biological diversity
biological diversity
orbiodiversity,
the number of species in a given habitat. Scientists have variously estimated that there are from 3 to 30 million extant species, of which 2.5 million have been classified, including 900,000 insects, 41,000 vertebrates, and 250,000 plants; the remainder are invertebrates, fungi, algae, and microorganisms. Although other species remain to be discovered, many are becoming extinct through deforestation, pollution, and human settlement. Much of this diversity is found in the world's tropical areas, particularly in the forestforest,a dense growth of trees, together with other plants, covering a large area of land. The science concerned with the study, preservation, and management of forests is forestry.
..... Click the link for more information. regions. A habitat in equilibrium has a balance between the number of species present and its resources. Diversity is affected by resources, productivity, and climate. The more pristine a diverse habitat, the better chance it has to survive a change or threat—either natural or human—because that change can be balanced by an adjustment elsewhere in the community; damaged habitats may be destroyed by breaking the food chain with removal of a single species. Thus, biological diversity helps prevent extinction of species and helps preserve the balance of nature. At the 1992 United Nations Conference on Environment and DevelopmentUnited Nations Conference on Environment and Development
(UNCED) or Earth Summit,
an 11-day meeting held in June, 1992, in Rio de Janeiro, Brazil, to discuss the global conflict between economic development and environmental protection.
..... Click the link for more information. , more than 150 nations signed a treaty intended to protect the planet's biological diversity. See also ecologyecology,
study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of organisms is called synecology.
..... Click the link for more information. .
Bibliography
See E. O. Wilson, ed., Biological Diversity (1988); N. Eldredge, Life in the Balance (1998).