Wednesday, September 18, 2013

Biodiversity

BIODIVERSITY

Biodiversity or biological diversity is a term used to describe life on earth.  It refers to the wide variety of ecosystems and living organisms (plants, animals, their habitats and their genes).

Biodiversity is the foundation of life on earth. It is essential for the functioning of ecosystems. We depend on biodiversity for our security and health. It affects our social relations and gives us freedom and choice.

Biodiversity is extremely complex, dynamic and varied. Biodiversity occurs both on land and in water. Biodiversity is difficult to measure precisely. There are many measures of biodiversity. Species richness (number of species in a given area) is an important metric concerning the diversity of life. 

Genetic diversity- a population with many different genotypes or genotype combinations
Species diversity- a biome or ecosystem with many differerent species
Ecosystem diversity- a biome with many different ecosystems

Genetic diversity is how much genetic variation there is in a population. Genetic diversity is related to the ability of a species to adapt to a changing environment.

Species diversity is a measure of the diversity within an ecological community that incorporates both species richness (the number of species in a community) and the evenness of species abundances. Species diversity is one component of the concept of biodiversity.

Ecosystem diversity is the global or continental distribution of ecosystems of different types. Ecosystem diversity is conditioned by vegetation, climate, biogeography and influence of human beings. Eg: Forest
ecosystem, Desert ecosystem, Tundra ecosystem, Coastal ecosystem, etc.

Value of biodiversity is classified into:
             I.      Direct values and
          II.      Indirect values

Direct value of biodiversity:
Biodiversity has direct consumptive use in
  1. Agriculture
  2. Medicine and
  3. Industry.

Two types of direct values are
  1. Consumptive use value and
  2. Productive use value

Consumptive use value is placed on nature’s products that are consumed directly, without passing through a market or they are harvested and consumed directly.
Ex: Firewood, Food and Meat (from hunting in the wild)

The following are the disadvantages associated with consumptive use value
  1. Over-exploitation of wildlife in developing countries.
  2. Loss of traditional controls on hunting and
  3. Loss of wildlife populations at productive levels.

Productive use value refers to products that are commercially harvested and sold in a market. Its value is estimated at the production end, rather than the retail end. Productive use value is the value of biological resources reflected in national income accounts and may have a major impact on the national economy.
Ex: Timber, Fish, Honey, Mushroom, Fruits, Meat and Medicinal plants sold in a market have productive use value.

Indirect value of biodiversity:
The indirect effects of biodiversity are intangible and difficult to quantify. These are described below:
  1. Social and cultural value: Few plants and animals are considered sacred and worshipped in India. Ex: Tulsi, Peepal, Cow, Snake, etc. Wild life in the forest is given cultural value. Ex: Tiger is the national animal, Peacock is the national bird and Lotus is the national flower.
  2. Ethical value: In order to conserve biodiversity, this ethical value is laid down saying, “All life forms must be preserved”. This value is linked to human existence as biodiversity is directly related to the survival of the human race. Moreover, all species have a moral right to exist.
  3. Aesthetic value: This value is indicated by the pleasure we experience when we see a beautiful landscape. These landscapes also provide ample opportunities for recreational activity like bird watching, photography, etc. It promotes eco-tourism and generates revenue from zoological parks, botanical gardens, national parks, etc.
Ex: Ecotourism, etc.
  1. Option value: Option values are the unexplored or unknown potentials of biodiversity.
Ex: Medicinal plants and herbs play a very important growth in the economic growth of India.
  1. Environment service value: The most important benefit of biodiversity is maintenance of environment services including:
    1. Carbon dioxide fixation through photosynthesis
    2. Maintenance of essential nutrient (C, H, O, P, S) cycles
    3. Maintaining water cycle and recharging ground water
    4. Soil formation and protection from erosion
    5. Regulating climate by recycling moisture into the atmosphere
    6. Detoxification and decomposition of waste.



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