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INTRODUCTION OF
ENVIRONMENTAL STUDIES
• The word environment is derived from the
French word “Environ” meaning
Surroundings.
• Every organisms is surrounded by
materials and forces which constitute its
environment.
• Environment creates favourable conditions
for the existence and development of living
organisms.
• Enviromental science the scientific study of
human interactions with the environment.
• It is the branch of science concerned with the
relations between organisms and their
environment.
• Literally, environment means the surrounding
external conditions influencing development or
growth of people, animal or plants; living or
working conditions etc.
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•
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This involves three questions:
1. What is Surrounded
2. By what Surrounded
3. Where Surrounded
DEFINITIONS
• Environment – The sum of total of all the
living and non-living things around us
influencing one another.
• Environmental Science– The study of the
environment its biotic(biological) and
abiotic components and their
interrelationship.
• Environmental Engineering–
• The application of engineering principles to the
protection and enhancement of the quality of
the environment and to the enhancement and
protection of public health and welfare.
• Environmental Studies /Education– The
process of educating the people for preserving
quality environment
Types of Environment
• Natural environment
Natural environment is characterized by
natural components.
 All biotic (living) and abiotic (non-living)
are created through a natural process.
 Natural components do not require any
human support.
Man-made environment
It is powerful environment
agent modified using modern
technologies according to his needs
created by man.
Components of the Environment
• Abiotic or Non-living components
• Biotic or Living components
• Energy components
Abiotic or Non-living or Physical
components
• Example : Air, water, soil and minerals.
Abiotic components enter the body of
living organisms directly or indirectly
takepart in metabolic activities and then
return to the environment.
•
Abiotic – three categories
1. Atmosphere
2. Lithosphere
3. Hydrosphere
1. Atmosphere :
Air envelopes the earth is knowns
atmosphere. It extends upto 500 kms from
the earth surface.
It comprises 78% of Nitrogen, 21% of
oxygen and 1% of other gases.
Structure of atmosphere
Sl
Region
no.
Altitude in
km
Temperatu Chemical
re in C
species
1
Troposhere
0-18
15 to -56
N2,H2O,CO
2,O2
2
Stratosphere
18-50
-56 to -2
Ozone
3
Mesosphere
50-85
-2 to -92
NO+, O2+
4
Thermosphere 85-500
-92 to
1200
NO+, O+,
O2+
5
Exosphere
Very high
He, H2
Upto 1600
• Composition of Atmospheric Air
• Gas
Relative %byVolume
Nitrogen (N2)78.09
Oxygen (O2)20.93
Argon (A)00.93
Carbon di oxide- CO2)0.032
Miscellaneous0.02
Total
100.000
Functions of atmosphere
• It maintains the heat balance on the earth
by absorbing the IR radiations
• The gaseous constituents play an
important role in sustaining life on earth
Oxygen
- supports life of living
organisms
Carbon-dioxide- essential for photosynthetic
activity of plants
Nitrogen
– essential nutrient for plant
growth
2.Lithosphere
• The soil and rock components of the earth
• Functions :
1. Home for human beings and wildlife
2. Storehouse of minerals and organic
matter
3.Hydrosphere
• The aqueous envelope of the earth .
Oceans, lakes,streams,rivers and water
vapour constitute hydrosphere. 97% of
earth water is in oceans. 3% is available
as fresh water.
Functions :
1. It is used for drinking purpose and
also supports the aquatic life.
2. It is also used for irrigation, power
production,industries and transport
Biotic or Living components
• Example: Animals,plants and micro
organism.
Biosphere:
The living organism live and interact
with physical environment(soil, water and
air) is called biosphere.
Functions:
Plants ↔ animals
Energy components
• The components of energy flows across
biotic and abiotic components .
Example :
Solar energy, nuclear energy,
geochemical energy, thermo electrical
energy.
SCOPE OF ENVIRONMENTAL
STUDIES
• To get awareness and sensitivity to the total
environment and its related problems.
• To motivate the active participation in
environmental protection and improvement
• To develop skills for identifying and solving
environmental problems
• To know the necessity of conservation of natural
resources
• To evaluate environmental programmes interms
of social,economic, ecological and aesthetic
factors
Importance or significance of
Environmental studies
• People will understand the concept of need
of development without destruction of
environment.
• People can gain the knowledge of different
types of environment and the effect of diff.
envir. Hazards.
• It inform the people About their role in
protecting the envir. By demanding changes
in laws and enforcement systems
• It have direct relation to the quality of life we
live
• It develop a concern and respect for the
environment
Need for Public awareness
• Increasing population, urbanisation and
poverty have generated pressure on the
natural resources and lead to a
degradation of the environment
• Supreme court initiated to the public
through Government and Non-government
agencies to take part to protect our
environment
Public Participation and types
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1.
2.
3.
4.
Public participation is useful in law
making process and controlling the
pollution activities
Types:
Pressure Group
Watch dog
Advisory council
Enforcing the environmental laws
ECOSYSTEM
• ECOLOGY: Study of ecosystems
• ECOSYSTEM: A group of organisms
interacting among themselves and with
the environment exchanging energy
and matter.
• BIOME: It is a small ecosystem within
an ecosystem
TYPES OF ECOSYSTEM
ECOSYSTEM
NATURAL
TERRESTRIAL
AQUATIC
ARTIFICIAL /
MANMADE
CROPLANDS
DAMS ETC.,
TYPES OF NATURAL ECOSYSTEM
NATURAL
ECOSYSTEM
TERRESTIAL
RELATED TO LAND AND
TYPES OF VEGETATION
LIKE GRASSLAND,FOREST
DESERT ECOSYSTEMS
AQUATIC
RELATED TO WATER
TYPES OF AQUATIC ECOSYSTEM
AQUATIC
ECOSYSTEM
MARINE
SEAS AND SEASHORES
FRESH WATER
RIVERS, PONDS ,
LAKE ,STREAMS ETC.,
TYPES OF FRESH WATER ECOSYSTEM
FRESH
ECOSYSTEM
LOTIC
RUNNING WATER
RIVERS STREAMS
LENTIC
STANDINGWATER
POND LAKE ETC.,
STRUCTURE OR COMPONENTS OF ECOSYSTEM
• 2 Major components are there namely ABIOTIC and BIOTIC
• Structure of an ecosystem explains relationship between the A biotic
and biotic components
• The relationship between the biotic components and a biotic
components of an ecosystem is called 'holocoenosis
A biotic components
ECOSYSTEM
Biotic components
Abiotic components
• These are the non living components collectively forming
a community
• They are classified in to chemical and physical
components
• Physical components involves energy, climate, raw
materials living space air water soil sunlight etc.,
• Chemical components involves the essential nutrient
sources which may be organic like proteins lipids
carbohydrates or inorganic like micro (Al Co Zn Cu) or
macro nutrients ( C H O P N S K )
• Biotic Components
• It comprises the living part of the environment,
which includes the association of a number of
interrelated populations belonging to different
species in a common environment.
• The populations are that of animal community,
plant community and microbial community.
• Biotic community is distinguished into
autotrophs, heterotrophs and saprotrophs.
• Autotrophs (Greek: auto - self, trophos - feeder)
are also called producers, converters or
transducers.
• These are photosynthetic plants, generally
chlorophyll bearing,
• which synthesize high-energy complex organic
compounds (food) from inorganic raw materials
with the help of sunlight, and the process is
referred as photosynthesis.
• Autotrophs form the basis of any biotic system.
• In terrestrial ecosystems, the Autotrophs are
mainly the rooted plants.
• In aquatic ecosystems, floating plants called
phytoplankton and shallow water rooted plants
called macrophytes are the dominant producers
• Heterotrophs (Gr: heteros - other; trophs feeder) are called consumers, which are
generally animals feeding on other organisms.
• Consumer's also referred as phagotrophs
(phago - to ingest or swallow) or
macroconsumers are mainly herbivores and
carnivores.
• Herbivores are referred as First order
consumers or primary consumers, as they feed
directly on plants
• For e.g., Terrestrial ecosystem consumers like cattle,
deer, rabbit, grass hopper, etc.
• Aquatic ecosystem consumers like protozoans,
crustaceans, etc.
• Carnivores are animals, which feed or prey upon other
animals.
• Primary carnivores or Second order consumers
include the animals which feed on the herbivorous
animals.
• For e.g., fox, frog, predatory birds, smaller fishes,
snakes, etc.
• Secondary carnivores or Third order consumers
include the animals, which feed on the primary
carnivores.
• For e.g., wolf, peacock, owl, etc
• Secondary carnivores are preyed upon by some
larger carnivores.
• Tertiary carnivores or Quaternary consumers
include the animals, which feed on the
secondary carnivores.
• For e.g., lion, tiger, etc.
• These are not eaten by any other animals.
• The larger carnivores, which cannot be preyed
upon further are called top carnivores
• Saprotrophs (Gr: sapros - rotten; trophos feeder) are also called decomposers or
reducers.
• They break down the complex organic
compounds of dead matter (of plants and
animals).
• Decomposers do not ingest their food. Instead
they secrete digestive enzymes into the dead
and decaying plant and animal remains to
digest the organic material.
• Enzymes act upon the complex organic
compounds of the dead matter.
• Decomposers absorb a part of the
decomposition products for their own
nourishment.
• The remaining substances are added as
minerals to the substratum (mineralisation).
• Released minerals are reused (utilised) as
nutrients by the plants (producers).
Function of an Ecosystem
• It is to allow flow of energy
• It is of three types namely primary
secondary and tertiary
• Primary is to manufacture starch by
photosynthesis
• Secondary is to distribute energy in the
form of food to all consumers
• At tertiary level dead living systems are
decomposed for cycling
• Thus the functioning of an ecosystem can
be understood by understanding the
following terms
• Energy and material flow
• Food chains
• Food webs
• Food pyramids
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ENERGY FLOW IN AN ECOSYSTEM
Energy is the capacity to do work. Solar energy is transformed into chemical
energy by the process of photosynthesis, and is stored in plant tissue and then
transformed into mechanical and heat forms during metabolic activities.
The energy, in the biological world, flows from the sun to plants and then to all
heterotrophic organisms such as microorganisms, animals and man.
Thus the energy flow through atmosphere to an ecosystem involves the
radiation from sun was 50% absorbed by the atmosphere itself. From remaining
50% of radiations a few % absorbed by plants for the process of photosynthesis
6CO2 + 6H2O ----------sunlight --- C12H22O11 + 6O2
I law of thermodynamics:
Energy can neither be created nor be destroyed but one form of energy can be
converted in to another form
i.e. solar energy in to chemical energy
II law of thermodynamics:
Whenever energy is transformed there is a loss of energy through the release of
heat
i.e. the loss of energy takes place by respiration, running , hunting etc., the
reaction during respiration is
C12H22O11 + 6O2 --------------- 6CO2 + 6H2O
RELATIONSHIP BETWEEN STRUCTURE AND FUNCTION (FLOW MODEL)
NUTRIENT FLOW (OR) CYCLING (OR)
BIOGEOCHEMICAL CYCLE IN AN ECOSYSTEM
• Nutrients are the elements essential for the growth of plants and
animals. Elements needed in huge quantity are macro
(O,C,H,N,P,Ca)and needed in minimum are called micro nutrients(
B,Co,Sr,Zn,Cu)
• The cyclic flow of nutrients between the biotic and a biotic
components is known as nutrient cycle
• CARBON CYCLE:
• Carbon is the basic component in all living organisms present in
different forms as food like carbohydrates proteins lipids etc.. It is
present in atmosphere as CO2 which was taken up by plants during
photosynthesis and converted to carbohydrates (food) which moves
through various food chains and finally the carbon present in the
dead matter returned to the atmosphere as CO2 by microorganisms
Some sources of CO2 are respiration of animals and plants,
combustion of fuels and volcanic eruptions
CARBON CYCLE
NITROGEN
NITROGEN CYCLE
CYCLE
• 78% of atmospheric air is nitrogen
• It is present in all biotic components in different forms of foods as
proteins vitamins amino acids etc.,
• The N2 from atmosphere is taken up by the green plants for
biosynthesis of different food and used in metabolism
• The food move through the food chain after death the organic
nitrogen decomposed by several microorganisms like nitrifying
bacteria (nitrobacter, nitrosomonas) ammonifying bacteria in to
nitrites, nitrates, ammonia which are again used by plants
• Some bacteria's convert nitrates in to molecular nitrogen called
denitrifying bacteria's (pseudomonas , florescence) which is
again released back in to atmosphere and cycle goes on
NITROGEN CYCLE
PHOSPHORUS CYCLE
• Phosphorous is mainly present in the rocks and fossils
and also in all biotic components in different forms
• Phosphate rocks are excavated by man to use ti as a
fertilizer. Over usage of which moves through the
surface run off in to the oceans rivers and lost in to deep
sea sediments
• Sea birds eat sea fishes and their excreta returns
phosphates to land surface
• Thus the sea birds and man consuming fish returns the
phosphates lost to land
• Which the animals and plants use in their dissolved
forms for their bio synthesis
PHOSPHORUS CYCLE
ECOLOGICAL SUCCESSION
• Progressive replacement of one community by another till the
development of a stable community in a particular area is called
ecological succession
• There are two stages or community (group of plants or animals living
in an area)
• Pioneer community is one who first group of organisms to establish
their community
• Seres are the various developmental stages of a community in an
area
• There are two types of succession namely primary and secondary
• Primary type starts with gradual establishment of a biotic community
on a lifeless community. Depending on the area i.e if in water called
hydrarch and if it is in dry area called xerarch
• Secondary succession involves establishment of a biotic community
in an area where already other biotic communities exist.
Stages of Ecological succession
• Nudation: developing a bare area without any life form
• Invasion: establishment of one more species on a bare area
through migration followed by establishment
• For example migration of seeds brought about by wind water etc.,
these seeds then germinate and establishes their pioneer
communities
• Competition: when no of individuals increases competition between
same and different species arises for food water etc.,
• Reaction: The above steps modify the environment and called as
reaction. which affects certain existing species and replaced by
some other new species which leads to seral communities
• Stabilization: It leads to the formation of a stable community which
is in equilibrium with the environment
ECOLOGICAL SUCCESSION
Food chain
• The sequence of eating and being eaten in
an ecosystem is known as food chain. In a
grass land
Food chain in a pond and forest
Characteristics of food chain
• In a food chain,
• a) there is repeated eating in which each group eats the smaller one and is
eaten by the larger one. Thus, it involves a nutritive interaction between the
biotic components of an ecosystem.
• b) the plants and animals which depend successively on one another form
the limbs of a food chain.
• c) there is unidirectional flow of energy from sun to producers and then to a
series of consumers of various types.
• Thus, a food chain is always straight and proceeds in a progressing straight
line
• d) usually 80 to 90% of potential energy is lost as heat at each transfer on
the basis of second law of thermodynamics (transformation of energy
involves loss of unavailable energy).
• e) usually there are 4 or 5 trophic levels. Shorter food chains provide greater
available energy and vice - versa.
• f) omnivores occupy more than one trophic level and, some organisms
occupy different trophic positions in different food chains
Types of foodchain
• There are mainly two types of food chains operating in
nature.
• a) Grazing food chain
• b) Detritus food chain.
• Grazing food chain is generally seen in ecosystems such
as grassland, pond or lake where a substantial part of the
net primary production is grazed on by herbivores (cattle
and rodents).
• Usually upto 50% of the NPP is grazed on by these
animals in their respective ecosystems and the remaining
50% goes to the decomposer organisms as dead organic
matter.
• Thus, in these ecosystems, the food chain is herbivore
based.
Food web
• Food web can be defined as, "a network of food
chains which are interconnected at various
trophic levels,
• so as to form a number of feeding connections
amongst different organisms of a biotic
community".
• Food webs are indispensable in ecosystems as
they allow an organism to obtain its food from
more than one type of organism of the lower
trophic level.
• Generally, a food web operates according to
taste and food preferences of the organism, yet
availability of food source and other
compulsions are equally important.
• For e.g., tigers normally do not eat fish or crabs,
but Sunderbans they are forced to feed on them
in the absence of their natural prey.
A Food Web in Terrestrial and
Aquatic Ecosystem
Ecological pyramids
• Ecological pyramids can be defined as,
• "a geographical representation of an ecological
parameter like number of individuals or amount
of biomass or amount of energy present in
various trophic levels of a food chain with
producer forming the base and top carnivores
at the tip".
• Graphical representation of the trophic structure
is done by drawing ecological pyramids, where
the basal, mid and top tiers show the parameter
values for producers, herbivores and carnivores
in the ecosytsem.
• An ecological pyramid may be upright (tapering
towards the tip), or inverted (widens towards
the tip) or spindle shaped (broader in the middle
and narrow above and below).
• On the basis of the parameters used, ecological
pyramids are of three types.
• Pyramid of Numbers
• Pyramid of Biomass
• Pyramid of Energy
• "Pyramid of numbers is the graphic
representation of number of individuals per unit
area of various trophic levels stepwise with
producers forming the base and top carnivores
the tip".
Pyramid of Numbers in a
Grassland Ecosystem
• The shape of the pyramid of numbers vary from
ecosystem to ecosystem.
• In aquatic ecosystems and herbaceous
communities, autotrophs are present in large
numbers per unit area.
• They support a lesser number of herbivores,
which inturn support fewer carnivores
Pyramid of Numbers in a
Aquatic Ecosystem
• So, the producers are smallest sized but
maximum in number while, top carnivores are
larger in size but lesser in number,
• so these cannot be used as prey by another.
• Hence the pyramid of numbers is upright
• In a parasitic food chain, for e.g., an oak tree,
the large tree provides food to several
herbivorous birds.
• The birds support still larger population of
ectoparasites leading to the formation of an
inverted pyramid.
• When a large tree support larger number of
herbivorous birds which inturn are eaten by
carnivorous birds like falcon and eagle, which
are smaller in number, it forms a spindle
shaped pyramid.
• Pyramid of biomass is the graphic
representation of biomass present per unit area
of different trophic levels, with producers at the
base and top carnivores at the tip".
• The total amount of living or organic matter in
an ecosystem at any time is called 'Biomass'.
• In a terrestrial ecosystem, the maximum
biomass occurs in producers, and there is
progressive decrease in biomass from lower to
higher trophic levels.
• Thus, the pyramid of biomass in a terrestrial
ecosystem is upright.
• In an aquatic habitat the pyramid of biomass is
inverted or spindle shaped where the biomass
of trophic level depends upon the reproductive
potential and longivity of the member.
• Pyramid of energy is a graphic representation
of the amount of energy trapped per unit time
and area in different trophic level of a food
chain with producers forming the base and the
top carnivores at the tip".
• Representation of Pyramid of Energy
• Pyramid of energy is always upright.
• It is so because at each transfer about 80 90% of the energy available at lower trophic
level is used up to overcome its entropy and to
perform metabolic activities.
• Only 10% of the energy is available to next
trophic level (as per Lindemann's ten percent
rule).
Forest ecosystem
• In the Forest ecosystem animals are the consumers.
• They influence the flow of energy and cycling of nutrients through systems
as well as structure and composition of forests through their feeding
behaviour and the disturbances that they create.
• In turn their abundance and diversity is influenced by the composition of the
forest and the various disturbances that occur in the forest.
• Animals in an ecosystem form the heterotrophic stratum or brown belt of an
ecosystem .
• The animals in the ecosystem can be classified on the basis of their feeding
habits into:• 1. Herbivores are animals that consume plants and get their energy by
eating plants.
• They form the primary consumers of the ecosystem.Cow ,sheep ,goat
,deer,rabbit,horse ,zebra are some of the herbivorous animals.
• Carnivores or predators are animals that feed on the herbivores or other
animals in order to derive energy and nutrients required for their diet.
• They form the secondary consumers of the ecosystem.Mammals like
dogs,cats,mongoose ,hyennas;
• birds like hawks,eagle,falcon, reptiles like crocodile,snake,turtles are
examples of carnivorous animals.
• The tertiary consumers are also carnivores that feed on primary consumers
like herbivores and also feed on secondary consumers .
• Lion,tiger are examples of tertiary consumers.
• Scavengers are flesh eaters and eat the dead flesh from left over of the
carnivores.
• Jackal,vultures are examples of scavengers.
• 4.Parasites are organism consumes blood or tissues of the host animal
without killing the host
• 5.Decomposers break down complex compounds of dead tissues of
producers and
• consumers,absorb some of the decomposition products and release simple
substances consumable by autotrophic organisms.
• Decomposers include earthworms,bacteria, fungi,actinomycetes etc
TYPES OF FOREST ECOSYSTEM
• The forest ecosystem is of 3 types-tropical rain forest,tropical
deciduous forest and temperate coniferous forest.
• Tropical rain forest provides both shelter and food for huge number of
animals which include birds like cuckoo bird,parrot ,swallows
humming bird eagles;mammals like orangutans ,monkeys
gibbons,tiger,foxes,hippopotamus,jaguar,reptiles like
crocodiles,alligators,anaconda,flying gecko etc.
• Tropical deciduous forest contains animals like
deer,elephants,sambars ,cheetahs,wild buffaloes tiger ,leopard.Birds
,reptiles,amphibians are also found in abundance.
• Coniferous forests consists of rich and varied animal life which
includes mammals like mouse deer,musk,
rat,porcupine,rabbit,squirrels etc;
• insectivorous birds like grouse,jay cross bill etc and reptiles like
snakes and lizards
Uses of forest
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Forests can be described as uncultivated and uninhabited pieces of land covered by
trees and shrubs.
Forests play a vital role in the life and culture of the people.
They form an important renewable natural resource.
India has about 63.5% million hectares of forests and forms 1/5th of the
geographical area of the country.
Forests are intimately linked with our culture and civilization. Forests are useful to us
in many ways:
Forests provides timber for the furniture and building
Forests provides raw material for paper, board and plywood industry
Forests provides fodder for cattle, sheep, goat and other animals
Tropical deciduous forest contains animals like deer,elephants,sambars
,cheetahs,wild buffaloes tiger ,leopard.Birds ,reptiles,amphibians are also found in
abundance.
Coniferous forests consists of rich and varied animal life which includes mammals
like mouse deer,musk, rat,porcupine,rabbit,squirrels etc;
insectivorous birds like grouse,jay cross bill etc and reptiles like snakes and lizards
• Forests provides bamboo which is called poor man's timber
• Forests gives protection to wild life
• Forests helps in balancing the carbon dioxide and oxygen in the
atmosphere. During photosynthesis, plants release O2 and use CO2 thus,
they put check on the green house effect.
• Forests regulate the earth's temperature and weather cycle. They enhance
local rainfall
• Forests check soil erosion, landslides and also prevent floods
• Forests protect wild life
• Forests also provide fruits, nuts, gums, rubber, dyes, fibre, medicines,
camphor, essential oils etc.
• Forests are major sources of various animal products such as honey, wax,
tussore, lac etc
Grassland ecosystem
• Any unit that includes all the organisms i.e. the communities in a given area,
• interact with the physical environment so that a flow of energy leads to
clearly defined trophic structure,
• biotic diversity and material cycle (exchange of materials between living and
non living components) within the system, known as an ecological system or
ecosystem. The term ecosystem is derived from two different words, eco =
environment ; system = an interacting, interdependent complex.
• About Ecosystem
• Grassland is a type of terrestrial ecosystem.
• Grasslands occupy a comparatively fewer area, roughly 19% of the earth’s
surface.
• The various components of a grassland ecosystem are as follows
• Abiotic components• These are nutrients present in soil and the aerial environment.
• Thus, the elements like C, H, O, N, P, S etc. are supplied by carbon dioxide,
water, nitrates, phosphates and sulphates etc., present in air and soil of the
grassland.
• Moreover, in addition to the above, some trace elements are also present in
soil.
• Biotic components• These may be categorized as:
• 1. Producers- They are mainly grasses. Besides them a few herbs and
shrubs also contribute to primary production.
• 2. Consumers- These occur in the following sequence:
• a) Primary consumers- In grasslands, the herbivores feeding on grasses are
mainly such grazing animals as cows, buffaloes, deer, sheep, rabbit, mouse
etc.
• Besides them, there are also present some insects that feed on the leaves
of grasses.
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Secondary consumersThese are the carnivores feeding on herbivores.
These include the animals like fox, jackals, snakes, frogs, lizards, birds etc.
Sometimes the hawks feed on the secondary consumers, thus occupying
tertiary consumer level in the food chain.
• 3. Decomposers• The microbes active in the decay of dead organic matter of different forms of
higher life are fungi, and some bacteria and actinomycetes.
• They bring about the minerals back to the soil, thus making them available to
the producers
Desert ecosystem
• A desert ecosystem may seems to be barren land and devoid of life but
plants and animals do exist in desert.
• But their number of plants and animals is not as large as that in other
ecosystems.
• A desert ecosystem is a type of arid ecosystem that exists where there is
very little rainfall and the climate is usually extreme in harshness.
• Other arid ecosystems are semidesert, subdesert, steppe, and semiarid
or arid grasslands.
• Due to the low moisture content in desert the biological activities are
regulated by ephemeral water availability .
• These ecosystems are either barren or with scanty vegetation consisting
of mainly thorny bushes.
• Deserts are classified as warm (hot) and cold (temperate) deserts
• The hot deserts are the Sahara in Northern Africa, Kalahari in Southern
Africa, Thar in India, Atacama in South America, deserts of Mexico and
Australia.
• The deserts of Iran and Turkey, Gobi desert of Mongolia, some deserts of
Argentina are recognised as temperate or cold deserts
Plants in Desert Ecosystem
• Plants in the desert ecosystem are generally dwarfed because of the
lack of rainfall.
• The most common plant that is seen in the desert ecosystem is the
cactus.
• More than hundreds of different types of cactus are found in desert
ecosystem and each one has evolved to suit the particular desert
ecosystem to which they are endemic.
• Other plants of desert ecosystem are saltbush and gravillias.
• Plants of the desert ecosystem have evolved with succulent bodies that
can retain the precious moisture needed for growth and narrow needle
like leaves that reduces the lose moisture easily.
• Other plants spread across the ground or grow under shades of larger
plants
Animals in Desert Ecosystem
• Animals present in the desert ecosystem include very few
large mammals but camel is one of the prominent animals
found in this environment.
• Other animals found in desert ecosystem includes rats,
small rodents, rabbits, moles and fox like creatures.
• Burrowing creatures, snakes, insects, ants, birds, lizards,
and beetles are regular inhabitants that are found in desert
ecosystem
• Animals and other creatures present in desert ecosystem
have managed to survive in the harsh climate, hot days and
freezing nights, by controlling their body heat.
• It is essential for any desert ecosystem animals to adjust to
the particular aspects of their environment.
• The fragile balance of the desert ecosystem is nowadays
damaged by excess human activity.
Characteristics of Deserts
•
•
•
i) Most deserts receive some rain every year but not uniform.
ii) Light green covering of annuals is seen just after rains.
iii) Have scanty vegetation, clear skies, hot days and extremely cold nights.
•
•
iv) Soil is rocky and encrusted with sand or salt.
Long periods without precipitation and extreme temperature (50 - 60oC)
conditions (arid lands) impose considerable restraints on the flora and fauna
which inhabit there.
Sandy storms are very frequent.
Occur generally in rain shadow areas.
Flora
1) Includes succulents such as Cacti and Euphorbias, which can store water in
their tissues.
2) Trees with long spreading roots such as Acacia, Prosopis, Phoenix (dates)
are found.
3) Ephemerals (short lived) such as Boerhaavia repens are seen only during
rainy season.
•
•
•
•
•
•
• Fauna
• Most desert animals are nocturnal and avoid the heat of the day by
burrowing into the cooler soil.
• Animals include ants, locusts, lizards, Gila monster, coral snake, rattle
snake, burrowing owls, Gambel's quail, kangaroo rats, rabbits, camel,
skunk, badger foxes, jackals and desert cats.
• In general, the organisms having specialised structural and physiological
and behavioural adaptations to withstand the extreme temperatures only
can survive in a desert.
Grassland Ecosystem
•
•
•
•
•
Introduction
Types of grassland ecosystem
Features of different types of grassland
Characteristics of grassland ecosystems
Structure and function of grassland
ecosystem
introduction
• It occupies about 20% of earth surface.
• In addition some trees and shrubs also
present.
• Limited grazing improves the net
production grasslands.
• Over grazing leads to degradation.
Types of grassland ecosystem
• Tropical grasslands
• Temperate grasslands
• Polar grasslands
Tropical grassland
• Found near the borders of tropical rain
forests.
• High temperature and moderate rainfall.
• It is also known as savanna type.
• Tall grasses,scattered shrubs,stunted
trees.
• Animals- zebras, giraffes, antelope.
Temperate grassland
• Found in the centers of continent.
• Characterised by very cold winters and hot
summers.
• Intense grazing and summer fires, do not
allow shrubs or trees to grow.
polar grassland
• Found in artic polar regions.
• Characterised by severe cold and strong
winds along with ice and snow.
• In summer annual plants grow.
• Animals- artic wolf, weasel, artic fox.
Characteristics of grassland
ecosystems
• It is a plain land occupied by grasses.
• Soil is very rich in nutrients and organic
matter.
• It is ideal place for grazing animals.
• Characterised by low or uneven rainfall.
Features of different types of
grassland &
• Tropical grasslands
• Temperate grasslands
• Polar grasslands
Structure and function of grassland
ecosystem
• Abiotic components (e.g.,) Nutrients, C, H, O,
N, P , S, etc.
• Biotic components
• 1. Producers e.g., Grasses, herbs and shrubs
• 2. Consumers
• a. Primary consumers (herbivores)
(e.g.) cows, buffalos, deer, sheep, etc.
• b. Secondary consumers (Primary carnivores)
(e.g.) Snakes, lizards, birds, Jackals, fox
• c. Tertiary Consumers (e.g.) Hawks, eagles,
etc.
• 3. Decomposers e.g., bacteria and fungi
DESERT ECOSYSTEM
•
•
•
•
•
Introduction
Types of desert ecosystem
Features of different types of desert
Characteristics of desert ecosystems
Structure and function of desert
ecosystem
introduction
• It occupies about 35% of our world`s land
area.
• Characterised by less than 25 cm rainfall.
• Atmosphere is dry.
Types of desert ecosystems
• Tropical deserts
• Temperate deserts
• Cold deserts
Features of different types of
deserts.
• Tropical deserts are found in Africa; sahara
desert. Rajasthan; thar desert.
• They are characterised by only few species,
wind blown and sand dunes are common.
• Temperate deserts are found in South
California-majave.hot summer and very cold
winter.
• Cold deserts are found in china-gobi desert.
Cold winters and warm summers.
characteristics of deserts
• Desert air is dry and the climate is hot.
• Annual rainfall is less than 25cm.
• Soil is very poor in nutrients and organic
matter.
• Vegetation is poor.
Structure and function of desert
ecosystem
• Abiotic components (e.g.,) temperature, rainfall,
sunlight, water, etc.temperature is very high.
• Biotic components
• 1. Producers e.g., Grasses, few trees, herbs and
shrubs.eg; succulent
• 2. Consumers (e.g.) squirrels, mice, foxes, rabbits,
deer and reptiles, etc. dig holes.
• 3. Decomposers (e.g., bacteria and fungi-low dead
organic matter.
AQUATIC ECOSYSTEM
• Introduction
• Types of aquatic life zone
– Fresh water life Zone (examples : Ponds,
Streams, Lakes, Rivers)
– Salt water life Zones (examples : Oceans,
estuaries)
Aquatic ecosystems
• Ecosystem is an biological community of an
area, of interacting organisms and their physical
and chemical environment.
• Earth’s surface can be described by a series of
interconnected ecosystems. Ecosystem can be
classified into 2 main categories:
• Terrestrial ecosystems: where organisms and
their environment interacts on landmasses.
• Aquatic ecosystems: where plants, animals and
their physical environment interact in water.
• Types of Aquatic Ecosystems
• Fresh water:
• Very small proportion of earth’s area that is only 0.8
percent of the earth’s surface is covered by them.
• Primary production in a fresh-water ecosystem is
controlled by light and nutrient availability.
• Fresh water can be defined as the water that
contains a relatively small amount of dissolved
chemical compounds.
• It includes :Standing Water- lakes & ponds and
Moving Water- rivers & streams
• Significance of Different Types of Aquatic
Ecosystems
• The study of aquatic ecosystem helps to understand
the biodiversity (flora and fauna)of the aquatic
ecosystem and their interaction with the physical and
chemical environment .
• Aquatic ecosystems are in danger mainly because of
human activities like: Overfishing, Transportation,
waste disposal , recreation and other activities which
might harm the ecosystem
Fresh water ecosystem
Pond Ecosystem
• Introduction
• Characteristics and Features of Pond
ecosystems
• Structure and function of Pond ecosystem
Structure and functions of the Pond
ecosystem
• Abiotic components
(e.g.,) temperature, light, water and
Organic and Inorganic Components etc.
Structure and function of Pond
ecosystem –Biotic Components
• 1. Producers
A. Phytoplankton
e.g., Algae Small floating Plants like
volvax, Pandorina, Anabaena, Cosmarium
B. Microphytes
e.g., Large floating plants and submerged
plants like hydrilla, Jussiaea, Wolfia,
demna
• 2. Consumers
A. Primary Consumers (Zooplanktons)
(e.g.) Protozoa, very small fish, ciliates,
flagellates and protozoans
B. Secondary Consumers (Carnivores)
(e.g.) Insects like water beetles, and small fish
C. Tertiary consumers
e.g., large fish like game fish
• 3. Decomposers (e.g.) bacteria, fungi and
flagellates
Fresh water ecosystem - Lake
EcoSystem
•
•
•
•
Introduction
Type of lakes
Zones of Lake
Characteristics and Features of Lake
ecosystems
• Structure and function of Lake ecosystem
Types of Lakes
•
•
•
•
•
•
Oligotrophic lakes
Eutrophic lakes
Dystrophic lakes
Volcanic lakes
Meromictic lakes
Artificial lakes
Zones of Lake
•
•
•
•
Littoral Zones
Limnetic Zone
Profundal Zone
Benthic Zone
Structure and function of the Lake
ecosystem.
• I. Abiotic components
(e.g.,) temperature, light, proteins, lipids,
turbidity, O2 and CO2
Structure and function of Lake
ecosystem
• Biotic components
•
1. Producers
•
e.g., Phytoplankton, Algae and flagellates
•
2. Consumers
•
A. Primary Consumers(Zooplanktons)
(e.g.) Cilictes, protozogans, etc,
•
B. Secondary Consumers(Carnivores)
•
(e.g) Insects and small fishes
•
C. Tertiary consumers
•
e.g., large fishes like game fish
•
3. Decomposers (e.g.), bacteria, fungi and
actinomycetes
RIVER OR STREAM ECO
SYSTEM
• Introduction
• Characteristics and Features of River or
stream ecosystems
• Structure and function of river or stream
ecosystem
Structure and function of the river
or Stream ecosystem
• I. Abiotic components
•
(e.g.,) temperature, light, pH, Nutrients, Organic
and inorganic components
• II. Biotic components
•
1. Producers
•
e.g., Phytoplankton, Algae, water grasses, aquatic
masses and amphibious plants
•
2. Consumers
•
A. Primary Consumers
(e.g.) Water insects, snails and fishes
•
B. Secondary Consumers
•
(e.g) Birds and Mammals
•
3. Decomposers (e.g., bacteria, and fungi
• Standing Water- lakes & ponds:
Standing water ecosystems are known as Lentic
ecosystems such as lakes and ponds.
• The organisms in lentic ecosystem includs algae,
rooted and floating-leaved plants, invertebrates such
as crabs, shrimps, crayfish, clams etc, amphibians
such as frogs and salamanders; and reptiles like
alligators and water snakes.
•
• Moving Water- rivers & streams:
• flowing-water ecosystems are known as Lotic
ecosystems with water flowing in uniform
direction and in a unidirectional way.
• Examples are rivers and streams, which harbor
several species of insects and fishes.
• Crustaceans like crayfish and crabs; and
mollusks such as clams and limpets
SALT WATER ECOSYSTEM
• OCEAN ( MARINE) ECO SYSTEMS
• ESTUARINE ECO SYSTEMS
Estuaries
• Areas where freshwater dumps into ocean.
• So the water is neither truly fresh water, since it has
salt content, but it is also not consider salt water
because it has a lower level of salt than the ocean.
• Estuaries are always productive and has rich
biodiversity. Organisms are well adapted to varying
levels of salinity.
• Wetlands- bogs/fens, swamps, marshes: Here
the water is completely or partially shallow.
• Has a rich biodiversity because they receive
plenty of sunlight which supports life.
• Plants include water lilies, mangrove, tamarack
and sedges are commonly found in wetlands.
• Various species of reptiles and amphibians are
also found in wetlands.
ESTUARINE ECO SYSTEMS
• Introduction
• Characteristics and Features of
ESTUARINE ecosystems
• Structure and function of ESTUARINE
ecosystem
Structure and function of the
ESTUARINE ecosystem
• Abiotic components
(e.g.,) temperature, pH, Na, K, salts and various nutrians
• Biotic components
• 1. Producers
•
e.g., Phytoplankton, marsh grasses, sea weeds, and
sea grasses
• 2. Consumers
(e.g) Oysters, crabs, sea birds, small fishes
• 3. Decomposers (e.g., bacteria, fungi and
actenomycetous
Marine Ecosystem
• About 71% of the earths surface is covered by marine ecosystem.
Marine ecosystem involves:
• Shorelines, Coral Reefs, Open Ocean
• Shorelines : are where oceans and seas meet land.
• Since its close to the sea its always prone to hurricanes and
erosion.Habitat fo burrowing animals.
• Coral Reefs: Cover less than 1% of the oceans.Also known as
“Rainforests of sea”.
• These are clear warm shallow sea’s.Made up of as a result of
accumulation of calcium carbonate deposited by marine organisms like
corals and shellfish.
• Open Ocean: Oceans have a great impact on the biosphere.Its the
source of rainfall.
• ocean temperatures determine climate and wind patterns
OCEAN ( MARINE) ECO
SYSTEMS
• Introduction
• Zones of oceans
• Characteristics and Features of OCEANS
ecosystems
• Structure and function of OCEAN
ecosystem
Zones of oceans
•
•
•
•
•
Coastal Zones
Open Sea
Euphoric zone
Bathyal Zone
Abyssal zone
Structure and function of the
OCEAN ecosystem
•
•
•
•
•
•
•
•
•
•
•
•
•
Abiotic components
(e.g.,) temperature, light, NaCl, K, Ca, and Mg salts
Biotic components
1. Producers
e.g., Phytoplankton(Diatoms, unicellular Algae), marine plants(sea
wheats)
2. Consumers
A. Primary Consumers
(e.g.) Crustaceans, moiluses, fish
B. Secondary Consumers
(e.g) Herring Sahd, mackerel, etc.
C. Tertiary Consumers
(e.g) Cod, Haddock
3. Decomposers (e.g., bacteria, and fungi
BIODIVERSITY
INTRODUCTION
• Bio means ‘life’ and diversity means ‘variety’,
hence biodiversity refers wide variety of life on the
earth.
• Our planet earth contains more than 20 million
species of organisms.
• Only 1.4 million species have been identified so
far
• These species differ widely from one another.
• This variation in living organisms is called
biodiversity.
• Diversification in the species is influenced by
various physical and climatic factors, resulting in
the production of new sub-species.
• The species which are unable to adjust with the
new environment gradually become extinct.
• Definition:
Biodiversity is defined as “the variety
and variability among all the groups of living
organisms and the ecosystem in which they occur.”
SIGINIFICANCE OF BIODIVERSITY
1.Biodiversity is very important for human life, as
we depend on plants, micro organisms, earth’s
animals for our food, medicine and industrial
products.
2.protects the fresh air, clean water and land.
3.important for forestry, fisheries and agriculture,
which depend on rich variety of various
biological resources available in nature.
4.Loss of biodiversity has serious economic and
social cost for any country.
Loss of biodiversity
1.
2.
3.
The farmers prefer hybrid seeds, as a result, many
plant species become extinct.
for the production of drugs the pharmaceutical
companies collect wild plants, so several medicinal
plants now become extinct.
Tropical forest is the main sources of world’s medicine.
Every year these forests are disappearing due to the
agriculture, mining, logging.
Examples
Taxus baccate, a tree growing in subHimalayan regions, once believed to be of no value is
now found to be effective against cancer. However,
this plant has become an endangered species now.
Classification (or) Levels of Biodiversity
• Biodiversity is generally classified into
three types
1. Genetic diversity.
2. Species diversity.
3. Community (or) Ecosystem diversity
1. Genetic diversity.
• Genetic
A species with different genetic characteristics
is known as sub-species or “genera”.
Genetic diversity is the diversity within species
within individual species, there are
number of varieties, which are slightly different from
one another. These differences are due to
differences in the combination of genes. Genes are
the basic units of hereditary information transmitted
from one generation to other.
Examples:
1. Rice varieties : All rice varieties belong to the
species “oryzasativa” but there are thousands
of rice varieties, which show variation at the
genetic level differ in their size, shape, color
and nutrient content.
2. Teak wood varieties:
There are number of teak
wood varieties found available.
Examples:
Indian teak, Burma teak, malasian
teak etc
.
2.Species diversity
Species :
A discrete group of organisms of the same kind is
known as species
Species diversity is the diversity between different
species. The sum of varieties of all the living
organisms at the species level is known as species
diversity.
• EXAMPLE.
• PLANT SPECIES: APPLE.MANGO,GRAPES,WHEAT,RICE.
• ANIMAL SPECIES : LION,TIGER,ELEPHANT,DEER.
• The different
sample areas
showing species
richness (sample
area 1),
• Species
evenness
(sample area 2)
• diversity due to
taxonomically
unrelated
species (sample
area 3)
3.COMMUNITY DIVERSITY
• It is a set of biotic componenents interacting with one
another and wit abiotic components.
• The diversity at the ecological or habit level is known as
ecosystem diversity. A large region with different
ecosystems can be considered as ecosystem diversity.
Example:
River eco system;
The river which include the fish, aquatic insects, mussels
and variety of plants that have adapted.
Thus the ecosystem diversity is the aggregate of different
environmental types in a region. It explains the
interaction between living organisms and physical
environment in an ecosystem.
VALUES OF BIODIVERSITY
• Biosphere is a life supporting system to the
human beings. It is the combination of different
organisms. Each organisms in the bio sphere
has its own significance.
• Biodiversity is vital for healthy biosphere
• Biodiversity is must for the stability and proper
functioning of the biosphere .
CLASSIFICATION OF VALUES OF
BIODIVERSITY
•
•
•
•
•
•
CONSUMPTIVE USE VALUE
PRODUCTIVE USE VALUE
SOCIAL VALUES
ETHICAL VALUES
AESTHETIC VALUES
OPTION VALUES
CONSUMPTIVE USE VALUE
• These are direct use values, where the biodiversity
products are harvested and consumed directly.
EXAMPLES; FOOD ,DRUG ,FUEL, etc.
1.Food:
A large number of wild plants are consumed by human beings as
food.
EXAMPLES
cerepogia bulbosa: Central India and western ghats.
Codonopsis: Himalayan region
cicer microphyllum: Kashmir
Insects: molluscs, spiders, and wild herbivores are consumed by many
tribal and non-tribal communities in India.
Food
DRUGS
•
Around 70% of modern medicines are derived
from plant and plant extracts.
• 20,000 plant species are believed to be used
medicinally, particularly in the tration system of
unani, ayurvedha and sidha.
Examples:
1.
2.
3.
Germany; 2,500 species of plants for medicine in
Homeopathy
India ; 3,000 species of plants for medicine in
Ayurvedha, Homeopathy and unani
Primary health care; 85% of global community plants
1. Arthritis; bee-sting venom for latest medicinal
science.
2. Life saving drugs like quinine (malaria), reserpine
(hypertension), penicillin (antibiotic) and Morphine
9pain kill) are all of plant origin.
3. Peepal tree leaves, trunk and roots: curing fever,
cough, stomach and skin disease
4. Neem tree: 30 medicines prepared and very
effective for stomach oilments, eye irritations, skin
eruptions and diabetics.
5. Maxican yarn has been proved as a versatile to
produce birth control in human beings.
Medicinal plants
Fuel
• Fire woods are directly consumed by
villagers, tribals.
• The fossil fuels like coal, petroleum and
natural gas are also the products of
fossilized biodiversity.
PRODUCTIVE USE VALUES
• Bio diversity products have obtained a
commercial value.
• These products are marketed and sold.
• These products may be derived from the
animals and plants.
• ANIMAL PRODUCTS
•
•
•
•
•
•
SILK- SILK WORM
WOOL- SHEEP
MUSK- MUSKDEER
TUSK – ELEPHANTS
LEATHER- ALL ANIMALS
FOOD- FISH AND ANIMALS
• PLANT PRODUCTS
•
•
•
•
•
•
WOOD- PAPER, PLYWOOD, PULP, RAILWAYSLEEPER INDUSTRY.
COTTON- TEXTILE INDUSTRY
FRUITS,VEGETABLES- FOOD INDUSTRY.
LEATHER- LEATHER INDUSTRY
IVORY- IVORY WORKS
PEARL- PEARLS INDUSTRY.
• (a) Rice accounts for 22% of the cropped area and
• cereals accounts for 39% of the cropped area
• (b) Oil seed production also helped in saving large amount
of foreign exchange spent on importing edible oils.
SOCIAL VALUES
• Social value of the biodiversity refers to the manner
in which the bio-resources are used to the society.
• These values are associated with the social life,
religion and spiritual aspects of the people.
Examples:
• HOLY PLANTS- TULSI, PEEPAL, LOTUS.
• HOLY ANIMALS- COW ,SNAKE, BULL, PEACOCK,RAT.
ETHICAL VALUES
• It involves ethical issues like “all life must be preserved”
• In India and in other countries biodiversity is considered
to have great value on religious and cultural basis.
• Our rich heritage teaches us to worship plats, animals,
rivers and mountains.
• It is existence in nature gives as pleasure.
• Examples:
• The river ganga is holy river.
• Vembu, tulsi, vengai are worshipped by tamilians
• Kangaroo,zebra,giraffe exist in nature.
AESTHESTIC VALUE
• The beautiful nature of plants and animals
insist us to protect the biodiversity.
• The most important aesthetic value of
biodiversity is eco-tourism.
Examples:
1.Eco-tourism: people from far place spent a lot of
time and money to visit the beautiful areas,
where they can enjoy the aesthetic value of
biodiversity. This type of tourism is called ecotourism.
2. The pleasant music of wild birds
• colour of butterfly
• colour of flowers
• colour of peacocks. Are very important
aesthetic value.
OPTION VALUES
• The option values are the potentials of biodiversity that
are presently unknown and need to be known.
• The optional values of biodiversity suggests that any
species may be proved to be a valuable species after
someday.
Examples:
• The growing biotechnology field is searching a species
for causing the disease of cancer and AIDS.
• Medicinal plants and herbs play a very important role in
our Indian economic growth.
BIO DIVERSITY AT GLOBAL LEVEL
• Total number of living species in the world are about 20
million. But, of which only about 1.5 million species are
found and given scientific names. Tropical deforestation
alone is reducing the biodiversity by 0.5% every year.
• Terrestrial biodiversity (or) Biomass:
It is the largest ecological units present in different
geographic areas and are named in different ways.
Examples; Tropical rain forests, Savannas, desert, tundra, etc.
Tropical rain forests:
• These are earths largest storehouse of biodiversity.
• They are inhabited by millions of species of plants,
insects, birds, amphibians and mammals.
• About 50-75%of global biodiversity lies in these
tropical rain forests .
MEDICINAL PLANTS
• More than 25% of the worlds prescription drugs
are extracted from plants growing in tropical
forest.
Examples;
• About 3000 plants identified by NCRI as cancer
fighting chemicals.
• 70% is derived from tropical rain forest.
• Extracts from creeping vines at Cameroon
effective in the inhibition of AIDS virus.
(b) FLOWERING PLANTS
• It has been estimated that nearly 1,30,000
flowering plants are available.
• we know only1-3%.
PROTECTION OF TROPICAL RAIN FOREST:
Thus it is essential to project our tropical rain forests.
• Silent valley in kerala is only place in India.
• In order to protect our only tropical rain forest biodiversity,
silent valley Hydroelectric project was abandoned.
2.TEMPERATE RAIN FORESTS
• They have much less biodiversity, globally,
they have nearly,
• 1,70,000 Flowering plants.
• 30,000 Vertebrates
• 2,50,000 Other group of species.
MARINE DIVERSITY
• Marine diversity is much higher than
terrestrial biodiversity, but it is less known
and described.
• Estuaries, coastal waters, oceans are
biologically diverse but the diversity is very
low.
• sea cradle of every phylum.
• Out of the 35 existing phyla of multicellular
animals, 34 are marine.
TAXNOMIC GROUP
Protozoans
Bacteria
Algae
Fungi
Higher plants
Jelly fish, Coarls
sponges
NUMBER
31,000
5,000
27,000
45,000
2,50,000
10,000
5,000
Earthworms
36,000
Insects
Snails, Slugs
Fish
Amphibians
Reptiles
Mammals
Birds
TOTAL
7,50,000
70,000
22,000
4,000
5,000
4,000
9,000
1,400,000
BIODIVERSITY AT NATIONAL LEVEL
• India is a second largest- 5% of world’s
biodiversity and 2% of the earth surface.
• Rank of India biodiversity:
• 10 rank- plant rich of world
• 11 rank- endemic species of higher
vertebrates.
• 6 rank- centers of diversity and origin of
agricultural crops
MEDICINAL VALUE
• More than 2000 medicinal plants are
cultivated in India, which can cure
many disease.
• Example:
• Tulsi and Neem
• Turmeric – anticarcinogen
COMMERCIAL VALUE
•
•
•
•
•
Sandal wood. It is sold in abroad.
Tobacco- Indian tobacco-high nicotin
Edible mushrooms
Ornamental plants flowers and fruits
More than100 species microorganisms were
collected from Indian soils and cultured,
developed and formulated in the abroad
laboratories.
BIODIVERSITY AT LOCAL LEVEL
• Point richness: It refers no.of species that can be
found at single point in a given space.
• Alpha richness or Alpha diversity: It refers no.of
species found in a small homogeneous area. It is
strongly correlated with physical variables .
• Beta richness or Beta diversity: It refers to
the rate of change in species composition
across different habitats.
• Gamma richness or Gamma diversity: It
refers to the rate of change across large
landscape.
Community and ecosystem diversity
• Diversity at the level of community and ecosystem exists along 3
levels. It could be within-community diversity (alpha diversity),
between-communities diversity (beta diversity) or
• diversity of the habitats over the total landscape or geographical area
(gamma diversity).
BIODIVERSITY AT TAMILNADU
• The distribution of plants and animals among
different districts of tamilnadu is uneven.
• Examples:
• There are some dense forest in salem district.
• Western ghats has 1500 species of plants, 50 species of
mammals and 90 reptiles species.
• Birds of several species is coming to vedanthangal from far
off places.
• Elephant sanctuaries at anaimalai.
• Tiger sanctuary at mundanthurai.
MEGA DIVERSITY
• There are nearly 170 countries in the world and
12 of them contain 70% of our planets
biodiversity.
• Mega diversity regions:
• The following 12 countries,
• Australia, brazil, china, Colombia, Ecuador, U.S,
India, Indonesia, Madagascar, Mexico, Peru and
Democratic republic of the Congo regions are
known as mega diversity regions. These
countries have the worlds selected few rich floral
and faunal zones.
• INDIA AS A MEGA DIVERSITY NATION :
• India one among 12 mega-diversity countries in the
world.
• 89,450 animal species-7.31% of global faunal species
• 47,000 plant species -10.8% of world floral species
• The loss of biodiversity or endemim is about 33%
ENDEMISM OR ENDEMIC SPECIES
• The species which are confined to a particular are called
endemic species.
• Our country has a rich endemic flora and fauna.
• About 33% of the flowring plants, 53% of fresh water fishes,
60% amphibians , 36% reptiles and 10% mammalian are
endemic species.
• 1.Plant diversity: 5000 flowering plants and 166 crop
plant species have their origin in India.
• 2.marine diversity: More than 340 coral species of
the world are found here. Mangrove and sea grasses
are also found in our country.
• 3.Agro-diversity: There are 167 crop species
and wild relatives. India is considered to be the
centre of origin of 30,000 to 50,000 varieties of
rice, mango, turmeric, ginger, sugarcane etc.
• 4.Animal biodiversity: There are 75,000 animal
species including 5,000 insects. India is a
home to about nearly 2,00,000 living
organisms.
RED-DATA BOOK
• Red book is a catalogue of taxa facing risk of
extinction.
• The purpose of preparation of red list is to
• provide awareness to the degree of threat to
biodiversity.
• provide global index on decline of biodiversity.
• identification of species at high risk.
• help in conservation action.
• information about international agreements.
• India's biodiversity is threatened due to habitat
destruction, degradation, fragmentation and over
exploitation of resources.
• According to ‘RED’ data book 44 plant species
are critically endangered, 54 endangered,143 are
vulnerable.
• India ranks 2nd interms of the number of
threatened mammals and 6th among the
countries with the most threatened birds.
• Examples:
• 1.pitcher plant has become endemic in eastern
Himalayas.
• 2.taxus wallichina has become under red data
category due to its over exploitation.
HOT-SPOTS OF BIODIVERSITY
• The most remarkable and threatened areas,
many of them have been reduced to less
than 10% of their original vegetation. These
areas are called hot-spots of biodiversity.
or
The hot spots are the geographic areas
which possess high endemic species.
• CRITERIA FOR RECOGNISING HOT SPOT
• The Richness of endemic species is the primary
criterion for recognizing hot spots.
• Significant percentage of specialized species.
• Site is under threat.
• It should contain important Gene pools plants of
potentially useful plants.
Reason for rich biodiversity in the tropics
• The tropics have a More stable climate.
• Warm temperatures and high humidity in the
tropical areas provide favorable conditions.
• No single species can dominate and thus there is
an Opportunity for many species coexist.
• Among plants, rate of out-crossing appear to be
higher in tropics.
Area of hot spot
• These hot spots covering less than 2% of the
worlds land are found to contain 50,000
endemic species.
• According to myersetal (2000), an area is
designated as a hot spot when it contains at
least 0.5% of the endemic plant species.
• About 40% of terrestial plants and 25% of
vertebrate species are endemic and are found
in these hot spots.
• These are the areas of high diversity,
endemism and are also threatened by many
human activities.
HOT SPOTS OF BIODIVERSITY IN INDIA
• Myers etal recognized 25 hot spots in the
world as shown in table. Two of which are
found in India.
1.
Eastern Himalayas
Indo-Burma region.
2.
Western ghats
Srilanka region
Eastern Himalayas: - 35,000 plant species found
in the Himalayas, of which 30% endemic.
• The eastern Himalayas are also rich in wild
plants of economic value
• Examples: rice, banana, citrus, ginger, chilly,
jute and sugarcane.
Western ghats
• The area comprises Maharastra, Karnataka,
Tamilnadu, and Kerala.
• Nearly 1500 endemic dicotyledone plant
species are found from western ghats.
• 62% amphibians and 50% lizards endemic in
western ghats.
• It is reported that only 6.8% of the original
forests are existing today while the rest has
been deforested or degraded.
• Some common plants- Ternstroemia
Japonica, Hypricum.
• Some common animals- Blue bird, lizard,
hawk.
THREATS TO BIODIVERSITY
• Any disturbance in an natural ecosystem
tent to reduce its biodiversity.
• The waste generated due to increase in
human population and industrialization,
spoils the environment and leads to more
diversity in biological species.
• Any change in the system leads to major
imbalance and threatens the normal
ecological cycle.
VARIOUS THREATS TO INDIAN BIODIVERSITY
• Habitat loss: The loss of populations of
interbreeding organisms is caused by habitat
loss. Habitat loss threatened a wide range of
animals and plants.
• Factors influencing Habitat loss:
•
•
•
•
•
•
•
DEFORESTATION
DESTRUCTION OF WETLANDS
HABITAT FRAGMENTATION
RAW MATERIAL
PRODUCTION OF DRUGS
ILLEGAL TRADE
DEVELOPMENTAL ACTIVITIES
POACHING (OVER HARVESTING) OF
WILD LIFE
• Poaching means killing of animals (or)
commercial hunting. It leads to loss of
animal biodiversity.
• SUBSISTENCE POACHING: To provide
enough food for their survival and killing.
• COMMERCIAL POACHING: hunting and
killing animals sell their products .
FACTORS INFLUENCING POACHING
•
•
•
•
•
•
Human population
Commercial activities
Wild life products
Wealth of wildlife
Importers of wild life
Examples: male gorilla, blue morpho butterfly,
snowy large egret, blubber;, baleen, elephant
feet, elephant, Bengal tigers, bush meat,
dynamite fishing, seahorses, star turtles.
REMEDY MEASURES
• Illegal hunting and trade of animals and
animal products should be stopped
immediately.
• We should not purchase furcoat, purse or
bag or items made of crocodile skin or
python skin.
• Bio-diversity laws should be strengthened.
MAN-WILDLIFE CONFLICTS
• Man-wildlife conflicts arise, when wildlife
starts causing immense damage and danger
to the man.
• Under such condition is very difficult for the
forest department to compromise the
affected villagers and to gain the villagers
support for wildlife conservation.
Examples:
• In Sambalpur ,Orissa-195 humans were killed
by elephants. Villagers killed 98 elephants and
badly injured 30 elephants.
• Man-eating tiger killed 16 Nepalese
• Two men were killed by leopards in Powai,
Mumbai
• 14 persons were killed during 19 attacks by
leopards in Sanjay Gandhi National park at
Mumbai
Factors influencing man-animal conflicts
• Shrinking of forest cover compels wildlife
to move outside the forest and attack the
fields and humans.
• Human encroachment into the forest area
induces a conflict between man and the
wildlife.
• Injured animals have a tendency to attack
man.
• Earlier, forest departments used to
cultivate sugarcane paddy, coconut trees,
in the sanctuaries.
• Often the villagers put electric wiring around
their crop fields. The elephants get injured,
suffer in pain and start violence.
• The cash compensation paid by the
government for damage caused by the wild
animal is not enough. So farmers revengeful
and kill the wild animals.
• Garbage near human settlements or food crops
near forest areas attracts wild animals.
Remedial measures (or) Conservation of
Biodiversity
1. Adequate crop and cattle compensation schemes must be
started.
2. Solar powered fencing must be provided along with electric
current proof trenches to prevent the animals from entering
into the fields.
3. Cropping pattern should be changed nearest the forest
borders.
4. Adequate food and water should be made available for the
wild animals within forest zones.
5. The development and constructional work in and around
forest region must be stopped.
ENDANGERED AND ENDEMIC SPECIES
OF INDIA
• According to IUCN the species are classified into various
types.
• Extinct species: A species is said to be extinct, when it is
no longer found in the world.
• Endangered species: A species is said to be
endangered, when its number has been reduced to a
critical level.
• Vulnerable species: A species is said to be vulnerable
when its population is facing continuous decline due to
habitat destruction or over exploitation.
• Rare species: A species is said to be rare, when it is
localized within restricted area.
ENDANGERED SPECIES OF INDIA
• A species is said to be endangered, when its
number has been reduced to a critical level. Unless
it is protected and conserved, it is in immediate
danger of extinction.
• In India 450 plant species have been identified as
endangered species.
• About 100 mammals and 150 birds are endangered
species.
• India's biodiversity is threatened due to habitat
destruction, degradation and over exploitation of
resources.
Categories of threatened
species
IMPORTANT ENDANGERED
SPECIES
• REPTILES-TORTOISE,GREEN SEA
TURTTLE,PYTHON
• BIRDS-PEACOCK, PELICAN,INDIAN
BUSTARD
• MAMMALS-INDIAN WOLF,RED
FOX,TIGER,INDIAN LION GOLDEN
CAT,DESERT CAT
• PRIMATES-HOOLOCK GIBBON,CAPPED
MONKEY,GOLDEN MONKEY
• PLANTS-SANDAL WOOD,MEDICINAL
PLANTS
FACTORS AFFECTING
ENDANGERED SPECIES
• POLLUTION
• OVER-EXPLOITATION
• CLIMATIC CHANGE
REMEDIAL MESURES
International treaties on endangered
species {ITES}
“CONVENTION ON INTERNATIONAL
TRADE IN ENDANGERED
SPECIES”{CITSE}-signed by 160
countries
It list 900 species –cannot be traded
It restricts international trade of 2900
other species
ENDEMIC SPECIES
• The species which are found only in a
particular region are known as endemic
species
• India is rich in plant and animal endemic
species
• FLORA- e.g.. Sparia himalayana,ovaria
lurida
• Out of 81,000 species –large no is endemic.
• Western Ghats rich in 60% amphibians,
50%,reptiles endemic species
• FAUNA- e.g. monitor lizards, reticulated
python, Indian salamander
• Out of 47,000 species,7,000 –endemic
• 62% endemic found in Himalayas and western
Ghats
Endemic species in India
•
•
•
•
•
•
•
•
Plants
Pteridophyta-200
Angiosperms-4950
Animals
Land-878
Freshwater-89
Insecta-16214
Reptilia-214
FACTORS AFFECTING ENDEMIC
SPECIES
• HABITAT LOSS AND
FRAGMENTATION
• POLLUTION
• E.G. frog eggs, tadpoles and adultssensitive to pesticides
• Over hunting frog legs in Asia and
France
CONSERVATION OF BIO DIVERSITY
• Conservation is the management of
biosphere so that it will yield the greatest
sustainable benefit to present generation
while maintaining its potential to meet the
needs of future generation
• Factors affecting biodiversity:
• 1.Human activities like construction, pollution,
urbanization
• 2.poaching, over exploitation, degradation of
habitats etc.,
• 3.oil spills, discharge of effluents disturb marine
ecosystem
• 4.Global warming , ozone hole , acid rain etc.,
• Need for bio diversity conservation:
• 1.immediate benefit like recreation and tourism
• 2.drugs, herbs, food, raw materials derived
easily
• 3.preserve genetic diversity of plants and
animals
• 4.ensures sustainable utilization
• 5.conserve ecological diversity and life
supporting systems
• 6.to prevent environmental deterioration
IN – SITU CONSERVATION
• It involves protection of fauna and flora within
its natural habitat, where the species normally
occurs
• The natural habitats or ecosystems maintained
under in – situ conservation are called protected
areas.
• Biosphere reserves, national parks, wildlife
sanctuaries, gene sanctuary etc., are some of in –
situ conservation
• 4% geographical area of a country used for this
• It is best method for long term conservation
•
•
•
•
•
•
•
•
BIOSPHERE RESERVES:
Cover large area, more than 5000 sq.km
Gives long term survival of evolving ecosystem
Protects endangered species
Protect max. no of species and communities
Site for recreation and tourism
Used for educational and research purposes
Remains as open system and changes in land
use restricted
BIO SPHERE RESEVES OF INDIA
• NATIONAL PARKS:
• Area dedicated for the conservation of wild life along with its
environment. Smaller than reserves and covers 100 to 500 sq.kms.
Exist within reserves
•
•
•
•
For tourism without affecting environment
Protect, propagate and develop the wildlife
Grazing is strictly prohibited
Private rights and forestry activities are
also prohibited
• WILDLIFE SANCTUARIES:
• Area reserved for conservation of animals only.there
are 492 in our country
• It protects animals only
• Allows timber extraction and collection of forest
products
• Private ownership rights and forestry operations which
will affect animals adversely are allowed
• Killing, hunting, shooting, or capturing of wildlife is
prohibited except under the control of higher authority
• GENE SANCTUARY:
• Area where plants are conserved
• In northern India one to preserve citrus family and other to preserve
pitcher plant was operating
• OTHER PROJECTS FOR
CONSERVATION OF ANIMALS:
• Project tiger
• Gir lion project
• Crocodile breeding project
• Project elephant
• Merits of in – situ conservation:
• Cheap and convenient method
• Species adjusted to natural disasters
• Demerits of in – situ conservation:
• Large area needed
• Maintenance is not proper hence cause
pollution
•
•
•
•
•
EX – SITU CONSERVATION
It involves the protection of fauna and flora
outside the natural habitats
It involves maintenance and breeding of
endangered species in controlled conditions
It identify the species under risk of extinction
It prefers species of more important for mankind
in near future
Botanical gardens seed banks microbial culture
collections tissue and cell cultures museums
zoological gardens are the places where it is
carried out
BOTANICAL GARDENS
ZOOLOGIAL GARDENS
MUSEUM
METHODS OF EX – SITU CONSERVATION
• NBPGR: National bureau of plant genetic
resources is located in Delhi using
cyropreservation technique to preserve
agricultural and horticultural crops.
• Seeds and pollens of certain plants are
preserved in liquid nitrogen at a temperature of 1960C for several years
• NBAGR: National bureau of animal genetic
resources is located in karnal Haryana. It
preserves the semen of domesticated bovine
animals
• NFPTCR: National facility for plant tissue culture
repository develops varieties of plants or trees
by tissue culture
• Merits of Ex- situ conservation:
• Special care and attention increased no of
endangered species. In captive breeding animals are
assured food water shelter and security for longer
time. Ususally carried out for endangered species
which do not have chance of survival
• Demerits
• Expensive, freedom of wildlife lost, cannot survive in
natural environments and adopted only for certain
species
TISSUE CULTURE IN PLANTS
BIO GEOGRAPHICAL CLASSIFICATION OF INDIA
• India is a mega diversity nation with different
climatic conditions and topography in different
parts of it
• Occupies 10th position in plant richness
• It important to study the distribution evolution and
environmental relationship of plants and animals in
time space.
• Bio geographers classified our country in to ten bio
geographic zones to study about it
• Each zone has its own characteristic climate, soil
and bio diversity
S.N
O
Bio geographic zone
Biotic province
Total area
biomass
1
Trans Himalayan region
Upper regions
5.7%
186200
2
Himalayan mountain
North west,
west,
east,
central
17%
6900,
720000,
123000
83000
3
Desert (arid)
Kutch
Thar
Ladakh
45000
18000
NA
4
Semi arid
6.9%
Central india
Gujarat – rajwara
15 – 16%
107600
404400
S.NO
Bio geographic zone
Biotic province
Total area
biomass
5
Western ghats
Malabar coast
Western ghats
Mountains 5.8%
59700
99300
6
Deccan peninsula
South plateau
Central plateau
Eastern plateau
Chotta nagpur
Central highlands
4.3%
378000
341000
198000
217000
287000
7
Gangetic plain
Upper
Lower 4.3%
206400
153000