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Biodiversity is defined as the variability among living organisms and the ecological complexes that they are part of. This includes diversity within species, between species and of ecosystems. It also refers to the interrelatedness of genes, species and ecosystems and in turn, their interactions with the environment.

Conservation and sustainable use of biodiversity is fundamental to ecologically sustainable development. It is a part of our daily luves and livelihood and constituyes resources upon which families, communities, nations and future generations depend. 

Biodiversity found on earth consists of numerous distinct biological species which is a product of 4 billion years of eveolution. It is considered to exist at three levels:

  • Genetic Biodiversity : It is the variation in genes within a particular species and allows species to adapt to changing envionments. Each member of a particular species differs from others due to genetic makeup. It is responsible for myriad of shapes, colors and sizes among species. It ensures survival and healthy breeding of species during drastic changes and allows carrying of  desirable genes to future generations.

  • Species Diversity : It is the variation in living organisms on earth which differ from each other in their genetic makeup and are not able to inter-breed. The diversity of species can be measured through its richness, adundance and types. The areas which are rich in diversity are called Hotspots. Closely related species have common hereditary characteristics which can be observed in humans and chimpanzees sharing more than 98% of common gene sequence. 

  • Ecosystem/Community Diversity : Earth has a variety of different ecosystems based on cumulative factors of climate, vegetation and geography of a region.  Each of the factors influence the other and each species adapts to a particular kind of environment. Each ecosystem has a collection of distinctive but interlinked species. This type of diversity is generally descibed for a specific geographical region but the boundaries of these ecosystems in not rigidly defined. A species best adapted to a particular environment becomes dominant in it.

How do we measure biodiversity?

Biodiversity is measured by 2 major components:

1. Species Richness : It is the number of species found in a community. It has 3 levels of heirarchy starting from diversity within in particular ecosystem (Alpha), diversity between ecosystems (Beta) and overall diversity within a region (Gamma)

2. Species Evenness : It is a measure of proportion of species at a given site. A low evenness score means only few species dominate a particular region. 

Importance of Biodiversity

The importance of biodiversity is best viewed in terms of benefits we get from it directly or indirectly. It can be categorised into:

a) Ecological Values : Since all living organisms are supported by interactions among them and ecosystems, the depletion of biodiversity makes an ecosystem unstable and vulnerable to extreme events. The loss of biodiversity weakens the natural cycles of an ecosystem which help in mainitainance of essential building blocks of plants and animals namely the elements - carbon, oxygen, nitrogen and hydrogen. This disturbs the cycling of nutrients and other necessary elements required for life.

b) Economic Values : Nature provides us with raw materials needed for survival and is the basis of global economy. A robust and diverse ecosystem has variety of plants and animal products that have medicinal and commerical uses. They also help in climate regulation, water purification, soil regeneration, nutrient recycling, waste recirculation, crop pollination and production of timber, fodder and biomass.

c) Cultural Values : Human culture around the world reflect the connection with natural world. A biodiverse ecosystem is worshipped and considered essential for survival and provides a strong spriritual bond to mankind. It is visible in presence of sacred groves which are preserved by the locals around the world.  

Causes of Biodiversity Loss

Biodiversity loss occours when the essential habitat of a species is damaged or the species is exploited for economic gains or when it is excessively hunted for sport and food. Extinction of a species may also be caused due to environmental factors such as unneccesary substitutions, pathogens and other biological causes which may be natural or human induced. 

a) Natural Causes : It includes aspects such as floods, earthquakes, landslides, rivalry among species, invasiveness, lack of pollination and other diseases. 

b) Man-Made Causes : Humans have impacted the habitat destruction, uncontrolled commerical explitation, poaching, extension of agriculture, excessive pollution, destruction of coastal areas and wetlands. 

Modes of Biodiversity Conservation

a) Ex-Situ Conservation : This is the process of conservation of biodiversity outside the areas of their natural occurence. Animals and plants are reared and protcted in zoological parks and botanical gardens. Animals are usually reintroduced to their natural habitat after they've matured in a safer environment. Along with zooza and botanical gardens, seed banks and horticultre parks are important centres of ex-situ conservation. 

b) In-Situ Conservation : It involves conservation of animals and plants in their natural habitats by establishing protected areas such as national parks, sanctuaries, biosphere reserves, reserved forests and protected forests. 


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