situ protection fails for a species already reduced to a handful of individuals. A conservation plan that names both, and says which threat each addresses, is stronger than one that chooses a side.