evs 2 ecosystem

7/27/2019 Evs 2 Ecosystem

1/27

ENVIRONMENTAL SCIENCE AND ENGINEERING

UNIT 1

OBJECT:-

To develop the students fundamental knowledge on human welfare measures and the role

of a human being in eco system to maintain and save the clean environment for presentand future generations.

Environmental Engineering:-

Its the application of engineering principles to the protection and enhancement ofthe quality of the environment components and to the enhancement and protection of

public health and welfare

DefinitionEnvironment is derived from the French word Environ which means to

encircle or surround.

Environment is sum total of water, air, and land, inter-relationships amongthemselves and also with the human beings, other living organisms and property.

The above definition given in Environment Act, 1986 clearly indicates that

environment includes all the physical and biological surroundings and their interactions

Environmental Science

Its the study of the environment, its biotic (ie., biological) and abiotic (ie., non

biological) components and their interrelationshipEnvironmental Engineering

Its the application of engineering principles to the protection and enhancement

of the quality of the environment components and to the enhancement and protection ofpublic health and welfare

Environmental Studies (or) Environmental Education

Environmental studies are the process of educating the people for preserving

quality environment.

Man-made environment Its powerful environment agent

Modifies the environment using modern technologies, according to his needs to agreat extent

Created by man


2/27

Examples

House, road, schools, railway lines, parks, etc.,

SCOPE OF ENVIRONMENTAL STUDIES.

Environmental study is an important tool to educate the people for preserving

quality environment.The main scope of environmental studies include To get an awareness and sensitivity to the total environment and its

related problems. To motivate the active participation in environmental protection

and improvement. To develop skills for identifying and solving environmental

problems. To know the necessity of conservation of natural resources.

To evaluate environmental programmes interms of social,economic, ecological, and aesthetic factors.

IMPORTANCE (or) SIGNIFICANCE OF ENVIRONMENTAL STUDIES

The air we breathe, the water we drink, the food we consume and the land we liveon are all contaminated by the industrial activities.

There is no zero pollution industry. Because of the lack of self discipline and notworrying about our, future generation, the valuable resources are polluted.

To solve the above problems, the knowledge of environmental studies is veryimportant.

By environmental studies, people will understand the concept of "Need of

development without destruction of environment". Through environmental studies, people can gain the knowledge of different

types of environment and the effects of different environmental hazards.

Environmental studies inform the people about their effective role in protecting

the environment by demanding changes in laws and enforcement systems.

Environmental studies have a direct relation to the quality of life we live. Environmental studies develop a concern and respect for the environment.

NEED FOR PUBLIC AWARENESS

Increasing population, urbanisation and poverty have generated pressure on thenatural resources and lead to a degradation of the environment.

To protect or prevent the environment from the pollution,

Supreme Court has ordered and initiated the environmental awareness tothe public through Government and Non - government agencies to take part to protect our

environment.


3/27

Importance of Public (or) Community participationEnvironmental pollution cannot be removed by the laws alone.

The proper implementation and especially public participation are theimportant aspects, which should be given importance and stress.

The public participation is useful in law making process and controlling

the pollution activities.Thus the public participation plays a major role in the effectiveenvironmental management.

TYPES OF PUBLIC PARTICIPATION

Types of Public participation in the decision making process can be at anystage and of various forms.

(i) Pressure Group: The public "Pressure group" may be formed to influence thegovernment on one hand and the industries on the other hand.

(ii) Watch dog: The public can act as "watch dog" to protect the interests of publicagainst environmental hazardous activities.

(iii) Advisory council: The public can also act as advisory council and agencies, which isconstituted to keep the environment suitable for living.

(iv) Enforcing the environmental laws: The services of public can be utilized to enforcethe environmental laws. If necessary the member of public should conduct public interest

litigations.

What is an Ecosystem? Term proposed by British ecologist A. G. Tansley in 1935.

An Ecosystem is a Natural unit. Consisting of all Plants, Animals and Micro- organisms in an area functioning

together with all the physical & chemical (soil, climate, water and light) factors ofthe environment.

An ecosystem is formed by the interactions between all living and non-livingthings.

Eco = The Environment; System = regularly interacting and interdependentcomponents forming a unified whole.

DefinitionA group of organisms interacting among them and with environment is

known as ecosystem

An ecosystem is a community of different species interacting with oneanother and with their non-living environment exchanging energy and matter

Ecology :It's the study of ecosystem

Structure of an Ecosystem: Ecosystem can be described according to its Trophic structure.


4/27

The trophic structure constitutes the levels of feeding (tropic = food) and the

feeding relationships of the components of the ecosystem.

Trophic structure is the pattern of movement of energy and matter through an

ecosystem.

All ecosystems must be based upon Autotrophs.

Autotrophs (Self feeders) produce organic food for themselves and all members of

their community. The green plants (with chlorophyll) & certain bacteria produce food.

Since these organisms produce food for all the other organisms, they are known asProducers

Autotrophs (Greek; auto = self & trophe = nutrition) take energy from theenvironment in the form of sunlight or inorganic chemicals and use it to create

energy-rich molecules such as Carbohydrates. Green plants & photosynthtic bacteria are able to do this by means of

Photosynthesis, where the sun provides the necessary energy. Therefore these green plants are the autotrophic organisms or primary producers

in most ecosystems.

A Heterotrophs (Greek; heteros = another & trophe = nutrition) are anorganisms that uses organic substrates to get its chemical energy for its life cycle.

It is the component in which utilization, rearrangement & break down of complexorganic substances predominate.

They are dependant upon autotrophic organisms.

The members (organisms) of heterotrophic component are calledConsumers The heterotrophs are further categorized as: Macro- Consumers:

Heterotrophs, which in an order as they occur in a food chain are:

1) Herbivores: Also primary consumers, feed directly on living plants or plant residues.They have vegetarian diet.

2) Carnivores: Also secondary/ tertiary consumers, which feed on consumers, i.e. theyhave non- vegetarian diet.

They are also calledPredators


5/27

3) Omnivores: Consumers, which feed on producers as well as on primary consumers, i.e.they have vegetarian as well as non- vegetarian diet.

Micro-consumers: Also Saprotrophs/ Detritivores . They are popularly known asdecomposers, such as bacteria, fungi, flagellates & actinomyctes.

They feed on organic compounds of dead or living protoplasm of plants and

animals for their food and energy They absorb some of the decomposition or breakdown products & releaseinorganic compounds (nutrients) in the ecosystem, making them available again

to producers.

MACRONUTRIENTS:The nutrients, or elements used by all organisms for growth and

reproduction, are termed essential elements or macronutrients, and include Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N),

Phosphorus (P), Sodium (Na),

Sulphur (S), Chlorine (Cl),

Potassium (K), Calcium (Ca)

Magnesium (Mg).

Biogeochemical cycles:- Water

Carbon Nitrogen

Phosphorous Oxygen cycle


6/27

Elements move among compartments at different rates:-

Inorganic carbon released through respiration may be taken up quickly throughphotosynthesis. The organic carbon fixed may be respired again quickly by

plants.

Organic carbon stored in deposits of coal, oil, or peat is not readily accessible andmay remain in storage for millions of years. Inorganic carbon may also be taken out of circulation for millions of years by

precipitation as calcium carbonate in aquatic systems.


7/27

After death of the plants and animals, the organic nitrogen in dead tissues is decomposedby several micro organisms (ammonifying and nitrifying bacteria) into ammonia, nitrites

and nitrates, which are again used by the plants.

Some bacteria convert nitrates into molecular nitrogen which is again released back intoatmosphere and the cycle goes on.

Proteins, nucleic acids, and other organic chemicals contain nitrogen, so nitrogen is a

very important atom in biological organisms

Ammonification:-

Plants assimilate inorganic nitrogen into proteins, which may be passed throughvarious trophic levels.

Ammonification (dissimilation of N) is carried out by all organisms: initial step is breakdown of proteins into constituent amino acids by

hydrolysis carbon (not nitrogen) in amino acids is then oxidized, releasing ammonia

(NH3)

Nitrification is oxidation of ammonia: first step is oxidation of ammonia to nitrite (NO2

-), carried out by

Nitrosomonas in soil andNitrosococcus in oceans nitrite is then oxidized to nitrate (NO3

-) by Nitrobacter in soil and

Nitrococcus in oceans nitrification is an aerobic process; the nitrifying organisms involved are

chemoautotrophic bacteria

Denitrification is the reduction of nitrate to nitric oxide (NO), which escapes as agas:

occurs in waterlogged, anaerobic soils, oxygen-depleted sediments, andbottom waters in aquatic ecosystems

carried out by heterotrophic bacteria such as Pseudomonas denitrificans further N-reductions may lead to production of nitrous oxide (N2O) and

molecular nitrogen (N2), both gases denitrification may be one of the principal causes of low availability of

nitrogen in marine systems

Denitrification

The conversion of nitrates into nitrogen (N2) is termed as denitrification. This

process is brought about by denitrifying bacteria.

Loss of nitrogen to atmosphere by denitrification is offset by nitrogen fixation: fixation is carried out by:


8/27

free-living bacteria such asAzotobacter symbiotic bacteria such asRhizobium, living in root nodules of

legumes and other plants cyanobacteria

N-fixation is an energy-requiring process, with energy supplied by

oxidation of organic detritus (free-living bacteria), sugars supplied byplants (bacterial symbionts), or photosynthesis (cyanobacteria)

Significance of Nitrogen Fixation:-

Nitrogen fixation balances denitrification on a global basis:

these fluxes amount to about 2% of total cycling of nitrogen throughecosystems

Nitrogen fixation is often very important on a local scale: N-fixers dominate early colonizers on nitrogen-poor substrates, such as

lava flows or areas left bare by receding glaciers

Biological nitrogen fixation (by bacteria and cyanobacteria) is essential tocounterbalancing N losses associated with denitrification.

Nitrogen is often implicated as a limiting nutrient in terrestrial and aquaticsystems.

Nitrogen fixation is critical to ecosystem development in primary succession. Continued nitrogen input is essential for long-term health of natural ecosystems.

The Phosphorus Cycle:-

Phosphorous is an essential element, constituent of nucleic acids, cell membranes,energy transfer systems, bones, and teeth.

Phosphorus may limit productivity: in aquatic systems, sediments act as a phosphorus sink unless oxygen-

depleted in soils, phosphorus is only readily available between pH of 6 and 7

Phosphorus undergoes relatively few transformations:

plants assimilate P as phosphate (PO43-) and incorporate this into organic

compounds

animals and phosphatizing bacteria break down organic forms ofphosphorus and release the phosphorus as phosphate

phosphorus does not: undergo oxidation-reduction reactions in the ecosystem

circulate through the atmosphere, except as dust


9/27

The Sulfur Cycle :- Sulfur is an essential element and, like nitrogen, has many oxidation states and

follows complex chemical pathways. Sulfurreduction reactions include:

assimilatory sulfate reduction to organic forms and dissimilatory oxidation

back to sulfate by many organisms reduction of sulfate when used as an oxidizer for respiration byheterotrophic bacteria in anaerobic environments

Sulfuroxidation reactions include:

oxidation of reduced sulfur when used as an electron donor (in place ofoxygen in water) by photosynthetic bacteria

oxidation of sulfur by chemoautotrophic bacteria that use the energy thusobtained for assimilation of CO2

Energy flow in Eco System:-

All organisms must obtain a supply of energy and nutrients from theirenvironment in order to survive.

The transformations of energy in an ecosystem begin first with the input of energyfrom the sun.

Because, it is the first step in the production of energy for living things, it is calledPrimary production.

Photosynthesis -- Chemical reaction where green plants use water & carbondioxide to store the suns energy in glucose.

ENERGY is stored in glucose. Glucose is stored as starch in plants


10/27

Energy flow cannot occur in reverse direction.

Starts from autotrophic (the producer level, i.e., first trophic level) toHeterotrophic including plant eaters or Herbivores (second trophic level) and so

on.

The amount of energy decreases with successive trophic levels. Only About 1% of energy from the sun is used by green plants & rest remainsunutilized.

Similarly, there is loss of energy in each trophic level.

Ecological Succession:

Ecological succession is defined as, A change in the community in which new

populations of organisms gradually replace existing ones. There are two types of ecological succession:

1) Primary Succession: Occurs where there is no soil, e.g. after a volcanic eruption or a glacial retreat.

Pioneer organisms Simple plants first no or shallow roots.

Gradual influx of more complicated and larger plants as the habitat changes Unfavorable for life at first.

Ends with a climax community ecosystem stays constant, providedthere are no changes in abiotic influences.

2) Secondary Succession:

Community development in the areas that were previously occupied by a othercommunity.

Occurs after a disturbance. E.g., loss of trees after disease, Fire or wind,deforestation etc.

Conditions are favorable for as soil and nutrients are already present. More rapid than primary succession.

Primary Succession Vs Secondary Succession:

No soil.

Pioneer species. Weathering & decomposition

Humus and sand increase over time.End = climax community

Vs

Soil already exists.

Seeds have suitable soil. conditions. Occurs much faster.


11/27

Climax community.

Energy flow in ecosystem:

The transfer of food energy between the organisms in an ecosystem can betracked by constructing food chains, food webs, pyramids of numbers, biomassand energy and energy flow diagrams.

Food Chain: A food chain may be defined as, the transfer of energy and nutrients through a

series of organisms with repeated process of eating and being eaten. In an ecosystem, all the organisms are linked together with one another by food

relationship.Each organism living or dead is potential food for some other organism

Food web:

Under natural conditions, the linear arrangement of food chains hardly occurs &these remains connected interconnected with each other through different types of

organisms. Interlocking pattern of several interlinked food chains is termed as FOOD WEB.

An Ecological pyramid is a graphical representation that shows the relative

amounts of energy or matter contained within each trophic level in a food chain orfood web.

An ecological pyramid shows the relationship between consumers and producersat different trophic levels in an ecosystem

There are three ecological pyramids recognized by ecologists:1) Pyramid of Numbers:

Shows the relative number of individual organisms at each trophic level.2) Pyramid of Biomass:

A pyramid of biomass represents the total dry mass (in grams per square metre ofarea) of all the organisms in each trophic level at a particular time.

3) Pyramid of Energy: A pyramid of biomass represents the rate of energy flow and/or productivity at

successive trophic levels. The pyramid of energy are always upright.

Forest Ecosystem:

Apart from environmental values, forest ecosystems have some traditional valuesas well.

Examples are: Fire Wood & Timber.

Fruits. Gums.

Herbs & drugs. The various components of a Forest Ecosystem are:


12/27

Biotic components: The various biotic components, representatives from thethree functional groups, of a forest ecosystem are:

1) Producer Organisms: In a forest, the producers are mainly trees.

Trees are of different kinds depending upon the type of forest developed in that

climate.

Apart from trees, climbers, epiphytes, shrubs and ground vegetation.

Dominant species of trees in major types of forest ecosystems are: Tectona grandis, Acer, Betula, Picea, Pine, Cedrus.

2) Consumers: In a forest, consumers are of three main types;

a) Primary Consumers:

These are Herbivores which feed directly on producers. E.g.

Ants, Beetles, Bugs, spiders etc. feeding on tree leaves. Larger animals such as Elephants, Deer, giraffe etc. grazing

on shoots and/or fruits of trees.b) Secondary Consumers:

These are carnivores and feed on primary consumers. These include Birds, Lizards, Frogs, Snakes, Foxes, etc.

c) Tertiary Consumers:

These are secondary carnivores and feed on secondary consumers

These include top carnivores like Lion, Tiger, etc.3) Decomposers:

These include wide variety of saprotrophic micro- organism like;Bacteria (Bacillus Sp., Clostridium sp.,pseudomonas, etc.)

Fungi (Aspergillus sp., Ganoderma sp., Fusarium, etc.)Actinomycetes (Streptomyces, etc).

They attract the dead or decayed bodies of organisms & thus decomposition takesplace.

Therefore, nutrients are released for reuse.Abiotic components:

These include basic inorganic & organic compounds present in the soil &atmosphere.

In addition dead organic debris is also found littered in forests.

Grassland Ecosystem:

Grasslands (also called Greenswards) are areas where the vegetation is dominatedby grasses and other herbaceous (non-woody) plants.

Grasslands occupy about 24% of the earths surface. Grasslands occur in regions too dry for forests and too moist for deserts

The annual rainfall ranges between 25- 75 cm, Usually seasonal The highest abundance & greatest diversity of large mammals are found in these

ecosystems. The dominant animal species include


13/27

Wild horses, asses & antelope of Eurasia, Herds of Bison of America; and

The antelope & other large herbivores of Africa The various components of a grassland Ecosystem are:

Biotic components: Three functional groups which are:

1) Producer Organisms: In grassland, producers are mainly grasses; though, a few herbs & shrubs also

contribute to primary production of biomass. Some of the most common species of grasses are:

Brachiaria sp., Cynodon sp., Desmodium sp., Digitaria sp.

2) Consumers: In a grassland, consumers are of three main types;

a) Primary Consumers:

The primary consumers are herbivores feeding directly on grasses. These are

grazing animals such as Cows, Buffaloes, Sheep, Goats, Deer, Rabbits etc.

Besides them, numerous species of insects, termites, etcare also present.

b) Secondary Consumers:

These are carnivores that feed on primary consumers (Herbivores)

These include; Frogs, Snakes, Lizards, Birds, Foxes, Jackals etc.

c) Tertiary Consumers: These include hawks etc. which feed on secondary consumers.

3) Decomposers:

These include wide variety of saprotrophic micro- organism like:

Bacteria; Fungi; Actinomycetes They attract the dead or decayed bodies of organisms & thus decomposition takes

place. Therefore, nutrients are released for reuse by producers.

Abiotic components:

These include basic inorganic & organic compounds present in the soil & aerialenvironment.

The essential elements like C, H, N, O, P, S etc. are supplied by water, nitrogen,nitrates, sulphates, phosphates present in soil & atmosphere.

Desert Ecosystem:

A desert is a landscape orregion that receives almost noprecipitation


14/27

Deserts are defined as areas with an average annual precipitation of less than250 millimeters per year.

It occupy about 17% of the earths surface. Deserts are characterized by hot days & cold nights.

The deserts of the world are mainly located in the

South- western United States, Mexico, North America, Asia (Thar, Gobi, Tibet )& west Asia. Deserts are characterized by scanty flora & fauna.

Soils of deserts often have abundant nutrients but little or no organic matter.

The various components of a Desert Ecosystem are:Biotic components:

1) Producer Organisms: In a desert, producers are mainly shrubs/bushes; some grasses & a few trees.

Dominant plant species include: Succulents (water - retaining plants adaptedto arid climate or soil conditions ) & hardy grasses.

Besides some lower plants such as lichens & xerophytic mosses are also present.2) Consumer Organisms: These include animals such as insects, reptiles which are

capable of living in xeric conditions Besides some nocturnal rodents, birds & some mammalians like camel etc are

also found.3) Decomposers:

Due to poor vegetation with very low amount of dead organic matter,decomposers are poor in desert ecosystem.

The common decomposers are some bacteria & fungi, most of which arethermophillic.

Abiotic components:

Due to high temperature & very low rainfall, the organic substances are poorlypresent in the soil.

Aquatic Ecosystems:

Aquatic ecosystems deal with biotic community present in water bodies.

In terrestrial ecosystem, carbon dioxide & oxygen are present in gaseous formwhereas in aquatic ecosystem, these are available in dissolved state.

Depending upon the quality and nature of water, the aquatic ecosystem arecategorized into:

Freshwater Ecosystem and Marine Ecosystem.

Freshwater Ecosystems: Freshwater ecosystems cover 0.8% of the Earth's surface and contain 0.009% of

its total water. Freshwater ecosystems contain 41% of the world's known fish species.


15/27

Aquatic ecosystems perform many important environmental functions. Forexample:

They recycle nutrients, purify water, attenuate floods, recharge groundwater and provide habitats for wildlife.

Aquatic ecosystems are also used for human recreation, and are very

important to the tourism industry, especially in coastal region. There are three basic types of freshwater ecosystems: Lentic: slow-moving water, including Pools, Ponds, and Lakes.

Lotic: rapidly-moving water, for example Streams and Rivers. Wetlands: areas where the soil is saturated with water or

inundated for at least part of the time

Lakes & pond Ecosystem:

A pond is a place where living organisms not only live but interact with biotic &abiotic components.

Ponds are often exposed to tremendous anthropogenic pressure whichsignificantly affects the system.

Lakes are usually big standing freshwater bodies. They have a shallow water zone calledLittoral zone; an open water zone where

effective penetration of solar light takes place, calledLimnetic zone and a deepwater zone where light penetration is negligible, calledProfoundal zone.

Biotic components:

1) Producer Organisms: It includes submerged, free floating and amphibious macrophytes (like;Hydrilla,

Utricularia, Wolfia, Azolla, Typha etc.) and minute floating and suspended lowerphytoplanktons (like; Ulothrix, Spirogyra, Oedogonium etc.)

2) Consumer Organisms:a) Primary consumers: These are zooplanktons (ciliates, flagellates, other protozoan,

small crustaceans) and benthos.b) Secondary consumers: These are carnivores like insects and fishes feeding on

herbivoresc) Tertiary consumers: These are the large fishes feeding on small fishes.

3) Decomposers: Micro organisms like bacteria, fungi and actinomyctes.

Abiotic component: These are the inorganic as well as organic substances present in the bottom soil or

dissolved in water. In addition, to the minerals, some dead organic matter is alsopresent.

Marine or Ocean Ecosystem:

Marine ecosystems are among the Earth's aquatic ecosystems. They

include: Oceans, Estuaries and Lagoons, Mangroves and Coral reefs, the Deepsea and the Sea floor.


16/27

These are the gigantic reservoirs of water covering approximately 71% ofthe Earth's surface (an area of some 361 million square kilometers).

These ecosystem is different from freshwater ecosystem mainly because of itssalty water.

The salt concentration in an open sea is usually 3.5% (35 parts per thousand (ppt)

). Dominant ions are sodium & chloride. Average temperature of Marine ecosystem is 2-3 degree centigrade, devoid oflight.

Biotic components:

1) Producers: It includes phytoplanktons (diatoms, dinoflagillates), large seaweeds(mainly algae like chlorophyceae, phaeophyceae & rhodophyceae; angiosperms like

Ruppia, Zostera, posidonia etc.), and mangrove vegetation (likeRhizophora, Carapaetc.)

2) Consumers:a) Primary consumers: These are herbivores and feed directly on producers (Crustaceans,

Mollusks, fish etc.)b) Secondary consumers: These are carnivorous fishes(Herring, Sahd and Mackerel)

c) Tertiary consumers: These are top carnivorous fishes (Cod, Haddock, etc.)3) Decomposers: These are micro organisms like bacteria, fungi

Abiotic components:

High Na, Ca, Mg and K salt concentration, variable dissolved oxygen content,light & temperature make a unique physiochemical conditions in marine water.

BIOGEOGRAPHICAL CLASSIFICATION OF INDIAThe Biographic zone The Himalaya, The western gatsThe Biotic Province particular community

The Land Region ex - Aravalli mountains, Gujarat Rajwara province

India is classified into 10 biogeographic zones, further divided into 26 biotic

provinces.1. Trans-Himalaya with 2 provinces2. The Himalaya with 4 provinces

3. The Indian desert with 2 provinces4. The semi Arid zone with 2 provinces

5. The western Ghats with 2 provinces6. The Deccan peninsula with 5 provinces

7. The gang etic plain with 2 provinces8. The coasts with 3 provinces

9. North east india with 2 provinces10. The islands with 2 provinces


17/27

Biodiversity:

Biodiversity is the variety and differences among living organisms from allsources, including terrestrial, marine, and other aquatic ecosystems and the

ecological complexes of which they are a part.

It is virtually synonymous with Life on earth. Biologists most often define "biological diversity" or "biodiversity" as the"totality of genes, species, and ecosystems of a region".

The biodiversity found on Earth today consists of many millions of distinctbiological species, which is the product of nearly 3.5 billion years of evolution.

Levels of Biodiversity:

1) Genetic diversity:It is a level of biodiversity that refers to the total number of genetic characteristics in the

genetic makeup of a species.

It is distinguished from genetic variability, which describes the tendency ofgenetic characteristics to vary.

2) Species diversity:

It refers to the variety of species within a region.

Species diversity is an index that incorporates the number of species in an areaand also their relative abundance.

It is generally a much more useful value than species richness.

3) Community and Ecosystem diversity:

Ecosystem diversity refers to the diversity of a place at the level of ecosystems.This has 3 perspective:

Alpha Diversity: Within community diversity. Alpha diversity refers to the

diversity of organisms sharing the same Community/Habitat.

Beta Diversity: Between community diversity. It refers to the diversity oforganisms sharing two habitat.

Gamma Diversity : Diversity of the habitat over the total landscape or

geographical area is called gamma diversity

Values of Biodiversity: Food: About 80,000 edible plants and about 90% of present day food crops have

been domesticated from wild.


18/27

Drugs & Medicines: About 75% of worlds population depend on plants or plantextracts.

Fuel: Forests have been used since ages for fuel wood. Fossil fuels are alsoproducts of Biodiversity.

Social Value: Many of the plants like Tulsi, Lotus, Peepal etc are considered holy

and sacred.

About 2.1 million species have been identified till date, while many more species

are believed to exist. According to UNEP estimate, approximately 9.0 52 million of species exist on

Earth

SIGNIFICANCE OF BIODIVERSITY1. Its very important for human life

2. It protects the fresh air, clean water and productive land3. It is also important for forestry, fisheries and agriculture, which depends on rich

variety of various biological resources available in nature4. Loss of biodiversity has serious economic and social costs for any country

Loss of biodiversity1. The farmers prefer hybrid seeds, as a result, many plant species become extinct2. Pdn of drugs- wild life, medical plant extinct

3. Tropical forest medicine use

GLOBAL BIODIVERSITY Total no. of living species in the world-about 20 millions.

But Roughly 2.1 million species are known till date and given scientific names

Most of the worlds bio-rich nations are in the south developing nations.

Tropical deforestation alone reducing the biodiversity 0.5% every year About 70% of all known species are invertebrates (animals without backbones

such as insects, sponges, worms, etc.); while, about 15% are plants.

Terrestrial biodiversity (or) BiomassIts the largest ecological unit present in different geographic areas

Ex: Tropical rain forest, Savannas, Desert, Tundra, etc.,

Tropical rain forestLargest storehouse of biodiversityAbout 50 to 80% of global biodiversity lies in these rainforests

1. medicinal plants:More than one-fourth of the worlds prescription drugs are extracted from

plants growing in tropical forests.

2. flowering plants1, 30,000 = flowering plants species are available

Till we know only 1-3% of these plant species


19/27

Temperate forestsIt have much less biodiversity.

Globally, we have roughly

1, 70,000 = flowering plants

30,000 = vertebrates

2, 50,000 = other groups of speciesMarine diversityMuch higher than terrestrial biodiversity

Less known and describedEx: protozoan's (31,000), bacteria(5,000), algae(27,000), fungai (mushrooms) 45,000,

higher plants (2,50,000), jelly fish, corals etc. (10,000), sponges(5,000),worms(36,000),insects (7,50,000), snails, fish birds. (Total- 1,400,000)

The species richness depends on the following environmental conditions:

Warmer areas hold more species than the colder areas; Wetter areas hold more species than the drier ones;

Areas of varied climate and topography hold more species than the areas ofuniform climate and topography; Areas at lower altitude (elevation) hold more species than the high altitude areas;

Less seasonal areas hold more species than the highly seasonal areas.

BIOLOGICAL DIVERSITY AT NATIONAL LEVEL

INDIAN BIODIVERSITY: Every country is characterized by its own biodiversity depending mainly on its

climate.

India has a rich biological diversity of flora and fauna. Overall 6% of the global species are found in India.

It is estimated that India ranks 10th among the plant rich countries of the world, India ranks 11th in terms of number of endemic species of higher vertebrates. India ranks 6th place among the centres of diversity and origin of agricultural

crops.

The total number of living species identified in our country is 150,000. Indian is also one of the 12 mega-biodiversity countries in the world.

Out of a total of 25 biodiversity hot-spots in the world, India possesses 2, one in

the northeast region and second one in the western Ghats.

MEDICINAL VALUEMore than 2000 plants are cultivated , which can cure many disease

Ex: Neem and Tulsi and turmeric

COMMERCIAL VALUE:

sandal, Indian tobacco, non-wild edible mushrooms, plants, flower, fruits

and micro organisms


20/27

MEGA DIVERSITYContain 70% our planets biodiversity

India is one of the 12 mega diversity countries in the world.

Australia Brazil

China ColumbiaEcuador The United StatesIndia Indonesia

Madagascar MexicoPeru The democratic Republic of Congo

India occupies 2.4% of the total land area of the world, but India contributes

8.22% of the known global biodiversity. India is in the 10

thposition in the world and fourth in the Asia in terms of plant

diversity.

India ranks 10

th

in the world in terms ofnumber of mammalian species India ranks 11

thin the world in terms ofendemic species of higher vertebrates

In terms of number of species contributed to agriculture and animal husbandry, it

ranks 7th

in the world. India has three biomes, namely the tropical humid forests, the tropical dry

deciduous forests and the warm desert/semi-deserts. India can be divided into10 biogeographic zones and 26 biotic provinces which represent the major

ecosystems of the world. Out of 25 hotspots in the world, India has two hotspots. the Western Ghats and

the Eastern Himalayas.

Endemism:The species which are restricted only to a particular area are known as endemic.

About 62% of amphibians and 50% of lizards are endemic to India. Western Ghats arethe site of maximum endemism. India has 26 recognized endemic centres.

Biosphere reserves:

Which protect larger areas of natural habitat ,it includes National Parks, preserves,along buffer zones that are open to some economic uses. The World has 482 biosphere

reserves in 102 countries.


21/27

The Ministry of Forests and Environment (MOEF) reports that India has at

present 89,317 species of fauna and 45,364 species of flora representing about7.31% of the world fauna and 10.88% the world flora described so far.

PLANT DIVERSITY:India has been the center of origin for

Flowering plants - 5000 species Cultivated crop plants - 166 species

Wild crops - 320 species

MARINE DIVERSITY:The number of zooplankton recorded is about 16,000 species. Over 30 species of

marine algae and 14 species of sea grass have been reported. There are over 45 species of

mangrove plants. Over 342 species of corals have been reported and about 50% of theworlds reef building corals are found in India.

AGRO BIODIVERSITY:

Cultivated crop plants - 166 speciesIndia has been the center of origin for 30,000 to 50,000 varieties of rice, mango,

turmeric, ginger, sugarcane, etc.,

HOT SPOTS OF BIO-DIVERSITY: Areas which exhibit high species richness as well as high species endemism are

termed as hot spots of biodiversity.

Hotspots are the main areas of focus for biodiversity conservation.

These are the areas that are extremely rich in biodiversity, have high level ofendemism, and are under constant threat of species extinctions and habitat

destruction. Myers et al (2000) recognized 25 hot spots ay global level. Out of 25, two are

present in India, namely the Eastern Himalayas and Western Ghats.

Nearly 70% of the bird species in this hotspot are endemic. These are the areas ofhigh diversity, endemism and are also threatened by human activities.

About 40% of terrestrial plants and 25% of vertebrate species are endemic andfound in these hotspots.

It has been estimated that 50,000 endemic plants, which comprise 20% of global

plant life, probably occur in only 18 hotspots in the world. Countries which have a relatively large proportion of these biodiversity hotspots

are referred to as mega-diversity nations..

Reason for rich biodiversity in the tropics1. More stable climate2. Warm temp and high humidity provide favorable conditions

3. No single species can dominate many species to coexist


22/27

4. Among plants, rate of out-crossing appear to be higher in tropics

HOTSPOTS IN INDIA: Indo- Burma (earlier The Eastern Himalayas) and

The western Ghats & Sri Lanka

EASTERN HIMALAYAS: The area comprises Nepal, Bhutan, and neighbouring states of northern India,

along with some place of the Yunnan province in Southwest china. All Himalayan forests lie north of the Tropic of Cancer, and some of them are at

attitudes of 1780 -3500 m, they can be considered tropical forests. The Eastern Himalayas display an varied topography, a factor that fosters species

diversity and endemism.

Many deep and semi-isolated valleys are exceptionally rich in endemic plantspecies,

In Sikkim, in an area of 7298 km2 , of the 4250 plant species , 2550 (60%) are

endemic.

In Indias sector of the area, there are about 5800 plant species of which roughly2000(36%) are endemic. In Nepal, there are around 7000 plant species, many of which overlap with those

of India, Bhutan, and even Yunnan. OF these species atleast 500(8%) are believedto be endemic to Nepal.

Bhutan possesses an estimated 5000 species, of which as many as 750 (15%) are

considered to be endemic to the Eastern Himalayas

Western Ghats: Out of India 49219 plant species , 1600 endemics(40% of the total number of

endemics) are found in an 17000km2

along the sea side of the Western Ghats The area comprises Maharashtra, Karnataka, TamilNadu, Kerala Forest track up

to 500 in elevation.

One fifth of the entire forest expanse, are mostly evergreen, while those in 500-1500 m range are semi- evergreen.

There are two main centres of diversity, the Agasthyamalai Hills and the SilentValley/New Amambalam Reserve Basin. The forest cover in Western Ghats has

reduced 34 % from 1972- 1989.

THREATS TO BIO-DIVERSITY

Extinction or elimination of a species is a natural process of evolution.

However, the rate of loss of species in geologic past has been a slowprocess.

The process of extinction has become particularly fast in the recent yearsof human civilization

One of the estimates by E O. Wilson puts the figure of extinction at 10,000species per year.


23/27

MAJOR CAUSES FOR LOSS OF BIODIVERSITYHabitat Loss

The major proximate causes of species extinction, affecting 89% of all threatenedbirds, 83% of mammals and 91% of all threatened plants assessed globally

The main causes( factor) of habitat loss are Agricultural activities ( deforestation)

Raw material and production of drugs Destruction of wetlands ( draining, filling and pollution)

Habitat fragmentation

Harvesting or extraction (including mining, fishing, logging, etc.) and

Development of human settlements, Industry and Associated infrastructure.

POACHING: Poaching is another threat to living species. ( killing of animal)

Wildlife is sold for live specimens, folk medicines, furs, hides, skin (or leather)

and other products such as ivory, antlers and horns.1. Subsistence poaching provide enough food

2. Commercial poaching sell their products

Factors:Human population

Commercial activities

Man-Wild Life ConflictsWhen wildlife starts causing immense damage and danger to man and under such

conditions it becomes very difficult for the forest department to pacify the affectedvillagers and gain local support for wild-life conservation.

Ex: In Sambalpur, Orissa 195 humans were killed in the last 5 years by elephants. In

retaliation the villagers killed 98 elephants and badly injured 30 elephants. Several instances of killing of elephants in the border regions of Kote-

Chamarajanagar belt in Mysore because of the massive damage done by the

elephants to the farmers cotton and sugarcane crops. Recently, in early 2004, a man-eating tiger was reported to kill 16 Nepalese

people and one 4- year old child inside the Royal Chitwan National Park, 240 KmSouth-west of Kathmandu.

Causes of Man- Wild life conflicts due to shrinking forest cover compels them to move outside the forest

Usually the ill, weak and injured animals have a tendency to attack man.

Very often the villagers put electric wiring around their ripe crop fields. Theelephants get injured, suffer in pain and turn violent.

ENDANGERED AND ENDEMIC SPECIES:According to The International Union of Conservation of Nature and Natural

Resources (IUCN), the species are classified into various types


24/27

Extinct speciesTo be extinct, no longer found in the world

Endangered speciesTo be endangered, when its number has been reduced to a critical level

Vulnerable speciesWhen its population is facing continuous decline due to habitat destruction or

over exploitation

Rare speciesWhen its localised within restricted area.

ENDANGERED AND ENDEMIC SPECIES IN INDIA In India, nearly 450 plant species have been identified in the categories of

endangered, threatened or rare.

150 mammals and 150 species of birds is estimated to be threatened while anunknown number of species of insects are endangered.

Reptiles:Gharial, green sea turtle, tortoise, python

Birds:Great indian bustard,Peacock,

Pelican,Great indian hornbill,

Siberian white crane

Carnivorous:Indian wolf,Red fox,

Sloth bear,Red panda,

Mammals tiger, leopard, striped hyena, Indian lion, golden cat, desert cat

Primates:Hoolock gibbon, lion-tailed macaque, Nilgiri langur, Capped monkey, golden

monkey

Plants:A large number of species of orchids, Rhododendrons, medicinal plants like

Rauvolfia serpentina, the sandal wood tree Santalum, Cycas beddonei

ANIMALS Critically endangered = 10 Endangered animals= 54

Vulnerable animals= 143


25/27

Near threatened= 99

PLANTS Critically endangered plants= 44 Endangered plants= 113

Vulnerable plants= 87 Near threatened=38

Some of the animal species that have been identified as endangered or threatened

mammals are listed below: Golden monkey,

Indian wolf, Jackal Red fox, Indian fox

Wild dog, Himalayan brown beer

Red panda, Tiger

Indian Lion, Leopard, Desert Cat

Jungle Cat, Leopard Cat Golden Cat, Indian wild ass

The endemism of Indian biodiversity is quite high.

About 33% of the countrys flora are endemic to the country and are concentrated mainly

in the North-East, Western Ghats,

North-West Himalaya and

The Andaman and Nicobar Islands.

Out of about 47,000 species of plants in our country 7000 are endemic.

Thus, Indian subcontinent has about 62% endemic flora, restricted mainly toHimalayas, Khasi Hills and Western Ghats

A large number out of a total of 81,000 species of animals in our country isendemic.

The Western Ghats are particularly rich in Amphibians (frogs, toads etc.) and

Reptiles (lizards, crocodiles etc.).

About 62% amphibians and 50% lizards are endemic to Western Ghats.

Conservation of Biodiversity

The convention on Biological Diversity held in June, 1992 stressed the need ofthe conservation of Biodiversity for sustainable development and perpetuation of

human beings on earth.Definition : The act or process of conserving. The protection, preservation,

management, or restoration of wildlife and of natural resources such as forests, soil, andwater.


26/27

Conservation is defined as The management of human use of the biosphere

so that it may yield the greatest sustainable benefit to the present generation

while maintaining its potential to meet the needs and aspirations of the future

generations.

Conservation of our natural resources has the following three specific objectives:

(i) To maintain essential ecological processes and life-supporting systems(ii) To preserve the diversity of species or the range of genetic material found in the

organisms on the planet; and

(iii) To ensure sustainable utilization of species and ecosystems which supportmillions of rural communities as well as the major industries all over the world.

The two basic approaches to wildlife conservation in protected habitats are:

1) In- situ conservation and

2) Ex- situ conservation

In situ conservation (within habitat):This is achieved by protection of wild flora and fauna in nature itself, e.g.

Biosphere Reserves, National Parks, Sanctuaries, Reserve Forests etc.

Ex situ conservation (outside habitats)This is done by establishment of gene banks, seed banks, zoos, botanical gardens,

culture collections etc.

IN- SITUCONSERVATION: It simply means conservation of species in its natural ecosystem or even in man

made ecosystems. This strategy emphasizes protection of total ecosystem through a network of

protected area. Protected Areas: an area of land and/or sea specially dedicated to the protection

and maintenance of biological diversity and managed through legal effectivemeans.

There are different categories ofprotected areas which are managed withdifferent objectives. These include; Biosphere reserves,National parks, Wild

Life Sanctuaries etc. At present we have 11 major biosphere reserves, 80 National parks, 420 wildlife

sanctuaries in our country covering 4% of the geographic area. The JIM CORBETT National Park was 1

stnational park established in India.

Examples of Biosphere reserves of India:

1. Nilgiri- 5,520 sq.km2. Nanda Devi- 5,860.69 sq. km


27/27

3. Manas 2837 sq. km4. Gulf of Mannar 10,500 sq. km

5. Great Nicobar 885 sq. km6. Panchmarhi 4,926.28 Sq Km

Examples of some National park in India1. Kaziranga- Assam, Gir National Park- Gujarat, Periyar Kerala, Sariska Rajasthan

Examples of some Wild Life Sanctuaries of India:

1. Ghana Bird sanctuaries2. Hazaribagh sanctuaries

3. Abohar wild life sanctuaries4. Jaldapara wild life sanctuaries

5. Mudamalai wild life sanctuaries

Ex- situ conservation:

It is defined as the conservation of component of biological diversity (Sample ofgenetic diversity, particularly of endangered species) outside their natural

habitats. It involves maintenance and breeding of endangered plant and animal species

under partially or wholly controlled conditions. E.g. Zoos, Botanical Gardens,Aquaria, Nurseries, DNA bank, Seed bank, Gene bank etc.

There are more than 1500 Botanical gardens in the world containing more than80,000 species.

There are more than 800 zoos around the world with about 3,000 species ofmammals, birds, reptiles and amphibians.

In India, we have many gene bank. The important ones are:

National Bureau of Plant genetic Resources (NBPGR), New Delhi: Agricultural and horticultural crops and their wild varieties are preserved by cryo-

preservation of seeds (at -196 C in Liquid Nitrogen), pollen etc.

National Facility for Plant Tissue Culture Repository (NFPTCR) at NBPGR

Campus New Delhi: It has been set up for the development of a facility of conservation of varieties of

crop plants/ trees by tissue culture.

evs 2 ecosystem

Documents