Conservation Biology

Concept of biodiversity

Biodiversity (biological diversity) is the variety of life on earth at all its levels, genetic diversity (variation within a species), species diversity (variety of species in a region), and ecosystem diversity (variety of habitats/ecosystems). Nepal, though a small country, has extraordinarily rich biodiversity because of its huge range of altitude (about 60 m to over 8,000 m) and climate within a short distance, giving it tropical, subtropical, temperate, alpine and nival ecosystems side by side.

Biodiversity is essential for maintaining stable, self-sustaining (viable) ecosystems: it keeps food webs and nutrient cycles functioning, buffers ecosystems against disease and climate shocks, and is the source of food, medicine, timber, fresh water and genetic material on which human life directly depends.

Causes of extinction of biodiversity

• Habitat destruction and fragmentation: deforestation, urbanisation and conversion of land to agriculture remove or break up the natural habitat a species needs.
• Overexploitation: excessive hunting, poaching, fishing and collection reduce populations faster than they can recover.
• Pollution: air, water and soil pollution poison or degrade habitats.
• Invasive/alien species: introduced species that outcompete, prey on, or bring new diseases to native species.
• Climate change: shifting temperature and rainfall patterns alter or destroy habitats faster than species can adapt or migrate.
• Human-wildlife conflict: retaliatory killing where wildlife damages crops, livestock or human life near settlements.

The loss of biodiversity affects humans directly, through the loss of potential food, medicinal and genetic resources, disruption of pollination and natural pest control, and breakdown of ecosystem services such as clean water and climate regulation.

Biodiversity conservation strategies

Biodiversity is conserved mainly through the in-situ approach (protecting species within their natural habitat via legally protected areas) and the ex-situ approach (breeding/preserving species outside their natural habitat, see the Vegetation chapter for detail on both). Other supporting strategies include community-based conservation and buffer zone programmes around protected areas, captive breeding and release programmes (e.g. the gharial breeding centre at Chitwan), strict legal protection and anti-poaching enforcement (Nepal's National Parks and Wildlife Conservation Act, 1973), and international cooperation through treaties such as CITES (the Convention on International Trade in Endangered Species), which regulates cross-border trade in threatened wild plants and animals.