Biodiversity And Its Conservation Revision Notes For NEET

BIODIVERSITY AND ITS CONSERVATION

        Biodiversity is the degree of variation of life, it can either be genetic variation, species variation or ecosystem variation with in an area or biome.

        Genetic diversity shows high diversity at gene level greater the genetic diversity among organisms of a species, more sustenance it has, against environment disturbances.

        Species diversity is the measure of the varieties of species and their abundance present within the region, e.g. Western ghats has more amphibians than Eastern ghats. Species richness and species evenness are the two important measures of species diversity.

        Ecological diversity refers to the diversity of species. It also related to the genetic diversity at ecological level. It has three perspectives, i.e. 𝛼, 𝛽, and 𝛾-diversity.

        Patterns of biodiversity is not uniform throughout the world. It decreases as we move away from the equator towards the poles.

        Importance of biodiversity can be categorised into three main aspects, i.e. stability, productivity and ecosystem health. More biodiversity provides more stability to the ecosystem.

        Loss of biodiversity is a global crisis. The major threat to biodiversity is extinction of species. Extinction is the total elimination or dying out of species from the earth.

        Natural extinction is a slow process of replacement of existing species with the better adapted species due to alternate evolution, changes in environmental condition, predators and diseases.

        Mass extinction occurred about 225million years ago in Permian period. Another mass extinction occurred between cretaceous and tertiary period over 60 million years ago.

        Anthropogenic extinction occurred by human activities like hunting, overexploitation and habitat destruction.

        The main causes of biodiversity loss are habitat loss, overexploitation, alien species invasion and coextinctions, etc.

        Red data book or Red list is a catalogue of taxa facing risk of extinction. It is maintained by IUCN. Red list has nine categories of species, i.e. extinct, extinct in the wild, critically endangered, endangered, vulnerable, threatened species, low risk, data deficient, not evaluated.

        The reasons for conservations of biodiversity can be grouped into three categories, i.e. narrowly utilitarian, broadly utilitarian and ethical argument.

        In situ conservation is the conservation of living resources within the natural ecosystems in which they occur. It is mainly of two types, i.e. hotspots and protected area.

        Hotspots are areas that are extremely rich in species diversity have high endemism and are under constant threat.

        Ramsor sites are areas that are extremely rich in species diversity, have high endemism and are under constant threat. These are the wetlands of international importance, recognised globally due to the Ramsor convention.

        Protected areas are the part of land and sea, especially dedicated to protection and maintenance of biological diversity along with its natural and associated cultural resources. These includes sacred groves, national parks, wildlife sanctuaries and biosphere reserves.

        National parks are maintained by government and reserved for betterment of wildlife, cultivation, grazing, forestry and habitat manipulation, e.g. Jim Corbett National Park.

        Biosphere reserves are a special category of protected areas of land and coastal environments, wherein people are an integral part of the system. Biosphere reserves represent a specified area Zone for particular activity. These consist of core zone, buffer zone and manipulation zone.

        Ex situ conservation is the conservation of organisms outside the habitats by perpetuating sample in genetic resource centre, e.g. zoos, botanical gardens, culture collections, etc.

        In 1992 at Rio de Janeiro promoted convention on biological diversity which was signed by 152 nations. India became part of this convention in 1994.

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