Tuesday 19 February 2013

Biodiversity


Biodiversity

The variety or variability of organisms and ecosystem is referred to as biodiversity. 
The existence of million of plants, animals, and micro-organisms, their genetic backgrounds, and the complex ecosystems to which they belong show the immense biodiversity present in the biosphere.
Types of Biodiversity
Genetic diversity - Diversity of genes within a species, i.e., genetic variability among the populations and the individuals of the same species.
Species diversity- Diversity among species in an ecosystem. ‘Biodiversity hotspots’  are excellent examples of species diversity.
Ecosystem diversity- Diversity at a higher level of organization, i.e., the ecosystem. It concerns the variety of ecosystems on Earth.
Value of  Biodiversity
Survival
Health and healing
Food security
Productive value
Ethical value
Aesthetic pleasure
Ecological services
Hotspots of Biodiversity
Hotspots are the richest and the most threatened reservoirs of plant and animal life on earth.
Hotspots are classified on the basis of three criteria :
The number of species present
The number of those species that exist exclusively in the given                                                      ecosystem
The degree of threat they face
Endangered Species
The species which are at the verge of extinction are known as endangered species. For example
Asiatic elephant
Great Indian Rhino
Endemic Species
The species which are confined to a particular region are known as endemic species.
These species remain limited in their distribution because of certain geographical barriers, such as sea, valley, mountain, etc.
Threats to Biodiversity
Unplanned development and habitat destruction
Poaching
Environmental pollution
Global climate change
Invasion by introduced species
Nature of legal systems
Mining
Exploitation of water resources
Eutrophication
Waste disposal
Conservation of Biodiversity
In situ Conservation
National parks
Wildlife sanctuaries
Biosphere reserves
Ex situ Conservation
Gene banks
Botanical gardens
Aquaria
Tissue culture technique
DNA technology
Biodiversity at Global  Level
On the Basis of  Vegetation
Arctic  Zone
Northern Temperate  Zone
South Temperate Zone
Tropical  Zone
On the Basis of  Fauna
 
Oriental Region
Australian Region
Neotropical Region
Nearctic Region
Paleartic Region
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 




 
 

 

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