Environment, Ecosystems and Biodivdersity

7/29/2019 Environment, Ecosystems and Biodivdersity

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Paavai Institutions Department of ECE

Unit - I 1.1

UNIT - 1

ENVIRONMENT, ECOSYSTEM

AND BIODIVERSITY


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Unit - I 1.2

CONTENTS

1.1 Definition, Scope and Importance

1.1.1 Definition

1.1.2 Scope

1.1.3 Importance

1.2 Need for Public Awareness

1.3 Concept of Ecosystem

1.4 Structure and Functions of Ecosystem

1.4.1 Structure of Ecosystem

1.4.2 Functions of Ecosystem

1.5 Producers, Consumers and Decomposers

1.6 Energy Flow in Ecosystem

1.7 Ecological Succession

1.7.1 Primary succession

1.7.2 Secondary succession

1.8 Food Chain

1.9 Food Web

1.10 Ecological Pyramids

1.10.1 Pyramid of Numbers

1.10.2 Pyramid of Biomass

1.10.3 Pyramid of Energy

1.11 Forest Ecosystem

1.11.1 Introduction


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Unit - I 1.3

1.11.2 Types

1.11.3 Characteristics

1.11.4 Structure and Functions of Forest Ecosystem

1.12 Grassland Ecosystem (Terrestrial Ecosystem)

1.12.1 Introduction

1.12.2 Types



1.13 Desert Ecosystem

1.13.1 Introduction

1.13.2 Types



1.14 Aquatic Ecosystems

1.14.1 Introduction

1.14.2 Freshwater Ecosystem

1.14.2.1 Lake and Pond Ecosystem

1.14.2.2 Stream Ecosystem

1.14.2.3 River Ecosystem

1.14.3 Marine or Ocean Ecosystem

1.14.4 Estuary

1.15 Biodiversity

1.15.1 Genetic diversity

1.15.2 Species diversity

1.15.3 Ecosystem diversity

1.16 Biogeographical Classification of India


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Unit - I 1.4

1.16.1 Indias biogeographical zones

1.17 Values of biodiversity

1.17.1 Consumptive use

1.17.2 Productive use

1.17.3 Social value

1.17.4 Ethical and Moral value

1.17.5 Aesthetic value

1.17.6 Option value

1.18 Biodiversity at global, national and local levels

1.19 India as a Mega diversity nation

1.20 Hotspots of biodiversity

1.20.1 Criteria for Determining Hotspots

1.21 Threats to Biodiversity

1.21.1 Habitat loss, degradation, fragmentation

1.21.2 Poaching of Wildlife

1.21.3 Human Caused Reduction

1.21.4 Hunting

1.22 Man - Wildlife Conflicts

1.23 Endangered and Endemic Species of India

1.24 Conservation of Biodiversity

1.24.1 In-situ conservation

1.24.2 Ex-situ conservation


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Unit - I 1.5

TECHNICAL TERMS

1. Environment: Sum total of water, air, and land, inter-relationships among themselves and

also with the human beings, other living organisms and property.

2. Abiotic Environment: Physical environment consisting of air, water and soil or sediment

3. Biotic Environment: Biological environment consists of flora, fauna and micro-

organisms.

4. Biosphere: The part of lithosphere, hydrosphere and atmosphere in which living

organisms live and interact with one another is called biosphere

5. Ecosystem: A group of organisms interacting among themselves and with environment.

6. Ecology: Study of the distribution and abundance of organisms, the flows of energy and

materials between abiotic and biotic components of ecosystems.

7. Energy flow: The flow of energy from producer level to top consumer level.

8. Ecological succession: The gradual change in species composition of a given area.

9. Food chain: Sequence of eating and being eaten in an ecosystem.

10. Food web: Most consumers feed on more than one type of organism, and most organisms

are eaten by more than one type of consumer. This interrelated food chains form food web.

11. Ecological pyramid: The trophic structure and function at successive trophic levels

12. Producers: Biotic component which can manufacture food.

13. Consumers: Organisms which cannot prepare its own food.

14. Decomposers: Bacteria and fungi that attack the dead bodies of producers and consumers

and decompose them into simpler compounds.

15. Bio diversity or Biological diversity: The total variety of life on our planet, total number

of races, varieties of species, the sum of the various types of microbes, plants and animals

present in a system.


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Unit - I 1.6

16. Ecological diversity: The richness and complexity of a biological community, including

tropic levels, ecological processes (which capture energy), food webs and material recycling.

17. Species diversity: The number of kinds of organisms within individual communities orecosystems.

18. Genetic diversity: The total number of genetic characteristics in the genetic makeup of a

species.

19. Bio diversity hotspots: Biogeographic region with a significant reservoir

of biodiversity that is threatened with destruction.

20. Ex-situ conservation: Flora and fauna are preserved outside natural habitats.

21. In- situ conservation: Flora and fauna are preserved with in natural habitat.


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Unit - I 1.7

UNIT - 1

ENVIRONMENT, ECOSYSTEM AND BIODIVERSITY

1.1DEFINITION, SCOPE AND IMPORTANCE1.1.1 Definition

Environment is derived from the French word Environ which means to encircle or

surround. It is the total of water, air, and land, inter-relationships among themselves and

also with the human beings, other living organisms and property.

Figure 1.1: Concept of Environment

Environmental science is the study of nature and the facts about environment.

Figure 1.2: Types of Environment


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Unit - I 1.8

1.1.2 Scope

Scope of environmental science is broad. Some of the aspects of scope of environmental

science are:

Studying the interrelationships among biotic and abiotic components for sustainable

human ecosystem,

Carrying out impact analysis and environmental auditing for the further catastrophic

activities

Developing and curbing the pollution from existing and new industries.

Stopping the use of biological and nuclear weapons for destruction of human race,

Managing the unpredictable disasters and so on.

There are some major issues like global warming, depletion of ozone layer, dwindling

forests and energy resources, loss of global biodiversity etc., that are going to affect

the mankind as a whole and for that we have to think globally.

1.1.3 Importance According to ancient man the environment was the Panchaboodhas (i.e) air, water,

land, sky and energy. The human were disciples of nature. They were able to protect

themselves from harmful one and protect the others. But according to modern man the

environment. is only air land and water. Exploitation of various earth resources to

satisfy the increasing needs of human population has resulted in 1) depletion of

various resources of earth 2) pollution. Principles of environmental education:

Examine the major environmental issues

Discover the root cause

Develop problem solving skills

Promote co-operation in solving problems

Emphasis active participation in prevention and solution to problems

1.2 NEED FOR PUBLIC AWARENESS

Public awareness is very essential to help understand pros and cons of environmental

problems.


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Unit - I 1.9

The United Nations Conference on Environment and Development held in Rio de

Janerio in 1992 and popularly known as Earth summit followed by the world summit

on sustainable Development in 2002, have highlighted key issues of global

environmental concern.

Environmental pollution cannot be removed by laws alone.

The proper implementation and especially public participation are important aspects.

Public participation is possible only when the public is aware about the ecological and

environmental issues.

A drive by the government to ban the littering of polythene cannot be successful until

the public understands the environmental implications of the same.

The public has to be educated about the fact that if we are degrading our environment

we are actually harming ourselves.

Figure 1.3: Nobel prize for Environmentalists


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Unit - I 1.10

1.3 CONCEPT OF ECOSYSTEM

Living organisms cannot be isolated from their non-living environment because the

later provides materials and energy for the survival of the farmer. An ecosystem istherefore defined as a natural functional ecological unit comprising of living

organisms and their non-living environment that interact to form a stable self

supporting system .

Eg. Pond, lake, desert, grassland, forest, etc.

Ecology - Study of the distribution and abundance of organisms, the flows of energy

and materials between abiotic and biotic components of ecosystems.

1.4 STRUCTURE AND FUNCTIONS OF ECOSYSTEM

1.4.1 Structure of Ecosystem

Abiotic or non-living components or physical components.

Biotic or Living components : Plants , animals and microorganisms

Energy components.

Abiotic Components: Abiotic components enter the body of living directly or

indirectly take part in metabolic activities and return to environment.

Abiotic components are as follows

AtmosphereThe cover of air that envelopes the earth is known as atmosphere.

CompostionNitrogen-78%, oxygen- 2%, other gases- 1%

Lithosphere or Interior of EarthSolid EarthRadius 6371- density -5.5

Hydrosphere97% earths water is in oceans Fresh water3%.

1.4.2 Functions of Ecosystems:

I. Primary Function

Its primary function of all ecosystems is manufacture of starch. In the presence of

sunlight, chlorophyll containing plants use use carbon dioxide and water to

manufacture starch through a process called photosynthesis.


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Unit - I 1.11

All aspects of production in ecosystems form the subject matter of productivity

in ecosystems.

II. Secondary Function

The secondary function of all ecosystems is distributing energy in the form of

food to all consumers. All aspects concerning this function form the subject

matter of energy flow through ecological pyramids. The living components are

not immortal. All living systems die at a particular stage. These dead systems are

acted upon by decomposers to initiate the third function of ecosystems namely

material cycling.

1.5 PRODUCERS, CONSUMERS AND DECOMPOSERS

Producers : They are the only biotic component which can manufacture food. So,

without producers, life system will complete collapse.

Consumers : They are the organisms that cannot prepare their own food and depends

directly or indirectly on the producers they feed upon other organisms

Types : HerbivoresPlant eating animalsprimary consumers Eg ; rabbit

Carnivores : Feed on consumersSecondary Consumers - feed on other carnivores

Tertiary / Consumers.

Omnivores : Feed on both plants and animalseg. Humans, rat, fox.

Detritivores : (Detritus feeder or Saprotrophs )feed on dead on organisms or

decomposed matter eg; beetles, termites,ants , crabs, earthworms.

Decomposers: These include microorganisms like bacteria and fungi which attack the

dead bodies of producers and consumers and decompose them in to simpler compounds.

During the decomposition inorganic nutrients are released. These substances, together

with other organic substances are then utilized by the producers for the synthesis of their

own food.

1.6 ENERGY FLOW IN ECOSYSTEM

All organisms must obtain a supply of energy and nutrients from their environment in

order to survive.


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Unit - I 1.12

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

from the sun.

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

Primary production.

Photosynthesis -- Chemical reaction where green plants use water & carbon dioxide to

store the suns energy in glucose.

ENERGY is stored in glucose.

Glucose is stored as starch in plants

The majority of autotrophs are photoautotrophs that harness the energy of the sun and

pass some of this energy onto consumers through feeding pathways.

The energy contained within producers and consumers is ultimately passed to the

decomposers that are responsible for the constant recycling of nutrients.

Thus, there is a one-way flow of energy through the biotic community and a cycling

of nutrients between the biotic and abiotic components of the ecosystem

Energy flow cannot occur in reverse direction.

Starts from autotrophs (the producer level, i.e., first trophic level) to Heterotrophs

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 remains

unutilized.

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

The transfer of food energy between the organisms in an ecosystem can be tracked by

constructing food chains, food webs, pyramids of numbers, biomass and energy and

energy flow diagrams.


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Unit - I 1.13

Figure 1.4: Energy Flow

1.7 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:

1.7.1 Primary Succession

Occurs where there is no soil, e.g. after a volcanic eruption or a glacial retreat.

Pioneer organisms

Simple plants firstno 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, provided there are no

changes in abiotic influences.

1.7.2 Secondary Succession

Community development in the areas that were previously occupied by a other

community.


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Unit - I 1.14

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.

Table 1.1: Primary Succession Vs Secondary Succession

Primary Secondary

No soil.

Pioneer species.

Weathering & decomposition

Humus and sand increase over time.

End = Climax community.

Soil already exists.

Seeds have suitable soil conditions.

Occurs much faster.

Climax community.

1.8 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.


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Unit - I 1.15

Figure 1.5: Food Chain

1.9 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.


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Unit - I 1.16

Figure 1.6 Food web in grassland ecosystem

1.10 ECOLOGICAL PYRAMIDS

AnEcological pyramid is a graphical representation that shows the relative amounts

of energy or matter contained within each tropic level in a food chain or food web.


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Unit - I 1.17

An ecological pyramid shows the relationship between consumers and producers at

different tropic levels in an ecosystem

There are three ecological pyramids recognized by ecologists:

1.10.1 Pyramid of Numbers

Shows the relative number of individual organisms at each tropic level.

Figure 1.7 Pyramid of Numbers

1.10.2 Pyramid of Biomass

A pyramid of biomass represents the total dry mass (in grams per square meter of

area) of all the organisms in each tropic level at a particular time.

Figure 1.8 Pyramid of Biomass


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Unit - I 1.18

1.10.3 Pyramid of Energy

A pyramid of biomass represents the rate of energy flow and/or productivity at

successive tropic levels. The pyramids of energy are always upright.

Figure 1.9 Pyramid of Biomass

1.11 FOREST ECOSYSTEM (TERRESTRIAL ECOSYSTEM)

1.11.1 Introduction

A forest is an area with a high density of trees.

Worlds total land area is 13,076 million hectares - (Source: FAO; 1989)

Of which total forests account for about 31% of the worlds land area.

In India, the forest cover is roughly 19% of the total land area.

The forest ecosystems are of great concern from the environmental point of view.

It provides numerous environmental services like;

Nutrient cycling,

Maintaining biodiversity

Providing wildlife habitat

Affecting rainfall patterns

Regulating stream flow

Storing water

Reducing flooding


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Unit - I 1.19

Preventing soil erosion

Reclaiming degraded land & many more.

Apart from environmental values, forest ecosystems have some traditional values aswell.

Examples are:

Fire Wood & Timber.

Fruits.

Gums.

Herbs & drugs.

1.11.2 Types

Tropicaldeciduous, Evergreen, Wet green, Littoral and Swamps


Abiotic : Soil, Sunlight and Temperature etc..

Biotic : Trees, Shrubs and Animals.

1.11.4 Structure and Function of Forest Ecosystem

I. Biotic components

The various biotic components, representatives from the three 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.


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Unit - I 1.20

2)Consumers

In a forest, consumers are of three main types;

a)Primary Consumers

These are Herbivores which feed directly on producers. Eg:

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.

Eg: Birds, Lizards, Frogs, Snakes and Foxes.

c) Tertiary Consumers

These are secondary carnivores and feed on secondary consumers

These include top carnivores like Lion, Tiger.

3) Decomposers

These include wide variety of saprotrophic micro- organism like;

Bacteria (Bacillus Sp., Clostridium sp., pseudomonas.

Fungi (Aspergillus sp., Ganoderma sp., Fusarium.

Actinomycetes (Streptomyces).

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

takes place.

Therefore, nutrients are released for reuse.

II. Abiotic components

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

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


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Unit - I 1.21

Figure 2.0 Forest Ecosystem

1.12 GRASSLAND ECOSYSTEM (TERRESTRIAL ECOSYSTEM)

1.12.1 Introduction

Grasslands (also called Greenswards) are areas where the vegetation is dominated

by 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 principal grasslands include:

Prairies (Canada, USA),Pampas (South America),Steppes (Europe &Asia)

Veldts (Africa)

The highest abundance & greatest diversity of large mammals are found in these

ecosystems.


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Unit - I 1.22

1.12.2 Types

Tropical grass landsfound near the boarders of tropical rain forests. Eg. Savannas in

Africa. AnimalsZebra, giraffes etc.fires are common in dry seasonstermite

mounds produce methaneleads to firehigh in photosynthesisdeliberate burning

leads to release of high CO2global warming.

Temperate grasslandsflat and gentle slopes of hills. Very cold winter and very hot

summer - dry summer fires do not allow shrubs and trees to growsoil is quite fertile

cleaned for agriculture.

Polar grasslandsfound in arctic polar regionorganismarctic wolf, fox, etc.A

thick layer of ice remains frozen under the soil surface throughout the yearknown as

permafrostsummer insects and birds appear.


The dominant animal species include

Wild horses, asses & antelope of Eurasia,

Herds of Bison of America; and

The antelope & other large herbivores of Africa.

1.12.4 Structure and Functions of Grassland Ecosystems

I. Biotic components

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;


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Unit - I 1.23

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, etc are 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.


These include basic inorganic & organic compounds present in the soil & aerial

environment.

The essential elements like C, H, N, O, P, S etc. are supplied by water, nitrogen,

nitrates, sulphates, phosphates present in soil & atmosphere.


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Unit - I 1.24

Figure 2.1: Grassland Ecosystem

1.13 DESERT ECOSYSTEM

1.13.1 Introduction

A desert is a landscape orregion that receives almost no precipitation.

Deserts are defined as areas with an average annual precipitation of less than

250 millimeters per year.

It occupies 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.

1.13.2 Types

Tropical desert-found in Africa-Sahara and RajasthanThar

Temperate desert-south California-Majave

Cold desert-China-Gobi desert
http://en.wikipedia.org/wiki/Landscapehttp://en.wikipedia.org/wiki/Regionhttp://en.wikipedia.org/wiki/Precipitation_(meteorology)http://en.wikipedia.org/wiki/Precipitation_(meteorology)http://en.wikipedia.org/wiki/Regionhttp://en.wikipedia.org/wiki/Landscape


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Unit - I 1.25


Air is dry

Climate is hot

Annual rainfall is less than 25 cm

Vegetation is poor

1.13.4 Structure and Functions of Desert Ecosystems

I. Biotic Components


In a desert, producers are mainly shrubs/bushes; some grasses & a few trees.

Dominant plant species include: Succulents (water - retaining plants adapted

to 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 are

thermophillic.


Due to high temperature & very low rainfall, the organic substances are poorly

present in the soil.


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Unit - I 1.26

Figure 2.2: Desert Ecosystem

1.14 AQUATIC ECOSYSTEMS

1.14.1 Introduction

Aquatic ecosystems deal with biotic community present in water bodies.

In terrestrial ecosystem, carbon dioxide & oxygen are present in gaseous form

whereas in aquatic ecosystem, these are available in dissolved state.

Depending upon the quality and nature of water, the aquatic ecosystem are

categorized into:

Freshwater Ecosystem and

Marine Ecosystem.

1.14.2 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.

Aquatic ecosystems perform many important environmental functions.

They recycle nutrients, purify water, attenuate floods, recharge ground water

and provide habitats for wildlife.


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Unit - I 1.27

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

1.14.2.1 Lakes & Pond Ecosystem (A Type of freshwater 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 which

significantly affects the system.

Lakes are usually big standing freshwater bodies.

They have a shallow water zone called Littoral zone; an open water zone

where effective penetration of solar light takes place, called limnetic zone anda deep water zone where light penetration is negligible, called Profoundal

zone.

1.14.2.2 Stream Ecosystem (A Type of freshwater Ecosystem)

Its a fresh water ecosystem where water current plays a major role. Oxygen

and nutrient content are uniform.

Stream organisms have to face extreme difference in climatic conditions but

they do not suffer from oxygen deficiency as pond and lake organisms.

This is because large surface area of running water provides more oxygen

supply.

The animals have very narrow range of tolerance towards oxygen deficiency.

Thus stream are worst victims of industrial pollution.


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Unit - I 1.28

1.14.2.3 River ecosystem

Large streams flowing from mountain highlands are rivers.

Mountain highlandsrushing down water fall of waterlarge quantity of

dissolved oxygenplants attached to rocks and fishes that require more oxygen

are found.

Gentle slopes of hillswarmersupports the growth of plants and fishes that

require less oxygen are seen.

River shapes the landlots of silts, nutrients are broughtdeposited in plains

and deltavery rich in biodiversity.

Biotic Components:


It includes submerged, free floating and amphibious macrophytes (like;

Hydrilla, Utricularia, Wolfia, Azolla, Typha etc.) and minute floating

and suspended lower phytoplanktons (like; Ulothrix, Spirogyra,

Oedogonium etc.)

2) Consumer Organisms

Primary consumers:These are zooplanktons (ciliates, flagellates, other

protozoan, small crustaceans) and benthos.

Secondary consumers: These are carnivores like insects and fishes

feeding on herbivores

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

3) Decomposers Microorganisms like bacteria, fungi and actinomyctes.


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Unit - I 1.29

Abiotic Components:

These are the inorganic as well as organic substances present in the

bottom soil or dissolved in water. In addition, to the minerals, some deadorganic matter is also present.

Figure 2.3: Zonation in a lake ecosystem

1.14.3 Marine or Ocean Ecosystem

Marine ecosystems are among the Earth's aquatic ecosystems. They include: Oceans,

Estuaries and Lagoons, Mangroves and Coral reefs, the Deep sea and the Sea floor.

These are the gigantic reservoirs of water covering approximately 71% of

the Earth's surface (an area of some 361 million square kilometers).

These ecosystems are different from freshwater ecosystem mainly because of its salty

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 of light.

Biotic Components

1) Producers : It includes phytoplanktons (diatoms, dinoflagillates), large seaweeds

(mainly algae like chlorophyceae, phaeophyceae & rhodophyceae; angiosperms like

Ruppia, Zostera, posidonia ), and mangrove vegetation (like Rhizophora, Carapa etc.)


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Unit - I 1.30

2) Consumers

Primary consumers: These are herbivores and feed directly on producers

(Crustaceans, Mollusks, fish etc.)

Secondary consumers: These are carnivorous fishes (Herring, Sahd and

Mackerel)

Tertiary consumers: These are top carnivorous fishes (Cod, Haddock, etc.)

3) Decomposers These are microorganisms 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.

Figure 2.4: Ocean Ecosystem

Characteristics:

Structural Components: Abiotic: pH, nutrients, D.O, temp, climatic conditions, etc.

Biotic: Phytoplankton, fishes, snails insects, birds, etc. Functional components:

Ecological pyramid


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Unit - I 1.31

1.14.4 Estuary

Coastal area where river meet oceanstrongly affected by tidal actionsvery rich in

nutrientsvery rich in biodiversity alsoorganisms are highly tolerantmany

species are endemichigh food productivityhowever to be protected from

pollution.

Characteristics:

Structural Components: Abiotic: pH, nutrients, D.O, temp, climatic conditions, etc.

Biotic: Phytoplankton, fishes, snails insects, birds, etc.

1.15 BIODIVERSITY

Biodiversity is the variety and differences among living organisms from all sources,

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 distinct biological

species, which is the product of nearly 3.5 billion years of evolution. Its various levels

are as follows,

1.15.1. 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 of

genetic characteristics to vary.

1.15.2 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 area

and also their relative abundance.


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Unit - I 1.32

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

1.15.3 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 of

organisms sharing two habitats.

Gamma Diversity: Diversity of the habitat over the total landscape orgeographical area is called gamma diversity.

1.16 BIOGEOGRAPHIC CLASSIFICATION OF INDIA

Our country can be conveniently divided into ten major regions, based on the

geography, climate and pattern of vegetation seen and the communities of mammals,

birds, reptiles, amphibia, insects and other invertebrates that live in them. Each of

these regions contains a variety of ecosystems such as forests, grasslands, lakes,

rivers, wetlands, mountains and hills, which have specific plant and animal species.

1.16.1 Indias Biogeographic Zones

The cold mountainous snow covered Trans Himalayan region of Ladakh.

The Himalayan ranges and valleys of Kashmir, Himachal Pradesh,

Uttarakhand, Assam and other North Eastern States.

The Terai, the lowland where the Himalayan rivers flow into the plains.

The Gangetic and Bhramaputra plains.

The Thar Desert of Rajasthan.

The semi arid grassland region of the Deccan plateau Gujarat, Maharashtra,

Andra Pradesh, Karnataka and Tamil Nadu.


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The Northeast States of India,

The Western Ghats in Maharashtra, Karnataka and Kerala.

The Andaman and Nicobar Islands.

The long western and eastern coastal belt with sandy beaches, forests

and mangroves.

1.17 VALUES OF BIODIVERSITY Food: About 80,000 edible plants and about 90% of present day food crops have been

domesticated from wild.

Drugs & Medicines: About 75% of worlds population depends on plants or plant

extracts.

Fuel: Forests have been used since ages for fuel wood. Fossil fuels are also products

of Biodiversity.

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

believed to exist.

According to UNEP estimate, approximately 9.052 million of species exist on

Earth

Indias position is 10th in the world & 4th in Asia in terms of Plant diversity.

1.17.1 Consumptive use

The direct utilisation of timber, food, fuelwood, fodder by local communities.

The biodiversity held in the ecosystem provides forest dwellers with all their daily

needs, food, building material, fodder, medicines and a variety of other products. They

know the qualities and different uses of wood from different species of trees, and

collect a large number of local fruits, roots and plant material that they use as food,

construction material or medicines. Fisherfolk are highly dependent on fish and know

where and how to catch fish and other edible aquatic animals and plants.


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Unit - I 1.34

1.17.2 Productive use

Marketable goods. The biotechnologist uses biorich areas to prospect and search for

potential genetic properties in plants or animals that can be used to develop bettervarieties of crops that are used in farming and plantation programs or to develop

better livestock.

To the pharmacist, biological diversity is the raw material from which new drugs can

be identified from plant or animal products.

To industrialists, biodiversity is a rich store-house from which to develop new

products.

For the agricultural scientist the biodiversity in the wild relatives of crop plants is the

basis for developing better crops.

Genetic diversity enables scientists and farmers to develop better crops and domestic

animals through careful breeding.

Originally this was done by selecting or pollinating crops artificially to get a more

productive or disease resistant strain. Today this is increasingly being done by genetic

engineering, selecting genes from one plant and introducing them into another.

New crop varieties (cultivars) are being developed using the genetic material found in

wild relatives of crop plants through biotechnology. Even today, species of plants and

animals are being constantly discovered in the wild. Thus these wild species are the

building blocks for the betterment of human life and their loss is a great economic loss

to mankind.

Among the known species, only a tiny fraction has been investigated for their value in

terms of food, or their medicinal or industrial potential. Preservation of biodiversity

has now become essential for industrial growth and economic development.

A variety of industries such as pharmaceuticals are highly dependent on identifying

compounds of great economic value from the wide variety of wild species of plants

located in undisturbed natural forests. This is called biological prospecting.


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Unit - I 1.35

1.17.3 Social values

While traditional societies which had a small population and required less resources

had preserved their biodiversity as a life supporting resource, modern man has rapidlydepleted it even to the extent of leading to the irrecoverable loss due to extinction of

several species. Thus apart from the local use or sale of products of biodiversity there

is the social aspect in which more and more resources are used by affluent societies.

The biodiversity has to a great extent been preserved by traditional societies that

valued it as a resource and appreciated that its depletion would be a great loss to their

society. The consumptive and productive value of biodiversity is closely linked to

social concerns in traditional communities.

Ecosystem people value biodiversity as a part of their livelihood as well as through

cultural and religious sentiments.

A great variety of crops have been cultivated in traditional agricultural systems and

this permitted a wide range of produce to be grown and marketed throughout the year

and acted as an insurance against the failure of one crop.

In recent years farmers have begun to receive economic incentives to grow cash crops

for national or international markets, rather than to supply local needs. This has

resulted in local food shortages, unemployment (cash crops are usually mechanised),

landlessness and increased vulnerability to drought and floods.

Table 1.2 Drugs from plant sources


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Unit - I 1.36

1.17.4 Ethical and Moral Values

Ethical values related to biodiversity conservation are based on the importance of

protecting all forms of life. All forms of life have the right to exist on earth. Man isonly a small part of the Earths great family of species.

Dont plants and animals have an equal right to live and exist on our planet which is

like an inhabited spaceship? We do not know if life as we know it exists elsewhere in

the universe. Do we have the right to destroy life forms or do we have a duty to

protect them? Apart from the economic importance of conserving biodiversity, there

are several cultural, moral and ethical values which are associated with the sanctity of

all forms of life. Indian civilization has over several generations preserved nature

through local traditions. This has been an important part of the ancient philosophy of

many of our cultures.

We have in our country a large number of sacred groves or deoraispreserved by

tribal people in several States. These sacred groves around ancient sacred sites and

temples act as gene banks of wild plants.

1.17.5 Aesthetic Value

Knowledge and an appreciation of the presence of biodiversity for its own sake is

another reason to preserve it.

Quite apart from killing wildlife for food, it is important as a tourist attraction.

Biodiversity is a beautiful and wonderful aspect of nature. Sit in a forest and listen to

the birds. Watch a spider weave its complex web. Observe a fish feeding. It is

magnificent and fascinating. Symbols from wild species such as the lion of Hinduism,

the elephant of Buddhism and deities such as Lord Ganesh, and the vehicles of several

deities that are animals, have been venerated for thousands of years.

Valmiki begins his epic story with a couplet on the unfortunate killing of a crane by a

hunter. The Tulsi has been placed at our doorsteps for centuries.


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Unit - I 1.37

1.17.6 Option Value

Keeping future possibilities open for their use is called option value. It is impossible

to predict which of our species or traditional varieties of crops and domestic animalswill be of great use in the future. To continue to improve cultivars and domestic

livestock, we need to return to wild relatives of crop plants and animals.

Thus the preservation of biodiversity must also include traditionally used strains

already in existence in crops and domestic animals.

1.18 BIODIVERSITY AT GLOBAL, NATIONAL AND LOCAL LEVELS

There are at present 1.8 million species known and documented by scientists in the

world.

However, scientists have estimated that the number of species of plants and animals

on earth could vary from 1.5 to 20 billion! Thus the majority of species are yet to be

discovered.

Most of the worlds bio-rich nations are in the South, which are the developing

nations. In contrast, the majority of the countries capable of exploiting biodiversity

are Northern nations, in the economically developed world. These nations however

have low levels of biodiversity.

Thus the developed world has come to support the concept that biodiversity must be

considered to be a global resource.

However, if biodiversity should form a common property resource to be shared by

all nations, there is no reason to exclude oil, or uranium, or even intellectual and

technological expertise as global assets.

Indias sovereignty over its biological diversity cannot be compromised without a

revolutionary change in world thinking about sharing of all types of natural resources.

Countries with diversities higher than India are located in South America such as

Brazil, and South East Asian countries such as Malaysia and Indonesia. The species

found in these countries, however, are different from our own. This makes it

imperative to preserve our own biodiversity as a major economic resource.


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Unit - I 1.38

While few of the other megadiversity nations have developed the technology to

exploit their species for biotechnology and genetic engineering, India is capable of

doing so.

Throughout the world, the value of biologically rich natural areas is now being

increasingly appreciated as being of unimaginable value.

International agreements such as the World Heritage Convention attempt to protect

and support such areas. India is a signatory to the convention and has included several

protected Areas as World Heritage sites. These include Manas on the border between

Bhutan and India, Kaziranga in Assam, Bharatpur in U.P., Nandadevi in the

Himalayas, and the Sunderbans in the Ganges delta in West Bengal.

India has also signed the Convention in the Trade of Endangered Species (CITES)

which is intended to reduce the utilization of endangered plants and animals by

controlling trade in their products and in the pet trade.

1.19 INDIA AS A MEGA DIVERSITY NATION

Geological events in the landmass of India have provided conditions for high levels ofbiological diversity.

A split in the single giant continent around 70 million years ago, led to the formation

of northern and southern continents, with India a part of Gondwanaland - the southern

landmass, together with Africa, Australia and the Antarctic.

Later tectonic movements shifted India northward across the equator to join the

Northern Eurasian continent. As the intervening shallow Tethis Sea closed down,

plants and animals that had evolved both in Europe and in the Far East migrated into

India before the Himalayas had formed.

A final influx came from Africa with Ethiopian species, which, were adapted to the

Savannas and semi-arid regions.

Thus Indias special geographical position between three distinctive centres of

biological evolution and radiation of species is responsible for our rich and varied

biodiversity.


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Unit - I 1.39

Among the biologically rich nations, India stands among the top 10 or 15 countries for

its great variety of plants and animals, many of which are not found elsewhere.

India has 350 different mammals (rated eight highest in the world), 1,200 species of

birds (eighth in the world), 453 species of reptiles (fifth in the world) and 45,000 plant

species, of which most are angiosperms, (fifteenth in the world). These include

especially high species diversity of ferns (1022 species) and orchids (1082 species).

India has 50,000 known species of insects, including 13,000 butterflies and moths.

It is estimated that the number of unknown species could be several times higher. It is

estimated that 18% of Indian plants are endemic to the country and found nowhere

else in the world.

Among the plant species the flowering plants have a much higher degree of

endemism, a third of these are not found elsewhere in the world.

Among amphibians found in India, 62% are unique to this country.

Among lizards, of the 153 species recorded, 50% are endemic. High endemism has

also been recorded for various groups of insects, marine worms, centipedes, mayflies

and fresh water sponges.

Apart from the high biodiversity of Indian wild plants and animals there is also a great

diversity of cultivated crops and breeds of domestic livestock. This is a result of

several thousand years during which civilizations have grown and flourished in the

Indian subcontinent.

The traditional cultivars included 30,000 to 50,000 varieties of rice and a number of

cereals, vegetables and fruit.

The highest diversity of cultivars is concentrated in the high rainfall areas of the

Western Ghats, Eastern Ghats, Northern Himalayas and the North-Eastern hills.

Gene-banks have collected over 34,000 cereals and 22,000 pulses grown in India.

India has 27 indigenous breeds of cattle, 40 breeds of sheep, 22 breeds of goats and 8

breeds of buffaloes.


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Table 1.3: Indias ranking at world level

1.20 HOT- SPOTS OF BIODIVERSITY

A biodiversity hotspot is a biogeographic region with a significant reservoir

of biodiversity that is threatened with destruction.

An area is designated as a hot spot when it contains at least 0.5% of plant species as

endemic.

There are 25 such hot spots of biodiversity on a global level, out of which two are

present in India.

These are: Indo- Burma (earlier The Eastern Himalayas) ,The western Ghats & Sri

Lanka..

These hot spots covering less than 2% of the worlds land area are found to have

about 50% of the terrestrial biodiversity.

1.20.1 Criteria for determining hot-spots

No. of Endemic Species i.e. the species which are found no where else.

Degree of threat, which is measured in terms of Habitat loss.

E.g. Indo- Burma (Eastern Himalayas) Hotspot

The hotspot includes all of Cambodia, Vietnam & Laos, and nearly the entire areas of

Thailand, Myanmar & Bhutan as well as part of Nepal, far eastern India and extreme

southern China.

In addition, it covers several offshore Islands including Mainan Islands in the south

China Sea and Andaman & Nicobar Islands in Indian Ocean.


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Indo-Burma is one of the most threatened biodiversity hotspots, due to the rate of

resource exploitation and habitat loss.

E.g. Western Ghats and Sri Lanka

Western Ghats and Sri Lanka, also known as the Sahyadri Hills encompasses the

montane forests in the southwestern parts of India and on the neighboring Islands of

Sri Lanka.

The entire extent of hotspot was originally about 1,82,500 square kms, but due to

tremendous population pressure, now only 12,445 square Km or 6.8% is in pristine

condition.

The important populations include Asian elephant, Indian tigers and the endangered

lion tailed macaque.

1.21 THREATS TO BIODIVERSITY

Extinction is a natural event and, from a geological perspective, routine.

In last century, human impact has been so severe that thousands of species and

varieties are becoming extinct annually.

Some of the main causes are:

1.21.1 Habitat loss, degradation, fragmentation

Habitat loss & degradation are major causes of species extinction, affecting 89% of all

threatened birds, 83% of mammals & 91% of all threatened plants assessed globally

(IUCN, 2000)

The main causes of habitat are agriculture activities, Mining, development of human

settlement, industry etc.

According to ICUN, UNEP report, more than 50% of wildlife habitat has been

destroyed in 49 out of 61 old world tropical countries.

1.21.2 Poaching of wild life: Due to poaching, illegal trade and smuggling activities

most of our valuable fauna are under threat organised crime has moved into illegal

wild life smuggling because of huge profit Eg. Tiger, Deerfor hides, Rhinoceros

for horns, Elephant for ivory tusk, Sea Horse, Star turtle sold to foreign market.


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Unit - I 1.42

(Extinction, the elimination of species, is a normal process of the natural world.

Species die put and are replaced by others as part of evolutionary change.

1.21.3 Human Caused Reduction: The climate change caused by our release ofgreen house gases in the atm. could have catastrophic effects. Human disturbance of

natural habitat is the largest single cause pf loss of biological diversity. Woodlands

and grasslands are converted now use about 10% of the worlds land surface for crop

production and about twice the amount for pasture and grasslands.)

1.21.4 Hunting: Over harvesting is responsible for depletion or extinction of many

species. Eg. The American passenger pigeon was the worlds most abundant bird. In

spite of this vast population, market hunting and habitat destruction caused the entire

population to crash with in 20 years.

1.22 MANWILDLIFE CONFLICTS

The conflict between man and wildlife started with the evolution of man, but intensity

increased due to the activities of modern man

Due to the lack of stable food and disruption of movement, wild animals came out of

forest area and attack the agricultural field and humans and in turn got killed by the

humans.

Mangroves have been cleared for fuelwood and prawn farming, which has led to a

decrease in the habitat essential for breeding of marine fish.

Wetlands have been drained to increase agricultural land. These changes have grave

economic implications in the longer term.

The current destruction of the remaining large areas of wilderness habitats, especially

in the super diverse tropical forests and coral reefs, is the most important threat

worldwide to biodiversity. Scientists have estimated that human activities are likely to

eliminate approximately 10 million species by the year 2050.

There are about 1.8 million species of plants and animals, both large and microscopic,

known to science in the world at present. The number of species however is likely to

be greater by a factor of at least 10. Plants and insects as well as other forms of life


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Unit - I 1.43

not known to science are continually being identified in the worlds hotspots of

diversity.

Unfortunately at the present rate of extinction about 25% of the worlds species will

undergo extinction fairly rapidly. This may occur at the rate of 10 to 20 thousand

species per year, a thousand to ten thousand times faster than the expected natural

rate! Human actions could well exterminate 25% of the worlds species within the

next twenty or thirty years.

Much of this mega extinction spasm is related to human population growth,

industrialization and changes in land-use patterns. A major part of these extinctions

will occur in biorich areas such as tropical forests, wetlands, and coral reefs. The

loss of wild habitats due to rapid human population growth and short term economic

development are major contributors to the rapid global destruction of biodiversity.

1.23 ENDANGERED AND ENDEMIC SPECIES OF INDIA

According to The International Union of Conservation of Nature and Natural

Resources (IUCN), the species that considered in imminent danger of extinction and

whose survival is unlikely, if factors causing their decline continue to operate are

called endangered species.

The endangered species in the country are categorised as Vulnerable, Rare,

Indeterminate and Threatened.

Other species are found only in India and are thus endemic or restricted to our

country. Some of these may have very localized distribution and are considered highly

endemic.

Among the important endangered animals are charismatic species such as the

tiger, the elephant, the rhino, etc.

There are also endangered bird species such as the Siberian crane, the Great

Indian Bustard, the Florican and several birds of prey.

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

India contains 172 species of animals considered globally threatened by IUCN, or

2.9% of the worlds total number of threatened species.


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Unit - I 1.44

These include 53 species of mammals, 69 birds, 23 reptiles and 3 amphibians

As many as 3,000- 4,000 higher plants may be under high degree of threat in

India

Thus Indian subcontinent has about 62% endemic flora, restricted mainly to

Himalayas, khasi Hills & Western Ghats.

Sapria himalayana, Uvaria lurida, Napenthes khasians etc. are some endemic

flora of our country.

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

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

Golden monkey, Niligiri Langur, Indian Wolf, Red Fox, Himalayan Brown Bear,

Great Indian One Horned Rhinoceros, White Winged Wood Duck, Black Necked

Crane, Indian Pea Fowl, Gharial, Indian egg eating Snake, Indian Salamandar etc. are

some examples of endemic animal species of India.

1.24 CONSERVATION OF BIODIVERSITY

The convention on Biological Diversity held in June, 1992 stressed the need of the

conservation of Biodiversity for sustainable development and perpetuation of human

beings on earth.

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.

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

1) In- situ conservation 2) Ex- situ conservation.

1.24.1 In- situ Conservation

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.


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Unit - I 1.45

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

and maintenance of biological diversity and managed through legal effective means.

There are different categories of protected areas which are managed with

different 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 1st national park established in India.

Examples of Biosphere reserves of India:

Nilgiri- 5,520 sq.km

Nanda Devi- 5,860.69 sq. km

Manas2837 sq. km

Gulf of Mannar10,500 sq. km

Great Nicobar885 sq. km

Panchmarhi4,926.28 Sq Km

Examples of some National park in India : Kaziranga- Assam, Gir National Park-

Gujarat, PeriyarKerala, SariskaRajasthan

Examples of some Wild Life Sanctuaries of India:

Ghana Bird sanctuaries

Hazaribagh sanctuaries

Abohar wild life sanctuaries

Jaldapara wild life sanctuaries

Mudamalai wild life sanctuaries

1.24.2 Ex- situ Conservation

It is defined as the conservation of component of biological diversity (Sample of

genetic diversity, particularly of endangered species) outside their natural habitats.


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Unit - I 1.46

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 than

80,000 species.

There are more than 800 zoos around the world with about 3,000 species of

mammals, birds, reptiles and amphibians.

QUESTION BANK

Part-A (2 marks)

1. Define Environmental studies.

2. What are the principles of Environmental Education?

3. Mention the scope and importance of Environmental studies?

4. Define Ecology.

5.

Define Ecosystem with example?

6. What are the components of an Ecosystem?

7. List any two characteristics of an Ecosystem.

8. What are autotrophs and Heterotrophs?

9. What is biotic and abiotic resources?

10.What is energy flow?

11.Explain producer, consumer and decomposer.

12.What are decomposers?

13.Name any four Ecosystems.

14.What are the Structural components of an Ecosystem?

15.Bring out the Functional features of an Ecosystem?

16.

Define Food chain with an example.


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Unit - I 1.47

17.Define Food web with an example.

18.Differentiate between Food chain and Food web.

19.

What are Ecological pyramids? Give examples.

20.Pyramid of energy is always upright. Explain.

21.What is the significance of Ecological pyramids?

22.What is Ecological succession. Mention its types.

23.Discuss about the prime characteristics of a) Forest Ecosystem b) Grassland

Ecosystem, c) Desert Ecosystem and d) Acquatic Ecosystem.

24.

Define genetic diversity or Differentiate species and genera.

25.Differentiate between biodiversity and ecosystem biodiversity.

26.What are the hotspots of biodiversity?

27.Justify India to be a great spot of biodiversity.

28.Bring out the threats towards biodiversity. How poaching affects biodiversity?

29.Write a short note on Social Value of biodiversity.

30.Write a short note on Ethical Value of biodiversity.

31.Write a short note on Productive value of biodiversity.

32.Write a short note on Consumptive value of biodiversity.

33.Write a short note on Aesthetic Value of biodiversity.

34.What is Red Data Book?

35.

Write the Hot-spot regions of India.

36.Define Endemism with an example.

37.What are Endangered species? Give examples.

38.What are the aesthetic values of biodiversity.

39.What are national parks? Name a few in India.

40.Explain the necessity to conserve biodiversity.

41.Bring few methods to conserve biodiversity.


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Unit - I 1.48

42.Explain ecolological pyramids with respect to pond ecosystem.

43.What is ecosystem diversity?

44.

Bring out the Bio- geographical classification of India.

45.Comment on local or regional biodiversity.

46.Explain endemism with respect to india.

47.Bring out the order of distribution of biodiversity through out the world with reasons.

48.Explain biosphere

49.Explain threatened species.

50.What are Endemic and Endangered species?

51.India is a Mega Diversity NationAccount.

52.Enumerate the human activities which destroy the biodiversity.

53.What are coral reefs?

54.What is stratification?

Part B (16 marks)

1. Explain the components, characteristics and biodiversity of Forest ecosystem.

2. Explain the structure and functional features of Aquatic ecosystem.

3. Discuss in detail about Ecological succession stating the various stages.

4. Explain the structure and function of Ecosystem with a neat sketch.

5. How does energy flow takes place in an Ecosystem. Explain briefly

6. Explain the two models of energy flow in an ecosystem.

7. Define Ecological pyramids and explain its different types; Describe the types,

characteristic features, structure and function of forest and acquastic Ecosystem.

8. Discuss the value of biodiversity.

9. What are the threats faced by biodiversity. What are the solutions for the threats.

10. Explain In-situ and Ex-situ conservation of biodiversity.(or) What are the measures

recommended for conservation of biodiversity.

11. i) What is the biodiversity? What are the reasons for decline for biodiversity?

ii) Write short notes on 1)Producers 2)Consumers 3)Decomposer


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12. Explain biodiversity at national and global level ; India is a mega Bio-diversity nation-

justify.

Documents

Environment, Ecosystems and Biodivdersity