***************Biodiversity**************

The World's attention was perhaps never so focused on the issue of biodiversity than during the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro, May, 1992. One product of the conference was the Convention on Biological Diversity (and supporting action plan) designed to protect the world's declining ecological resources in manner that will make them available for the future (UNEP, 1992). The Convention defines biological diversity as: "the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems. *Biodiversity* Rapid over population, continuous pollutants and the spread of urban developments are increasing the destruction of our biodiversity. Here is more information aboutBiodiversity Biodiversity represents long term insurance: the genetic information and ecosystem function insure these biologically derived essentials and others as yet undiscovered will be available in the future. To illustrate this, consider that as much as 60% of the exceptional agricultural yield increases of the last 40 years has been credited to improvements made through breeding made possible by freely available germplasm (Plowman, 1993). In the medical field, the National Cancer Institute had already screened 7000 plants throughout the world for use against cancer and HIV by 1992 (Reynolds, 1992). The chances of finding a winner are slim; only one assay in ten thousand turning into a new product or drug (Reid et al. 1993).

Genetic diversity versus species richness Comparative species richness only tells part of the story when considering the value of biodiversity in arid lands. Alpha, beta, and gamma diversity measures all assume that species are taxonomically equivalent. Faced with ever rising extinction rates, some researchers are now suggesting that distinctiveness of taxonomic form should be given higher priority in decisions about relative importance of species (Pielou, 1975; Atkinson, 1989; Vane-Wright, et al. 1991). Where two communities are compared, these authors would give a higher measure of relative diversity to the one with most dissimilar taxa. The underlying assumption is that such a ranking correlates with higher genetic diversity and thus increased overall information. The Cost of not addressing the problem Most economists would define biochemical resources as "non-rival public goods" where use by one individual does not reduce their value to others. Therefore, all users benefit from investment into conservation. As a result, the World Resource Institute (Reid et al, 1993) predicts that market forces will lead to less conservation than the value of biodiversity warrants. Indeed a market valuation of a bio-resource was challenged by a 1989 Ohio court. The court ruled that "natural resources have value that is not readily measured by traditional means," yet economists are far from agreement on valuation methods (Eberle and Hayden, 1991).