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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