The products and services offered by natural ecosystems are increasingly appreciated as a resource for sustainable development.

Harvesting wild resources:

Forest lands offer a wealth of products other than wood, that benefit both rural communities and humanity as a whole.

Three-quarters of the world's people use folk medicines derived largely from forest plants and animals, while the Worldwatch Institute estimates that more than US$ 100 000 million worth of drugs with active ingredients developed from the forests are sold worldwide each year.

Meat from wild animals may be a major source of protein for many remote villages. Leaves, bark and seeds supplement diets, providing vitamins and trace minerals, while genes from forest plants are used to boost agricultural yields around the world.

Global trade in forest products, other than wood, runs into thousands of millions of dollars annually. In the state of Manipur, India, for example, 90 percent of the people depend on them as a major source of income.

Many food crops and non-wood industrial, commercial and pharmaceutical materials originated as products long harvested from the wild by indigenous peoples. The economic and social incentives for non-wood harvesting encourage conservation and offer a defence against the loss of biodiversity.

Animal products: food, insect products, perfumes, fertilizers, insects, fish, mammals, reptiles, birds, other wild animals, live animal trade.

Plant products: food, vines, fungi, grasses, other wild plants, perfumes, fodder, fibres, horticulture, extracts medicines.

Services: employment, range land, plant protection, soil improvement, watershed care, parks and reserves, ecotourism, heritage, amenities, landscapes, pollination.

Animal products

By conservative estimates wild animals provide more than three-quarters of dietary protein in Zaire. The world's 240 000 square kilometres of coastal mangrove forests provide vital nursery, feeding and breeding grounds for commercially valuable fish and shellfish including, for example, nearly 90 percent of the commercial catch in the Gulf of Mexico.

Insects are rich in vitamins and minerals: bee larvae contain ten times more vitamin D than fish-liver oil. Honey supports an important forest industry, as well as providing a particularly nutritious food: Indian villages are estimated to produce more than 37 000 tonnes of it a year. And a drug obtained from the saliva of leeches is used worldwide in skin transplants, and to treat rheumatism and thrombosis.

The glands of the musk deer are used to make perfume, while the tree iguanas of Latin America are farmed for both their meat and their skins, which are sold to make hefts, watch bands and shoes.

Plant products

More than 6 000 forest plants have long been used as natural medicines, and many have become the basis for modern pharmaceuticals. The rosy periwinkle, from the forests of Madagascar, has revolutionized the chances of children surviving leukemia. Taxol, from the western yew in northwestern American forests, is one of the most potent anti-cancer drugs ever found.

The sago palm is a staple food for more than 300 000 people in Melanesia; the 700 000 people of the Upper Shaba area of Zaire consume 20 tonnes of mushrooms every year. Genes from wild forest species have been used to improve wheat, sugar, coffee and many other crops and to protect them from devastating outbreaks of disease.

Exports of rattan and of palm nuts and kernels are worth more than US$ 2 000 million a year, and some 1.5 million people in the Brazilian Amazon get much of their income from harvesting rubber and other forest products.

Services

The value of forests in protecting soils and regulating water supplies and the climate is incalculable and the effects of their disappearance are often catastrophic. Wind erosion can strip 150 tonnes of topsoil from a single hectare in just one hour; water erosion may wash away 25 000 million tonnes worldwide every year. Deforestation in the Himalayas contributes to the flooding of nearly 5 million hectares annually. Forests and trees are a source of fodder for livestock, particularly where grazing is poor or three-quarters of the nearly 3 000-5 000 tree species in Africa are used in this way. Domestic animals may rely on leaves, fruits and seedpods from trees and shrubs for up to six months every year.

Forests preserved in parks and reserves provide habitats for hundreds of thousands of species, many of them endangered. These are usually very beautiful, and often have great potential for recreation and ecotourism.

What are forests worth?

Forests are usually worth much more left standing than when they are cut down. Studies in Peru, the Brazilian Amazon, the Philippines and Indonesia suggest that harvesting forest products sustainably is at least twice as profitable as clearing them for timber or to provide land for agriculture.

A study in Peru showed that sustainably harvesting forest products from just 1 hectare of forest could be worth US$ 422 annually, year after year. Cutting down and selling the timber from the same hectare would yield a one-time return of US$ 1 000.

Another study in Palawan, the Philippines, showed that coastal fisheries could earn local fishermen US$ 28 million a year if forests on the island's watershed were left intact, thus preserving the coral reef upon which the fisheries were based. As it happened, the trees were cut, the resulting soil erosion killed the reef and the fisheries disappeared.

Many benefits follow when forests are conserved:

· protection of wild species which could provide future crops, medicines or industrial raw materials;
· prevention of erosion, conservation of water resources and stabilization of local climates;
· the safeguarding of productive wild resources and encouragement of tourism.

Trekking in Himalayan mountain forest, Nepal.

People and wildlife

Wildlife conservation is generally most effective when local people benefit from it; when they are hostile, there is little chance of effective protection. Wildlife reserves often try to keep local people out, denying them the chance to make a living from the land, while elephants, tigers and other large animals often trample crops or kill livestock and people in areas adjacent to them.

Policies and protected areas are increasingly being designed to attract local support. Quotas have been set for hunting antelope in Zambia's Kafue Flats wetlands. The local people decide how many to kill themselves and how many to reserve for trophy hunting tourists at US$ 500 a time: under this regime, the antelope, threatened by poaching before the change of policy, have flourished and increased. Zimbabwe has also introduced trophy hunting, at high prices, and ploughs the money back into conservation and local communities.

Protected areas in Papua New Guinea are often run by local committees, and the people are given incentives to exploit the forest sustainably, such as through butterfly farming. Game ranching also holds promise for conservation. In New Zealand, some 4 500 farmers manage forested rangeland, yielding more than US$ 26 million a year in exports.

Ecotourism

Ecotourism is one of the fastest growing areas of the tourism industry. It is estimated to be increasing by some 10-15 percent a year.

Two-fifths of visitors to Costa Rica - one of the pioneers of ecotourism - now come to see its forests, landscape and wildlife. Ecotourists in South Florida are thought to spend almost US$ 2 000 million a year and trips to Antarctica increased four-fold in as many years in the early 1990s.

Ecotourism offers an important opportunity to earn many millions of dollars per year from conservation. But ecotourists can end up damaging the very wild areas they have come to admire. Coral reefs around the world have been ruined by visitors. The lodges in one village on the Nepalese hiker trails fell a hectare of forest every year, causing more than 30 tonnes of soil to be eroded away.

Experts say that the effects of ecotourism should be monitored and the industry regulated if it is to achieve its potential for conservation. Small-scale operations are usually the most benign, but only a few, like the Toledo Ecotourism Association in Costa Rica, are run by local villagers.