BIODIVERSITY AND CONSERVATION CHAPTER 15 CLASS 12 NCERT CBSE BOARDS

2. Biodiversity
• Biological diversity‘ or biodiversity is that part of nature which
includes the differences in genes among the individuals of a species, the
variety and richness of all the plant and animal species at different
scales in space, locally, in a region, in the country and the world, and
various types of ecosystems, both terrestrial and aquatic, within a
defined area.
• The term biodiversity was coined by Edward Wilson.
• The word BIODIVERSITY originates from the Greek word
BIOS = LIFE and Latin word
DIVERSITAS = VARIETY or DIFFERENCE.
The whole word BIO DIVERSITY generally therefore means:
VARIETY OF LIFE.

3. Why Biodiversity is Important
Everything that lives in an ecosystem is part of the web of life, including
humans. Each species of vegetation and each creature has a place on the
earth and plays a vital role in the circle of life.
Plant, animal, and insect species interact and depend upon one another for
what each offers, such as food, shelter, oxygen, and soil enrichment.
Maintaining a wide diversity of species in each ecosystem is necessary to
preserve the web of life that sustains all living things. In his 1992 best-
seller, "The Diversity of Life," famed Harvard University biologist
Edward O. Wilson -- known as the "father of biodiversity," -- said,
"It is reckless to suppose that biodiversity can be diminished indefinitely
without threatening humanity itself."

4. Levels of biodiversity
1. Genetic biodiversity
• Variation of genes found with in a species is called genetic diversity.
• Includes the differences in DNA composition among individuals within
a given species.
• Adaptation to particular environmental conditions may weed out
genetic variants that are not successful.
• But populations benefit from some genetic diversity, so as to avoid
inbreeding or disease epidemics.
• Ex: There are more than 50,000 genetically different strains of rice and
1000 varieties of mango are in India.

5. 2. Species biodiversity
• The variety of species found in a habitat is called species
biodiversity.
• species = a particular type of organism; a population or group of
populations whose members share certain characteristics and can
freely breed with one another and produce fertile offspring
• Species diversity = the number or variety of species in a particular
region
• Species richness = number of species
• Evenness, or relative abundance = extent to which numbers of
different species are equal or skewed
• Ex: The Western Ghats has greater diversity of amphibian species
than Eastern Ghats.

6. Importance of Species Diversity to Ecosystem
• Communities with more species tend to be more stable than those
with less species.
• A stable community has following characters,
1. Productivity should not vary too much from year to year.
2. It should not show too much variation
3. It has resistance to seasonal disturbances and to invasion by alien
species.

7. 3. Ecological biodiversity
• The variety of different habitat found in the particular area is called
ecosystem biodiversity.
• Includes diversity above the species level. Biologists have viewed
diversity above the species level in various ways. Some alternative
ways to categorize it include –
1. Community diversity
2. Habitat diversity
3. Landscape diversity

11. Global Biodiversity
• According to IUCN (2004) the total number of plant and animal
species described is about 1.5 million.
• It is estimated that global biodiversity has 7 million species.
• More that 70% of all species recorded are animals. Plants account for
about 22% of the total.
• Insects are more species rich group. 70% of the animal are insects.

12. India’s Biodiversity
• India is known for its rich heritage of biodiversity.
• India is one of the 17 mega-diverse countries in the world.
• With only 2.4 % of the world‘s area, India accounts for 7–8 % of the
world‘s recorded plant and animal species.
• India‘s ten biogeographic zones possess an exemplary diversity of
ecological habitats like alpine forests, grasslands, wetlands, coastal
and marine ecosystems, and desert ecosystems.
• Amongst the existing biota, 91,307 species of animals of which 2,557
Protista, 12,470 general invertebrates, 69,903 arthropods, 4,994
vertebrates, and 45,500 species of plants as well as 5,650 microbial
species have been documented in its 10 bio-geographic regions.
• India has four out of thirty-four global biodiversity hotspots, which is
an indicator of high degree of endemism (of species) in India.
• About 5,150 plant species and 1,837 animal species are endemic to
India.
• India‘s biodiversity includes wild relatives of agricultural crops and
domesticated animals.

13. • India has 16 major types and 251 subtypes of forests.
• Indigenous medicine systems utilize nearly 6,500 native plants for both
human and animal healthcare.
• India‘s diverse preponderance of native tribal and ethnic groups has
contributed significantly in the conservation and diversification of
biodiversity. Its cultural and ethnic diversity includes over 550 tribal
communities of 227 ethnic groups spread over 5,000 forested villages.
India proudly upholds the tradition of nature conservation.
• In 252 B.C., the Emperor Asoka established protected areas (PAs) for
mammals, birds, fish and forests through a proclamation. Jim Corbett
National Park covering an area of 325 sq km came into being as the
India‘s first and world‘s third National Park in 1936.
• India has currently 4.79 % of total geographic area under an elaborate
network of PAs, which includes 99 National Parks, 513 wildlife
sanctuaries, 43 conservation reserves, 4 community reserves and 3
biodiversity heritage sites.
• India has a National Wildlife Action Plan, which envisages 10 % of the
geographical area of the country under PA coverage.

14. Measurement of biodiversity
Biodiversity is measured in three ways,
1. α-Biodiversity: It refers to number of species found in the particular
area.
2. β- Biodiversity: It is the comparison of biodiversity between two
habitats.
3. γ- Biodiversity: It is the measure of overall biodiversity in large land
scale.

15. Patterns of Biodiversity
Biodiversity is not uniform throughout the world but shows uneven
distribution.
Biodiversity is affected by two factors:
1. Latitudinal Gradient
• In general, species diversity decreases as we move away from the equator
towards the poles.
• Few exceptions: tropics (latitudinal range of 23.5° N to 23.5° S) harbour
more species than temperate or polar areas.
• Colombia located near the equator has nearly 1,400 species of birds while
New York at 41° N has 105 species and Greenland at 71° N only 56
species.
• India, with much of its land area in the tropical latitudes, has more than
1,200 species of birds.

16. GREATER BIOLOGICAL DIVERSITY IN TROPICS
Various hypotheses for higher diversity in tropics proposed by ecologists
and evolutionary biologists are :
• Temperate regions have undergone frequent glaciations in the past. It
killed most the species. Tropical latitudes have remained relatively
undisturbed for millions of years.
• Tropical environments are less seasonal which promote niche
specialization and lead to a greater species diversity.
• More solar energy is available in the tropics which contributes to higher
productivity and in turn might contribute indirectly to greater diversity.

17. 2. Species- area relationship
• Alexander von Humboldt was a German naturalist and explorer.
• He observed that within a region species richness increased with
increasing explored area, but only up to a limit.
• The relation between species richness and area for a wide variety
of taxa is to be a rectangular hyperbola.
On a logarithmic scale, the relationship is a straight line described by
the equation:
log S = log C + Z log A
Where
S= Species richness
A= Area
Z = slope of the line (regression coefficient)
C = Y-intercept

19. Loss of biodiversity
• Due to human activities biological resources have been declining
rapidly.
• The colonization of tropical Pacific Islands by humans led to the
extinction of more than 2,000 species of native birds.
• More than 15,500 species are facing the threat of extinction in the
worldwide.
• At present,12 % of birds, 23 % of mammals, 32 % of amphibians
and 31% of gymnosperms face the threat of extinction.

20. Effect of Biodiversity Loss
1. Decline in plant production
2. Lowered resistance to environmental perturbations such as
drought
3. Increased variability in certain ecosystem processes such as plant
productivity, water use, and pest and disease cycles

21. Mass extinction
• Due to natural calamities a large number of species become extinct
which is called mass extinction.
• Since the origin and diversification of life on earth there were five
episodes of mass extinction of species.
• The "Big Five" mass extinctions are as follows:
1. End Ordovician (Ordovician-Silurian extinction)
2. Late Devonian (Late Devonian extinction)
3. End Permian (Permian-Triassic extinction)
4. End Triassic (Triassic-Jurassic extinction)
5. End Cretaceous (Cretaceous-Tertiary extinction)

22. Sixth extinction
• The ‘Sixth Extinction’ is presently in progress which is different from
the previous episodes.
• The current species extinction rates are to be 100 to 1,000 times faster
than in the pre-human times and human activities are responsible for
the faster rates.
• Ecologists warn that if the present trends continue, nearly half of all
the species on earth might be wiped out within the next 100 years.

23. Biodiversity loss
The four major causes of biodiversity loss are -
1. Habitat loss
2. Over-exploitation
3. Alien species
4. Co-extinction

24. 1. Habitat loss and Fragmentation
• Habitat loss is the destruction of ecosystem by unwanted human
activities such as urbanization, intensive farming, deforestation,
mining activities and so on.
• When the vegetation is cleared for human activities the continuous
habitats become fragmented. This is called habitat fragmentation.
Degradation of natural habitats are threatening the species.
• Destruction of habitat is the primary cause of extinction of species.
• The tropical rainforests initially covered 14% of land but now only
6%.
• The Amazon rain forest is called ‘‘The lungs of the planet’’.
• When large sized habitats are broken into small fragmented due to
human activities certain animals are badly affected and threatens
their survival.

25. 2. Over-exploitation
• It is the harvesting of renewable resources to the extent. It is the
harvesting of renewable resources to the extent.
• When natural resources are over exploited by human due to his greed,it
results the degradation and extinction of the resources.
• e.g. Steller’s sea cow, passenger pigeon

26. 3. Alien species
• Invasion of alien species in the natural habitats cause decline in the
native species.
• E.g. The introduction of Nile perch into lake Victoria led extinction of
more than 200 species of indigenous cichild fish.
• The recent illegal introduction of the African catfish Clarias
gariepinus is posing Threat to indigenous catfishes in India.
• Alien Weeds - Carrot Grass : Parthenium, Lantana, Water hyacinth:
Eicchornia

27. 4. Co-extinction
• when one organism becomes extinct , the other associated obligatory
species also tend to extinct.
• For example, if the host fish species becomes extinct, all those
Parasites exclusively found on it will also become extinct.

28. CONSERVATION OF BIODIVERSITY

29. Reasons for Biodiversity Conservation
Narrowly Utilitarian
Broadly Utilitarian
Ethical Arguments

30. Narrowly Utilitarian
Economic benefits from nature -
1. Food - cereals, pulses, fruits
2. Firewood
3. Fibre
4. Industrial products – Dyes, Perfumes etc
5. Construction material
6. Medicines

31. Broadly Utilitarian
Various Ecosystem Services like -
1. Amazon forest produce 20% of the total oxygen in the atmosphere
on earth.
2. Aesthetic pleasures of walking through thick woods, watching spring
flowers etc.
3. Pollination of plants through pollinators: bee, birds and bats.

32. Ethical Arguments
• There are millions of plants, animals and microbes on this earth with
whom we share.
• Each species on this earth has some intrinsic value.
• It is therefore our moral duty to take care of all the living creatures
and pass on our biological legacy in good order to future
generations.

33. Approaches to Biodiversity conservation
Conservation of biodiversity is done by two methods:
1. In-situ conservation
• It is the conservation of wildlife within their natural habitat.
• Conservation and protection of whole ecosystem, protection of its
biodiversity at all levels.
• Ex: National parks, sanctuaries and biosphere reserves.
2. Ex-situ conservation:
• It is the conservation of wildlife outside their natural habitat.
• Protection of animals or plants when they are in endangered or
threatened and needs urgent measures to save from extinction.
• Ex: Zoo, Botanical garden, Seed bank etc.

34. Biodiversity loss and species extinction
Threatened species: The species whose population number is decreasing
and likely to decrease more in future is called threatened species.
• IUCN: International union for conservation of nature and natural
resource.
• Red Data Book: The book maintained by IUCN in which threatened
species are recorded is called red data book.
• MAB: Man and Biodiversity Programme
• WWF: The World Wildlife Fund for nature
• IBWL: Indian Board for Wildlife
• IBP: International Biological Programme
• UNDP: United Nation Development Programme.

35. Major categories of threatened species:
• Extirpation: disappearance of a particular population, but not the
entire species globally.
• Extinct species: The species that completely disappeared from earth
are called extinct species.
• Endangered species: The species whose population is drastically
reduced and are in danger of extinction are called endangered
species. Ex: Asiatic lion, One horned rhinoceros. Lion tailed
macaque. Nilgiri tahr.
• Vulnerable species: The species that likely enters the endangered
category are called vulnerable species. Ex: wild goat. Wild yak.
Barasinga. Wild ass, etc.
• Rare species: the species with small population which are neither
endangered nor vulnerable are called rare species.

36. Major categories of threatened species:
• Sacred species: The traditionally conserved species of plant and
animals on religious believes are called sacred species.
Ex: cow, snake, monkey, elephant, tulasi, neem, banyan tree, etc.
• Sacred groves: Traditionally conserved patches of forest that
dedicated to local deity are called sacred groves.
Ex: Devara kadu. Nagarabana, Boothasthana, Devabana etc.
• Sacred landscape: It is the traditionally conserved land areas with its
natural features. In these areas human activities and hunting is
banned. It includes forest, grass land, rivers, ponds etc.
Ex: kodachdri hills at kollur. Biligiri ranganatha hills. Etc.

38. Threatened endangered species In India

39. Endangered golden lion tamarin, endemic to Brazil’s Atlantic rainforest,
which has been almost totally destroyed.

40. Biodiversity depletion
The reduction or loss of plants and animals of biodiversity is called
biodiversity depletion. It causes due to natural disasters and human
activity.
Anthropocentric causes of biodiversity depletion: The cause of
biodiversity depletion due to human activity is called Anthropocentric
causes. These are ,
1. Urbanization.
2. Expansion of agriculture.
3. Deforestation.
4. Pollution.
5. Acidification of soil and water.
6. Soil erosion.
7. Mining activity.
8. Desertification.

41. • Deforestation: The destruction of forest for agriculture, industrial or
domestic use is called Deforestation.
• It leads to loss of habitat, soil erosion, Desertification, global worming,
and biodiversity depletion.
• Acidification of soil and water: The decrease in pH value of soil and
water is called Acidification of soil and water.
• It causes due to acid rain usage of high chemical fertilizer. Mining
activity, industrialization, etc.
• Most of the soil microbes, insect, plants aquatic animals are sensitive to
acidic condition. Hence acidification leads to biodiversity depletion

42. • Mining activity: It is the extraction of non renewable geological
materials from earth. It results in,
1. Exploitation of non renewable resource.
2. It brings deforestation.
3. It causes air, water soil and noise pollution.
4. It causes soil erosion.
5. It result in biodiversity depletion.

45. Conservation approaches
1. Biological hotspots
• Biological hotspots are natural environment with high biodiversity
and endemic species.
• Among 34 hotspots of world, the two biodiversity hotspots of India
are western Ghats and Eastern Himalayas.

46. 2. Biosphere reserves
• The large undisturbed area where the wild life is protected in their
natural habitat is called biosphere reserves.
• The biosphere reservoir is divided into 3 zones:
1. Core zone: Inner most area of biosphere reservoir where human
activity is prevented.
2. Buffer zone: It is out side the core zone where human activity is
permitted. In buffer zone publics are not allowed, only research
activities to wild life is allowed.
3. Transition zone: Agricultural activities are noticed in this area. Soil
erosion, deforestation and over grazing are common in this area.

47. 3. National park
• National parks are protected areas which is strictly reserved for
conservation of wild life. The human activity, grazing, cultivation are
strictly banned in this area.
Imp national parks of India.
1. Bandipur national park in Karnataka. Protected animals are elephants
2. Kaziranga national park at Assam. Protected animals are one horned
rhinoceros.
3. Sundarbans national park at West Bengal. Protected animals are
Bengal tigers. Ridley sea turtle
4. Ranathambore national park at Rajasthan. Protected animals are
tigers, leopards, Wild Boars.

48. 5. Manasa national park at Himalaya foothills. Protected animals are
tigers, rhinoceros, elephants.
6. Gir national park at Gujarat. Protected animals are Asiatic lion.
7. Kanha national park at madya Pradesh. Protected animals are Swamp
deer.
8. Dachigam national park at Jammu- Kashmir. Protected animals are
Hangul (Kashmir stag)

49. 4. Sanctuaries
These are the smallest area than the national parks. In this area human
activity is allowed to collect fruits, seeds, honey, animal grazing etc.
Wildlife sanctuaries of India.
• Ranganthittu bird sanctuary in Karnataka. Assembled species of birds
are protected.
• Badra wildlife sanctuary in Kanata. The protected animals are Tigers.
• Periyar wildlife sanctuary at Kerala. The protected animals are
elephants.
• Annamalai wildlife sanctuary at Tamilnadu. The protected animals
are Tigers.

50. 5. Zoological garden
The zoo are the place where different endangered animals are protected.
IBWL: Indian board of wild life.
WWFI: world wild life India.
• Chamarajendra zoological park at Mysore.
• Bannergatta zoological park at Bangalore.
• Pilikula zoological park at Mangalore.
• Lion safari in talaguppa shimoga

51. Conventions on Biodiversity
The Earth Summit held in Rio de Janeiro in 1992.
The World Summit on Sustainable Development held in Johannesburg,
South Africa in 2002 .
In this Summit, 190 countries pledged their commitment to reduce the
current rate of
biodiversity loss at global, regional and local levels by 2010.
It aims to:
• Conserve biodiversity
• Use it sustainably
• Ensure fair distribution of its benefits

52. • THANK YOU •