Biodiversity refers to the variety of genes, species, and ecosystems on Earth. It is divided into genetic, species, and ecological diversity. Genetic diversity refers to variety within a species. Species diversity measures variety between species in a region. Ecological diversity looks at diversity at the community and ecosystem levels. Biodiversity provides humans with resources and is declining at an alarming rate due to habitat loss, overexploitation, invasive species, and co-extinctions. Conservation efforts focus on in situ protection of habitats and species in their natural environment and ex situ conservation of threatened species in special care units.

1. BIODIVERSITY

2. BIODIVERSITY
The occurrence of different types of genes, gene
pools, species, habitats and ecosystems in a particular
place and various parts of earth is called biodiversity.
The term biodiversity was coined by WALTER
G.ROSEN in 1985.
Biodiversity is divided into three levels:
1. Genetic diversity
2. Species diversity
3. Ecological diversity

3. GENETIC DIVERSITY
It is the measure of variety in genetic information contained
in the organisms. It enables a population to adapt to its environment.
EXAMPLE:
Genetic diversity in Dogs:
BEAGLE CHIHUAHUA ROTTWEILERS BOXER

4. SPECIES DIVERSITY
It is the measure of the variety of species and their relative
abundance present within a region.
EXAMPLE:
Monkeys, dragon flies, meadow beauties, etc. are all different
species found in the same community.
Saki Monkey Golden Skimmer Meadow Beauty

5. ECOLOGICAL DIVERSITY
It is a measure of the diversity at community and
ecosystem levels. They represent the local, unique
habitat and regional components of species diversity.
Ecological diversity is the largest scale of biodiversity,
and within each ecosystem, there is a great deal of
both species and genetic diversity.
EXAMPLE:
An example of ecological diversity on a global scale
would be the variation in ecosystems, such as deserts,
forests, grasslands, wetlands and oceans.

6. GLOBAL SPECIES DIVERSITY
More than 70% of all the species
are animals, while plants account
for about 22% of the total.
Amongst animals, insects comprise
more than 70% that means, out of
every 10 animals on this planet, 7
are insects on this earth.
India has only 2.4% of world’s land
area and 8.1% global species
diversity. There are nearly
45,000 plants and twice as many
animals.

7. IMPORTANCE OF BIODIVERSITY
Human beings derive direct economic benefits from nature,
like food, firewood, fibre, construction material, industrial
products (resins, gums, dyes, tannins, etc.) and medicinally
important products.
More than 25% of the drugs are derived from plants and
about 25,000 species of plants are used by native people as
traditional medicines.
Biodiversity plays a major role in maintaining and sustaining
supply of goods and services from various species as well as
ecological systems.

8. LOSS OF BIODIVERSITY
The current rate of global biodiversity loss is estimated to be
100 to 1000 times higher than the normal extinction rate and
expected to still grow in upcoming years.
Some extinct species are:
Dodo Quagga Thylacine

9. CAUSES OF BIODIVERSITY LOSSES
Habitat loss and fragmentation
Destruction of habitat is the primary cause of extinction of
species. When large sized habitats are broken or
fragmented due to human settlements, building of roads,
digging of canals, etc., the population of animals requiring
large territories and some animals with migratory habitats
declines.
Over exploitation
When biological system is over exploited by humans for the
resources, it results in degradation and extinction of the
resources

10. Alien (exotic) species invasions
Some exotic species when introduced unintentionally,
become invasive and cause harmful impact, resulting in
extinction of the indigenous species.
Co-extinctions
When a species become extinct, the plant and animal
species associated with it, also becomes extinct.

11. BIODIVERSITY CONSERVATION
There are two basic approaches for conservation of
biodiversity:
1. In situ Conservation
This approach involves protection of species in their natural
habitat.
(a)Biodiversity Hot spots
These are regions of high level of species richness. There are
34 hot spots in the world. These reduce mass extinction by
30%.
(b) Protected areas
India has 14 biosphere reserves, 90 national parks and 448
wildlife sanctuaries.

12. (c) Ramsar sites
Ramsar sites are wetlands which are considered to be of
national importance.
Ramsar Convention is an international treaty for conservation
of wetlands.
There are 26 Ramsar sites in India. Some of these are
Ashtamudi wetland, Sambhar lake, Chilka lake, etc.
(d) Sacred Groves
These are forest patches set aside for worship. All the trees
and wildlife within are given total protection by tribal people.
Some of the sacred groves in India are: Khasi and Jaintia
Hills in Meghalaya, Aravalli Hills of Rajasthan, etc.

13. 2. Ex situ Conservation
This approach involves placing threatened
animals and plants in special care units for
their protection.
It is desirable approach to save species from
extinction.