Biodiversity

Contents
• Introduction
• Types of Biodiversity
• Biogeographical classification of India
• Value of Biodiversity
• Global Biodiversity
• Biological diversity at national level
• India as mega-diversity nation
• Hotspots of Biodiversity
• Threats to Biodiversity
• Endangered and Endemic species of India
• Conservation of Biodiversity
 Biodiversity
What does “Bio” means?

Bio = Life
What does “Diversity” means?

Diversity = Variety
INTRODUCTION

The term Biodiversity was first coined by Walter G. Rosen in 1986.

The biosphere comprises of a complex collections of innumerable

organisms, known as the Biodiversity, which constitute the vital
life support for survival of human race.

Biological diversity, abbreviated as biodiversity, represent the

sum total of various life forms such as unicellular fungi, protozoa,
bacteria, and multi cellular organisms such as plants,
fishes, and mammals at various biological levels including
genes, habitats, and ecosystem .
• The word Biodiversity originates from Greek word BIOS = life and
Latin word DIVERSITAS = variety. Therefore, the whole word means
Variety of life.
• It is the variety and variability of life on Earth.
• For any kind of plant or animal- each individual is not exactly the
same as any other, nor are species or ecosystem.
LEVELS OF BIODIVERSITY - The concept of
biodiversity may be analyzed in 3 different levels.

These are

1. Ecosystem diversity

2. Species diversity

3. Genetic diversity
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.
 Ecosystem diversity (contd)
• An example of ecological diversity on a global scale would be the
variation in ecosystems, such
as deserts, forests, grasslands, wetlands and oceans.
• Ecological diversity is the largest scale of biodiversity, and within
each ecosystem, there is a great deal of both species and genetic
diversity.
Species diversity
 A discrete groups 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. Plant species: Apple, Mango, Wheat,
Grapes, Rice etc Animal species: Lion, Tiger, Elephant, Deer etc.
Species richness: Number of different species present in an
ecosystem. Tropical areas have greater species richness as the
environment is conducive for a large number of species
Species evenness: Relative abundance of individuals of each of
those species.
It is possible in an ecosystem to have high species richness, but
low species evenness.
For example: In a forest, there may have a large number of
different species (high species richness) but have only a few
members of each species (low species evenness). Or, there may
be only a few plant species (low species richness) but a large
number of each species (high species evenness).
The species diversity varies in a different geographical location
with tropics having highest and declines as we move towards
poles. The most species-rich environments are tropical
rainforests, coral reefs and ocean bottom zone.
Variation in the type of organisms present in a community is species
diversity
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.
 Genetic diversity (contd.)
• It is important for a healthy population by maintaining different
varieties of genes that might be resistant to pests, diseases or
other conditions.
• New varieties of plants can be grown by cross-breeding different
genetic variants and produce plants with desirable traits like
disease resistance, increased tolerance to stress. This ensures
that at least there are some survivors of a species left.
 Genetic diversity (contd.)
For instance: Dogs are selectively bred to get the desired traits.

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.
(ii) Teak wood varieties: The various teak wood varieties
available are - Indian teak, Burma teak, Malaysian teak etc.
 Biogeographical Classification of India
• It is the division of India according to biogeographic characteristics
i.e., study of the distribution of species, organisms, and ecosystems in
geographic space and through geological time.
• India has a rich heritage of natural diversity. It ranks fourth in Asia
and tenth in the world amongst the top 17 mega-diverse countries in
the world.
• India harbors nearly 11% of the world’s floral diversity comprising
over 17500 documented flowering plants, 6200 endemic species,
7500 medicinal plants and 246 globally threatened species in only
2.4% of world’s land area.
• India is also home to ten biogeographical zones which are Himalayan,
trans-Himalayan, desserts, Deccan peninsula, Gangetic plain, North-
East India, Islands and the Western Ghats.
 Biogeographical Classification of India (contd.)
1. Trans-Himalayas: The trans-himalayas is an extension to the
Tibetean plateau. This region harbors the high-altitude cold desert
in ladakh (Jammuand Kashmir) and Lahaul Spiti (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.
 Biogeographical Classification of India (contd.)
4. Semi-arid: This zone lies between the desert and the Deccan plateau.
It includes the Aravalli hill range. It overs 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.
 Biogeographical Classification of India (contd.)

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
experience 600 mm rainfall annually. Sunderbans 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 Lakshwadeep
islands are included in this but the area of these islands is negligible.
 VALUES of BIODIVERSITY

Direct Values Indirect Values

Social
Consumptive
Ethical
Productive Aesthetic
Option
Ecosystem Service
Consumptive use value: The consumptive use value is
the value placed on nature's products that are consumed directly,
without passing through a market.
Some of these are fuel, food, and drugs and medicine.
Food:
• A large number of wild plants and
animals are consumed by human
beings as food.
• About 80,000 edible plant species
have been reported from wild.
• About 90% of present day food crops
have been domesticated from wild
tropical plants.
• Our agricultural scientists make use of
the existing wild species of plants that
are closely related to our crop plants
for developing new hardy strains.
Fuel:
• Our forests have been used since ages
for fuel wood
• The fossil fuels, coal, petroleum and
natural gas are also products of
fossilized biodiversity.
• Firewood collected by individuals are
not normally marketed, but are directly
consumed by tribals and local villagers,
hence fall under consumptive values.
Drugs and medicines:
• About 75% of the world’s population depends upon plants or
plant extracts for medicines

Drug Source
Penicillin Fungus (Penicillium)
Tetracyclin Streptomyces (Bacteria)
Quinine Cinchona tree
Digitalin Digitalis (foxglove)
Productive use value:
• Productive use value refers to products that are commercially
harvested (sold in a market).

• Its value is estimated at the production end rather than retail

end by adding an inflated cost to the finished product.

• Productive use value is often the only value of biological

resource reflected in national income accounts and may have
a major impact on the national economy.

• Timber, fish, honey, construction materials, mushrooms,

fruits, medicinal plants and game meat sold in a market have
productive use value.
Indirect Values
1. Social value: These values are associated with social life, customs, religion
and psycho- spiritual aspects of the people. Plants like Tulsi, Peepal, Mango,
Lotus are considered sacred and are used in worship. Many animals like cow,
bull, peacock, owl etc. also have significant importance in our psycho-
spiritual arena.

2. Ethical value: It is sometimes also known as existence value. Based on the

concept of “ live and let live” i.e., if we want our human race to survive , then
we must protect all biodiversity, because biodiversity is valuable.

3. Aesthetic value: “Willingness to pay” concept on eco tourism gives

monetary estimate for aesthetic value of biodiversity.

4. Optional value: These values include the potentials of biodiversity that are
presently unknown and need to be explored. For ex. We may have some
potential cure for AIDS or cancer existing within depths of marine ecosystem
or tropical rainforest.
 Global biodiversity
• It is the measure of biodiversity on planet Earth and is defined as the total
variability of life forms.
• Roughly 1.5 million species are known till date which is perhaps 15% or just 2% of
the actual number.
• First 1992”Earth Summit” at Rio de Janeiro (The United Nations Conference on
Environment and Development ), convened to address urgent problems of
environmental protection and socio-economic development.
• Mapping biodiversity has therefore been rightly recognized as
an emergency task in order to plan its conservation and
practical utilization in a judicious manner.
• Terrestrial biodiversity is best described as biomes, which are
largest ecological units present in different geographic areas
and are named after dominant vegetation e.g., tropical
rainforests, tall grass prairies, savannas, desert, tundra etc. The
tropical rainforests are inhabited by teeming millions of species
of plants, birds, amphibians, insects as well, as mammals.
• The silent valley in Kerala is the only place where tropical
rainforest occur.
27
 Biological diversity at national level (Indian
biodiversity)
• India ranks 10th among the plant rich countries while 11th in terms of number of
endemic species of higher vertebrates and 6th among the centers of diversity and
origin of agricultural crops.
• At regional level, biodiversity is categorized into four types based on spatial
distribution:
1. Point richness: Refers to number of species fount at a single point in a given
space.
2. Alpha (α-) richness: Refers to number of species found in a small homogeneous
area.
3. Beta (β-) richness: Refers to rate of change in species composition across different
habitats.
4. Gamma (γ-) richness: Refers to rate of change across large landscape gradients.
 India as Mega-diversity nation
• India is one of the 12 mega-diversity countries in the world.
• The ministry of environment and forests, Government if India records 47,000
species of plants and 81,000 species of animals which is about 7% and 6.5%
respectively of global flora and fauna.
 Hotspots of biodiversity
• Areas which exhibit richness as well as high species endemism are termed as hot
spots of biodiversity. There are 25 such hot spots of biodiversity on a global level
out of which two are present in India, namely the Eastern Himalayas and Western
Ghats. According to Myers et al.(2000) an area is designated as a hotspot when it
contains 0.5% of plant species as endemics(native to).
1. Eastern Himalayas: They display an ultra- varied topography that fosters species
diversity and endemism. In an area of 7298 Km2 about 4250 plant species are
found of which 60% are endemic.
2. Western Ghats: It extends along 17,000 Km2 strip of forests in Maharashtra,
Karnataka, Tamil Nadu and Kerala and has 40% of the total endemic plant species.
62% amphibians and 50% lizards are endemic to Western Ghats.
• The major centers of diversity are Agastyamalai Hills and Silent Valley- the New
Amambalam reserve basin.
 Threats to Biodiversity
The core threat to biodiversity on the planet, and therefore a threat to
human welfare, is the combination of human population growth and
resource exploitation.
The human population requires resources to survive and grow, and
those resources are being removed unsustainably from the
environment.
Some of the major causes and issues related to threats to biodiversity
are:
1. Loss of Habitat: Loss of natural habitat is the single largest cause of
biodiversity loss. Conversion of forests into agricultural lands or
development projects is reason behind it.
2. Poaching: Illegal trade of wildlife products by killing endangered
animals is defined as poaching. Despite ban in trade, furs, horns,
tusks are smuggled every year. Japan, Taiwan, Hong Kong etc. are
major importers of wildlife products.
3. Man wildlife conflicts: Conflicting situation arises when wildlife
start causing damage and danger to man. For instance: In
Sambalpur, Orrisa 195 humans were killed in last 5 years by
elephants. In retaliation villagers killed 98 of them.

Cause for man- animal conflicts:

• Diminishing habitats of tigers, elephants, rhinos etc.;
• Usually weak and injured animals attack man;
• Electric wiring around crop fields get elephants injured and turn
violent.
4. Chemicals in environment: The discharge of toxic synthetic chemicals and
heavy metals into the environment has a huge impact on species abundance
and can lead to extinctions.

For example, nitrogen and phosphorous are important nutrients for plant
growth, but when they concentrate in water systems after being applied as
agricultural fertilizers, they can cause “dead zones” that are unhabitable for fish
and other wildlife.
Also, carbon dioxide is a “natural” component of the atmosphere but is
considered a pollutant when emitted by human industrial activities.

POPs (Persistent Organic Pollutant) are easily incorporated into organisms like
bacteria, phytoplankton, and other invertebrates at the bottom of marine food
chains. As those organisms are eaten by fish, and fish are eaten by marine
mammals, the POPs move up the food chain.
 Endangered species in India
The International Union for Conservation of Nature and natural
resources(IUCN) publishes the Red Data Book which includes list
of endangered species of plants and animals.

Few endangered reptiles, birds, mammals, plant are as follows:

1. Reptiles: Gharial, tortoise, python.
2. Birds: Great Indian Bustard, Peacock, Great Indian Hornbill.
3. Carnivorous mammals: Indian wolf, red panda, sloth bear,
Indian lion, desert cat.
4. Plants: Large number of species of Orchids, rhodendrons,
sandal wood tree.
• Extinct: A species is said to be extinct if not seen in the wild for 50 years
at a stretch. E.g. Dodo, passenger pigeon
• Endangered: A species is said to be endangered if its number has been
reduced to a critical level and if species is not protected or conserved. E.g.
cheetah, spotted owl.
• Vulnerable: A species is said to be vulnerable if its population is facing
continuous decline due to overexploitation or habitat destruction. E.g.
Common leopard.
 Endemic species of India
Endemic Species are species of those plants and animals which
are found in just one particular region and nowhere else in the
world.
India having two Biodiversity hotspots possesses large number
of endemic species.
Out of 47,000 plants, 7000 are endemic. 62% flora, is restricted
mainly to Himalayas, Khasi Hills and Western Ghats.
Total of 81,000 species of animals is endemic.
Western Ghats are rich in phibians (frogs,
toads) and reptiles (lizards).
 Conservation of Biodiversity
The following measures should be taken to conserve biodiversity
1. Illegal hunting and trade of animals and animal products should
be stopped immediately
2. People-at-large should boycott purchasing coats, purse or bags
made of animal skin
3. Bio-diversity laws should be strengthened.
4. Adequate crop and cattle compensation schemes must be
started
5. Solar powered fencing must be provided with electric current
proof trenches to prevent animals from entering fields.
6. Cropping pattern should be changed near the forest borders
7. Adequate food and water should be made available for wild
animals within forest zones.
8. Development and construction work in and around forest region
must be stopped.
 Conservation of Biodiversity
Due to their genetic, commercial, medical, ecological and
optional importance emphasizes need to conserve biodiversity.
There are two approaches to conserve biodiversity:
1. In situ conservation (within habitat): This is achieved by
protection of wild flora and fauna in nature itself. E.g.
biosphere reserves, national parks, sanctuaries reserve
forests etc.
2. Ex situ (outside habitats): This is done by establishment of
gene banks, seed banks, zoo, botanical gardens, culture
collections etc.
Biosphere reserves: They cover large areas (>5000
sq.km.) They are normally used to protect species for a long
time.

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
vi. Biosphere reserves function as an open system and
changes in land use are not allowed.
vii. No tourism and explosive activities are allowed in
biosphere reserves.
A national park: It is an area dedicated for the conservation
of wildlife along with its environment.
It covers an area ranging from 100 to 500 sq.km.

• One or more national parks may exist within a biosphere

reserve.
• A national park is used for enjoyment through tourism,
without affecting the environment.
• It is used to protect, propagate and develop wildlife.
Grazing domestic animals inside national parks is
prohibited
• All private rights and forestry activities are prohibited
inside a national park
Wildlife sanctuary is an area that is reserved for the
conservation of animals only.

i. It protects animals only

ii. It allows operations such as harvesting of timber,
collection of forest products, private ownership rights
and forestry operations, provided it does not affect
animals adversely
Advantages of in-situ conservation
i. It is cheap and convenient
ii. Species get adjusted to natural disasters like drought,
floods, forest fires etc.

Disadvantages of in-situ conservation

i. A large surface area of earth is required to preserve
biodiversity
ii. Maintenance is not proper due to shortage of staff
and pollution
Methods of ex-situ conservation

National Bureau of Plant Genetic Resources (NPBGR)

It is located in New Delhi and uses the Cryopreservation Technique
to preserve agricultural and horticultural crops. Cryopreservation
technique involves using liquid nitrogen at -196 C. Varieties of rice,
turnip, radish, tomato, onion, carrot, chili, tobacco have been
successfully preserved for years using this technique.
National Bureau of Animal Genetic Resources (NPAGR)
It is located in Karnal, Haryana and preserves the semen of
domesticated bovine animals.

National Facility for Plant Tissue Culture Repository (NFPTCR)

In this facility, conservation of varieties of crop plants or trees is
done using tissue culture. This facility has been created within the
NPBGR.
Advantages of Ex-situ conservation

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

and attention
2. In captive breeding the 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