Notes - BIODIVERSITY CONSERVATION NEET Notes | EduRev

NEET : Notes - BIODIVERSITY CONSERVATION NEET Notes | EduRev

 Page 1


1
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15
BIODIVERSITY CONSERVATION
A wide variety of living organisms including plants, animals and micro-organisms with
whom we share this planet earth makes the world a beautiful place to live in. Living organisms
exist almost everywhere from mountain peaks to the ocean depths; from deserts to the
rainforests. They vary in their habit and behaviour, shapes, sizes and colour . The remarkable
diversity of living organisms form an inseparable and significant parts of our planet however ,
the ever increasing human population is posing serious threats to bio-diversity.
In this lesson we shall learn the ways humans are causing loss of biodiversity and the
efforts that are being taken or need to be taken to protect and conserve the biodiversity.
 OBJECTIVES
After completing this lesson, you will be able to:
• explain the concept of biodiversity;
• describe the importance of biodiversity to human welfare and economic
development;
• explain the uniqueness of Indian biodiversity and associated regional specificity;
• list the causes of biodiversity depletion in Indian and global context;
• justify the conservation of biodiversity;
• distinguish between extinct, endangered and threatened species;
• describe various in-situ and ex-situ methods of conservation;
• explain the objectives of specific wildlife conservation projects like project tiger ,
project elephant, project crocodile etc.;
• describe the importance of national parks, sanctuaries and biosphere reserves;
• legal measures adopted by national and international bodies.
Page 2


1
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15
BIODIVERSITY CONSERVATION
A wide variety of living organisms including plants, animals and micro-organisms with
whom we share this planet earth makes the world a beautiful place to live in. Living organisms
exist almost everywhere from mountain peaks to the ocean depths; from deserts to the
rainforests. They vary in their habit and behaviour, shapes, sizes and colour . The remarkable
diversity of living organisms form an inseparable and significant parts of our planet however ,
the ever increasing human population is posing serious threats to bio-diversity.
In this lesson we shall learn the ways humans are causing loss of biodiversity and the
efforts that are being taken or need to be taken to protect and conserve the biodiversity.
 OBJECTIVES
After completing this lesson, you will be able to:
• explain the concept of biodiversity;
• describe the importance of biodiversity to human welfare and economic
development;
• explain the uniqueness of Indian biodiversity and associated regional specificity;
• list the causes of biodiversity depletion in Indian and global context;
• justify the conservation of biodiversity;
• distinguish between extinct, endangered and threatened species;
• describe various in-situ and ex-situ methods of conservation;
• explain the objectives of specific wildlife conservation projects like project tiger ,
project elephant, project crocodile etc.;
• describe the importance of national parks, sanctuaries and biosphere reserves;
• legal measures adopted by national and international bodies.
Environmental Science Senior Secondary Course
Notes
2
MODULE - 5
Environmental
Conservation
 15.1 WHAT IS BIOLOGICAL DIVERSITY
Sum total of all the variety of living organisms on earth constitute biodiversity. Biological
diversity is usually considered at three different levels – a) genetic diversity i.e. at genetic
level , b) species diversity i.e. at the level of species, and c) ecosystem diversity i.e. at the
level of ecosystem.
15.1.1 Genetic diversity
Each species, varying from bacteria to higher plants and animals, stores an immense amount
of genetic information. For example, the number of genes is about 450-700 in mycoplasma,
4000 in bacteria (eg. Escherichia coli) , 13,000 in Fruit-fly (Drosophila melanogaster);
32,000 – 50,000 in rice (Oryza sativa); and 35,000 to 45,000 in human beings (Homo
sapiens sapiens). This variation of genes, not only of numbers but of structure also, is of
great value as it enables a population to adapt to its environment and to respond to the
process of natural selection. If a species has more genetic variation, it can adapt better to
the changed environmental conditions. Lower diversity in a species leads to genetic uniformity
of genetically similar crop plants. This homogeneity is desirable in producing uniform quality
of grain. But genetic uniformity restricts adaptability of a species to environmental stress as
all the plants have same level of resistance.
With the above background, genetic diversity refers to the variety of genes contained
within species of plants, animals and micro-organisms. New genetic variation in individuals
occurs by gene and chromosomal mutation, and in organisms with sexual reproduction
may be spread across the population by recombination. For instance, two brothers differ
in their structure, although their parents are the same. The differences could be in alleles
(different variants of the same gene), in entire gene (the traits determining particular
characteristics) or in chromosomal structure. The amount of genetic variation (gene pool)
present in an inter-breeding population is shaped or decided by the process of natural
selection. Selection leads to certain genetic attributes being preferred and results in changes
in the frequency of genes within this pool. This forms the basis of adaptation among the
living organisms. India has high genetic diversity and is regarded as a V avilov’s centre of
high crop genetic diversity – so named after the Russian agro-botanist N I V avilov, who
identified eight such centres of origin of cultivated plants around the world in the 1950s.
15.1.2 Species diversity
Species diversity refers to the variety of species within a geographical area.
Species diversity can be measured in terms of:
(a) Species richness – refers to the number of various species in a defined area.
Page 3


1
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15
BIODIVERSITY CONSERVATION
A wide variety of living organisms including plants, animals and micro-organisms with
whom we share this planet earth makes the world a beautiful place to live in. Living organisms
exist almost everywhere from mountain peaks to the ocean depths; from deserts to the
rainforests. They vary in their habit and behaviour, shapes, sizes and colour . The remarkable
diversity of living organisms form an inseparable and significant parts of our planet however ,
the ever increasing human population is posing serious threats to bio-diversity.
In this lesson we shall learn the ways humans are causing loss of biodiversity and the
efforts that are being taken or need to be taken to protect and conserve the biodiversity.
 OBJECTIVES
After completing this lesson, you will be able to:
• explain the concept of biodiversity;
• describe the importance of biodiversity to human welfare and economic
development;
• explain the uniqueness of Indian biodiversity and associated regional specificity;
• list the causes of biodiversity depletion in Indian and global context;
• justify the conservation of biodiversity;
• distinguish between extinct, endangered and threatened species;
• describe various in-situ and ex-situ methods of conservation;
• explain the objectives of specific wildlife conservation projects like project tiger ,
project elephant, project crocodile etc.;
• describe the importance of national parks, sanctuaries and biosphere reserves;
• legal measures adopted by national and international bodies.
Environmental Science Senior Secondary Course
Notes
2
MODULE - 5
Environmental
Conservation
 15.1 WHAT IS BIOLOGICAL DIVERSITY
Sum total of all the variety of living organisms on earth constitute biodiversity. Biological
diversity is usually considered at three different levels – a) genetic diversity i.e. at genetic
level , b) species diversity i.e. at the level of species, and c) ecosystem diversity i.e. at the
level of ecosystem.
15.1.1 Genetic diversity
Each species, varying from bacteria to higher plants and animals, stores an immense amount
of genetic information. For example, the number of genes is about 450-700 in mycoplasma,
4000 in bacteria (eg. Escherichia coli) , 13,000 in Fruit-fly (Drosophila melanogaster);
32,000 – 50,000 in rice (Oryza sativa); and 35,000 to 45,000 in human beings (Homo
sapiens sapiens). This variation of genes, not only of numbers but of structure also, is of
great value as it enables a population to adapt to its environment and to respond to the
process of natural selection. If a species has more genetic variation, it can adapt better to
the changed environmental conditions. Lower diversity in a species leads to genetic uniformity
of genetically similar crop plants. This homogeneity is desirable in producing uniform quality
of grain. But genetic uniformity restricts adaptability of a species to environmental stress as
all the plants have same level of resistance.
With the above background, genetic diversity refers to the variety of genes contained
within species of plants, animals and micro-organisms. New genetic variation in individuals
occurs by gene and chromosomal mutation, and in organisms with sexual reproduction
may be spread across the population by recombination. For instance, two brothers differ
in their structure, although their parents are the same. The differences could be in alleles
(different variants of the same gene), in entire gene (the traits determining particular
characteristics) or in chromosomal structure. The amount of genetic variation (gene pool)
present in an inter-breeding population is shaped or decided by the process of natural
selection. Selection leads to certain genetic attributes being preferred and results in changes
in the frequency of genes within this pool. This forms the basis of adaptation among the
living organisms. India has high genetic diversity and is regarded as a V avilov’s centre of
high crop genetic diversity – so named after the Russian agro-botanist N I V avilov, who
identified eight such centres of origin of cultivated plants around the world in the 1950s.
15.1.2 Species diversity
Species diversity refers to the variety of species within a geographical area.
Species diversity can be measured in terms of:
(a) Species richness – refers to the number of various species in a defined area.
3
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
(b) Species abundance – refers to the relative numbers among species. For example,
the number of species of plants, animals and microorganisms may be more in an area
than that recorded in another area.
(c) T axonomic or phylogenetic diversity – refers to the genetic relationships between
different groups of species.
Kinds of species that are present in an area is also important. When taxonomically unrelated
species are present in an area, the area represents greater species diversity as compared
to an area represented by taxonomically related species. Observe the diagram shown
below. Fig. 15.1
Sample Area A
Sample Area B
Sample Area C
Fig. 15.1: The different sample areas showing species diversity.
{Note – Know that all the three sample areas are represented by three kinds of species.
(species richness is same). However they vary in species abundance varying number of
individuals per species) and in taxonomic diversity . Observe that sample C has the highest
species diversity as it is represented by taxonomically unrelated species}
Page 4


1
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15
BIODIVERSITY CONSERVATION
A wide variety of living organisms including plants, animals and micro-organisms with
whom we share this planet earth makes the world a beautiful place to live in. Living organisms
exist almost everywhere from mountain peaks to the ocean depths; from deserts to the
rainforests. They vary in their habit and behaviour, shapes, sizes and colour . The remarkable
diversity of living organisms form an inseparable and significant parts of our planet however ,
the ever increasing human population is posing serious threats to bio-diversity.
In this lesson we shall learn the ways humans are causing loss of biodiversity and the
efforts that are being taken or need to be taken to protect and conserve the biodiversity.
 OBJECTIVES
After completing this lesson, you will be able to:
• explain the concept of biodiversity;
• describe the importance of biodiversity to human welfare and economic
development;
• explain the uniqueness of Indian biodiversity and associated regional specificity;
• list the causes of biodiversity depletion in Indian and global context;
• justify the conservation of biodiversity;
• distinguish between extinct, endangered and threatened species;
• describe various in-situ and ex-situ methods of conservation;
• explain the objectives of specific wildlife conservation projects like project tiger ,
project elephant, project crocodile etc.;
• describe the importance of national parks, sanctuaries and biosphere reserves;
• legal measures adopted by national and international bodies.
Environmental Science Senior Secondary Course
Notes
2
MODULE - 5
Environmental
Conservation
 15.1 WHAT IS BIOLOGICAL DIVERSITY
Sum total of all the variety of living organisms on earth constitute biodiversity. Biological
diversity is usually considered at three different levels – a) genetic diversity i.e. at genetic
level , b) species diversity i.e. at the level of species, and c) ecosystem diversity i.e. at the
level of ecosystem.
15.1.1 Genetic diversity
Each species, varying from bacteria to higher plants and animals, stores an immense amount
of genetic information. For example, the number of genes is about 450-700 in mycoplasma,
4000 in bacteria (eg. Escherichia coli) , 13,000 in Fruit-fly (Drosophila melanogaster);
32,000 – 50,000 in rice (Oryza sativa); and 35,000 to 45,000 in human beings (Homo
sapiens sapiens). This variation of genes, not only of numbers but of structure also, is of
great value as it enables a population to adapt to its environment and to respond to the
process of natural selection. If a species has more genetic variation, it can adapt better to
the changed environmental conditions. Lower diversity in a species leads to genetic uniformity
of genetically similar crop plants. This homogeneity is desirable in producing uniform quality
of grain. But genetic uniformity restricts adaptability of a species to environmental stress as
all the plants have same level of resistance.
With the above background, genetic diversity refers to the variety of genes contained
within species of plants, animals and micro-organisms. New genetic variation in individuals
occurs by gene and chromosomal mutation, and in organisms with sexual reproduction
may be spread across the population by recombination. For instance, two brothers differ
in their structure, although their parents are the same. The differences could be in alleles
(different variants of the same gene), in entire gene (the traits determining particular
characteristics) or in chromosomal structure. The amount of genetic variation (gene pool)
present in an inter-breeding population is shaped or decided by the process of natural
selection. Selection leads to certain genetic attributes being preferred and results in changes
in the frequency of genes within this pool. This forms the basis of adaptation among the
living organisms. India has high genetic diversity and is regarded as a V avilov’s centre of
high crop genetic diversity – so named after the Russian agro-botanist N I V avilov, who
identified eight such centres of origin of cultivated plants around the world in the 1950s.
15.1.2 Species diversity
Species diversity refers to the variety of species within a geographical area.
Species diversity can be measured in terms of:
(a) Species richness – refers to the number of various species in a defined area.
3
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
(b) Species abundance – refers to the relative numbers among species. For example,
the number of species of plants, animals and microorganisms may be more in an area
than that recorded in another area.
(c) T axonomic or phylogenetic diversity – refers to the genetic relationships between
different groups of species.
Kinds of species that are present in an area is also important. When taxonomically unrelated
species are present in an area, the area represents greater species diversity as compared
to an area represented by taxonomically related species. Observe the diagram shown
below. Fig. 15.1
Sample Area A
Sample Area B
Sample Area C
Fig. 15.1: The different sample areas showing species diversity.
{Note – Know that all the three sample areas are represented by three kinds of species.
(species richness is same). However they vary in species abundance varying number of
individuals per species) and in taxonomic diversity . Observe that sample C has the highest
species diversity as it is represented by taxonomically unrelated species}
Environmental Science Senior Secondary Course
Notes
4
MODULE - 5
Environmental
Conservation
At the global level, an estimated 1.7 million species of living organisms have been described
to date and many more are yet to be discovered. It has been currently estimated that the
total number of species may vary from 5 - 50 millions. Species diversity is not evenly
distributed across the globe. The overall richness of species is concentrated in equatorial
regions and tends to decrease as one moves from equatorial to polar regions. In addition,
biodiversity in land ecosystems generally decreases with increasing altitude. The other
factors that influence biodiversity are amount of rainfall and nutrient level in soil. In marine
ecosystems, species richness tends to be much higher in continental shelves.
India is a country of vast diversity (Fig. 15.2) and it is among the 12 “mega-diversity”
countries in the world.
(a) Number of species of plants and bacteria
(b) Number of species of animals
Fig. 15.2: Number of plant and animal species in different groups recorded in
India
2577
5070
68389
8329
1 1 9
2546
209
456
1 232
390
0 1 0000 20000 30000 40000 50000 60000 70000 80000
Protozoa
M ollusca
Arthropoda
Other invertebrates
Protochordata
Pisces
Amphibia
Reptilia
Aves
M ammalia
Bacteria
Page 5


1
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15
BIODIVERSITY CONSERVATION
A wide variety of living organisms including plants, animals and micro-organisms with
whom we share this planet earth makes the world a beautiful place to live in. Living organisms
exist almost everywhere from mountain peaks to the ocean depths; from deserts to the
rainforests. They vary in their habit and behaviour, shapes, sizes and colour . The remarkable
diversity of living organisms form an inseparable and significant parts of our planet however ,
the ever increasing human population is posing serious threats to bio-diversity.
In this lesson we shall learn the ways humans are causing loss of biodiversity and the
efforts that are being taken or need to be taken to protect and conserve the biodiversity.
 OBJECTIVES
After completing this lesson, you will be able to:
• explain the concept of biodiversity;
• describe the importance of biodiversity to human welfare and economic
development;
• explain the uniqueness of Indian biodiversity and associated regional specificity;
• list the causes of biodiversity depletion in Indian and global context;
• justify the conservation of biodiversity;
• distinguish between extinct, endangered and threatened species;
• describe various in-situ and ex-situ methods of conservation;
• explain the objectives of specific wildlife conservation projects like project tiger ,
project elephant, project crocodile etc.;
• describe the importance of national parks, sanctuaries and biosphere reserves;
• legal measures adopted by national and international bodies.
Environmental Science Senior Secondary Course
Notes
2
MODULE - 5
Environmental
Conservation
 15.1 WHAT IS BIOLOGICAL DIVERSITY
Sum total of all the variety of living organisms on earth constitute biodiversity. Biological
diversity is usually considered at three different levels – a) genetic diversity i.e. at genetic
level , b) species diversity i.e. at the level of species, and c) ecosystem diversity i.e. at the
level of ecosystem.
15.1.1 Genetic diversity
Each species, varying from bacteria to higher plants and animals, stores an immense amount
of genetic information. For example, the number of genes is about 450-700 in mycoplasma,
4000 in bacteria (eg. Escherichia coli) , 13,000 in Fruit-fly (Drosophila melanogaster);
32,000 – 50,000 in rice (Oryza sativa); and 35,000 to 45,000 in human beings (Homo
sapiens sapiens). This variation of genes, not only of numbers but of structure also, is of
great value as it enables a population to adapt to its environment and to respond to the
process of natural selection. If a species has more genetic variation, it can adapt better to
the changed environmental conditions. Lower diversity in a species leads to genetic uniformity
of genetically similar crop plants. This homogeneity is desirable in producing uniform quality
of grain. But genetic uniformity restricts adaptability of a species to environmental stress as
all the plants have same level of resistance.
With the above background, genetic diversity refers to the variety of genes contained
within species of plants, animals and micro-organisms. New genetic variation in individuals
occurs by gene and chromosomal mutation, and in organisms with sexual reproduction
may be spread across the population by recombination. For instance, two brothers differ
in their structure, although their parents are the same. The differences could be in alleles
(different variants of the same gene), in entire gene (the traits determining particular
characteristics) or in chromosomal structure. The amount of genetic variation (gene pool)
present in an inter-breeding population is shaped or decided by the process of natural
selection. Selection leads to certain genetic attributes being preferred and results in changes
in the frequency of genes within this pool. This forms the basis of adaptation among the
living organisms. India has high genetic diversity and is regarded as a V avilov’s centre of
high crop genetic diversity – so named after the Russian agro-botanist N I V avilov, who
identified eight such centres of origin of cultivated plants around the world in the 1950s.
15.1.2 Species diversity
Species diversity refers to the variety of species within a geographical area.
Species diversity can be measured in terms of:
(a) Species richness – refers to the number of various species in a defined area.
3
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
(b) Species abundance – refers to the relative numbers among species. For example,
the number of species of plants, animals and microorganisms may be more in an area
than that recorded in another area.
(c) T axonomic or phylogenetic diversity – refers to the genetic relationships between
different groups of species.
Kinds of species that are present in an area is also important. When taxonomically unrelated
species are present in an area, the area represents greater species diversity as compared
to an area represented by taxonomically related species. Observe the diagram shown
below. Fig. 15.1
Sample Area A
Sample Area B
Sample Area C
Fig. 15.1: The different sample areas showing species diversity.
{Note – Know that all the three sample areas are represented by three kinds of species.
(species richness is same). However they vary in species abundance varying number of
individuals per species) and in taxonomic diversity . Observe that sample C has the highest
species diversity as it is represented by taxonomically unrelated species}
Environmental Science Senior Secondary Course
Notes
4
MODULE - 5
Environmental
Conservation
At the global level, an estimated 1.7 million species of living organisms have been described
to date and many more are yet to be discovered. It has been currently estimated that the
total number of species may vary from 5 - 50 millions. Species diversity is not evenly
distributed across the globe. The overall richness of species is concentrated in equatorial
regions and tends to decrease as one moves from equatorial to polar regions. In addition,
biodiversity in land ecosystems generally decreases with increasing altitude. The other
factors that influence biodiversity are amount of rainfall and nutrient level in soil. In marine
ecosystems, species richness tends to be much higher in continental shelves.
India is a country of vast diversity (Fig. 15.2) and it is among the 12 “mega-diversity”
countries in the world.
(a) Number of species of plants and bacteria
(b) Number of species of animals
Fig. 15.2: Number of plant and animal species in different groups recorded in
India
2577
5070
68389
8329
1 1 9
2546
209
456
1 232
390
0 1 0000 20000 30000 40000 50000 60000 70000 80000
Protozoa
M ollusca
Arthropoda
Other invertebrates
Protochordata
Pisces
Amphibia
Reptilia
Aves
M ammalia
Bacteria
5
Biodiversity Conservation
Notes
MODULE - 5
Environmental
Conservation
15.1.3 Ecosystem diversity
It refers to the presence of different types of ecosystems. For instance, the tropical south
India with rich species diversity will have altogether different structure compared to the
desert ecosystem which has far less number of plant and animal species. Likewise, the
marine ecosystem although has many types of fishes, yet it differs from the freshwater
ecosystem of rivers and lakes in terms of its characteristics. So such variations at ecosystem
level are termed as ecosystem diversity.
As stated above, ecosystem diversity encompasses the broad differences between
ecosystem, and the diversity of the habitats and ecological processes occurring within
each ecosystem type. India has very diverse terrestrial and aquatic ecosystems ranging
from ice-capped Himalayas to deserts, from arid scrub to grassland to wetlands and
tropical rainforests, from coral reefs to the deep sea. Each of these comprises a great
variety of habitats and interactions between and within biotic and abiotic components. The
most diversity-rich are western-ghats and the north-eastern region. A very large number of
species found in these ecosystems are endemic or found in these areas only in India i.e.
they are found no where else except in India. The endemics are concentrated mainly in
north-east, western-ghats, north-west Himalaya, and Andaman and Nicobar Islands. About
33% of the flowering plants recorded in India are endemic to our country . Indian region is
also notable for endemic fauna. For example, out of recorded vertebrates, 53% freshwater
fish, 60% amphibians, 36% reptiles and 10% mammalian fauna are endemic.
15.1.4 Hot spots of biodiversity
Biodiversity is not uniformly distributed across the geographical regions of the earth. Certain
regions of the world are very rich in biodiversity. We call such areas as “mega diversity
zones”. W e also refer to them as “hot-spots”. For example, India accounts for only 2.4 %
of the land area of the world; but it contributes approximately 8% species to the global
diversity due to existence of such pockets.
Norman Myers, a British Ecologist, developed the concept of hot spots in 1988 to designate
priority areas for in situ conservation. According to him, the hot spots are the richest and
the most threatened reservoirs of biodiversity on the earth. The criteria for determining a
hot spot are:
i) The area should support >1500 endemic species,
ii) It must have lost over 70 % of the original habitat
T wenty-five biodiversity hot spots have been identified in the world. These hot spots are
characterized by posing exceptionally high biodiversity. For example the total area of
these 25 hot spots cover 1.4% of the total land area, support 44% of plant and 35%
terrestrial vertebrates. (Refer to the Fig. 15.3)
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