Biodiversity

With 7 billion people living on earth, and many more arriving every day basic human need for fresh water, clean air, food, housing and energy is increasing and this need is fast depleting global and local ecosystems. This unprecedented rate of resource depletion is creating various environmental problems; the Biodiversity crisis is one of them. Biodiversity is a concept open to multiple interpretations and meanings and as such is vaguely defined and understood. The most widely accepted definition is set out in the convention on biological diversity (CBD 1992) in terms of the variety and variability of life. In a simple way biodiversity can be explained as a property of ecosystem related to number of different plant and animal species. In scientific manner biodiversity can be explained as the totality of genes, species and ecosystems in a region.
The first multicellular organisms appeared on earth about 4500 million year ago . Organism began to colonize the land about 440 million year ago . By 290 million year ago the dinosaurs had flourished and died out . at 250 million year ago mammals appeared and Humans arrived on the scene only 1.8 million years ago . On average a species last 1 to 10 million years . The general pattern has been an increase in the number of species , as rate of speciation have exceeded extinction . However , at least five times in the geological past , there have been mass extinctions . We are currently in middle of the sixth wave of extinction and for the first time this extinction is caused by a species known as Human.
To date approximately 1.8 million species have been described , the actual number of species on the earth could be anywhere between 3.6 and 111 million species . With a current knowledge , best guess being 13.6 million species

Importance of biodiversity - Biodiversity is important to people because existence of human being depend on other species and the ecosystem they create. Biodiversity provides -

1. Ecosystem services – like fresh water clean air and productive soil etc, which are necessary for the sustenance of human life on the earth. at the global level ,these life support system include the
· Transfer of energy from sunlight to plants and its distribution throughout food webs
· Storage , release and distribution of carbon by forests ,oceans and the atmosphere , which is essential building block of all life forms
· Cycling of nutrients such as nitrogen and phosphorus between air, water, soil and living organism.
· Water cycle , which purifies and distributes earth’s fresh water
· Oxygen cycle , through which plants and animals exchange carbon dioxide
· Decomposition of waste materials
· Renewal of soil that produce food crops
· Pollination
These above services are provided by the combined actions and relationships of many species within an ecosystem. A loss of biodiversity affects this relationship which in turns affects the ecosystem services. When biodiversity declines within a habitat or geographic area, greater fluctuations in ecosystem cycles tend to occur, and ecosystem becomes less stable. This instability reduces the productivity of the region.

2. Food, medicines and natural products:

Nature provides us with all our food. In total human use about 150 species of plants for food, out of 80,000 potentially edible plants. Because we depend on such a narrow range of plants, out ability to produce and sustain food crop is important for human survival. Buy cross-breeding domestic crops with wild relatives, using genetic variability and natural disease resistance in the wild varieties, a disease resistant species can be formed. When these wild relatives are lost to extinction, with them store houses of genetic information is also lost which was evolved over millennia.
Nature also provides us with medicines that save lives. But, the pharmaceutical potential hidden within the natural world is largely untapped, only 1% of the plant species in rain forests have been tested for their possible pharmaceutical value, and other ecosystems have been largely unexplored as well. Organism yet to be discovered or studied could hold the key to a future cure for some terrible disease If the present rate of species extinction is continued, number of beneficial medicines will be lost forever.
There is a correlation between loss of biodiversity and emergence, resurgence and redistribution of disease . There is safety in biodiversity , species dynamics help to control disease, disease have hosts redistribution of disease. There is safety in biodiversity, species dynamics help to without biodiversity humans are exposed to new pathogens. Many vector’s of disease have evolved to prefer animal hosts to human but once these animals are gone human hosts become their prime host. Many keystone/indicator species are rapidly disappearing all over the world , for example , frogs are disappearing worldwide. Amphibian have lived on this planet for over a hundred million years adapting to many climatic changes . The result of a loss of such an ancient and important species is unknown but frogs ( including tadpoles) are a major predators of invertebrates , many of which are disease vectors such as mosquitoes . A frog can eat over 100 mosquitoes in a night , frogs are also food to variety of larger predators . With out necessary balance of predator and prey relationships vectors will be able to multiply indefinitely in our dangerously unhealthy global ecosystem.
In addition to food , medicine and disease control , the natural world also provides raw materials for clothing, household goods and cosmetics. The world’s forests produce pulp for paper products and wood for construction of houses and furniture.

3. Economic Benefits:

Biodiversity has direct economic benefits; studies have estimated that biodiversity produces between 3 to 33 trillion dollars to the global economy (approximately 11% of world GDP).Though many bio-resources do not enter markets or provide financial income, they contribute significantly too many people’s nutrition and livelihoods. They are particularly important in times of hardship and in marginal areas. especially for the very poor and tribal people. It is estimated that wild foods from common property contribute some 20 % of the nutrition of the poor in dry season , in some part of the our country.

4. Other benefits:

Biodiversity has an intrinsic value beyond its tangible and intangible importance to humans. There is a perceived value in nature beyond health, economics and food. There is, in addition, the spiritual or symbolic significance of human’s place in an intact natural community.