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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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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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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
1.12.3 Characteristics
1.12.4 Structure and Functions of Forest Ecosystem
1.13 Desert Ecosystem
1.13.1 Introduction
1.13.2 Types
1.13.3 Characteristics
1.13.4 Structure and Functions of Forest Ecosystem
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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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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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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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 - 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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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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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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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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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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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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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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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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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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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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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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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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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
1.11.3 Characteristics
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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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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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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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.
1.12.3 Characteristics
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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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.
II. Abiotic components
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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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/Landscape7/29/2019 Environment, Ecosystems and Biodivdersity
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1.13.3 Characteristics
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
1) Producer Organisms
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.
II. Abiotic components
Due to high temperature & very low rainfall, the organic substances are poorly
present in the soil.
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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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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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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:
1) Producer Organisms
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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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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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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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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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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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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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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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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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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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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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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(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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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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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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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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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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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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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.