1. Observe the illustration. Do you have doubt like these. Do you think it is necessary
to conserve our biodiversity? Write your opinion in your science diary.
Biodiversity
starts in the
distant past and
it points towards
the future.
Save our
biodiversity
Is it necessary to
conserve
biodiversity? Is it
have that much
importance on
our biosphere?
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BASIC SCIENCE VIII
In our biosphere immense diversity exists not only at the species level but at all
levels of biological organization. Even the common man would find it hard to
believe that there are more than 20,000 species of ants, 3,00,000 species of
beetles, 28,000 species of fishes and nearly 20,000 species of orchids.
Biodiversity is our living wealth.
1.BIODIVERSITY
Biodiversity itself is the combination of two words, Bio (life) and Diversity
(variety). Biodiversity includes all the diverse organisms that inhabit the earth
along with their ecosystems. In simple terms, biodiversity is the number and
variety of organisms found within a specified area. It refers to the varieties of
plants animals and microorganisms.
WALTER G. ROSEN
He was a British environmentalist.
He coined the term biodiversity in
1985
Biodiversity is not found evenly
on earth. It is richer in tropics
than polar regions.
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1.1 Levels of Biodiversity
Biodiversity is the term popularized by the sociobiologist Edward Wilson to
describe the combined diversity at all the levels of biological organisation. Let’s
see what are the levels of biodiversity.
Indicators
• Genetic diversity
• Species diversity
• Ecosystem diversity
Fig. 1
Genetic diversity : A single species might show high diversity at the genetic level over
the distributional range. Genes are the basic building blocks of various life forms.
Genetic diversity refers to the variation of genes within the species.
Ecosystem diversity : It refers to the variety of ecosystems. India is rich in various
ecosystems like desert, rainforest, mangroves, coral reefs, wetlands, estuaries etc.
Species diversity : This refers to the variety of species. It relate to the number of species
in a defined area. For eg: Western Ghats have greater amphibian species than Eastern
Ghats.
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observe the illustration given below and based on the indicators prepare a note on
global biodiversity.
Illustration 2
Indicators
• Which invertebrate group occupy largest and least position in biodiversity?
• Why the number of amphibians reduces rapidly day by day?
• While considering global biodiversity which group of animal found the
most?
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1.2 Importance of Biodiversity.
What are the benefits of conserving biodiversity? In order to understand it, we
must identify the importance of biodiversity on earth.
Observe the illustration given below. On the basis of the illustration, prepare a note
on need for conserving biodiversity.
Illustration 3
Importance
of
biodiversity
Tourism
Boost ecosystem
productivity
Food
Medicine
Recreation
Ecological services
Auxiliary services
There are 12 mega
diversity countries in
the world. India is one
of them.
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Fig 2 Biodiversity then Fig. 3 Biodiversity now
What is the condition of biodiversity around us? What happens to the biodiversity?
Discuss the indicators.
Indicators
• Are all organisms that once existed in your locality still exist?
• Are changes in the agricultural field affect biodiversity?
• Are the changes in lifestyle leads to biodiversity depletion?
• What is the role of humans in biodiversity loss?
Along with the inferences formulated through discussion, collect relevant
supplementary materials and prepare a scientific article. Exhibit it on the wall
magazine.
How do you understand the changes in biodiversity?
• Through observation
• Bird watching
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Observe the fig. 3 and list out the reasons for biodiversity depletion.
•
•
•
1.3 Biodiversity Loss
While it is doubtful if any new species are being added into the earth’s treasury of
species, there is no doubt about their continuing losses. The biological wealth of
our planet has been declining rapidly and the accusing finger is clearly pointing to
human activities.
Illustration 4
Causes of
biodiversity
loss
Alien
species
invasion.
Climate
change.
Habitat loss
and
fragmentation
Over
exploitation
Co-
extinction.
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BASIC SCIENCE VIII
Try to find other causes of biodiversity loss?
▪ Pollution.
▪ Deforestation.
▪
▪
IUCN (International Union for Conservation of Nature) is an organization for
environmental protection, operating in different countries. Under the auspices of
IUCN, a list of endangered plants and animals is prepared every year. This is
known as Red Data Book. Some countries prepare Red Data Book on their own.
This information in Red Data Book is helpful to identify the extent of biodiversity
depletion and to plan out appropriate conservation methods.
RED DATA BOOK
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2. BIODIVERSITY CONSERVATION
Do you think conservation of biodiversity is necessary? Is it necessary to protect
organisms at the verge of extinction? What are the precautions we should adopt to
conserve biodiversity? Discuss and write your inferences.
2.1Biodiversity Conservation Methods
The enormous value of biodiversity due to their genetic, commercial, medical and
aesthetic importance emphasizes the need to conserve biodiversity. There are many
national and international organizations and legal systems working for the
conservation of biodiversity. The Government conserves bio-rich areas declaring
them as protected areas.
Two conservation methods are prevalent. They are:
1. In-situ conservation.
2. Ex-situ conservation.
1. In-situ conservation : Conservation methods in which organisms are protected
in their natural habitats.
2. Ex-situ conservation : Conservation method in which organisms are protected
outside their natural habitats.
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2.1.1 In-Situ Conservation
Biosphere reserve
These are vast regions designed with an aim to protect world’s important
ecosystems, biodiversity and genetic resources.
Biosphere reserves in India
State Biosphere reserve
Uttar Pradesh Nanda devi
Meghalaya Nokrek
Assam Manas
West Bengal Sundarbans
Kerala Nilgiri, Agastyarkoodam
Odissa Great Nicobar and
Similipal
Fig 4
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National park
National parks are designed to protect wild lives along with the protection of
historical monuments, natural resources and geographical features of an area.
National parks in India
National
Park
State Important
wildlife
Kaziranga Assam One horned
Rhino
Gir
national
park
Gujarat Indian lion
Bandipur Karnataka Elephant
Eravikulam Kerala Nilgiri tahr
Fig. 5
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Wild life sanctuary
These are forest areas declared as protected areas to prevent the extinction of wild
lives by protecting the ecosystems.
Wild life sanctuaries in India
Wildlife
Sanctuary
State
Ghana bird
sanctuary
Rajasthan
Vedanthangal
bird sanctuary
Tamil nadu
Peppara Kerala
Periyar Kerala
Wayanadu Kerala
Abohar
wildlife
sanctuary
Punjab
Fig 6
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Sacred grooves
These are small areas of biodiversity protected in
regions inhabited by human beings. Due to
change in life style many of these highly bio-rich
areas have been destroyed. Only a few are
remaining now. Sacred groves play an important
role in conservation of water also.
Fig 8
▪ Largest national park in
India – Hemis National
Park,jammu& Kashmir.
▪ Smallest national park in
India – South Button
Island national park,
Andaman and Nicobar
Islands.
▪ Largest wild life sanctuary
in india – Rann of Kutch,
Gujarat.
▪ Smallest wild life
sanctuary in India – Bor
tiger reserve, Maharashtra.
Community reserves
Community reserves are areas protected with the
participation of the public. These are ecologically
important places located in populated areas. The
Kadalundi community reserve spread over the Fig 7
district of Malappuram and Kozhikode is an example.
Fig 7
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Complete the illustration
Illustration 5
In-situ
conservation
National
park
---------------
----
Biosphere
reserve
---------
Community
reserve
------------
Wildlife
sanctuary
-----------------
-
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2.1.2 Ex-Situ Conservation
see ‘vanyajeevisamrakshanam’
in school resouces in IT @ School,
Edubundu
Zoological gardens
In zoological gardens
different varieties of
animals are protected
and housed separately
and necessary
arrangements are made
available for their
reproduction.
Eg: zoological gardens at
Thiruvananthapuram and
Thrissur in kerala.
Fig 9
Botanical gardens
These are wide research
centres where rare and
important plants of
diverse species are
protected.
Eg: Jawahalal Nehru
Tropicl Botanical Garden
and Reseach Institute
(JNTBGRI) at Palode &
Malabar Botanical
Garden (MBG) at
Olavanna.
Fig 10
Gene banks
These are research
centres with facilities to
collect seeds and
gametes to preserve
them for a long time.
Organisms canbe
recreated whenever
required.
Eg: Rajiv Gandhi
Centre For
Biotechnology at
Thiruvananthapuram.
Fig 11
Fig 11
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Indicators
▪ What is the scope for ex-situ conservation?
▪ What is the significance of gene bank?
2.2 Organizations and Conferences for Biodiversity Conservation
Many government and non-government organizations design and coordinate
environment protection activities. Let us familiarize ourselves with some of the
organisations and institutions at the national and international levels.
2.2.1 Organisations
IUCN
(International Union for
Conservation of Nature)
IUCN is a Switzerland based
independent organization
working for the protection of
biodiversity.
WWF
(World Wide Fund for nature)
Biodiversity conservation,
prevention of exploitation and
pollution of natural resources
are the objectives of WWF. Its
headquarters is also in
Switzerland.
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2.2.2 Conferences
The government of India along with 155 nations have signed the convention of
Biodiversity at Earth Summit held at Rio De Janeiro, Brazil in 1992. The world
conservation strategy has suggested the following steps for biodiversity conservation:
✓ Effort should be made to preserve the species that are endangered.
✓ Prevention of extinction requires proper planning and management.
✓ Varieties of food crops, forage plants, timber trees, livestock, animals and their wild
relatives should be preserved.
✓ Each country should identify habitats of wild relatives and ensure their protection.
✓ Habitats where species feed, breed, rest and nurse their young should be safeguarded
and protected.
✓ International trade in wild plants and animals be regulated.
RIO EARTH SUMMIT, 1992
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Significant learning outcomes
▪ Explain biodiversity
▪ Find out the causes of biodiversity loss.
▪ Engage in conservation activities realizing the importance of conservation of
biodiversity.
Let us assess
1. Find the odd one out;
a. Botanical garden, zoological gardens, sacred groves, gene bank.
b. Species diversity, forest diversity, genetic diversity, ecosystem
diversity.
2. Examine the statements given below and rewrite if there are errors.
a. Eravikulam is an example of community reserve.
b. In ex-situ conservation organisms are protected outside their natural
habitat.
c. Animals are reared and protected in botanical gardens.
3. What we can do for the protection of biodiversity?
Extended activities
▪ Prepare a poster that emphasize biodiversity depletion and its consequences.
▪ Conduct a seminar that emphasizes biodiversity and importance of
biodiversity conservation.
