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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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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 ofscience 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. 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. Components of the Environment
Man-made environment It is powerful environmentagent 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 activitiesand then return to the environment. Abiotic
three categories
1.Atmosphere 2.Lithosphere 3.Hydrosphere 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 no. Region Altitude in km Temperature in C Chemical species 1
Troposhere 0-18 15 to -56 N2,H2O,CO2,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 Upto 1600 Very high He,
H2 Composition of Atmospheric Air
Gas Relative %byVolume Nitrogen (N2) Oxygen (O2) Argon (A) Carbon
di oxide- CO2) Miscellaneous Total 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 knowledgeof
different types of environment and the effect of diff. envir.
Hazards. It inform the people About their role in protecting the
envir
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-governmentagencies to take part to protect our
environment Public Participation and types
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 TYPES OF
NATURAL ECOSYSTEM TYPES OF AQUATIC ECOSYSTEM TYPES OF FRESH WATER
ECOSYSTEM 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 allowflow 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 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 radiationsa 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 + 6O
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 asCO2 by microorganisms Some
sources of CO2 are respiration of animals and plants, combustion of
fuels and volcanic eruptions CARBON CYCLE NITROGEN CYCLE NITROGEN
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 andif 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 whichis 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
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 % 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
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 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 earths 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. Secondary consumers- These 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 ( oC) 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.
Earths 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 earths area that is only 0.8
percent of the earths 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 Characteristicsand 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 Characteristicsand
Features of Lake ecosystems Structure and function of Lakeecosystem
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) Insectsand 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 Characteristicsand Features of River or stream
ecosystems Structure and function of river or streamecosystem
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 isneither 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
thewater 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
Characteristicsand 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. Theseare clear warm
shallow seas.Made up ofas 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 Characteristicsand 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 lifeand 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 thevariety and
variability among all the groups of living organisms and the
ecosystem in which they occur. SIGINIFICANCE OF BIODIVERSITY
1.Biodiversity is very importantfor human life, as we depend on
plants, micro organisms, earths 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 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 worlds medicine. Every year these
forests are disappearing due to the agriculture, mining, logging.
Examples Taxus baccate, a tree growing in sub-Himalayan 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
withinspecies within individual species, there are number of
varieties, which are slightly different from one another. These
differences are due to differences in thecombination of genes.
Genes are the basic units of hereditary information transmitted
from one generation to other. There are number of teak wood
varieties found available.
Examples: 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. 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 bymany
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: Germany;2,500 species of plants for medicine in
Homeopathy India ; 3,000 species of plants for medicine
inAyurvedha, Homeopathy and unani Primary health care; 85% of
global community plants Arthritis; bee-sting venom for latest
medicinal science.
Life saving drugs like quinine (malaria), reserpine (hypertension),
penicillin (antibiotic) and Morphine 9pain kill) are all of plant
origin. Peepal tree leaves, trunk and roots: curing fever, cough,
stomach and skin disease Neem tree: 30 medicines prepared and very
effective for stomach oilments, eye irritations, skin eruptions and
diabetics. 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 obtaineda 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 (a) Rice accounts for 22% of the cropped
area and
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 eco-tourism. 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 Examples;
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 NUMBER Protozoans 31,000 Bacteria 5,000 Algae 27,000 Fungi
45,000 Higher plants 2,50,000 Jelly fish, Coarls 10,000 sponges
Earthworms 36,000 Insects 7,50,000 Snails, Slugs 70,000 Fish 22,000
Amphibians 4,000 Reptiles 5,000 Mammals Birds 9,000 TOTAL 1,400,000
BIODIVERSITY AT NATIONAL LEVEL
India is a second largest-5% of worlds 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 fromfar 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
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
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
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 adults-sensitive 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 capturingof wildlife is prohibitedexcept
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 watershelter 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.NO 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 % 6900,
720000, 123000 83000 3 Desert (arid) Kutch Thar Ladakh % 45000
18000 NA 4 Semi arid Central india Gujarat rajwara 15 16% 107600
404400 S.NO Bio geographic zone Biotic province Total area biomass
5 Western ghats Malabar coast Mountains5.8% 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