Martin Jenkins

Priorities for conserving global species richness and endemism

The Convention on Biological Diversity aims to encourage and enable countries to conserve biological diversity, to use its components sustainably and to share benefits equitably. Species richness and endemism are two key attributes of biodiversity that reflect the complexity and uniqueness of natural ecosystems. National data on vertebrates and higher plants indicate global concentrations of biodiversity and can assist in defining priorities for action. Projections indicate that species and ecosystems will be at maximum risk from human activities during the next few decades. Prompt action by the world community can minimise the eventual loss of species. Highest priorities should be to: (i) strengthen the management of ecosystems containing a large proportion of global biodiversity; (ii) help developing countries complete their biodiversity strategies and action plans, monitor their own biodiversity, and establish and maintain adequate national systems of conservation areas; (iii) support actions at the global level, providing benefit to all countries in managing their own biodiversity. Generally, resources will best be spent in safeguarding ecosystems and habitats that are viable and important for global biodiversity, and which are threatened by factors that can be controlled cost-effectively. Other important criteria are representativeness, complementarity and insurance.

Species extinctions, endangerment and captive breeding

During the last four hundred years some 490 described species of animal are known to have become extinct. In this chapter the patterns of animal extinction are analysed by taxonomic group, against time, and between islands and continental land masses. From species—area curves based upon extrapolation of the rate of habitat loss (particularly tropical forests) estimates have been produced of the future rates of species extinctions. These estimates vary considerably from less than 5% of all animal species between 1985 and the year 2025 to more than 25% if rates of forest clearance accelerate (WCMC, 1992).