This document contains notes from a biology lecture on biodiversity. It defines biodiversity as the variety of life, including species diversity, ecosystem diversity, and genetic diversity. It provides statistics on the number of known plant and animal species. It discusses factors influencing global patterns of biodiversity like latitude and area. It also covers threats to biodiversity like habitat loss, overexploitation, invasive species, and co-extinctions. Methods of biodiversity conservation like protected areas and ex situ conservation are presented. International agreements and Indian laws related to biodiversity conservation are also mentioned.

1. Indrani kailas PGT Biology
KV Ashok Nagar
10/16/2015 1
Earth provides enough to satisfy every man's needs, but not every man's greed.”
― Mahatma Gandhi

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A B

3. A B
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What does “Biodiversity” mean?
Bio = Life
Diversity =Variety

5. Diversity
 of Species
 of Ecosystem
 of Genes
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 According to the IUCN (2004), the total number
of plant and animal species are slightly more
than 1.5 million.
 More than 70 per cent of all the species recorded
are animals, while plants comprise about 22per
cent of the total.
 Among animals, insects are the most species-
rich group, making up more than 70 per cent of
the total( out of every 10 animals on this planet,
7 are insects)
 Robert May places the global species diversity
at about 7 million.

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Representing global
biodiversity:
proportionate
number of species
of major taxa of
plants,invertebrates
and vertebrates

8.  A stable community should not show too
much variation in productivity from year to
year.
 It must be either resistant or resilient to
occasional disturbances (natural or man-
made)
 It must also be resistant to invasions by
alien species.
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9.  Stanford ecologist Paul Ehrlich says in an airplane
(ecosystem) all parts are joined together using
thousands of rivets (species).
 If every passenger starts popping a rivet (causing
a species to become extinct), it may not affect
flight safety (proper functioning of the ecosystem)
initially, but as more and more rivets are removed,
the plane becomes dangerously weak.
 Which rivet(important rivet like the one on wings)
is removed may also be critical. (key species that
drive major ecosystem functions)
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10.  Species diversity decreases as we move away from
the equator towards the poles.
 Tropics have more species than temperate or polar
areas.
 (a) Tropical latitudes have remained relatively
undisturbed for millions of years and, had a long
evolutionary time for species diversification unlike
temperate regions subjected to frequent
glaciations in the past
 (b) Tropical environments, unlike temperate ones,
are less seasonal, relatively more constant and
predictable. Such constant environments promote
niche specialisation and a greater species diversity
and
 (c) There is more solar energy available in the
tropics, which contributes to higher productivity;
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 German naturalist
Alexander von Humboldt
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
(angiosperm plants, birds,
bats,freshwater fishes) is a
rectangular hyperbola S= Species richness, A= Area
Z = slope of the line (regression
coefficient)
C = Y-intercept

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 Ecologists have discovered that the value of Z
lies in the range of 0.1 to 0.2,regardless of
the taxonomic group or the region.
 The species-area relationships among very
large areas like the entire continents, you will
find that the slope of the line to be much
steeper (Z values in the range of 0.6 to 1.2).

13.  (a) decline in plant production,
 (b) lowered resistance to environmental
perturbations such as drought and
 (c) increased variability in certain ecosystem
processes such as plant productivity, water
use, and pest and disease cycles
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14.  The biological wealth of our planet has been
declining rapidly.
 The IUCN Red List (2004) documents the
extinction of 784 species (including 338
vertebrates, 359 invertebrates & 87 plants) in
the last 500 years.
 Dodo (Mauritius), Quagga(Africa), Thylacine
(Australia), Steller’s Sea Cow (Russia) and
three subspecies (Bali, Javan,Caspian) of tiger.
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Dodo QuaggaThylacine

15.  (i) Habitat loss and fragmentation - H
 (ii) Over-exploitation- O
 (iii) Alien species invasions A
 (iv) Co-extinctions X
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Land slides due to road
building and rains are very
common in Uttarakhand.
Many species are
experiencing habitat loss.
The Amazon rain forest (‘lungs of
the planet’)harbouring millions of
species is being cut and cleared
for cultivating soya beans or for
conversion to grasslands for
Raising beef cattle.

17.  When ‘need’ turns to ‘greed’, it leads to over exploitation.
 These two animals became extinct
due to hunting for meat.
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Over exploitation
The Passenger pigeon is an
extinct North American bird.

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•When alien species are
introduced unintentionally or
deliberately, some of them turn
invasive, and cause decline or
extinction of indigenous species.
•The Nile perch introduced into
Lake Victoria in east Africa led to
the extinction of more than 200
species of cichlid fish in the lake.
Cichilid fish
Nile perch

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 1.Parthenium entered India
accidently.
 2.Lantana camara & Eichorrnea
crassipes were intentionally
introduced for beautiful flowers
 3.African cat fish was
introduced into Indian water
bodies

20.  Water hyacinth often invades bodies of water that have been
impacted by human activities. The plants can unbalance
natural lifecycles in artificial reservoirs or in eutrophied lakes
that receive large amounts of nutrients.
 This was first introduced in India for its beautiful flowers.
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21. The extinct Passenger pigeon and
its parasitic liceColumbicola
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Co-extinctions
 When a species becomes
extinct, the plant and animal
species associated with it in an
obligatory way also become
extinct.
 A coevolved plant-pollinator
may become extinct if plant
becomes extinct.
 A parasite becomes extinct
along with its host.
 Co-extinction also affects
predators and their prey and
herbivores and their host plants

22.  The narrowly utilitarian argument -We derive countless direct
economic benefits from nature ,food firewood, fibre,
construction material, industrial products (tannins, lubricants,
dyes, perfumes ) & products of medicinal importance.
 Broadly utilitarian argument says that biodiversity plays a
major role in many ecosystem services that nature provides
like Oxygen. Pollinators help the crops to pollinate.Healthy
stable ecosystems are essential for our survival.
 Ethical argument for conserving biodiversity relates to what
we owe to millions of plant, animal and microbe species with
whom we share this planet
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23. Ecological services:
Balance of nature
Biological productivity
Regulation of climate
Degradation of waste
Cleaning of air and water
Cycling of nutrients
Control of potential pest and disease causing species
Detoxification of soil and sediments
Stabilization of land against erosion
Carbon sequestration and global climate change
Maintenance of Soil fertility 10/16/2015 24

24. Biodiversity
Conservation
In situ
Sacred
groves
and lakes
Biosphere
Reserves
Terrestrial
Marine
National
parks,
wildlife
sanctuaries
Ex situ
Sacred plant
home garden
Seed Bank, Gene
bank,
Cryopreservation
Botanical garden,
Zoological garden,
Aquaria10/16/2015 25

25.  Establishig Biosphere reserves, national parks
and wildlife sanctuaries and sacred groves.
 For maximum protection certain ‘biodiversity
hotspots’ regions with very high levels of
species richness and high degree of
endemism have been identified
as‘biodiversity hotspots’
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26.  India now has 14 biosphere reserves, 90 national parks and
448 wildlife sanctuaries.
 Sacred groves are found in Khasi and Jaintia Hills in
Meghalaya, Aravalli Hills of Rajasthan, Western Ghat regions
of Karnataka and Maharashtra and the Sarguja, Chanda and
Bastar areas of Madhya Pradesh.
 Three Biodiversity hotspots_Western Himalayas,Western
ghats, Indo burma.
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Western Ghats and Sri Lanka
Indo-Burma

28.  Threatened animals and plants are taken out from their
natural habitat and placed in special setting . For example
zoological parks, botanical gardens and wildlife safari parks.
 Gametes of threatened species can be preserved in viable
condition for long periods using cryopreservation techniques
 Eggs can be fertilised in vitro.
 Plants can be propagated by tissue culture methods.
 Seeds of different genetic strains of important plants can be
kept for long periods in seed banks.
 DNA of threatened species are perserved in gene banks.
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Gene Bank

29.  Convention on Biological Diversity (‘The Earth
Summit’) held in Rio de Janeiro in
1992.
 World Summit on Sustainable Development
held in 2002 in Johannesburg, South Africa
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30.  Wildlife protection act 1972.
 Forest Conservation Act 1980
 Biological Diversity Act 2002.
 Scheduled Tribes and other traditional forest
dwellers (recognition of rights) act 2006.
 National Environment Policy (2006).
 National Biodiversity Action Plan (2009).
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.

31.  During the long period (> 3 billion years) since the
origin and diversification of life on earth there were
five episodes of mass extinction of species.
 Now the current ongoing epissode is Sixth Extinction
 Species extinction rates are estimated to be 100 to
1,000 times faster than in the pre-human times and
our 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
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