Global Significance of the Biodiversity of Nepal
Nepal's richness of species diversity can be attributed to its large topographical and vertical dissimilarities, and climatic variations.
The great variation in altitude and climatic conditions over short distances has given rise to the many different species of plants and animals that are found in the Nepal.
This rich biodiversity has generated complex symbiotic relationships between plants, animals and humans. While still neither well documented nor well understood, many plant and animal species are already threatened due to overuse and misuse.
Efforts have been made to protect some of these in special conservation areas. Seventeen protected3 areas in different climatic regions ranging from sub-tropical to cold desert areas have been identified and these now constitute national parks, conservation areas, wildlife reserves, and hunting areas.
Outside these protected areas, habitats have suffered great loss or alteration from over extraction of forest resources, illegal collection of species, poaching or hunting of wild animals, over-grazing of rangelands and fire. The economic value of endangered or rare species on the world market remains very high and this encourages poaching. During the last two decades alone, Nepal has lost 63 rhinoceros due to poaching.
Nepal has a very extensive array of plant species in proportion to its relatively small area coverage in the world-wide terms. Nepal is home to slightly below 3 percent of the world's total non-flowering plants and over 2 percent of its flowering plant species (angiosperms and gymnosperms). Endemic species of plants discovered in Nepal are confined primarily to the Himalayan region. There are 246 flowering plants and 248 non-flowering plants as endemic. There are about 500 edible plant species, of which about 200 species have been domesticated. There are 60 nonendemic and 47 endemic plant species as threatened. Of the 60 non-endemic plant species, 22 are rare, 12 are endangered, and 11 are vulnerable. Of the endemic plants, 8 are extinct, 1 is endangered, 7 are vulnerable, and the remaining 31 fall into the International Union for the Conservation of Nature's (IUCN) red list category. Over 1,000 species of angiosperms have been identified in Nepal, of which 93 were first reported from Nepal. Of the 93 nepalensis plant species, 32 are endemic to Nepal. While Nepal occupies just over 0.1 percent of the earth's land surface, it supports a disproportionately high number of globally known animal species. For example, it supports: 4.2 percent of all known butterfly species (640 sps.), 2.2 percent of fresh water fish species (182 sps.), 1.1 percent of amphibians (43 sps.), 1.5 percent of reptiles (100 sps.), 8.5 percent of birds (852 sps.) and 4.2 percent of mammals (181 sps.).
Nepal also has a wide variety of domesticated plants and animals, including over 400 species of agro-horticultural crops and about 200 species of vegetables have been reported , of which approximately 50 species have been domesticated for commercial and household purposes. Fifteen fruits with more than 100 varieties, 50 vegetables with 200 varieties, and 10 varieties of potatoes are cultivated commercially. Some wild genotypes have also been identified and domesticated by local people for their economic value. The Nepal Agricultural Research Council (NARC) has stored the germplasm of various crops - cereals, grain, legumes, oilseeds, vegetables, and spice species – a total of about 11,000 accessions, including about 680 accessions for rice and 713 for finger millet. To ensure the conservation of biodiversity, the government has given legal protection status to 17 plant, 26 mammal, 9 bird, and 3 reptile species. Almost all of these faunal species and about 20 plant species are already included in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) appendices
Key Environmental Issues and Challenges
1. Nepal's ecology and environment are diverse and sensitive. A rapidly growing population is putting pressure on the natural resource base, particularly water, land, and forest resources. Much of the forestland between the Himalayas and the Terai has been cleared to provide room for crops, livestock, and human settlement. Landslides, erosion, and slope instability are common, particularly during the monsoon. These are exacerbated by the loss of vegetation, unmanaged water, and construction works. As a result, large segments of the topsoil on the hillsides are washed away every monsoon season. Population growth, together with haphazard urbanization and spreading transport links, has contributed to deforestation, overuse of limited available land for agricultural purposes, increasing congestion and sprawl-type development in urban centers, and environmental degradation associated with the disposal of solid wastes and other forms of pollution. Air and water pollution in Kathmandu Valley is particularly severe. The industrial base is limited, but this has already contributed to a variety of pollution problems at the local level.
2. The rapidly deteriorating environmental and natural resource base has contributed to poverty, as people find it more and more difficult to meet their basic resource needs in a sustainable manner. The high poverty incidence implies that there will be continued pressure on the natural resource base leading to further degradation of forests and water resources, a decrease in soil fertility, and an increase in land and air pollution. Given this intertwining of environmental degradation and poverty, sustainable use of natural resources is instrumental for Nepal's poverty reduction and development.
3. Nepal's forests are being depleted due to overexploitation. Nepal had a total of 6.4 million hectares of forest in 1964, reduced to 3.9 million hectares by 2000. The nation's forest coverage has declined from 37% in the late 1970s to 29% in the early 1990s. With the absence of other means of energy sources, fuel wood is the main source of energy for cooking and heating. This has been the main cause of deforestation. The forests are also used for infrastructure development, such as roads, schools, buildings, and houses. Deforestation has resulted in increased landslides, soil erosion, floods, and loss of biodiversity.
4. Nepal is rich in biodiversity in terms of fauna and flora due to
diverse climatic zones.