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Environmental Science

Environment – living and non-living things interacting with

one another

Environmental Science – Study of biotic and abiotic components

and their inter relationship

Environmental Engineering- Application of Engineering

principles for protection and conservation of environment

Environmental education- giving awareness on importance of

conserving environment.

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TYPES OF ENVIRONMENT

Natural

BioticFores

ts, animals,

Birds etc

Abiotic

minerals,

rocks, sand etc

Man made

Buildings, Farms, dams

etc

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Abiotic

Atmosphere

Lithosphere

Hydrosphere

Biotic

Biosphere

Animals, Plants,

Microorganisms

Energy

Flow of energy

Biotic- abiotic

Solar, Geothermal, wind

Nuclear etc

COMPONENTS OF ENVIRONMENT

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STRUCTURE OF THE ATMOSPHEREREGION ALTITUDE IN km TEMP CHANGE

CCHEMICAL SPECIES

TROPOSPHERE 0 11 15 to 56 N2, H2O, CO2, O2

STRATOSPHERE 11 50 56 to 2 O3

MESOSPERE 50 85 2 to 92 O2+ , NO+

THERMOSPERE/ IONOSHERE

85 500 92 to 1200 O+ , O2

+ , NO+

EXOSPHERE up to 1600 92 to 1200 H2 & He

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Major layers of the atmosphere

Thermosphere

Mesosphere

Stratosphere

Troposphere

Temperature 0C

Altit

ude

km

Clouds

Ozone

Meteor burns

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Atmosphere

•Maintains heat balance by absorbing IR radiations•Gases present sustain life

Lithosphere

•Home for all forms of life•Store house for organic and inorganic matter

Hydrosphere

•Supports life – all organisms need an aquatic environment

•Drinking, irrigation, power generation etc.

Functions

• To become aware of the importance of environmental issues

• To motivate participation in environmental protection• To develop skills for identifying and solving environmental

issues.• To be aware of the dire need for conservation• To relate environmental issues to social, economic and

ecological factors

SCOPE of environmental

studies

• To understand the need for development without environmental damage

• To comprehend the consequences of environmental hazards

• To appreciate the role of the individual in conservation and the related laws

• To enhance the quality of life through proper monitoring of the environment

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ROLE OF PUBLIC

• Pressure groups – to influence the govt and industries

• Watch Dogs – to keep an eye on processes that harm the environment

• Advisory council – Can set up advisory councils to educate the public on environmental issues

• Enforcement of law – to ensure that laws pertaining to environment are in force and if necessary file PIL for the same

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ECOSYSTEM

NATURAL

Terrestrial

Fauna Flora

AQUATIC

Marine Freshwater

Lotic / Running

Lentic/Standing

ARTIFICIAL

Cropland, Dams etc.

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Biotic EnvironmentAutotrophicProducers

Plants – Make their own food

HeterotrophicConsumers

Primary consumers– Herbivores-Deer, Rabbit

Secondary Consumers- Primary Carnivores – frogs,

snakes etc.

Tertiary consumers – Secondary

Carnivores- Tigers, Lions etc

Saprotrophs- decomposers /

microocnsumers – Bacteria/ Fubgi

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Food Chain Food Web

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Ecological Pyramids

• Graphical Representation of structure and function of the ecosystem

• Producers form the base, then the primary consumers etc.

• Usually upright pyramids – in some cases inverted pyramids

• Pyramids of numbers, biomass, energy

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Pyramid of Numbers in a Grassland & Aquatic Ecosystems

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Pyramid Of Biomass

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Pyramid of Energy

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Ecological succession• Stages: Pioneer Community, Seres/ Seral Stage- developmental stages of a

community• Types of succession

– Primary• Hydrarch/ hydrosere• Xerarch/ xerosere

– Secondary succession• Process of succession

– Nudation- bare area development– Invasion- establishment of species throuh

MigrationEstablishment (pioneer community)

– Competition ( between same and other species for space and food)– Reaction- midification of environment through food and space demand- may

become unsuitable foe existing species and new species enter – seral communities

– Stablization -establishemnt of stable community – equilibrium with environment

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BIODIVERSITY

• Variety and variability among the living organisms• Influenced by physical and climatic factors• >20 million species- 1.4 million identified• Importance of diversity- survival and sharing of

resources-otherwise slowly extinct• Important for human existence- all food sources like

agriculture, fisheries , forestry depend on diversity• Important for preserving the abiotic environment

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Loss of biodiversity

• Economic and social lossReasons:• Biotechnology, hybrid seeds• Loss of medicinal plants – not replanted (Taxus

baccate) - Himalayan medicinal plant –anticancer-on endangered list

• Deforestation due to agriculture and urbanization

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Levels / classification

• Genetic-A species with different genes- subspecies or genera

• Species diversity- discrete group of organisms • Ecosystem diversity- diversity at the habitat

level- large region with different ecosystems

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VALUES OF BIODIVERSITY- LIFE SUPPOTING AND PRESERVING BIOTIC AND ABIOTIC ENVIRONMENT

Consumption use value

•Food from plants and animals•Drugs from plants and animals- India uses 3000 plant species •Quinine, reserpine, penicillin, morphine, neem products, •peepal tree leaves, tulasi•Firewood and fossil fuels

Productive use valueCommercial value

•Silk industry•Wool manufacture•Musk extraction•Tusks- ivory products•leather•Pearl fishing•Food industry•Paper industry•Textiles

Other Values

•Social-Worship / Holy animals and plants•Ethical- Preservation- Respect for nature•Optional – Yet to be discovered-

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Terrestrial Biodiversity• Tropical rain forests- Largest store house of

biodiversity-50-65% of globaldiversity-• Medicinal plants- 3000 plants identified for

cancer drugs- 70% from tropical rain forests- AIDS drugs

• Flowering plants –known -1-3% - 1,30,000• Protection of biodiversity- Silent valley in

Kerala, hydroelectric power given up• Temperate rain forests- 1,70,000 flowering

plants,30000 vertebrates, 2,50,000 other species

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Marine Biodiversity- > terrestrial but less knownSpecies Number

Protozoans (Unicellular) 31,000

Bacteria (Cyanobacteria) 5,000

Algae 27,000

Fungi 45,000

Higher Plants 2,50,000

Jelly fish, corals 10,000

Sponges 5000

Worms 36,000

Insects 7,50,000

Snails, Slugs etc. 70,000

Fish 22,000

Amphibians 4,000

Reptiles 5,000

Mammals 4,000

Birds 9,000

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Number of Animal / plant species in India

Flowering plants 20,000

Insects 67,000

Fish 1,460

Birds 1,200

Reptiles 420

Mammals 340

Domestic animals and plants 170

• 10th in plant richness•11th in endemic species•6th as centers of biodiversity &origin of agricultural crops•> 2000 medicinal plants including turmeric•Commercial value- sandalwood, tobacco with high nicotine content, edible mushrooms & ornamental plants•> 100 species of microorganisms in soil -formulated in foreign labs

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Biodiversity measurement• Point richness- number of species found at a single point in a

given space• richness (alpha diversity)-number of species in a small

homogeneous area- strongly correlates with physical variables –tunicates-number varies with temperature of the region-Arctic 100 species; temperate waters- 400 and tropical waters- 600

• richness – rate of change in species composition across different habitats- more number of species – more diversity

Example: ant species -10-2000 from north pole to equator• richness – rate of change of species across landscapes- large

areas.

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BIODIVERSITY IN TAMIL NADU

• Dense forests in Salem district• Western Ghats- plants, animals and reptiles• Elephants in Anamalai Sanctuaries • Tigers in Mundanthurai

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MEGADIVERSITY REGIONS IN THE WORLD-70% OF THE GLOBAL DIVERSITY

• Australia• India• China• Colombia• Ecuador• United States• Indonesia• Madagascar• Mexico• Peru• Congo

India-• Animal Species-

89,450-7.31% of global fauna

• Plant- 47,500- 10.8% of global flora

• Loss in biodiversity – 33%

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Endemic species in India-

Endemic biodiversity

Marine -> 340 coral species, mangroves

and sea grasses

Agro -> 166 crops, 30000-50000

varieties of rice, mango, turmeric,

ginger, sugarcane etc.

Animal-75000 species -2,00,000 living

organisms

Plants-5000 flowering,166 crop

plants

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RED DATA BOOK/ RED LIST• Catalogue of species facing extiction• Prepared for the following reasons:

Awareness of degree of threat to biodiversityGlobal index on declining speciesIdentification of species with high risk of extinction plan conservationInformation on international agreements

44 plant species are critically endangered, 54 endangered, 143 are vulnerableIndia- 2nd in the number of threatened mammals and 6th among most threatened for birds

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EXAMPLES• Pitcher plant is endemic in Himalayas

• Taxus Wallichiana – under red list due to over exploitation-Ayurvedic and Tibetian medecine- anti cancer drug

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Examples of endemic speciesPlants

• Sapria himalayana• Ovaria lurida• Nephenthes khasiana• Pedicularis Parroter

• Pteridophyta-200 species• Angiosperms- 4950

Animals

• Frogs• Toads• Reptiles• Crocodiles

• Land- 878 species• Freshwater- 89• Insects- 16214• Amphibians- 110• Reptiles-214• Aves- 69• Nannakua-38

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Factors affecting endemic species• Habitat loss• Fragmentation• PollutionThe above true specially for frogs, toads etc.• Drying of water sources• Overhunting• Introduction of predators and competitors• Disease producing organisms

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HOT SPOTS

Geographic areas which posses high endemic species and therefore also contain the threatened species- areas of high conservation priority- if species lost can never be regenerated or replaced

Hot spots - < 2% of world’s land- contain 50000 endemic species

An area should contain at least 0.5% of endemic species

40% of terrestrial plants , 25% of vertebrates are endemic and found in hot spots-

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• Criterion for a hot spot1. Richness of endemic species2. Significant % of specialized species3. Site under threat4. Should contain important gene pool of plants• Reason for rich biodiversity in tropics1. More stable climate2. High temp and humidity3. Many species – no dominance of one species4. Rate of out crossing higher in plants

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Global Hot Spots

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Hot Spots in IndiaEastern Himalayas

• Northern India, Nepal and Bhutan

• 35,000 plant species- 30% endemic- rich in wild plants of economic value

• 63% mammals• 60% birds of India• Huge numbers of fungi,

insects• Crops- Sugarcane, rice,

banana, ginger, chilli, jute

Western Ghats

• Maharashtra, Karnataka, Tamil Nadu, Kerala

• ~ 1500endemic species• 62% amphibians, 50%

lizards endemic• Only 6.8% of the original

forests area exists now.• Egs of endemic plants-

Ternstromia Japonica, Rhododendran, HyperciumS

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Threats to Indian Biodiversity/ Loss of biodiversity

• Habitat Loss:1. Deforestation-agriculture, settlement areas,

developmental projects2. Destruction of wet land- draining, filling, pollution-

loss of wetlands, mangroves and estuaries3. Habitat fragmentation- due to human practices4. Extracting raw materials- for food, medicine,

construction etc.5. Illegal trade of wild life6. Construction activities- dams, industries- effluents

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•Poaching:

Illegal hunting -Subsistence poaching- for food and survivalCommercial poaching- to sell the productsReasons:Human populationCommercial demand for prohibited goods-Deer skin, tiger skin, Rhino horns, sea turtles,

whales, gorillas etc.

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• POACHING-• Male Gorilla – hunted for body parts, head and hands

(Rwanda & Zaire)• Blue Morpho Butterfly- making attracive trays and other

objects (Brazil)• Snowy Large Erget- white plumes for ladies’ hat - U.S• Blubber- lamp and lubricating oils• Baleen – combs and similar articles• Elephant- feet to make ash trays and for ivory• Bengal tigers- for fur – valued > $1,00,000 • Bush meat- for food• Dynamite fishing- hi tech method – exhausts marine life• Sea Horses and turtles- for meat and money

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How to prevent:

• Strict law enforcement• Public awareness• Giving up use of articles made from ivory,

animal skins etc.

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Man- Wild life conflict

Examples• Killing of humans by

elephants-Orissa; by tigers and leopards

• Damage of crops by elephants

• Killing of elephants and other wild animals by electrocution; use of explosives

Resons• Shrinking of forest cover• Human encroachment into

forests• Injuring animals specially

cubs• Food requirement- wild life

and human• Compensation paid by the

govt for loss not adequate and hence poaching

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Remedial measures

• Adequate cattle and crop compensation schemes

• Solar powered fences and shock proof trenches

• Change of crop pattern near forests• Ensuring enough water and food available for

wild life.• Deforestation for any reason to be prevented.

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Endangered species in India

•No longer found in the worldExtinct•Number reduced to critical level- to be protected- immediate danger of extinctionEndangered

•Population on the decline due to habitat loss and over exploitation but still abundantVulnerable

Rare• Localized within an area or thinly scattered over a large area

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Group of threatened species

Number Examples

Plants 250 Rauvol Serpentina, Sandal wood tree

Birds 70 Peacock, Siberian white crane, Pelican, Indian Bustard, blue necked crane

Mammals 86 Indian wolf, red fox, sloth bear, tiger, Indian lion, desert cat, wild buffalo, gangetic dilphin

Reptiles 25 Tortoise, Green sea turtles, python, gharral, Estuarine crocodile

Amphibians 3 Viviparous toad, Indian Salamander

Fishes 3

Molluscs 2Insects 50

Primates Hoolock gibbon, lion tailed macaque, capped monkey, golden monkey

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Factors affecting Endangered species

• Pollution- habitat/ environmental degradation/ toxicity through food chain

• Over exploitation and poaching

• Climate change due to green house gases

Remedial Measures

International treaties on endangered species- Convention on international trade in Endangered species 1975- 900 species which are about to become extinct & 2900 endangered species cannot be traded.Enforcement very difficultMany countries do not come under the treaty

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CONSERVATION OF BIODIVERSITY The management of biosphere so

that it will yield the greatest sustainable benefit to the present generation and also will have the potential to meet the needs of the future generation

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Factors affecting biodiversity

• Construction of dams, release of industrial wastes, use of insecticides and pesticides

• Poaching of wild animals, over exploitation of resources leading to habitat loss

• Oil spills and discharge of effluents

• Global warming, acid rain, ozone depletion- climatic changes

Need for conserving biodiversity

• Societal needs such as tourism and recreation

• Important raw materials and drugs

• Preserves genetic diversity• Sustainable use of life

supporting systems• Loss of biodiversity may

lead to extinction od species and affect human life.

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TYPES OF CONSERVATION

• Natural habitat- preserves- protected areas

• Bio sphere reserves (7), national parks (80), wild life sanctuaries (420), gene sanctuary (botanical gardens 120)

• In-situ-within habitat

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Biosphere reserves

• Large area- > 5000 sq. km. – long term preservation

• Nanda Devi(UP)• Nokrek (Megalaya)• Manas( Assam)• Sunderbans( West Bengal)• Gulf of Mannar(Tamil Nadu)• Nilgiri ( TN, Kerala, Karnataka)• Great Nicobars & Similipal (Orissa)

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Role of biosphere Reserves

• Long time survival for evolving ecosystems• Protects maximum species and communities

& endangered species• Useful for educational and research purposes• Functions as open system- land use prohibited• No tourism / explosive activities permitted

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National parks- smaller than biosphere reserve-100-500 sq km- may be within a biosphere reserve

National parks

• Kaziranga- Assam- one horned Rhino

• Gir national Park- Gujarat – Indian lion

• Bandipur-Karnataka-Elephant• Dachigam- J&K-Hangul• Corbett- UP- Tiger• Kanha- MP- Tiger• Periyar- Kerala- Tiger, elephant• Dudwa- UP- tiger• Sariska&Ranthambore - Rajasthan-

Tiger

Role & Restrictions

• Enjoyment & Tourism without affecting environment

• Protect, propagate and develop wild life

• Grazing of domestic animals prohibited

• Private rights and private forestry prohibited

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Wild life Sanctuary- area for conservation of animals only-492 in India

Sanctuaries• Hazaribarg – Bihar-Tiger, Leopard• Ghana Bird Sanctuari-Haryana-

migratory Birds• Abohar Wild life Sanc.-Punjab- Black

Buck• Nal Sarovar- Gujarat- water Birds• Mudumalai- TN-Tiger, Elephant,

Leopard• Vedantangal- TN-water birds• Wild Ass Sanc- Gujarat-Wild Ass,

Wolf, Chinkara• Jaldapara- W. Bengal- Rhino,

Elephant, Tiger

Role and restrictions• Protects animals only• Allows harvesting of

timber, forest products, private ownership rights, forestry operations

• Killing, Hunting, shooting, capturing wild life prohibited except under control of authority

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Gene Sanctuary – for plants

In Northern India• For Citrus family• For pitcher plants

In situ conservation- merits• Cheap and convenient• Species ge adjusted to

natural disasters like drought, floods etc.

Demerits• Large area required• Maintenance difficult- due

to shortage of staff and pollution

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Ex- Situ conservation- protection outside natural habitat-mainly for crops

Role• Maintenance and breeding of

plants an danimals under controlled conditions

• Foe species which are at risk of extinction

• Preference given to those that are useful to human in near future

• Botanical gardens, seed banks, museums, zoological gardens, microbial culture, cell culture etc.

Methods of ex- situ conservation• National bureau of plant genetic

resources(NBPGR)- New Delhi• Cryopreservation- crops and

seeds at liquid N2 temp. (77K)rice, turnip, radish, carrot, chilli, tobacco etc – for several years.

• National Bureau of animal genetic resource- semen of domesticated bovine animals

• National facility for Plant tissue culture- crops and trees by tissue culture

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Merits

• Survival of endangered species on the increase- special care and attention

• Cative brreding- food , water etc. made available- longer life span

• Useful fo endangered species which have little chance of survival

Demerits

• Expensive• Freedom of wild life lost• Animals out of natural

environment- hence cannot be sent back to natural environment

• Can be adopted for selected species only.

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Biogeographical zones – characteristic climate, soil and biodiversity

S.no Biogeographic zone Biotic province Total area sq. km

1 Trans- Himalayan region Upper region-5.7% 186200

2 Himalayan mountain North-west, West, Central, east Himalayas-17%

6900,720000, 123000, 83000

3 Desert( Arid) Kutch, Thar, Ladakh-6.9% 45000, 180000, NA

4 Semi-Arid Central IndiaGujarat- Rajwara-15.6%

107600, 404400

5 Deccan Peninsula Deccan plateau- south, CentralEastern, Chotta, Central highlands-4.3%

378000,341000198000,217000287000

6 Western ghats Malabar Coast, Western Ghat Mountains

59700, 99300

7 Gangetic plane Upper and Lower gangetic planes- 11%

206400, 153000

8 North east India, islands, Coasts

Brahmaputra Valley, North eastern Hills, Andaman, Nicobar and Lakshadweep, west and east coast

65200, 106200, 6397, 1930, 180, 6500, 6500