BIODIVERSITY

Biodiversity refers to the totality of genes, species and ecosystems of a region.

The term Biodiversity was popularised by the the sociobiologist Edward Wilson.

It is the assemblage of different life forms.It is also be defined as the number of different organisms and their relative frequency in an ecological system.Biodiversity differs from place to place

SIGNIFICANCE OF BIODIVERSITYBiodiversity, besides its ecological significance provides a socio-economic and monetary asset to the Nation.Human society depends on biological resources.It provide essential goods and services for mankind.Values related to biodiversity can be grouped into three categories; a) Productive Use b) Consumptive Use c) Indirect Use

PRODUCTIVE USE

This is assigned to products that are commercialy harvested for exchange in formal markets.Here the only value of biological resources is that is concerned in National income.Biodiversity provides us many products such as fuel, timber, fish, fodder, skin, fruits, cerals and medicinal plants.

CONSUMPTIVE USE

Consumption value is related to natural products that are consumed directly that is the goods donot come under normal circulation of trade.Non timber forest products as soft broom grass and cane under this category.

INDIRECT USEThey may provide us indirect benefits as non-consumptive values such as maintenance of ecological balance, conservation of natural resources, and preservation of soil erosion may be considered as the examples of indirect use of biodiversity.TYPES OF BIODIVERSITYBiodiversity includes three hierarchial levels. They are; a) Genetic diversity b) Spcies diversity c) Ecosystem diversityThese levels of biodiversity are interrelated. Their interconnections support the life form earth.

Genetic diversity refers to the variation of genes within the species and the variation occures at the levels of alleles or entire genes of chromosomes. The genetic diversity helps a population to adapt to its environment. If a species has more genetic diversity it can adapt better to the changed environmental condition. Genetic variation results in the species variation.

Species diversity diversity means the variety of species within a region. Species are distinct unit of diversity. Loss of species leads to serious consequences affecting the total ecosystem. Simplest measure of species diversity is species richness, which is the number of species per unit area.Ecosystem diversity deals with the number of niches, trophic levels and various ecological processes that sustain energy flow, food webs and the recycling of nutrients. The number ecosystems varies within a geographical area.

HOT SPOTS OF DIVERSITYAreas that are rich in species diversity are called hot spots. There are over a thousand major ecoregions in the world. Contries which have a large area of biodiversity hot spots are refered as Mega-diversity nations. Our globally accepted national hotspots are in the forest of Western Ghats, Himalaya, which are included in the worlds most bio-rich areas. The Andaman and Nicobar Islands are extremly rich in species diversity.

THREATS OF BIODIVERSITYNatural calamities such as flood, drought, storms, forest fire, volcanic eruptions, epidemics etc are all threats to biodiversityArtificial causes such as habitat loss, over exploitation, pollution, introduction of exotic species, poaching of wild life & man and wildlife conflict.HABITAT LOSS: Distruction of is the primary reason for the loss of biodiversity. The natural habitat of some species is distroyed by cutting down trees, burning forest filling of wet lands. These activities can kill many plants, animals and micro organisms etc.

OVER EXPLOITATION: It is an another cause for extinction. Over exploitation of particular species reduces the size of its population to an extent that it become vulnerable to extinction. Ex: Indian cheetah, Mauritian bird Dodo.POLLUTION: Environmental pollution may reduce and eliminate population of sensitive species.

.INTRODUCTION OF EXOTIC SPECIES: New species entering a geographical area are called exotic species. Introduction of exotic species causes changes in biotic interactions leading to disappearence of native species. Intoduction of such invasive species are considered second only to habitat destruction as a major cause of extinction of species POACHING OF WILD LIFE : Specific threat to certain animals are related to large economic benefits. The skin of bones from tiger, ivory from Elephants, perfumes from musk deer are extensively used abroad. Bears are killed for their gall bladder. Corals and shells are also collected for export.

MAN-WILDLIFE CONFLICT: Man and wildlife conflict is another reason for depletion of biodiversity. Co-existence of man and wildlife exists in certain areas and that will enhance biodiversityMETHODS OF CONSERVATION OF BIODIVERSITYThe concept of conservation of biodiversty encomposes protection and sustained use of all genetic resources whether it is wild or domestic. There are two methods of conservation of biodiversity; a) In-situ conservation (on site) b) Ex-situ conservation (off site)

In-situ conservationIt means the conservation of ecosystem and natural habitat, and the maintenance and recovery of vulnerable populations or species in their natural surroundings.Protected areas such as National parks, Wild life sanctuaries, biosphere reserv are the important needs of in-situ conservation.

NATIONAL PARKSIt is an area which is strictly preserved for the betterment of the wildlife where activities such as foresting, grazing or cultivation not permitted. No private ownership right is allowed.Yellow stone national park is the first national park in the world (1872).Northest greenland national park (1974) is the largest national park in the world.Ex:Jim Corbet National Park Tiger - UP Eravikulam National Park - Nilgiri Tahr -Kerala

WILDLIFE SANCTUARIESIt is an area where protection of certain species get much emphasis.Sanctuaries provide protection and optimum living condition to wild animals.A sanctuary is created by order of a competent authority Ex: PeparaWildlife sanctuary Neyyar Parambikulam

BIOSPHERE RESERVES They are protected areas where all biological species, including wild population native tribals, cultivated plants and domesticated animals are given in protection and multiple land use is permitted.Biosphere are the larger protected areas of natural habitat.They include one or more national park and wildlife sanctuaries.In India there are 15 Biosphere reserves.Ex: Nilgiri biosphere reserve Kerala, TamilNadu, Karnataka Nanda Devi Biosphere Reserve UP Uttarkhand Biosphere Reserve North-West Himalayas

Ex-situ ConservationIt means the conservation of components of biological diversity outside their natural habitats.Endangered species and those are at the verge of extinction are protected here. Ex: Botanical gardens Zoological park (ZOO) Gene bank Gene plasm bank Breeding program