[Biological diversity] is usually considered at three different levels: genetic diversity, species diversity and ecosystem diversity. Genetic diversity refers to the variety of genetic information contained in all of the individual plants, animals and microorganisms. [Genetic diversity] occurs within and between populations of species as well as between species. Species diversity refers to the variety of living species. Alpha-diversity is the species diversity within a single site. Beta-diversity refers to species diversity between habitats (thus reflecting changes in species assemblages along environmental gradients). [Ecosystem diversity] relates to the variety of habitats, biotic communities, and ecological processes, as well as the tremendous diversity present within ecosystems in terms of habitat differences and the variety of ecological processes.
The Encyclopedia of World Problems and Human Potential is a collaboration between UIA and Mankind 2000, started in 1972. It is the result of an ambitious effort to collect and present information on the problems with which humanity is confronted, as well as the challenges such problems pose to concept formation, values and development strategies. Problems included are those identified in international periodicals but especially in the documents of some 60,000 international non-profit organizations, profiled in the Yearbook of International Organizations.
The Encyclopedia includes problems which such groups choose to perceive and act upon, whether or not their existence is denied by others claiming greater expertise. Indeed such claims and counter-claims figure in many of the problem descriptions in order to reflect the often paralyzing dynamics of international debate. In the light of the interdependence demonstrated among world problems in every sector, emphasis is placed on the need for approaches which are sufficiently complex to encompass the factions, conflicts and rival worldviews that undermine collective initiative towards a promising future.
Non-profit, apolitical, independent, and non-governmental in nature, the UIA has been a pioneer in the research, monitoring and provision of information on international organizations, international associations and their global challenges since 1907.