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BIODIVERSITY AND CONSERVATION

Indrani kailas PGT BiologyKV Ashok Nagar

Earth provides enough to satisfy every man's needs, but not every man's greed.” ― Mahatma Gandhi

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Which do you think is showing diversity?

A B

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A B

Which shows more biodiversity?

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BiodiversityWhat does “Biodiversity” mean?

Bio = Life

Diversity =Variety

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Diversity of Species

of Ecosystem

of Genes

There are three types of biodiversity

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Biodiversity 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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Comparison of biodiversity in groups of organisms

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

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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.

The importance of Species Diversity to the Ecosystem

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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)

Loss of Biodiversity -analogy the ‘rivet popper hypothesis-

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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;

Latitudinal gradients

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Species-Area relationships 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).

Larger Area Steeper Curve

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(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

CONSEQUENCE- Loss of Biodiversity

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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.

Loss of Biodiversity

Dodo QuaggaThylacine

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(i) Habitat loss and fragmentation - H

(ii) Over-exploitation- O

(iii) Alien species invasions A

(iv) Co-extinctions X

Causes of biodiversity losses-(HOAX)

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Habitat loss and fragmentation

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 clearedfor cultivating soya beans or for conversion to grasslands for Raising beef cattle.

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When ‘need’ turns to ‘greed’, it leads to over exploitation. These two animals became extinct due to hunting for meat.

Steller’s sea cow _North pacific

Over exploitation

The Passenger pigeon is an extinct North American bird.

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Invasion by Alien species

•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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Invasive weeds & fish in India

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

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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.

Eichhornia crassipes

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The extinct Passenger pigeon and its parasitic liceColumbicola

.  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

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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

Why Should We Conserve Biodiversity?

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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

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Biodiversity Conservation

In situ Sacred

groves and lakes

Biosphere ReservesTerrestri

al

Marine

National

parks, wildlif

e sanctuaries

Ex situ

Sacred plant home garden

Seed Bank, Gene bank,

Cryopreservation

Botanical garden, Zoological garden,

Aquaria

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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’

In situ conservation

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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.

In situ conservation

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The western Himalaya Hotspot

Western Ghats and Sri Lanka

Indo-Burma

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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.

Ex situ Conservation

Gene Bank

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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

World Initiatives

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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).

Some important initiatives in India

.

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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

Sixth Extinction