ABSTRACT
Biodiversity is under threat from the encroachment of agriculture and other forms of resource development in forests and other wildlands. The conservation of biodiversity is advocated by some for ethical or philosophical reasons. The total economic value of biodiversity or biological material is the sum of direct-use value, indirect-use value, option and bequest value, and existence value. Under many traditional resource systems and common-property regimes, biodiversity was little threatened by activities such as food production and the gathering of forest products. In some countries, protected areas are major attractions: over three-quarters of tourists in Ecuador and more than half in Mexico and Costa Rica visit national parks or other protected areas. In Britain, the modern nature-conservation effort can be traced back to protection afforded by law to certain species in the mid-nineteenth century. Whether or not environmental conservation was the main motivating factor, taboos and cultural pressures often helped to ensure protection of both habitat and species.
