Focus On Planet Earth - ASIA & THE PACIFIC BIODIVERSITY.

ASIA & THE PACIFIC ECOSYSTEMS BIODIVERSITY

[ Social | Economic | Institutional | Environmental ]

The region encompasses parts of three of the world's eight biogeographic realms and includes the world's highest mountain system, the second largest rainforest complex, and more than half of the world's coral reefs. Five of the 12 "mega-diversity" countries identified by McNeeley et al. are in this region (McNeeley et al., 1990). The rainforests of South-East Asia contain some 10 per cent of the flora of the world. The region as a whole encompasses two thirds of the world's flora. Almost all the nations in the region (with the exception of Singapore and Brunei Darussalam) depend heavily on direct harvesting from nature.

The flora and fauna of the region are more threatened now than ever before. (See Figure 2.8.) The drive for increased agricultural production has resulted in the loss of genetic diversity. Land under rice cultivation rose between 1960 and 1970 by only 25 per cent, but production rose by 77 per cent due to the replacement of traditional varieties with higher-yielding, semi-dwarf varieties. By 2005, India is expected to produce 75 per cent of its rice from just 10 varieties compared with the 30,000 varieties traditionally cultivated. In Indonesia , 1,500 varieties of rice disappeared during the period 1975-90 (WRI/UNEP/IUCN, 1992). Terrestrial biodiversity loss in various ecosystems has been identified as a major concern, but losses have still to be quantified. Overall habitat losses have been most acute in the Indian sub-continent, China , Vietnam , and Thailand (ESCAP, 1995b).

The Indo-west Pacific is the centre of shallow-water marine biodiversity. Coastal habitat loss and degradation, combined with increased sediment, nutrient, and pollutant discharge into coastal areas, are a major cause of concern, particularly in the insular countries of the region. Thailand alone lost about 200,000 hectares of mangrove from 1961-93 (Government of Thailand, 1994). Conversion of mangroves to shrimp mariculture and unsustainable fishing practices such as blast fishing are widespread. Although the impacts of such practices on regional biodiversity are difficult to quantify, it has been estimated that the rates of loss of coral reef and mangrove habitats are among the highest in the world.

The underlying causes of losses of biological diversity in the region include international trade, particularly in timber (which results in forest habitat losses); population growth (leading to accelerated rates of land use change); poverty (in conjunction with demand leading to unsustainable consumptive use of "common access resources"); the introduction of non-native species (leading to destruction of predator/prey equilibrium); and improper use of agrochemicals (leading to loss of aquatic species). Other major reasons for biodiversity loss include loss of keystone species, extensive deforestation and habitat loss, increased trafficking in animals and animal body parts, large-scale conversion of land for agriculture, and the construction of large-scale dams.

Biological diversity is recognized as a legitimate issue at national and international levels in Asia and the Pacific, and there has been a considerable response (such as the implementation of the Convention on Biological Diversity and designation of protected areas). (See Figure 2.9.) However, patterns of unsustainable use and conflicting policies contribute to continued losses of biodiversity throughout the region. With only 10-30 per cent of natural habitats left in many countries, any further decrease could have much more serious consequences for biodiversity than the initial stage, when 50 per cent of the original habitat was lost (ESCAP, 1995a).

United Nations Environment Programme