Biodiversity is the measure of variety of the Earth's animal, plant and microbial species; of genetic differences within species and of the ecosystems that support those species.
The term first came to public attention in 1992 at the Rio Earth Summit at which a convention for the preservation for the maintenance of biodiversity was signed by over 100 world leaders [excluding the USA as they feared it would undermine the patents and licences of US biotechnology companies] .
The maintenance of biodiversity is important for ecological stability and maintaining the gene pool, and as a resource for research into, for example, new drugs and crops.
What is causing a reduction in biodiversity in both the developed [EDC] and less developed [ELDC] worlds?.
Most of the threats currently faced by species of plants and animals are linked to human action. In some cases this action, for example, hunting, deliberately aims to reduce species numbers[ e.g. White Rhino-sole purpose of which is to cut the horn off for illegal sale to Asian (mainly China) who mistakenly believe it has aphrodisiac powers]. There few Rhinos left and some subspecies have disappeared altogether e.g. Javan and Sumatran. Similar fate is facing the tiger e.g. Bengal down to 1,500 in number, Siberian circa 250 left. .
In other situations species are inadvertently affected, for example, where habitats are destroyed or modified by people wishing to use the land for other purposes [For example , Korean Hyundai Company has just been given concession for deforestation and mineral exploration in key Siberian Tiger territory].
In extreme cases, a species may become extinct- this is irreversible- a loss of biodiversity. Extinction in the wild means that some individuals may still exist in captivity or in a seed bank. Extirpation is localized loss.
Habitat destruction and modification is the most serious threat to biodiversity. Some indication of the extent of this problem is given in the table below:.