BIODIVERSITY

INTRODUCTION

The number and variety of plants, animals and other organisms that exist in an
ecosystem is known as biodiversity.

Biodiversity can be defined as the variability and variety of life on our planet.

It is a measure of the variety of organisms present in different ecosystems The

richness of biodiversity depends on the climatic conditions and area of the region.

India has 2.4% of land area on the Earth, according to the species diversity it
carrying 8.1% of known species. India is one of the Seventeen mega diversity
countries of the world.

70% of the species in the world are animals and 22% of the species are plants,
according to animal’s insect number is 70%.

There are 3 types of biodiversity

Genetic diversity:

genetic variability or diversity within a species

Species diversity:

diversity between different species

Ecosystem diversity:

diversity between different region

1 Genetic diversity –
 A species with different genetic characteristics is known as a sub-species
or "genera".
 Genetic diversity is a measure of the variety of versions of same gene
within individual species.
 Within individual species, there are varieties, that are slightly different
from one other. These differences are due to differences in the
combination of genes.
 Genes are the basic units of hereditary information transmitted from one
generation to the other.
Ex: (i) Rice varieties - All rice varieties belong to the species "oryzasativa".
However, there are thousands of rice varieties that show variation at the genetic
level in the form of different size, shape, colour and nutrient content.

2.Species diversity –

 A discrete group of organisms of the same kind is known as species.

 Species diversity is the diversity between different species.
 The sum of varieties of all living organisms at the species level is known
as species diversity.
 Species diversity describes the number of kinds of organisms within
individual communities or ecosystems.
 The biotic component is composed of a large number of species of plants,
animals and microorganisms which interact with each other and with the
abiotic component of the environment.
Ex: The total number of species living on earth is approximately more than 2
million. However, only around 1.5 million are found and assigned
scientific names.
3. Community or Ecosystem diversity
 A set of biotic components (plants, animals and microorganisms) and
abiotic components (soil, air, water, etc.) interacting with each other is
known as an ecosystem.
 Ecosystem or ecological diversity means the richness and complexity of a
biological community, including tropic levels, ecological processes (which
capture energy), food webs and material recycling.
 The diversity at an ecological level or habitat level is known as ecosystem
diversity.
Ex: River ecosystem- Rivers include fish, aquatic insects, mussels and a
variety of plants that have adapted.
 Ecosystem diversity is the aggregate of different environmental types in a
region.
 It explains the interaction between living organisms and physical
environment in an ecosystem.
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.
 It is essential to acquire knowledge about the distribution and environmental
interaction of flora and fauna of India.
 Bio-geographers have classified India into ten bio-geographic zones with each
zone having characteristic climate, soil and biodiversity.
 These zones are described below:
1. Trans-Himalayas: The trans-Himalayas is an extension to the Tibetan
plateau. This region harbors the high-altitude cold desert in Ladakh
(Jammu and Kashmir) and Lahaul Spits (Himachal Pradesh). It accounts
for 5.7% of the country's landmass.
2. Himalayas: 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. The Himalayas comprise of a diverse range of
biotic provinces and biomes. The Himalayas cover 7.2% of the
country's landmass
3. Desert: The extremely dry area west of the Aravalli hill range, is
comprising both the salty desert of Gujarat and the sandy desert of
Rajasthan. Deserts occupy around 6.9% of the country's land mass.
The kinds of deserts found in India are:
a. The desert of western Rajasthan
b. The desert of Gujarat
c. The high-altitude cold desert of Jammu & Kashmir and Himachal
Pradesh. The Indian deserts have more diversified fauna.
4. Semi-arid: This zone lies between the desert and the Deccan
plateau. It includes the Aravalli hill range. It covers approximately
15.6% of the country's landmass.
5. 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. The mountains cover an area of about 160,000 sq. km. This
ghat section covers an extremely diverse range of biotic provinces and
biomes. It covers about 5.8% of the country's landmass.
 6. Deccan plateau: It is a large triangular plateau south of the Narmada
valley. Three sides of the plateau are covered by mountains slopes
towards east. Satpura mountains cover the north while western Ghats
cover the west side and eastern Ghats cover the eastern side of the
plateau. It is the one of largest zones covering the southern and south-
central plateau with mostly deciduous trees. It covers 4.3% of the
country's land mass.
7. 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
experiences 600 mm rainfall annually. Sundarbans forests are located
in this region and it covers 11% of the country's land mass.
8. North-east India These are pains and non-Himalayan ranges of
northeastern India and have a wide variety of vegetation. It covers
around 5.2% of the country's land mass.
9. Islands The Andaman and Nicobar Islands in the Bay of Bengal has
almost 300 big and small islands. Among these, only five islands are
inhabited. Only tribes are found in the island of Nicobar. These islands
have a highly diverse set of biomes and occupy 0.03% of the country's
biomass.
10. Coasts India has a large coastline distributed both to the east and west
with distinct differences between the two. The Lakshadweep islands are included
in this but the area of these islands is negligible.

THREATS TO BIODIVERSITY
 Any disturbance in a natural ecosystem tends to reduce its biodiversity.
 Waste generated due to increase in human population and industrialization spoils
the environment and leads to decreased diversity in biological species.
 Any change in the system leads to a major imbalance and threatens the normal
ecological cycle.
 The major threats to biodiversity include habitat loss and degradation, pollution,
overexploitation of resources, invasive species, and climate change.
 These threats are often interconnected and driven by human activities that
disrupt ecosystems and endanger species.
 Pollution:
  Air, water, and soil pollution from industrial and agricultural activities, as well as
plastic pollution, can harm organisms and disrupt ecosystems. Pollution can
contaminate food sources, alter habitats, and directly poison species.
 Overexploitation of Resources:
 This includes unsustainable logging, fishing, and hunting, which can deplete
populations of species and even drive them to extinction. Overfishing, for
example, can collapse fish populations and disrupt marine ecosystems.
 Invasive Species:
 The introduction of non-native species into new environments can outcompete
native species for resources, prey on them, or introduce diseases, leading to
declines in native biodiversity.
 Climate Change:
 Rising temperatures, altered precipitation patterns, and sea-level rise are
impacting ecosystems worldwide. Species may not be able to adapt to these rapid
changes, leading to range shifts, reduced populations, and even extinctions.
 Deforestation: Loss of habitat is mainly caused by deforestation activities.
Forests and grasslands are cleared for conversion into agriculture lands or
settlement areas or developmental projects. Forests and grasslands are natural
home to thousands of species which disintegrate due to loss of their natural
habitat.
 Destruction of wetlands: Wetlands, estuaries and mangroves are destroyed due
to farming, filling and pollution that cause loss of biodiversity
 Production of drugs: Pharmaceutical companies collect wild plants for the
production of drugs leading to extinction of several medicinal plant species.
 Illegal trade: Illegal trade of wildlife reduces biodiversity leading to habitat loss.

Developmental activities: Construction of dams in forest areas coupled with the

discharge of industrial effluents kills birds and other aquatic life.

ENDANGERED SPECIES OF INDIA:

A plant, animal or microorganism that is in immediate risk of biological extinction is

called endangered species or threatened species. In India, 450 plant species have been
identified as endangered species. 100 mammals and 150 birds are estimated to be
endangered. India's biodiversity is threatened primarily due to:
1. Habitat destruction
 2. Degradation and
3. Over exploitation of resources

 The IUCN (international union for conservation of natural resource) RED-data

book contains a list of endangered species of plants and animals. It contains a
list of species of that are endangered but might become extinct in the near
future if not protected.
 Some of the endangered animals found in India are:
1. Asiatic cheetah
2. Asiatic Lion
3. Asiatic Wild Ass
4. Bengal Fox
5. Gaur
6. Indian Elephant
7. Indian Rhinoceros
8. Marbled Cat
9. Markhor
Extinct species is no longer found in the world.
Endangered or threatened species is one whose number has been reduced to a critical
number. Unless it is protected and conserved, it is in immediate danger of extinction.
Vulnerable species is one whose population is facing continuous decline due to habitat
destruction or over exploitation. However, it is still abundant.

HOTSPOTS OF BIODIVERSITY
Rare species is localized within a restricted area or is thinly scattered over an extensive
area.

1. . Himalayas:
Includes parts of northeastern India, Bhutan, and Nepal, known for its high-altitude
biodiversity, including endangered species like the snow leopard and red panda.
2. Indo-Burma:
Encompasses northeastern India, Myanmar, and parts of Southeast Asia, rich in
amphibians, birds, and reptiles.
3. Western Ghats:
 Stretches along the western coast of India, known for its unique flora and fauna,
including the Nigiri Thar and Lion-tailed Macaque.
4. Sunderland:
Includes the Nicobar Islands and parts of Southeast Asia, known for its marine
biodiversity and unique terrestrial species.

Conservation Methods

 factors like pollution, soil erosion, evolution of urbanization, industrialization,

population, and resources depletion lead to the loss of wild life.
 Loss of wild life directly impacts the ecosystem and food chains
 biodiversity conservation plays an important role in the quality of life of all
living organisms.
 The protection and management of biodiversity in obtaining sustainable
development of resources are called wild life conservation
Two types of methods are employed to conserve biodiversity. They are
1. In-situ Conservation
2. Ex-situ Conservation
In-situ Conservation
 In this method preservation and protection of the species in their natural
habitat.
 It is budget related and convenient method of conserving wild life.
 A large number of living organisms can be conserved simultaneously.
 Organisms can evolve better and can easily adjust to different
environmental conditions.
Different methods of In-situ conservation include

 biosphere reserves,
 national parks
 wildlife sanctuaries
Biosphere reserves: They cover large areas (>5000 sq.km.) They are normally used
to protect species for a long time. The Nilgiri Biosphere Reserve was the first biosphere
reserve in India established in the year 1986. It is located in the Western Ghats. the roles
of biosphere reserves are listed below:

i. Long-term survival of evolving ecosystem

ii. Protect endangered species
 iii. Protect maximum number of species and communities
iv. Serve as site of recreation and tourism
v. May also be used for educational and research purposes
national parks

There are a total104 national parks maintained in India, These Biosphere

reserves are small reserves that are protected and maintained by the
government. Its boundaries are well protected, here human activities such
as grazing, forestry, habitat, and cultivation are restricted.

The largest National Park in the world is Greenland National Park, located in
Greenland. And the largest national park in India is the Hemis National Park,
located in Jammu and Kashmir

wildlife sanctuaries

The regions which are having more wild animals in India and maintained by government.
Human activities such as timber harvesting, cultivation, collection of woods and other
forest products are allowed here as long as they do not interfere with the conservation
project. tourists visit also allowed these places for recreation.

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. Gene banks
4. Microbial culture collections
5. Tissue and cell cultures
 6. Zoological gardens
India has more than 164 zoological parks having 3000 species and 1500 botanical
Garden and arboreta having more than 80,000 species

 Cryopreservation is the method of keeping the live cells, tissues and

other biological samples in a deep freeze at sub-zero temperatures. The
sample is commonly kept at −196°C.
 In this process, biological materials including cells, spermatozoa, tissues,
ovarian tissues, pre-implantation embryos, organs kept in extremely cold
temperatures without affecting the cell’s viability.
 Dry Ice and liquid nitrogen are generally used in this method.
 Cry protective agents such as glycerol, FBS, salts, sugars, glycols are
added to the samples.

GENE BANKS

Gene banks are a type of biorepository that preserves genetic material. For
plants this is done by in vitro storage, freezing cuttings from the plant, or
stocking the seeds. The pollen also stored in liquid nitrogen this method is
useful for crossbreeding.

According to the National Bureau of Plant Genetic Resources, there are 10

Regional gene banks across the country at Akola (Maharashtra), Bhowli
(Uttarakhand), Cuttack (Odisha), Hyderabad (Telangana), Jodhpur
(Rajasthan), Shillong (Meghalaya), Ranchi (Jharkhand), Shimla (Himachal
Pradesh), Thrissur (Kerala) and Srinagar (Jammu and Kashmir

SEED BANK

More than 1,000 seed banks exist around the world, varying in type, size and
focus. The largest seed bank in the world is the Millennium seed bank in
Sussex, the seeds are typically kept at low humidity and in cold conditions -
around -20°C. This helps to preserve the seeds, ensuring they can still grow
when they are needed later, it’s a type of gene bank here seeds are stored
for genetic diversity