© Saurabh

E.V.S - UNIT 3

Q1. ​Levels of Biodiversity

Biodiversity is the variety of all living things; the different plants, animals and
microorganisms, the genetic information they contain and the ecosystems they form.
Levels of biodiversity
Biodiversity is usually explored at three levels - genetic diversity, species diversity
and ecosystem diversity. These three levels work together to create the complexity
of life on Earth.
Genetic diversity
Genetic diversity is the variety of genes within a species. Each species is made up of
individuals that have their own particular genetic composition. This means a species
may have different populations, each having different genetic compositions. To
conserve genetic diversity, different populations of a species must be conserved.
Species diversity
Species diversity is the variety of species within a habitat or a region. Some habitats,
such as rainforests and coral reefs, have many species. Others, such as salt flats or
a polluted stream, have fewer.
Ecosystem diversity
Ecosystem diversity is the variety of ecosystems in a given place. An ecosystem is a
community of organisms and their physical environment interacting together. An
ecosystem can cover a large area, such as a whole forest, or a small area, such as a
pond.

Q2. ​Bio-geographical classification of India

India has different climate and topography in different parts and hence is termed as
a mega diversity country. India occupies 10th place among plant rich countries of
the world. Our country can be conveniently divided into eight major regions, based on
the geography, climate and pattern of vegetation seen and the communities of
Mammals, Birds, Reptiles, Amphibia, Insects and other Invertebrates that live in
them.
1. ​Himayalas:​ The Himalayas are the northern boundaries of India. The entire
mountain chain is running from Kashmir in the North-west to Assam in the
north-east.
2. ​Desert:​ The extremely dry area west of the Aravalli hill range comprises both the
salty desert of Gujarat and the sandy desert of Rajasthan. The kinds of deserts found
in India are:
(I) The desert of western Rajasthan
(II) The desert of Gujarat
(III) High-altitude cold desert of Jammu & Kashmir and Himachal Pradesh.
3. ​Gangetic Plain​: This plain covers the area between the south Himalayas to the
tropic of cancer. These Plains were formed by the Ganges river system and are
relatively homogeneous. This region experience 600 mm rainfall annually.
4. ​The Deccan Plateau:​ This zone lies between the desert and the Deccan plateau.It
is a large triangular plateau south of the Narmada valley.It is the one of largest zones
covering the southern and south-central plateau with mostly deciduous trees.
5. ​North-East India​: These are pains and Non-Himalayan ranges of northeastern
India and have a wide variety of vegetation.
6.​Western Ghats​: The Western Ghats are a mountain range that runs along the
western cost of India. They are a range extending north-south from southern tip of
Gujarat in the north to Kanyakumari in the south.
7. ​Islands​: The Andaman and Nicobar Islands in the Bay of Bengal has almost 300
big and small islands.
8. ​Coasts:​ India has a large coastline distributed both to the east and west with
distinct differences between the two. The Lakshwadeep islands are included in this
but the area of these islands is negligible.

Q3. Values of biodiversity.

Some of the major values of biodiversity are as follows:
1. Environmental Value:
The environmental value of biodiversity can be found by examining each ecosystem
process and identifying the ecosystem services that result. For instance, in wetlands
the vegetation captures water- carried sediment and the soil organisms break down a
range of nutrients and pollutants washed into the area.
2. Social Value:
The social value of biodiversity includes aesthetic, recreational, cultural and spiritual
values. Apart from the local use or sale of products of biodiversity there is the social
aspect in which more and more resources are used by affluent societies.
3. Ecosystem Services:
These services support human needs and activities.
Ecosystem service includes:
a. The production of oxygen by land based plants and marine algae;
b. The production and maintenance of fertile soil.
c. Pest control in agricultural land.
d. Greenhouse gas reduction.
e. Maintenance of habitats for native plants and animals;
4. Economic Value:
The economic potential of biodiversity is immense in terms of food, fodder,
medicinal, ethical and social values.
It is the source of food for all animals and humans.
The major fuel sources of the world including wood and fossil fuels have their origin
due to biodiversity.
5. Consumptive use value:
Many people around the world still depend on wild species for most of their needs
like food, shelter and clothing. The tribal people are completely dependent on the
forests for their daily needs.
6. Productive Use Value:
This is assigned to products that are commercially harvested and marketed.
Biodiversity represents the original stock from which new varieties are being
developed.
7. Ethical and Moral Value:
It is based on the principle of ‘live and let others live’. Ethical values related to
biodiversity conservation are based on the importance of protecting all forms of life.
8. Aesthetic Value:
The beauty of our planet is because of biodiversity, which otherwise would have
resembled other barren planets dotted around the universe. Biological diversity adds
to the quality of life and provides some of the most beautiful aspects of our existence.

Q4. Threats to biodiversity

Some of the main threats to biodiversity are:
1. Human Activities and Loss of Habitat:
Human activities are causing a loss of biological diversity among animals
and plants.
Biodiversity loss can result from a number of activities,
including:
(a) Habitat conversion and destruction;
(b) Over-exploitation of species;
(c) Disconnected patches of original vegetation; and
(d) Air and water pollution.

2. Deforestation:
Forest ecosystems are being cleared and degraded in many parts of the
world. Forest ecosystems contain about three times the amount of
carbon currently present in the atmosphere and about one-third of this
carbon is stored above ground in trees and other vegetation and
two-third is stored in the soil.
When forests are cleared or burned, much of this carbon is released into
the atmosphere.
3. Desertification:
The direct cost of deforestation is reflected in the loss of valuable plants
and animal species. Desertification process is the result of poor land
management which can be aggravated by climatic variations.
4. Marine Environment:
Oceans play a vital role in the global environment. Covering 70 per cent
of the earth’s surface, they influence global climate, food production and
economic activities. In coastal areas, where human activities are
concentrated, pollution, over-exploitation of resources, development of
critical habitats such as wetlands, and mangroves, and water-flow from
poor land-use practices have led to drastic reductions in near shore
fisheries production and aquatic biodiversity.
5. Climate Change:

As climate warms, species will migrate towards higher latitudes and

altitudes in both hemispheres. The increase in the amount of CO2 in the
air affects the physiological functioning of plant and species
composition.

Q5. Endangered and Endemic species of India

ENDANGERED SPECIES OF INDIA
A plant, animal or microorganism that is in immediate risk of biological extinction is
called endangered species or threatened species.
Endemic species​ are animals or plants exist only in some particular areas and
nowhere else in the world. In India, endemic species are mostly in Himalaya and
Western Ghats.

Some examples of endangered and endemic species are:

1. Asiatic Lion, Gir Forest
2. Sangai Deer, Loktak Lake
3. Lion Tailed Macaque, Western Ghats
4. Kashmir Stag, Kashmir Valley
5. Nilgiri Blue Robin, Nilgiri Mountain

Q5. Conservation of biodiversity, global and national efforts.

There are two types of biodiversity conservation:
1. In-situ conservation and
2. Ex-situ conservation

IN-SITU CONSERVATION
In-situ conservation involves protection of flora and fauna within its natural habitat. The
natural habitats or ecosystems under in-situ conservation are called "protected areas".

1. Biosphere reserves
2. National parks
3. Wildlife sanctuaries
4. Gene sanctuaries

Biosphere reserves​ cover large areas (>5000 sq.km.) They are normally used to protect
species for a long time​. ​Their main roles are:
Protect endangered species
Protect maximum number of species and communities.
A ​national park​ is an area dedicated for the conservation of wildlife along with its
environment.It is used to protect, propagate and develop wildlife.
Wildlife sanctuary​ is an area that is reserved for the conservation of animals only.

1. It protects animals only

2. It allows operations such as harvesting of timber, collection of forest products etc.

Gene sanctuary​ is an area where plants are conserved.

Advantages of in-situ conservation

1. It is cheap and convenient

2. Species get adjusted to natural disasters like drought, floods, forest fires etc.

Disadvantages of in-situ conservation

1. A large surface area of earth is required to preserve biodiversity

2. Maintenance is not proper due to shortage of staff and pollution.
Ex-situ conservation

Ex-situ conservation involves protection of flora and fauna outside their natural habitats. This
type of conservation is mainly done for conservation of crop varieties and wild relatives of
crops.

1. Ex-situ conservation involves maintenance and breeding of endangered plant and

animal species under controlled conditions
2. It identifies those species that are at a high risk of extinction
3. It prefers species that are important for man in the near future among the endangered
species.

Important centers of ex-situ conservation​:

1. Botanical gardens
2. Seed banks
3. Microbial culture collections
4. Tissue and cell cultures
5. Museums and
6. Zoological gardens

Advantages of Ex-situ conservation

1. Survival of endangered species is increasing due to special care and attention

2. In captive breeding animals are assured of food, water, shelter and security thereby
have a longer life span
3. It is carried-out in cases of endangered species that do not have any chance of survival
in the wild

Disadvantages of Ex-situ conservation

1. It is an expensive method
2. Freedom of wildlife is lost
3. Animals cannot survive in the natural environment.

--------------------------------------------------------------------------------------------------------------