Envirnmental_studies_-_NEP

ENVIRONMENTAL STUDIES
1 H.G. RAVI SHANKAR , DEPARTMENT OF EVS, BGS FIRST GRADE COLLEGE, MYSURU-23 / 2021-22
BGS FIRST GRADE COLLEGE
H.G. RAVI SHANKAR

FIRST SEMESTER
CHAPTER TITLE PAGE
I INTRODUCTION TO ENVIRONMENTAL
STUDIES
3 - 8
II ECOSYSTEMS 9 - 28
III NATURAL RESOURCES 29-50
IV BIODIVERSITY & CONSERVATION 51 -65
V ENVIRONMENTAL POLLUTION 66-78
VI
ENVIRONMENTAL POLICIES &
PRACTICES
79-89
VII HUMAN COMMUNITIES &
ENVIRONMENT
90-100
MR. H.G. RAVISHANKAR, M.Sc.,
DEPARTMENT OF STUDIES IN ENVIRONMENTAL STUDIES
BGS FIRST GRADE COLLEGE, MYSURU-23

DEFINITION & MEANING OF ENVIRONMENT:-
The term environment is derived from the French word “Environ”, which
means encircle or surround. Environment means all that environs (ie., surrounds)
us. In other words, environment means surroundings or surrounding conditions.
The environment is defined as “The sum total of all conditions, agencies and
influences which affect the development, growth life and death of an organism and
species.
IMPORTANCE OF ENVIRONMENT:-
The importance of environment is as follows –
• Environment is the sole source of life of all forms of life on the earth.
• Environment determines the existence, growth and development of all forms
of life including human beings.
• The various components of environment i.e., lithosphere, hydrosphere,
atmosphere and biosphere provide water, gases, materials and many other
ingredients for life to survive on the earth.
DEFINITION & MEANING OF ENVIRONMENTAL STUDIES
Environmental studies or environmental science is the study of the earth
(i.e., the environment) comprising air, water, land and living organisms.
The study of the interaction of the biotic (i.e., living) components of the
environment such as plants, animals, micro-organisms etc. among themselves and
also with the abiotic (i.e., non-living) components such as air, soil, water,
temperature, rainfall etc.
The systematic study of the relationship between the abiotic factors with the
biotic factors is known as the ENVIRONMENTAL SCIENCE.
MULTIDISCIPLINARY NATURE OF ENVIRONMENTAL STUDIES
There are three approaches to the study of a discipline or subject of study.
They are-
A) MONO OR INTRA – DISCIPLINARY APPROACH:-
The method of studying a discipline or subject by a single discipline i.e., by
itself is called mono (or) intra – disciplinary approach.
UNIT-1
INTRODUCTION TO ENVIRONMENTAL STUDIES

B) INTER-DISCIPLINARY APPROACH:-
The method of studying a discipline or subject by two related disciplines is
called inter-disciplinary approach.
(A) MULTIDISCIPLINARY NATURE OF ENVIRONMENTAL STUDIES
The method of studying a discipline or branch of knowledge by many related
disciplines is called multidisciplinary approach.
To understand the environmental concepts, it requires basic knowledge of
every branch of science, arts, commerce and engineering disciplines.
MULTIDISCIPLINARY NATURE OF ENVIRONMENTAL STUDIES
Science discipline:
Biology, Chemicstry
Mathematics, geology etc.,
Atmostpher discipline:
Law, philosophy, political
science etc.
Commerce discipline:
Economics, Business,
Accountancy, Management etc.
Engineering discipline:
Mechanical, Civil Industrial
etc.
Environmental Studies
(I) ENVIRONMENTAL STUDIES AND SCIENCE DISCIPLINE:- The science
discipline which involves the difference branches like physics, chemistry,
mathematics, Biology other sub branches like statistics, ecology, anthropology.
A) ENVIRONMENTAL STUDIES & BIOLOGY:- The environmental studies deals
about the life as one of main aspect is known as ENVIRONMENTAL BIOLOGY. It
helps us to understand the interaction of abiotic components with biotic
components how a toxic element reacts with living organisms etc.
B) ENVIRONMENTAL STUDIES & CHEMISTRY:- The Environment studies which
deal about the chemical reactions is known as ENVIRONMENTAL CHEMISTRY.
The environment chemistry help us to know what are the compounds present in
the environment and how do the chemical interact with each other, their reactions,
chemical effects & nature of chemicals present in water/ air.
C) ENVIRONMENTAL STUDIES & MATHEMATICS:- The environmental studies
which helps the environment to predict the amount and effect of pollutants in
particular area through their models. By using mathematical models we can
predicts the effect without the laboratory experiment through calculations.

D) ENVIRONMENTAL STUDIES & GEOLOGY:- The relationship between geology
and environmental studies is studied in a branch called ENVIRONMENTAL
GEOLOGY. This branch deals with the study of environment related to the earth
like earth quakes, volcanoes, natural resources etc.,
(II) ENVIRONMENTAL STUDIES & COMMERCE DISCIPLINE
The commerce disciplines comprise the subjects like economics, business
management, accountancy etc. The subjects of commerce discipline help
environmental studies in many ways.
(A) ENVIRONMENTAL STUDIES & ECONOMICS:- The branch of environmental
studies which deals with economic aspects is known as ENVIRONMENTAL
ECONOMICS. Increasing production and decreasing the cost of the production is
the main aim of the economics, but to get the sustainable production the
environmental economics play a vital role.
(B) ENVIRONMENTAL STUDIES & ACCOUNTANCY:- ENVIRONMENTAL
AUDITING is a branch of environmental studies which is primarily derived from the
accountancy practiced in major industries.
(C) ENVIRONMENTAL STUDIES & BUSINESS MANAGEMENT:- The business
management plays a key role in maintaining the business or industries. Some of
strategies derived from the business management is useful to manage the natural
resource which exist on earth to its optimum level with minimum degradation.
(III) ENVIRONMENTAL STUDIES & ARTS DISCIPLINE
Law, philosophy, political science, history are some of the major subjects of the
arts discipline. These subjects play a vital role in the environmental studies to
conserve the environment.
(A) ENVIRONMENTAL STUDIES & LAW:- Environmental law is a separate
branch of law derived to protect & conserve environment. The over exploitation of
natural resources leads to instability in the society.
(B) ENVIRONMENTAL STUDIES & PHILOSOPHY:- The environmental ethics
plays a vital role in the preaching about correct guidelines which should be
practiced in the conservation of natural resource.
(C) ENVIRONMENTAL STUDIES & POLITICAL SCIENCE:- The political science
with respect to environment tries to minimize the crises created by the political
issues towards the environment.

(IV) ENVIRONMENTAL STUDIES & ENGINEERING DISCIPLINES
The discipline of engineering plays a key role in the study and protecting the
environment by designing the industry, designing pollution control devices,
deriving the eco-friendly procedure in producing the materials etc.
(B) SCOPE OF ENVIRONMENTAL STUDIES
Environmental Studies play an important role in the present day
technological world. This subject is gaining a lot of importance in the field of
pollution control to sustain the life & nature.
• It helps to study the functions of various components of the environment.
• Studies the interaction between environment & living organisms.
• Analysis the life supporting process of water, air, land & other beneficial
organisms.
• It creates a standards for scientific fields which are accepted as safe, clean &
healthy environment to man.
• Studies about ecological imbalance in ecosystem.
• Studies about global issues such as greenhouse gases, global warming, acid
rain, ozone layer depletion etc.
• Management of hazardous waste municipal waste & sustains for cleaner
environment.
• Studies the proper management of usage of natural resources.
• Studies on environmental techniques known as environmental engineering
or environmental science |management.
• Creates public awareness to highlight the various environmental problems to
involve the public in the improvement of environment.
• Recycling of biodegradable waste needs the knowledge of environmental studies.
(C) IMPORTANCE OF ENVIRONMENTAL STUDIES
The main importance of environmental education is as follows:-
• Environmental education is important for the economy and welfare of human
society.
• It helps us in careful handling the issues like pollution, over exploitation of
natural resources & sustainable development.
• Environmental education helps us to find ways and means to maintain the
ecological balance.
• It helps to understand different food chains and the ecological balance in
nature.

• Environmental studies can help the students to acquire the knowledge, skills,
motivation and values needed to manage the earth’s resources.
• Environmental studies create awareness among the people to know about
various natural resources of a region and their conservation.
• Environmental studies is a key instrument for bringing about the changes in
the changes in the knowledge, values, behavior and lifestyles required to
achieve sustainability & stability within and among countries.
• Environmental studies help us in appreciating nature.
• Use of agrochemicals has degraded the environmental and has disturbed the
ecological balance.
(D) CONCEPT OF SUSTAINABILITY AND SUSTAINABLE DEVELOPMENT
The concept of sustainable development became well known through the
famous 1987 Brundtland report from the United Nations, entitled, “Our Common
Future”.
MEANING OF SUSTAINABLE DEVELOPMENT
A/c to Brundtland report sustainable development is a process of developing
(land, cities, business, communities etc) that meets the needs of the present
without compromising the ability of the future generations to meet their own needs.
From the above definition it is clear that sustainable development refers to
economic growth and the expansion of the economy.
In short sustainable development means the proper use of natural resources
for the benefits of human beings which in turn, improves the economy of the
country.
SIGNIFICANCE OF CONCEPT OF SUSTAINABLE DEVELOPMENT
The concept of sustainable development signifies that the natural resources
are exhaustible and the developmental process should be aimed at meeting the
needs of the present generation without compromising the ability of the future
generation to meet their needs.
• Sustainable development must overcome environmental degradation.
• Sustainable development as economic development, social development and
environmental protection.
• Sustainable development also signifies that sustainable development is not just
the development of human beings but the development of even other living beings.

GUIDELINES FOR ACHIEVING SUSTAINABLE DEVELOPMENT
There are certain guidelines for achieving sustainable development. Those
guidelines are-
• There should also be a change in people’s attitudes and value system.
• Sustainable development requires the development should last for generations
for which the present generation must be mindful to the future generation while
fulfilling its own needs.
• It requires the government to set higher environment standards in its energy
consumption & conservation policies.
• There should be provision for housing, health care and education for the poor.
• There should be education & empowerment of woman particularly in rural
areas.
• There should be afforestation in cities and rural areas.
• There should be proper treatment of urban wastes and industrial effluents.
• There should be efficient use of resources avoiding wasteful and excessive
utilization.
• There should be change in peoples thinking and attitude towards development.
• There should be people’s participation in conservation and improvement of
environmental quality.
………………………………………………………………………………………

INTRODUCTION:- The term ‘ecosystem’ was coined by A.G. Tansley an English
botanist, in 1935. The term ecosystem is derived from the words ‘eco’ and
‘system’. Eco refers to environment and system means an interacting /inter –
dependent complex. Ecosystem will be formed through levels of organization in
nature.
Biosphere
Ecosystem
Biotic
community
Abiotic
community
population
Species
Organisms
Levels of organisation in Nature
DEFINITION OF ECOSYSTEM:- “The system resulting from the integration of all
the living and non-living factors of the environment”. (OR) Any system of
organisms, functioning together with their non-living environment is called an
Ecosystem.
FEATURES OF ECOSYSTEM:- The chief features of the ecosystem are as follows.
• The concept of ecosystem is very broad.
• Ecosystem includes both living organisms and non-living substances.
• Ecosystem is a basic structural and functional unit of an environment.
• Ecosystem is an open system.
• Ecosystem is broad and flexible.
• Function of ecosystem is related to energy flow.
• Ecosystem is self-sustaining system of relationships between organisms and
their surroundings.
UNIT-2
ECOSYSTEMS

(I) STRUCTURE AND FUNCTIONS OF ECOSYSTEM
STRUCTURE OF AN ECOSYSTEM:- Ecosystem is the total assemblage of
component entering into interactions of a group of organisms.
COMPONENTS OF AN ENVIRONMENT:- There are two components of an
ecosystem.
(A) BIOTIC COMPONENTS:- It includes all living organisms.
(B) ABIOTIC COMPONENTS:- It includes physical /non-living environmental
components.
(A) BIOTIC COMPONENTS
Biotic components comprise all living organisms. In an ecosystem living organisms
are usually classified into two categories on the basis their trophic or nutritional
relationships. They are; (A) Autotrophs (B) Heterotrophs
AUTOTROPHS:- Those organisms which prepare their own food by using
sunlight, water and minerals present in soil called photosynthesis process. The
organisms are called Autotrophs. Eg: All green plants and certain Bacteria are
known as Producers.
HETEROTROPHS:- The organisms which depend directly or indirectly upon
autotrophs /producers for their food are called Heterotrophs or Heterotropic
organisms as they consume the food produced by the autotrophs, they are called
Consumers.
The biotic components of an ecosystem can be divided into three types.
(I) PRODUCERS:- Producers are autotrophs which are capable of producing food
from non-living inorganic substance. Eg: Green plants, algae & diatoms.
(II) CONSUMERS:- Consumers are heterotrophs which eat up other living
organisms. They include-
(A) HERBIVORES:- Animals which eat plants
(B) CARNIVORES:- Animals which eat other animals
(C) OMNIVORES:- Animals which eat plants & animals also
(D) DETRIVORES:- Animals which eat detritus (dead & decay)
(1) PRIMARY CONSUMERS:- These are herbivores which feed on green plants.
Eg: Deer, elephant, cattle, sheep, rabbit etc.
(2) SECONDARY CONSUMERS:- These are carnivores which feed on other animals
/primary consumers. Eg: Snake, Fox, Frogs, Cats etc.
(3) TERTIARY CONSUMERS:- These are top carnivores which feed on other
carnivorous /flesh-eating animals. They also include omnivores. Eg: Tiger, Lion,
Eagle etc.

DEPENDENCIES OF FOOD:- In an ecosystem, there are four types of
dependencies of food. They are;
• Producers depending on abiotic /inorganic substances.
• Primary consumers depending on the producers.
• Secondary consumers depending on primary consumers.
• Tertiary consumers depending on secondary consumers.
(III) DECOMPOSERS:- Decomposers include micro-organisms like bacteria and
fungi, which decompose the dead bodies of producers and consumers into simpler
compounds and components & release inorganic nutrients or matter into the
environment. Eg: Bacteria & fungi.
TROPHIC LEVELS
“The food energy passes from one group of organisms to other groups of organisms
at different level these levels are called “TROPHIC LEVEL”. There are four trophic
levels. They are;
TROPHIC LEVEL - I:- It includes producers /Autotrophs. It converts solar energy
into chemical energy in the form of organic substances such as food for other
organisms.
TROPHIC LEVEL II:- It includes primary consumers.
TROPHIC LEVEL III:- It includes secondary consumers.
TROPHIC LEVEL IV:- It includes Tertiary consumers.
(B) ABIOTIC COMPONENTS
Abiotic components refer to non-living /physical environmental factors. The
important factors are;

1) WATER:-
• Water is a necessity for all living organisms.
• Organisms require water for survival.
• Water is essential for photosynthesis.
• Water is responsible for migration of animals
2) SOIL:-
• Soil plays an important role in the ecosystem.
• It plays important role in plant growth.
• It provides all the nutrients to the plants.
• It helps for Agricultural production.
3) AIR:-
• Air is a mixture of several gases like nitrogen, oxygen, CO2 etc.
• It plays important role on plants and other living organisms of the
ecosystem.
• CO2 in the air affects the rate of photosynthesis.
4) TEMPERATURE:-
• Temperature is one of the important factors of the ecosystem.
• Each organism has a minimum, maximum & optimum temperature for life.
• It influences the behavior of plants, animals and even human beings.
5) LIGHT:-
• Light is one of the important factors of the ecosystem.
• It is the source of energy for all the life on land.
• It is an essential factor for the formation of chlorophyll.
• It is essential for human life.
FUNCTIONS OF THE ECOSYSTEM
Ecosystem is the functional unit of an environment ecosystem is not a static,
it is dynamic and changes will be occur in nature.
FUNCTIONING OF AN ECOSYSTEM:- The functioning of an ecosystem comprises
the three aspects;
(1) ENERGY FLOW (2) PRODUCTIVITY (3) BIOGEOCHEMICAL CYCLING
(A) ENERGY FLOW IN THE ECOSYSTEM
Energy is the ability to do work. The plants covert solar energy into chemical
energy in the process of photosynthesis. The chemical energy passed on from one

trophic level to next level. “The flow of energy that occurs along a food chain is
called Energy Flow”. The energy flow is unidirectional is an ecosystem and is
formed from producers to herbivores to carnivores. It cannot occur in the reverse
direction.
TEN PERCENT LAW REGARDING FLOW OF ENERGY
According to the ten percent law “there is a gradual decline in the amount of
energy available as we move from one trophic level to the next trophic level i.e.,
from the producer level to the next higher level”. During this transfer almost 90%
of the energy is lost to the environment in the form of heat which cannot be used
again. As we move up the trophic levels, the amount of available usable energy
keeps on decreasing at energy flow in an ecosystem
Producers Consumers
Inorganic
nutrients
Decomposers
Sun
10,000 units eneryg
100 units eneryg
10 units eneryg
Heat Heat
Heat
1000 units eneryg
IMPORTANCE OF ENERGY FLOW
• Every functioning of ecosystem is dependent the process of flow of energy.
• It maintains itself & stability through energy
• Ecosystems are under pressure from human beings.
(B) PRODUCTIVITY OF ECOSYSTEM
Productivity of an ecosystem means the rate of production ie., amount of
organic matter produced or accumulated by plants per unit of time and area. The
term productivity of ecosystem denotes the amount of organic matter accumulated
in any unit of time.
TYPES OF PRODUCTIVITY
1) PRIMARY PRODUCTIVITY:- Refers to the rate at which radiant energy is stored
by photosynthetic and chemosynthetic activities of producer organisms.
2) SECONDARY PRODUCTIVITY:- Refers to the capacity of energy storage at the
consumer level or second trophic level.

3) NET PRODUCTIVITY:- Net productivity refers to the rate of storage of organic
matter not used by the consumers at the consumer’s level or second trophic level.
(C) BIOGEOCHEMICAL CYCLING
The cycling of chemical elements within an ecosystem is called ECOSYSTEM
MINERAL CYCLING.
Ecosystem mineral cycling connects biological cycles to geological cycles.
Chemical elements cycle within an ecosystem from organism to organism through
water, air, soils and rocks.
The naturally available elements/chemicals are converted into useful forms
to through various processes like biological, geological and chemical processes are
called Biogeochemical Cycles.
There are many biogeochemical cycles in nature through which the
environment or ecosystem functions among them hydrological cycle, carbon cycle,
oxygen cycle, phosphorus cycle, nitrogen cycle and sulphur cycle are important.
The flow of energy is the main driving force among all these cycles.
HYDROLOGICAL CYCLE /WATER CYCLE
• Water cycle is the most important cycle
• It involves interchange of water between the earth’s surface & the
atmosphere through rainfall and evapo-transpiration.
NITROGEN CYCLE
• Nitrogen is an essential element of all forms of life
• The chief source of nitrogen is the atmosphere
• Atmosphere has about 79% nitrogen.
• The chief symbiotic nitrogen fixers are bacteria asymbiotic nitrogen fixers
and blue- green algae.
For all biogeochemical cycles microorganisms play a major role in the ecosystem or
our environment.
(II) ECOLOGICAL SUCCESSION
INTRODUCTION:- An ecosystem is never static. It is dynamic. Its structure and
function changes with time in a very orderly way and such a change can be
predicted.
DEFINITION:- “An orderly process of changes in the community structure and
function with time through modification in the physical environment which
ultimately in a stable ecosystem”
(OR)

“Transformation or orientation of a biological community plant and animal species
come into an area and alter the environmental conditions in favor of new plant and
animal species”.
Odum defined changes in communities /ecosystem development in terms of
three parameters;
1) An orderly process of biological community development that involves
changes in species structure.
2) The modification of the physical environment by the biological community
3) In ecosystem maximum biomass and symbiotic function between organisms
are maintained per unit of available energy flow.
FEATURES OF ECOLOGICAL SUCCESSION
• Causes climatic changes such as soil erosion, fire etc.,
• Causes successive changes in population.
• Causes stabilization of the community.
TYPES OF ECOLOGICAL SUCCESSION
1) PRIMARY SUCCESSION:- Takes place in plants and animal colonies such as
base rocks, new volcanic island etc.
2) SECONDARY SUCCESSION:- Starts from previously built-up community,
sudden change in climate factor, biotic intervention, fire etc.
The other types of ecological succession are;
(A) HYDROSERE OR HYDRARCH:- This type of ecological succession starts in
region where water is plenty like pond, lake etc. The pioneer community is plant
community.
(B) MESOSERE OR MESARCH:- This type of ecological succession starts in an
area where adequate moisture, conditions are present.
(C) XEROSERE OR XERARCH:- This type of succession starts in areas where
moisture is present in minimum amount such as deserts, rocks etc.,
It may be noted that Xerarch can be further divided into-
• Lithosere starts on a bare rock.
• Psammosere starts on sand
• Holosere starts on saline soil.
(II) FOOD CHAINS, FOOD WEB & ECOLOGICAL PYRAMIDS
(A) FOOD CHAIN

Food chain refers to the transfer of food energy from one organism to other.
The kind of nutritional relationship the food energy is transferred from one trophic
level to another trophic level is called Food Chain.
GENERAL PATTERN OF A FOOD CHAIN IN ECOSYSTEM
Plants
Primary porducers
Herbivorous Animals
[Primary consumers]
Carnivorous Animals
[Secondary Consumers]
Top carnivorous Animals
[Teritary Consumers]
Food
Energy
Food
Energy
Food
Energy
photo
synthesis
Sun
EXAMPLES OF FOOD CHAIN (GRASSLAND ECOSYSTEM)
Grass Grass hopper Frog Snake Hawk
EXAMPLES OF FOOD CHAIN (POND ECOSYSTEM)
Phytoplanktons Water Fleas Small fish Big fish
TYPES OF FOOD CHAIN
1) GRAZING /HERBIVOROUS FOOD CHAIN:- In this food chain, the transfer of
food takes place from green plants (producers), to the herbivore (primary
consumers) and ends with carnivore (secondary or tertiary consumers). Primary
consumer is plant eating animals. Eg: Grass→Rabbit→Fox→Wolf→Tiger
2) DETRITIVOROUS FOOD CHAIN:- In this type, food chain starts from dead
organic matter of decaying animals and plant bodies to the micro-organisms and
then to detritus feeding organism and to other predators.
Eg: Detritus → Earthworm→Birds
3) PARASITIC FOOD CHAIN:- In this type of food chain either the producer or the
consumer is parasitized. So the food passes to the smaller organism. Here the
transfer of food chain occurs through a series of parasites at each trophic level.
Eg: Trees→ Parasitic birds →Birds lice → Protozoans
Trees→ Fruit eating birds→ Lice and bugs→ Bacteria and fungi
(B) FOOD WEB
Food chains are different and are often inter linked to form food web. They are
inter-linked to form food web. The inter-locking /inter- linking pattern of food
chains is called the Food Web.

Grosshopper
Lizard
Hawk
Sanke
Mouse
Grass Rabbit
SIGNIFICANCE OF FOOD CHAIN & FOOD WEB
• Both play a very important role in the ecosystem.
• Helps in understanding the feeding relationships and the interactions
between organisms in any ecosystem.
• A study of food web provides information about the biological diversity of any
ecosystem.
• Food chain & food web balance the ecosystem.
• Food chains help in maintaining the population size of different animals.
• It helps to understand the mechanism of energy flow.
• It helps in the movement of toxic substances & biological magnification.
(C) ECOLOGICAL PYRAMIDS
DEFINITION:- “A graphic representation of the nutritional relationship between
the organism in terms of energy, biomass and number of individuals from one
trophic level to other’s level is called Ecological Pyramids”.
TYPES OF ECOLOGICAL PYRAMIDS
1) PYRAMID OF NUMBERS
2) PYRAMID OF BIOMASS
3) PYRAMID OF ENERGY
(A) PYRAMID OF NUMBER:- A pyramid constructed on the basis of number of
individuals present in each trophic levels. The individuals present in each trophic
level are called Pyramid of number. Depending upon the type of ecosystem and food
chains, the pyramid of number may be upright or inverted. There is a progressive
decrease in the number of organisms in an ecosystem from producers to primary
consumers and to secondary consumers.

Snake
Frog
Grasspopper
Grass
Producers
Teritary
Consumer
Secondary
Consumer
Primary
Consumer
Protozoans
Birds lice
Parasitic
Birds
Tree pr.
Parasitic
Food chain
Inverted pyramid of number
Upright Pyramid of number
(B) PYRAMID OF BIOMASS:- A pyramid constructed on the basis of the biomass
of each trophic levels is called pyramid of biomass. It represents the relationships
of the biotic components in an ecosystem. In pyramid of biomass, they occupy the
base. Hence, there is a gradual decrease in the biomass from the producers to the
higher trophic levels. The pyramid of biomass may be upright or inverted.
Snake
Frog
Grasspopper
Grass
Producers
Teritary
Consumer
Secondary
Consumer
Primary
Consumer
Big fish
Small fish
Insects
Phytoplanktons
Inverted pyramid of Biomass
Upright Pyramid of biomass
Pand- Ecosystem
(C) PYRAMID OF ENERGY:- A pyramid constructed on the basis of energy
accumulation pattern at different trophic levels of food chain is called pyramid of
energy. The pyramid of energy is always upright as energy gradually decreases in
the successive trophic level.
Producers
Teritary Consumer
Secondary Consumer
Primary Consumer
Pyramid of energy
(always upright)
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(III) MAJOR ECOSYSTEMS
An ecosystem may be natural or artificial.
1) NATURAL ECOSYSTEM →A natural ecosystem is an ecosystem which is found
in nature /natural conditions. It includes terrestrial and aquatic ecosystem.
TERRESTRIAL ECOSYSTEM (OR) LAND BASED ECOSYSTEM
(A) FOREST ECOSYSTEM
(B) GRASSLAND ECOSYSTEM
(C) DESERT ECOSYSTEM
AQUATIC ECOSYSTEM (OR) WATER BASED ECOSYSTEM
(A) FRESH WATER ECOSYSTEM
(I) LENTIC (OR) STANDING WATER ECOSYSTEM such as lake ecosystem pond
ecosystem, swamp ecosystem etc.,
(II) LOTIC (OR) RUNNING WATER ECOSYSTEM such as river ecosystem stream
ecosystem
(III) OCEAN OR MARINE ECOSYSTEM
(IV) ESTUARINE ECOSYSTEM
2) ARTIFICIAL ECOSYSTEM → An artificial ecosystem is man-made ecosystem
created by man. It includes
• CROPLAND ECOSYSTEM
• PARK ECOSYSTEM
• KITCHEN GARDEN ECOSYSTEM & AQUARIUM ECOSYSTEM
(1) TERRESTRIAL ECOSYSTEM (OR) LAND BASED ECOSYSTEM
(I) FOREST ECOSYSTEM
• About 30% of the land area of the earth is under forests.
• A forest is a community of living trees and other plants like shrubs,
climbers, creepers etc.
TYPES OF FORESTS:- There are 3 types of forests;
1) CONIFEROUS FORESTS:- Found in North America
2) TEMPERATE DECIDUOUS FORESTS:- Found in Eastern North America,
Europe, Japan & Australia.
3) TROPICAL RAIN FORESTS (OR) EVERGREEN FORESTS:- Found in south
America, Africa, Sri lanka etc.,
CHARACTERISTIC FEATURES OF FOREST ECOSYSTEM
• It is an important ecosystem.
• It is terrestrial or land based ecosystem

• It is a complex ecosystem contains a wide variety of plants and animals.
• It plays important role in ecological balance in nature like global warming
water cycle etc.
STRUCTURE AND FUNCTIONS OF FOREST ECOSYSTEM
The forest has two components (1) Abiotic components (2) Biotic components.
ABIOTIC COMPONENTS:- The biotic components in forest ecosystem includes
inorganic and organic substances present in the soil and atmospheric /climatic
factors like temperature, light, rainfall, soil, minerals.
BIOTIC COMPONENTS:- The biotic components of the forest ecosystem are mainly
trees of many species, shrubs and ground vegetation. There are 3 biotic
components: Producers, Consumers & Decomposers
(A) PRODUCERS:- In the forest ecosystem, the major producers are trees of
different species. The other producers are shrubs and undergrowth.
(B) CONSUMERS:- The consumers are of three types, they are: (1) PRIMARY
CONSUMERS (2) SECONDARY CONSUMERS (3) TERTIARY CONSUMERS
(I) PRIMARY CONSUMERS:- Smaller herbivores or animals feeding on tree leaves
such as ants, flies, beetles, leaf hoppers, bugs, spiders, etc. and larger animals
grazing on leaves, shoots and fruits such as elephants, deers, mongooses etc.
(II) SECONDARY CONSUMERS:- The secondary consumers are the carnivores like
snakes, birds, lizards, foxes etc., feeding on herbivores.
(III) TERTIARY CONSUMERS:- The tertiary consumers are the top carnivores like
lions, tigers etc., that eat carnivores of the secondary consumer level.
(C) DECOMPOSERS:- The decomposers are many varieties of micro-organisms
such as fungi, bacteria, worms etc. which convert the dead parts of plants and
trees into organic materials and finally into smaller element.
(II) GRASSLAND ECOSYSTEM
A grassland ecosystem is a luxuriant growth of grasses. The grassland
ecosystem is found on tropical and temperate regions of the world.
TYPES OF GRASSLANDS:- Grasslands are of two main types. They are;
(1) TROPICAL GRASSLANDS (2) TEMPERATURE GRASSLANDS
The tropical grasslands are popular called savannas. The temperate grasslands are
called prairies in North America, steppes in Europe.
CHARACTERISTIC FEATURES OF GRASSLAND ECOSYSTEM
1) Grassland ecosystem comprises different types of grasses with a little
amount of shrubs & a few trees.
2) The main vegetation of the grassland ecosystem is grasses.

3) Many grazing animals or herbivores & insects are found.
4) The edaphic conditions of grassland ecosystem do not permit the growth of
trees. Hence few trees are found in the grassland ecosystem.
STRUCTURE & FUNCTION OF GRASSLAND ECOSYSTEM
(1) ABIOTIC COMPONENTS (2) BIOTIC COMPONENTS
ABIOTIC COMPONENTS:- The abiotic components are inorganic & organic
substances present in the soil and in the atmosphere. In addition to minerals,
organic materials are also present.
BIOTIC COMPONENTS:- The biotic components consist of following components;
A) PRODUCERS B) CONSUMERS C) DECOMPOSERS
(A) PRODUCERS:- The producers include grasses, few herbs & shrubs.
(B) CONSUMERS:- The consumers include primary consumers, secondary
consumers & tertiary consumers.
(I) PRIMARY CONSUMERS:- Primary consumers include animals feeding on
grasses like cows, buffaloes, sheep, deer etc.,
(II) SECONDARY CONSUMERS:- The Secondary Consumers include carnivores
like snakes, lizards, fox etc. feeding on herbivores.
(III) TERTIARY CONSUMERS:- Tertiary Consumers include top carnivores like
fox, lion, tiger etc., feeding on secondary consumers.
(C) DECOMPOSERS:- The decomposers include variety of micro-organisms
including fungi, algae, bacteria etc. They decompose the dead organic matter and
help to bring minerals back to the soil.
(II) DESERT ECOSYSTEM
Desert ecosystem is present in regions where the annual rainfall is less than
25cm and the temperature is very high. Sahara desert in Africa, Thar desert in
India etc., About 17% of the total land area of the world is under desert ecosystem.
TYPES OF DESERT ECOSYSTEM:- Deserts may be tropical deserts or hot
deserts, temperate deserts and cold deserts. But hot deserts are more important
than temperate and cold deserts.
CHARACTERISTIC FEATURES OF DESERT ECOSYSTEM
• Desert ecosystem occurs in regions of very high temperature & low rainfall.
• Desert ecosystem occupies a greater part of the land.
• Due to high temperature and low availability of water it is poorly represented
by flora and fauna.
• The soil contain very little organic matters

STRUCTURE & FUNCTION OF DESERT ECOSYSTEM
The desert ecosystem has two components; abiotic & biotic components.
ABIOTIC COMPONENTS:- The abiotic components comprise organic substances
poorly present.
BIOTIC COMPONENTS:- The biotic components include; (a) Producers (b)
Consumers & (c) Decomposers
(A) PRODUCERS:- The producers cover desert shrubs, some grasses and very few
trees. There are three life forms of plants adapted to desert conditions.
(I) ANNUALS:- Grow only when there is adequate moisture.
(II) SUCCULENTS:- The succulents like cactus have high capacity to store water.
(III) DESERT SHRUBS:- Have numerous branches & special root system that
help them to adapt to desert conditions.
(B) CONSUMERS:- The consumers comprise desert animal’s like camels & goats
are the important desert animals. Apart from camels & goats, insects, reptiles etc.
are also found.
(C) DECOMPOSERS:- The decomposers are fungi and bacteria. The decomposers
vary and are few due to scarcity of flora & fauna.
(2) AQUATIC ECOSYSTEM (OR) WATER BASED ECOSYSTEM
Aquatic ecosystem comprises fresh water ecosystem like pond or lake
ecosystem, stream or river ecosystem, ocean or marine ecosystem & estuarine
ecosystem.
(I) POND ECOSYSTEM
A pond is shallow water body on the surface of the earth. A pond is not only a place
where plants and animals live. But also plants and animals make the pond what it
is.
CHARACTERISTIC FEATURES OF POND ECOSYSTEM
The chief features of pond ecosystem are
• Pond ecosystem is an aquatic ecosystem.
• It is a fresh water ecosystem.
• It is a good example of small, self-sufficient and self -regulating ecosystem.
• It is a simple aquatic ecosystem.
• The location size, depth & substratum of a pond influence the pond
ecosystem.
STRUCTURE & FUNCTIONS OF POND ECOSYSTEM
The components of the pond ecosystem can be abiotic and biotic components.

ABIOTIC COMPONENTS
• The abiotic components are temperature, water, light, several inorganic &
organic substances
• Water provides dissolved gases and nutrients for plants and microbes.
• The bottom soil provides substrata for the microbes and decomposers.
• Sunlight penetrates fairly deep into the pond water, depending upon the
turbidity & provides energy for photosynthesis.
• Organisms depend on the dissolved oxygen in water for respiration.
BIOTIC COMPONENTS
The biotic components of a pond are ecologically classified into three groups. They
are producers, consumers & decomposers.
(A) PRODUCERS:- Producers are green plants categorized into two types;
macrophytes and phytoplanktons.
(I) MACROPHYTES:- Rooted larger plants, submerged, free floating & amphibious
plants.
(II) PHYTOPLANKTONS:- Minute floating or suspended lower plants which belong
to algae & flagellates.
(B) CONSUMERS:- The consumers are of three types; primary, secondary &
tertiary consumers.
(I) PRIMARY CONSUMERS:- Primary consumers are zooplankton and benthos or
bottom forms.
(1) ZOOPLANKTONS:- Animals that drift with were currents and are found along
with phytoplankton. They feed on phytoplanktons.

(2) BENTHOS (OR) BOTTOM FORMS:- Comprises bottom dwell animals which
feed on plants directly or remain at the bottom.
(II) SECONDARY CONSUMERS:- Secondary Consumers are the carnivores which
feed on the herbivores. They include insects, fish and frogs.
(III) TERTIARY CONSUMERS:- Tertiary consumers or top consumers are some
large fish such as game fish which feed on smaller fish.
(C) DECOMPOSERS:- Several aquatic bacteria, fungi, etc. are distributed through
the pond. They decompose plants and animals. The play an important role in the
return of mineral elements i.e., the nutrients back into the ecosystem.
(II) LAKE ECOSYSTEM
A lake is large fresh water body with standing water. The Oal lake of
Srinagar, Naini Lake in Nainital in Uttarkhand & Loktak Lake in Manipur are some
of the famous lakes of India.
Lakes have a shallow water zone called LITTORAL ZONE, an open water
zone called LIMNETIC ZONE, where effective penetration of Solar-light takes place,
and a deep water zone called PROFUNDAL ZONE where light penetration is
negligible.
CHARACTERISTIC FEATURES OF LAKE ECOSYSTEM
The three temperature strata found in a deep lake are Epilimnion, Metalimnion &
Hypolimnion.
(1) EPILIMNION:- Is the upper strata of the water, which is exposed to solar
radiation. It is warm during summer & comparatively cooler during winter. Water
keeps on circulating in these strata.
(2) METALIMNION:- Is the transition zone between epilimnion and hypolimnion
where temperature change occur. The maximum temperature change occurs in the
middle part of the metalimnion.
(3) HYPOLIMNION:- Is the base stratum, where water is always cool water does
not circulate here.

ON THE BASIS OF THEIR PRODUCTIVITY LAKES CAN BE CLASSIFIED AS;
(A) OLIGOTROPHIC LAKES:- Have very little plant and animal life. Sambar lake
of Rajastan is an example. It has high salt content which makes it unfit for growth
of fresh water plants only a few green algae grow in these lakes.
(B) EUTROPHIC LAKES:- Comparatively shallow. Oal lake of Srinagar is an
example. In the littoral area are found amphibious plants and free-floating plants.
STRUCTURE & FUNCTIONS OF LAKE ECOSYSTEM
The components of the pond ecosystem can be abiotic and biotic components.
ABIOTIC COMPONENTS:- The abiotic components are the inorganic as well as
organic substances present in the bottom soil or dissolved in water. In addition to
the minerals, some dead organic materials are also found.
BIOTIC COMPONENTS:- The biotic components of a lake are of three groups.
They are producers, consumers & decomposers.
(A) PRODUCERS:- The biotic components of lake include submerged, free-floating
and amphibious macrophytes minute floating and suspended leaves,
phytoplanktons
(B) CONSUMERS:- Among consumers the primary consumers are zooplanktons
and benthos. The secondary consumers are the carnivores like insects & fishes
feeding on the herbivore. The tertiary consumers are the large fishes feed an small
fishes.
(C) DECOMPOSERS:- The decomposers are micro-organic like bacteria, fungi and
actinomycetes.
(III) STREAM (OR) RIVER ECOSYSTEM
• Stream or river ecosystem is called lotic or flowing water system, Since the
water keeps on flow in the hills, the streams have a high speed and so, there is very
little plant growth.

• In the plains, the flow is less turbulent; in the rainy season, most of the
steams and river possess muddy water, which does not allow the light to penetrate,
the banks of the stream or may possess marsh areas.
• Flowing water ecosystem has uniform oxygen tension with no thermal on
chemical zonation.
• It is not completely dependent on aquatic plants as producers, Detritus
eaters and decomposers are comparatively more abundant.
• They obtain their food from the dead and living land organisms which
happen to fall accidently or brought down by rain water.
STRUCTURE & FUNCTIONS OF RIVER/STREAM ECOSYSTEM
The components of stream ecosystem are abiotic and biotic components.
ABIOTIC COMPONENTS:- The abiotic components of river/stream ecosystem
include oxygen, nitrogen, phosphorus, Calcium, amino acid etc. Producers take
them in small amount in soluble forms to tolerate periods of low oxygen.
BIOTIC COMPONENTS:- The biotic components includes the following
components
(A) PRODUCERS:- The producers in river/stream ecosystem, ecosystems are the
phytoplankton.
(B) CONSUMERS:- The consumers are zooplanktons, insects, fish, turtles, water
snakes etc.,
(C) DECOMPOSERS:- The decomposers are micro-organisms like bacteria and
fungi.
(IV) MARINE (OR) OCEAN ECOSYSTEM
Oceans are gigantic reservoirs of water, covering nearly 70% earth’s surface
the major oceans of the world are the Pacific Ocean, Atlantic Ocean, the Indian
Ocean, the Arctic Ocean and the Antarctic Ocean.
Ocean ecosystem is different from freshwater ecosystem mainly because of
its salty water and also because the ocean is deep continuous and water is a
continuous circulation.
CHARACTERISTIC FEATURES OF MARINE ECOSYSTEM
• The trophic structure starts from the smallest autotrophs like planktons and
end with larger animals like giant fish and whales.
• In the marine ecosystem, the ecology of shallow and deep water as well as
estuarine part is different from each other and forms a separate ecosystem.

STRUCTURE AND FUNCTION OF MARINE ECOSYSTEM
The components of marine ecosystem are
ABIOTIC COMPONENTS:- High Na–, Ca–, Mg and K salt concentrations, variable
dissolved oxygen content, light & temperature make a unique physico-chemical
condition in marine water.
The concentration of dissolved nutrients remain low, which constitute an
important limiting factor determine the size of marine populations.
BIOTIC COMPONENTS:- The biotic components of marine ecosystem
(A) PRODUCERS:- Producers include phytoplanktons large seaweeds and
mangrove vegetations like Rhizophara, Avicennia, Carapa, Aegeros etc.,
(B) CONSUMERS:- The consumers comprise the following;
(I) PRIMARY CONSUMERS:- Herbivores and feed directly on producers like
crustaceans, mollusks, fish etc.,
(II) SECONDARY CONSUMERS:- It comprise fishes such as sea horse, cuttle fish
etc.,
(III) TERTIARY CONSUMERS:- Top carnivores fishes, feeding on small fishes eg:
Whales, Sharks, Cods etc.,
fungi.
(V) ESTUARINE ECOSYSTEM
• An estuary is a semi-enclosed coastal body of water connected on the one
side with open sea and with freshwater river on the other side.
• It is a transition zone which is strongly affected by tidal action, and within
this zone, sea water is mixed with fresh water from river.
• An estuary is highly productive and offer high food potential for human
beings due to the nutrient and energy inputs from both sea water and river water.
CHARACTERISTIC FEATURES OF ESTUARINE ECOSYSTEM
• Estuarine ecosystem is characterized as an ecosystem having fluctuating
water level.
• Because of fluctuating water level, the organisms present in an estuarine
ecosystem show wide range of tolerance to temperature and salinity.
• Estuarine ecosystem consists of endemic species confined to the estuarine
zone only.

STRUCTURE & FUNCTION OF ESTUARINE ECOSYSTEM
ABIOTIC COMPONENTS:- Abiotic components are limited distribution of organic &
inorganic substances and climatic factors are light, water, temperature etc.
BIOTIC COMPONENTS:- The biotic components of an estuarine ecosystem are
(A) PRODUCERS:- The producers are macrophtes (i.e. grasses, sea weeds, Sea
grasses, and phytoplankton).
(B) CONSUMERS:- The consumers are oysters, Crabs, Several kinds of shrimp and
many commercial sport fish.
fungi.
…………………………………………………………………………………………………

Any part of natural environment which can be utilized by man to satisfy his
wants and to promote his well-being is Natural Resource.
CLASSIFICATION OF NATURAL RESOURCES:- Natural resources can be
classified on the basis of 4 types.
(I) ON THE BASIS OF THEIR ORIGIN:- Natural resources are classified into two
classes they are;
(A) BIOTIC RESOURCES (OR) LIVING RESOURCES:- They include all living
organisms /things which are useful to man. Eg: Wild animals, fishery resources
forests etc.
(B) ABIOTIC (OR) NON-LIVING RESOURCES:- Abiotic resources refer to non-
living things which satisfy man’s needs. Eg: Mineral resources, power resources
like coal, petroleum and natural gas.
(II) ON THE BASIS OF RENEWABILITY:- Natural resources can be classified into
two types-
(A) RENEWABLE (OR) INEXHAUSTIBLE RESOURCES:- The resources which can
be regenerated replesinshedin nature. Eg: Water resources, Forest, fishery etc.
(B) NON-RENEWABLE (OR) EXHAUSTIBLE RESOURCES:- The resources which
cannot be replenished once depleted in nature. Eg: Mineral resources, fossil fuels.
The non-renewable resources are also classified into two types-
(I) RECYCLABLE RESOURCES:- The resources can be collected and reuse Eg:
minerals.
(II) NON-RECYCLABLE:- The resources cannot be collected once use eg: Fossil
fuels like petrol.
Renewable resources Non-Renewable resources
Can be renewed or regenerate in
nature
Cannot be renewed or regenerate
in nature
Inexhaustible resources Exhaustible resources
Flow resource Stock or fund resource
Mostly Biotic in nature Abiotic in nature
UNIT-3
NATURAL RESOURCES: RENEWABLE AND NON-
RENEWABLE RESOURCES

(III) ON THE BASIS OF DISTRIBUTION:- Natural resources are classified into
two types, they are
A) UBIQUITOUS RESOURCES:- Occurs almost everywhere in nature. Eg: Oxygen,
Sunshine etc.
B) LOCALISED RESOURCES:- Resources which are concentrated at specific
places. Eg: Minerals, fossil fuels etc.
(IV) ON THE BASIS OF UTILITY:- Natural resources can be classified into three
types. They are-
A) FOOD RESOURCES:- The resources which are used by man as food. They
include agricultural food crops, animal products, fish products etc.
B) RAW MATERIALS:- The resources which are used as raw materials in
industries. They may be agricultural products, forest products etc.
C) ENERGY RESOURCES:- The resources which are used as energy or power in
industries, ships, trains, automobiles etc., solar energy, tidal energy wind energy,
geothermal energy etc. are examples of energy resources.
……………………………………………………………………………………………………

(I) LAND RESOURCES
DEFINITION: Land resources are the natural resources that occur naturally within
environments that has undisturbed by mankind, in a natural form.
(A) LAND AS A RESOURCE
(I) Agriculture is land based in a predominant agricultural country.
(II) Animal Husbandry is almost land-based.
(III) Land supports the growth of forest & grasses.
(IV) Land sustains a wide variety of living beings.
(V) Human settlement requires vast areas of land.
(VI) Even wild life depends upon land.
(VII) Industrialization & urbanization depend on the availability of vast areas of
land.
(VIII) Construction of roads & railway lines depends on availability of suitable
lands.
(IX) Development of sanctuaries, parks, play grounds & public places depends on
the availability of lands.
(X) Construction of schools, colleges, universities, hospitals, etc. depends on the
availability of adequate lands.
(XI) Land regulates water cycle & carbon cycle.
(XII) Land acts as the store house of basic resources like fossil fuels & ground
water.
OVER-EXPLOITATION OF LAND RESOURCES: Over-use & abuse of land has
resulted in desertification, land slide, soil erosion, etc. Fertile agricultural lands
are diverted for other uses & are not available for agriculture. Hence there should
be proper check on the use of land & should be used in a planned manner.
(B) LAND USE CHANGE
The interaction of natural environment with human decisions changes land
use pattern. However some natural changes also leads to change in land use
pattern. For eg: Some wet conditions lead to development of rangeland but with
sudden drought or drier conditions, it gets converted to barren land.
“Land use” is the term used to describe the human use of land. It represents
the economic and cultural activities (e.g., agricultural, residential, industrial,
mining, and recreational uses) that are practiced at a given place. Public and
private lands frequently represent very different uses.
CAUSES OF LAND USE CHANGE:- Land use is also changed by both human and
climate factors. Technological innovation has also influenced land-use change, with

the expansion of cultivated lands from the development of irrigation technologies
and, more recently, decreases in demand for agricultural land due to increases in
crop productivity.
(C) LAND DEGRADATION
DEFINITION: Land degradation refers to the decline in the fertility of the soil
which reduces the productive capacity of the soil.
FACTORS RESPONSIBLE FOR LAND DEGRADATION
(I) Intensive agriculture results in removal of minerals from top layer.
(II) Growing same crop every year deprives soil of minerals.
(III) Flowing water, washing away the minerals of the top soil.
(IV) Improper irrigation, leading to salinization of soil making less productive.
(V) Addition of industrial waste changes the chemical nature & reduces fertility.
(VI) Misuse of land through short-sighted development policies.
(VII) Deforestation is one of the factors of land degradation.
(VIII) Over-grazing on grasslands is also responsible for land degradation.
(IX) Poor crop rotation & planting unsuitable crops.
(X) Frequent use of heavy machinery like tractors.
(XI) Soil erosion, landslides, Floods etc.
(XII) Desertification of land & persistent usage of chemical fertilizers.
CONTROL OF LAND DEGRADATION
(I) Degraded or waste land should be reclaimed & put to productive uses.
(II) In India, National Wasteland Development Board (NWDB) established to
formulate plans to prevent land degradation & deforestation.
(III) It is concerned with regeneration of degraded forest areas, reclamation of land,
arid tracts, mine spoils etc.
(IV) NWDB helps to check land degradation, bring wastelands into sustainable
use, increase biomass availability & restore ecological balance.
(D) SOIL-EROSION
DEFINITION:- Soil erosion refers to the loss of the top fertile layer or part of the
soil caused by natural agencies like running water, wind and sea waves.
TYPES OF SOIL EROSION:- Soil erosion is of four types and they are as follows;
(I) NORMAL SOIL EROSION:- Normal soil erosion is a natural phenomenon. It is
not harmful helps in soil formation.
(II) SOIL EROSION BY WATER:- It is mainly responsible for loss of soil and soil
fertility. It is of three types, viz,

(A) SHEET EROSION:- Refers to the uniform removal of soil over a large area from
the surface of sloping lands by rain water.
(B) RILL EROSION:- Refers to the eroding of the soil in its course by rain water
running along the slopes in the form of tiny channels.
(C) GULLY EROSION:- Refers to the eroding of the soil in its course by rain water
running along the slopes in the form of enlarged rills or valleys.
(III) WIND EROSION:- Caused by wind. Wind is an agent of soil erosion which is
effective in arid & semi arid regions.
(IV) ACCELERATED SOIL EROSION:- Caused by human activities which
accelerate the process of soil erosion by deforestation, over grazing, mining,
defective agricultural practices etc.
CAUSES OF SOIL EROSION
(I) Deforestation for various purposes like human settlement, construction of
dams, roads & railway lines, agriculture & forest products.
(II) Over-grazing or excessive grazing of animals affects plant growth on the soil
causes soil erosion.
(III) Rivers, when they are in floods.
(IV) Heavy downpour of rains.
(V) Strong winds.
(VI) Slope of the land.
(VII) Texture of the soil; hard soil resists soil erosion, whereas soft soil is easily
eroded.
(VIII) Faulty methods of cultivation like ploughing in the direction of slopes,
growing same crop on the soil year after year, shifting cultivation etc.
(IX) Careless & excessive exercise of irrigation.
(X) Removal of the top soil from the land for making bricks, tiles, pots & other
products.
EFFECTS OF SOIL EROSION
(I) It makes vast area of cultivable land unfit for cultivation.
(II) It reduces the fertility of the soil.
(III) Due to soil erosion, rivers are filled & floods are caused.
(IV) Due to the silting of rivers caused by soil erosion, rivers change their courses.
(V) Due to soil erosion, reservoirs & tanks are silted & storage capacity is reduced.
(VI) Soil erosion limits percolation of water, as a result natural springs dry up.
(VII) Soil erosion results in the blocking of navigable channels.
(VIII) Soil erosion reduces subsoil water.

(IX) Soil erosion results in desertification.
SOIL CONSERVATION
DEFINITION:- “Soil conservation means the prevention of soil erosion as well as
the protection & maintenance of the fertility of the soil.”
(A) CONTROL OF SOIL EROSION
(I) CONTOUR FARMING:- Ploughing across the slope rather than with the slope
which involves construction of horizontal bunds in the mountainous regions.
(II) STRIP CROPPING:- Strip cropping combined with crop rotation is helpful in
controlling soil erosion in increasing soil fertility.
(III) TERRACING:- The modern terracing is an embankment of earth constructed
across the slope to control water run-off and to minimize erosion.
(IV) GULLY PLUGGING:- Earthen stone & concrete dams may be built at intervals
along the gully. Once the dams are constructed & water run-off is restricted, soil
may be stabilized.
(V) MULCHING:- It is used on the surface of the soil to enrich productivity of the
soil. Mulch may be leaves, straw, litter or waste with properties to improve top soil.
Mulch reduces the growth of weeds, increases the infiltration of water in the soil,
maintains soil structure, and enhances humification & microbial activities.
(VI) SHELTER BELTS:- Shelter belts are green belts of trees, which help to break
the force of strong winds & prevent the blowing away of the loose top soil.
(VII) OTHER METHODS OF CONTROL OF SOIL EROSION:
(A) Afforestation (i.e., growing trees in hilly regions).
(B) Prevention of reckless felling (i.e., cutting of trees).
(C) Controlled grazing by cattle.
(D) Turfing (i.e., growing grasses on eroded lands).
(E) Growing cover crops after harvesting the main crops to keep soil covered.
(F) Construction of river embankments in places where rivers are likely to be in
spate.
(G) Prohibition of shifting cultivation.
(VIII) RECLAMATION OF WASTE LANDS: Wastelands can be reclaimed and used
for cultivation. This is one of the measures of soil conservation.
(E) DESERTIFICATION
DEFINITION:- It is defined as the destruction of the biological potential of the land
which can ultimately lead to desert-like conditions.

FEATURES OF DESERTIFICATION
(I) Desertification is deterioration of the ecosystem due to change in the pressure
of human adaptation.
(II) It is a process through which fertile land is converted into infertile land.
(III) It is a slow process in which land productivity decline steadily.
(IV) It is the end product of a combination of economic, political & technological
forces.
CAUSES OF DESERTIFICATION
(A) Deforestation is the cause for soil erosion, water erosion, wind erosion etc.,
which cause the desertification.
(B) Over-exploitation of vegetation cover, results in reduction of vegetation cover
leading to uncontrolled runoff, degradation of soil structure, loss of fertile surface
soil, reduction in water holding capacity etc.
(C) Strong winds are responsible for desertification causing blow-off of surf soil.
(D) Improper agricultural practices cause desertification.
(E) Over grazing, which causes soil erosion is also responsible for desertification.
(F) Faulty land use is one of the causes of desertification.
(G) Climatic factors such as low precipitation, high temperature, dry & dusty
winds, intense evaporation etc., are responsible for desertification.
CONSEQUENCES OF DESERTIFICATION
(I) Desertification adversely affects agriculture.
(II) Desertification results in loss of vegetation cover.
(III) Desertification affects the habitats of wild animals.
(IV) Desertification adversely affects transport & communication.
(V) Desertification affects the industrial & economic development of countries.
(VI) Desertification badly affects the life of millions of people all over the world.
(VII) It forces the people to migrate to urban areas from rural areas.
(VIII) The land gets degraded becomes unproductive & becomes a desert.
(IX) Loss of soil either by natural process or mismanagement is harmful to the
whole ecosystem.
MEASURES FOR CONTROL OF DESERTIFICATION
(A) Ban on cutting of desert vegetation.
(B) Plantation or growing of ecologically suitable plants.
(C) Control of overgrazing in desertified areas.
(D) Development of pasture lands to release pressure on susceptible areas.
(E) Stabilization of sand dunes.

(F) Proper use of available ground water resources in desertified areas.
(G) Proper management of land use.
(H) Adoption of proper farming practices.
(I) Intensification of national watershed programme.
(J) Generation of public awareness & the need for the control of desertification.
(K) Reduction of population pressure.
..............................................................................................................

(II) DEFORESTATION
Deforestation means “Reckless or large scale felling or cutting of trees by man for
commercial & other purposes.”
CAUSES OF DEFORESTATION
(I) Expansion of agriculture into forest lands.
(II) Population growth, resulting in felling of trees for human settlement.
(III) Large-scale felling of trees for industrial development.
(IV) Growth of towns in forest areas, resulting in deforestation.
(V) Construction of roads & railway lines across forests.
(VI) Mining in forest areas; cultivation on hill slopes.
(VII) Shift cultivation; cattle ranching;
(VIII) Reckless timber harvesting.
(IX) Fire wood collection by tribal people & diseases affecting forests.
CONSEQUENCES OF DEFORESTATION
(I) Desertification; soil degradation & soil erosion.
(II) Loss of vegetation cover.
(III) Destruction of natural habitats of wild life & loss of wild life.
(IV) Changes in climatic conditions.
(V) Environmental pollution; Damage to forest ecosystem & reduction in soil
moisture.
CONTROL OF DEFORESTATION
Deforestation can be checked through the following measures:
(I) Prevention of human settlement in forest areas.
(II) Check on expansion of agriculture into forest lands.
(III) Prohibition of setting up of industries in forest areas.
(IV) Check on the growth of towns & cities on forest lands.
(V) Check on reckless felling of timber trees.
(VI) Control of over-grazing on forest lands.
(VII) Controlled mining in forest areas.
(VIII) Check on construction of large dams in forest areas.
(B) MINING
DEFINITION:- “Extraction of minerals occurring on the under surface of the earth.”
CAUSES FOR MINING
➢ Population growth
➢ Income growth
➢ Increasing demand for resources

➢ Single source of income
➢ Advancements in technology
➢ Importance for industrial processes
➢ Lack in substitutability
➢ Economic factor for countries
ADVERSE EFFECTS OF MINING IN FOREST AREAS (FORESTS & TRIBAL
PEOPLE)
1. Excessive mining leads to deforestation & loss of vegetation cover.
2. Excessive mining results in depletion of forests & results in loss of habitats for
wild animals & tribal people.
3. Excessive mining causes large scale destruction of forests results in ecological
imbalance.
4. Excessive mining may lead to volcanic rise & causes ground subsistence.
5. Mining wastes cause many adverse impacts on environment.
6. Overlying minerals are ruthlessly destroyed resulting in total destruction of
plants & animal species.
7. In Mining, Overburden is removed & dumped to nearby areas susceptible to soil
erosion, resulting in reduction of productivity of the land.
8. Mining in forest areas, results in depletion of forests& deprives tribal people of
forest products.
9. Disposal of a large quantity of mining wastes is a daunting task for mining
industry.
10. Mining activities cause pollution in water bodies & pollution in water bodies
result in deterioration in water quality & degradation of aquatic system.
(C) DAMS
DEFINITION:- Barrier across the flowing water that obstructs directs or retards
the flow and often creates a reservoir, lakes or impoundment.
BENEFITS OF DAMS:- Dams provide water for irrigation, generation of hydro-
electric power, transportation, control floods & soil erosion, help fish culture,
recovery of water logged areas for cultivation.
DAMS BUILDING ON ENVIRONMENT, FORESTS, BIODIVERSITY & TRIBAL
POPULATIONS
(1) Large dams constructed across forests cause large –scale destruction of forests.
(2) By causing deforestation, dams cause soil erosion in the adjacent areas.
(3) Dams constructed across forests result in ecological imbalance in the area.

(4) Dams constructed across the forests cause the defacing of topography,
destruction of landscapes & loss of biodiversity.
(5) By causing large-scale destruction of forests, dams result in loss of habitats for
wild animals.
(6) Large dams by causing destruction of forests, damage the tribal people of their
livelihood.
(7) Large dams, by causing destruction of forests, cause the displacement of tribal
people from their original habitats to new areas.
(8) Large dams, causes destruction of forests, & displacement & resettlement of
tribal people in new areas make them lose their identity & culture.
(9) Dams, due to impounding of large quantity of water, may lead to seismic
impact.
(10) Sedimentation & consequent long term loss of storage is a serious concern.
(11) Water-logging & salinity caused by dams, affect about 1/5th of crop land.
..............................................................................................................

(III) WATER RESOURCES
(A) SURFACE & GROUND WATER
SURFACE WATER:- Surface water is any body of water found on the Earth's
surface, including both the saltwater in the ocean and the freshwater in rivers,
streams, and lakes
GROUND WATER:- Groundwater is water that comes from the ground. It is a
source of drinking water and also a major source of water for irrigation.
Groundwater sources are beneath the land surface and include springs and wells.
USES OF SURFACE WATER & GROUND WATER
(I) It is used for irrigation, which is essential for the agriculture.
(II) It is used for the hydro-electric power.
(III) Water is used for the production of thermal power.
(IV) Surface water & Ground water is used for Pisciculture (Development of
fisheries).
(V) Surface water & Ground water is used for industrial purposes.
(VI) Water resources provide navigation facilities (Transportation facilities).
(VII) Water is used for domestic purposes like cooking, washing, cleaning etc.
(VIII) Surface water & Ground water is indispensable for drinking.
(IX) Water is used for wild life preservation.
(X) Water resources are used for livestock.
(XI) Surface water & Ground water is used for recreation activities.
(XII) Water resources are used in mines in coal washeries. [A plant at a mine
where water or other liquid is used to remove dirt from a mineral]
(XIII) Water is used for extinguishing forest fires and fire in industries &
residencies.
(XIV) Water resources are used for treatment of industrial, domestic & municipal
wastes.
(XV) Availability of water plays an important role in the evaluation of earth’s
ecosystem.
(XVI) Water resources reduce climate change.
(XVII) Water resource is useful for diluting pollutants.
(XVIII) Water resources are used as coolant in industries.
OVER-UTILIZATION OF SURFACE & GROUND WATER
(1) The increased extraction of groundwater has led to decreased groundwater level.
The inadequate rainfall caused reduction in storage of water in reservoirs leading to
decrease of groundwater.

(2) Building construction activities seal permeable soil zone and reduce the area for
percolation of rainwater thereby increasing surface runoff.
(3) If groundwater withdrawal rate is higher than recharge rate, sediments in
aquifers get compacted resulting in sinking of overlaying land surface. This leads to
structural damage in buildings, and reverses the flow of canals leading to tidal
flooding.
(4) Over-utilization of groundwater in arid and semi-arid regions for agriculture
disturbs equilibrium of reservoir in the region causing lowering of water table and
decreased pressure in aquifers coupled with changes in speed and direction of
water flow.
(5) Over utilization of groundwater in coastal areas leads to rapid intrusion of salt
water from the sea thereby rendering it unusable for drinking and agriculture.
(6) Over-utilization of groundwater leads to decrease in water level thereby causing
earthquake, landslides and famine.
(7) Over-utilization of groundwater leads to drying-up of dug wells as well as bore
wells.
(8) Due to excess use of groundwater near agricultural fields, agricultural water
that contains nitrogen as a fertilizer pollutes the groundwater rendering water unfit
for potable use.
(9) LOSS OF INTEGRITY OF FRESHWATER ECOSYSTEMS:- Human activities
for infrastructure development like creation of dams, land conversion, etc.
responsible for loss of integrity of freshwater ecosystems.
(10) RISK TO ECOSYSTEM FUNCTIONS:- Population and consumption growth
increases water abstraction and acquisition of cultivated land.
(11) DEPLETION OF LIVING RESOURCES AND BIODIVERSITY:- Overharvesting
and exploitation causes groundwater depletion, collapse of fisheries. Production of
food, quality and quantity of water and supply of water affected by depletions of
living resources & biodiversity.
(12) POLLUTION OF WATER BODIES:- Release of pollutants to land, air or water
alters ecology of water bodies. Greenhouse gas emissions produce significant
changes in runoff and rainfall patterns.
(B) FLOODS
DEFINITION: Floods generally mean “Excess flow of water in the rivers resulting
from excessive and incessant rains, overflowing the river banks.”

CAUSES OF FLOODS
(A) Floods occur when there is excessive rainfall. For instance, floods occur in
India when there is excessive rainfall caused by monsoons (South-West & North-
East Monsoons).
(B) Heavy & sudden rainfall by cyclones also causes floods.
(C) Incessant rains & poor drainage are also responsible for floods.
(D) Melting of snow also causes floods.
(E) The occurrence of high tides at the time when the rivers are in spate.
(F) Earthquakes also cause floods.
(G) Deforestation is also one of the causes of floods.
(H) Lack of check dams across the rivers is also one of the causes of floods.
EFFECTS OF FLOODS
(A) Floods destroy standing crops. If the floods destroy standing crops over a vast
area, they may be even famine in the flood affected areas.
(B) Roads & railway lines are breached due to floods. As a result, traffic is
suspended for days together.
(C) Floods damage houses, particularly in rural areas. Floods ruin stored food
grains.
(D) Floods damage sewage system; as a result, drainage system is affected and
there is outbreak of serious epidemics.
(E) Floods cause soil erosion, especially on sloping lands.
(F) Floods uproot the trees on sloping lands.
(G) Floods uproot telephone & electric poles.
(H) Floods change the course of rivers.
(I) Floods result in silting of lakes, loss of wild animals & human life.
(J) Floods force the government to spend huge amounts on relief & rehabilitation
measures in the flood affected areas.
CONTROL OF FLOODS
The following measures may be taken for the control of floods:
(I) Construction of dams across rivers.
(II) Construction of embankment on river banks.
(III) Drainage channels in areas which suffer from Poor Drainage & Water-Logging.
(IV) Desilting of river channels.
(V) Afforestation, i.e., growing of trees on sloping lands.
(VI) Improvement of weather forecasting techniques for accurate forecasting of
weather conditions.

(VII) Quick relief & rehabilitation measures to provide relief to people affected by
floods.
(C) DROUGHT
MEANING OF DROUGHT: “Scarcity of rainfall is often called Droughts.”
CAUSES OF DROUGHTS
(I) Droughts occur mainly due to lack of rainfall. The intensity of droughts
depends upon the variability of rainfall.
(II) In areas of higher rainfall variability, there are frequent droughts. For
instance; in India droughts occur when the south-west monsoon is weak.
(III) When the amount of rainfall from south-west monsoon is less than expected
rainfall or behind the scheduled times, droughts occur.
(IV) Deforestation i.e., reckless cutting of trees and the result is scarcity of rainfall
is another cause for droughts.
(V) Unwise use of water and land is also responsible for droughts.
EFFECTS OF DROUGHTS
(I) Droughts cause damage to standing crops.
(II) Droughts disturb agricultural operations.
(III) Droughts directly affect the cropping pattern & types of crops.
(IV) Droughts cause scarcity of water for animals & human beings.
(V) Droughts lead to famine. In the past, the most serious effect of droughts was
famine.
(VI) Droughts, by causing famine may contribute to the spread of epidemics.
(VII) Droughts force government to spend huge amount on relief & rehabilitation
measures.
(VIII) Famine, caused by droughts may cause loss of human life & domestic
animals.
CONTROL MEASURES
(I) Efficient use of water available from rivers, lakes & wells.
(II) Desilting of rivers & lakes for increasing the quantum of water from lakes &
rivers.
(III) Efficient use of underground water by digging open wells & tube wells.
(IV) Economic use of water by the people without wastage.
(V) Artificial rains.
(VI) Quick relief & rehabilitation measures for providing relief to people affected
areas.
(VII) Prohibition of indiscriminate felling of trees.

(VIII) Afforestation, growing of more & more trees in the catchment areas of rivers.
(IX) Control on reckless digging of deep wells for underground water.
(D) CONFLICTS OVER WATER
MEANING: “It is river water disputes arising from rivers flowing over two or more
states in a country or flowing over two or more countries regarding sharing of their
water or in regard to water pollution caused by such rivers in downstream regions
or regarding sharing of cost of Joint River protected constructed on such rivers.”
CAUSES FOR CONFLICTS OVER WATER
(I) When a state on the upper course of a river flowing through two or more state
constructs a dam on the common river, but does not want to release the water to
the lower-lying state, dispute will naturally arise between the two states.
(II) When the river project causes the pollution problem to the lower-lying state
from the activities undertaken by the state on the upper course of the river,
conflicts over water may arise between the states.
(III) When the state on the upper course of a common river wants to construct a
dam on the river for power and irrigation, but the lower-lying state objects to the
construction, fearing shortage of water from that river for its use, there will be
conflicts over water between the states.
(IV) Conflicts may also arise over sharing of the cost of the joint river project.
EFFECTS OF INTER-STATE RIVER DISPUTES
(I) The direct effect of river water disputes is farms in the states are badly affected,
as they are not able to carry on farming throughout the year due to the short
supply of water.
(II) Power generation in both the upper-stream state and lower stream state is
badly affected by the river water disputes.
(III) The relations between the states may be strained.
(IV) The issues relating to the sharing of the common river water may affect the
government of the state.
(V) The inter-state river water disputes slow down the economic development of the
states.
SOLVING CONFLICTS OVER WATER
(A) Allowing the construction of an additional dam on the common river in the
lower lying state for its requirements.
(B) High level of inter-dependence between the states regarding the sharing of
water.
(C) Improved sharing of information between the states regarding sharing of water.

(D) Through intervention, mediation & arbitration.
(E) Through give & take policy of the state using the common river.
(F) Adjudication through the appointment of water dispute tribunals for solving
interstate water disputes.
(G) Judgement of the apex court.
(H) Changing the complex cropping pattern & thereby optimizing the use of
available water & reducing the requirement of more water for irrigation.
(I) Inter-linking the interstate rivers & bringing them under common control for the
proper sharing of river water.
………………………………………………………………………………………………………

(IV) ENERGY RESOURCES
DEFINITION:- A source from which useful energy can be extracted or recovered
either directly or by means of a conversion or transformation process
(A) GROWING ENERGY NEEDS
• Energy plays a key role in the process of economic growth of a nation. The
Industrial development of any country is dependent on the organized development
of its power resources.
• All industrial processes like mining, transport, lighting, heating & cooling in
buildings need energy.
• With the growing population, the world is facing an energy deficit. Lifestyle
change from simple to a complex and luxurious lifestyle adds to this energy deficit.
• Almost 95% of commercial energy is available from fossil fuels like coal and
natural gas. These fossil fuels will not last for more than a few years. Hence, we
must explore alternative fuel/energy options.
• Relying on fossil fuels alone to increase the energy production is impossible.
Due to lack of access to required resources and even if resources are available, it
would produce irreparable damage to the environment through global warming.
• Energy is a primary input in any industrial operation.
• It is also a major input in sectors such as commerce, transport,
telecommunications etc.
• The wide range of services required in the household and industrial sectors.
• Owing to the far-reaching changes in the forms of energy and their
respective roles in supporting human activities, research and training on various
aspects of energy and environment have assumed great significance.
• Energy is the capacity for doing useful work. It is an essential input for
economic growth. This energy is used in the form of electrical energy, thermal
energy, light, mechanical energy and chemical energy etc.
(B) RENEWABLE SOURCES OF ENERGY
DEFINITION:- Renewable energy comes from sources that can be renewed.
SOURCES OF RENEWABLE ENERGY
(1) SOLAR ENERGY:- It is energy derived from the sun and is form of alternative
energy. Electricity can be generated with the help of solar energy, using
photovoltaic technology or heat powered engines. Some of the more common uses
are solar cooking, heating water and battery powered electronics. Solar power has
also been adapted to industrial uses.

(2) WIND ENERGY:- These are similar to windmills in construction and work like
regular turbines. When the wind speed is high enough to move the turbines,
electricity can be produced by the movement. Higher the speed of the wind, more
the amount of electricity can be produced.
(3) HYDRO ELECTRIC POWER:- Sun provides with energy through water. Dams
are a common way to generate electricity on a large scale basis. The fall of water
powers turbines, are able to produce energy when they turn. Small waterfalls
occurring naturally are another source, along with systems that derive kinetic
energy from the movement of water in rivers, streams and oceans.
(4) GEOTHERMAL ENERGY:- Tremendous amount of energy stored within the
Earth. Many radioactive release great amounts of heat. This heat makes it away to
crust and finds a way out when cracks appear in the surface of the Earth. These
thermal vents, release super-heated steam & boiling water. These vents can be
adapted for the generation of electrical power which provides more renewable
sources of energy.

(5) BIOMASS ENERGY:- Plants contain energy is stored within them during
photosynthesis. This energy is broken down and made usable when the plants are
burnt. Biomass plants are furnaces that break down large amounts of raw
material. Leftover parts of crops, rotten plants, diseases vegetables and even waste
wood parts are usable as raw material.
(6) BIOFUELS:- Extracted from plants and crops. These are synthetic in nature
not utilized directly create electricity. Ethanol is the main form of biofuel, which is
created by the fermentation of sugar. It is regularly blended with gasoline as a form
of car fuel, as it produces lesser carbon dioxide when it burns.
(7) OCEAN ENERGY:- Ocean energy can be harnessed via 3 ways: wave energy,
tidal energy and Ocean thermal energy conversion (OTEC). The rise and fall of tides
is used by the tidal energy generators, which is then used to move turbines, which
in turn generate electricity. The tidal energy converts the kinetic energy to electrical
energy.

(C) NON-RENEWABLE SOURCES OF ENERGY
DEFINITION:- Non-renewable energy comes from sources that will run out or will
not be replenished.
SOURCES OF NON -RENEWABLE ENERGY
(1) COAL:- Coal is the most abundant form of fossil fuel found below the earth
and major source of fuel for electricity generation. When coal is burnt, it produces
heat which converts water into steam. The steam is used to move turbines which
in turns activate generators to produce electricity. Excessive extraction and use
has resulted in degradation of environment and ecological imbalance.
(2) OIL:- When plants and animals died they are covered with thick layer of mud
and sand which created huge pressure and temperature. Wide usage of oil its
products resulted in air pollution. It is a major source of fuel. Oil is transported to
other nations using pipelines or ships. Leakage in ships leads to oil spill which
affects animals and plants that live inside or around the sea.
(3) NATURAL GAS:- Natural gas is a mixture of several gases and burns
completely without leaving any ashes. It causes almost no pollution and is one the
cleanest form of fossil fuel. Of these gases, methane is highly inflammable. Hence
some chemicals are added to it so that leakage can easily be detected. This source
of fuel causes almost no pollution, cheap and environment friendly.
(4) NUCLEAR ENERGY:- Most of world’s electricity production comes through
nuclear energy. Nuclear power plants use Uranium as a fuel to extract energy from
it. Nuclear fission is the most common technique to harness nuclear energy. U-235
element is bombarded with slow moving neutrons which break the atom and
releases energy to produce mass amount of energy. These elements emit strong
radiations and must be buried deep underground so that they don’t affect human
life.

(D) USE OF ALTERNATE ENERGY SOURCES
ALCOHOL AS FUELS:- There are certain alcohols used as fuels, they are as
follows;
ETHYL ALCOHOL OR ETHANOL:- Ethanol is used as fuel. Ethanol is produced
by fermenting plant sugar with the help of yeast. It is cheaper than petrol. It is
water soluble and bio-degradable. It can be used as an alternate fuel for petrol. It
is eco-friendly.
METHYL ALCOHOL OR METHANOL:- It is an alternate source of energy. It burns
at a lower temperature than petroleum & diesel. It is advantageous alternate
source of fuel.
LIQUIFIED PETROLEUM GAS (LPG):- LPG is used as an alternate fuel in vehicles
in many countries including India. LPG can reduce pollution and emission in the
air.
HYDROGEN AS ENERGY:- It is a alternative source of energy. It is inexhaustible
and a renewable source of energy. It is free from pollution and ubiquitous in
nature. It is produced from many sources like fossil fuels, water, biomes etc.
BIOMASS ENERGY:- Biomass is the organic matter produced by plants or animals
which include wood, crop residue. Biomass produces energy by burning.
TIDAL ENERGY:- Tidal energy is a form of hydropower that converts energy
obtained from tides into useful forms of power, such as electricity
GEOTHERMAL ENERGY:- Tremendous amount of energy stored within the Earth.
Many radioactive release great amounts of heat. This heat makes it away to crust
and finds a way out when cracks appear in the surface of the Earth. These thermal
vents, release super-heated steam & boiling water. These vents can be adapted for
the generation of electrical power which provides more renewable sources of energy.
………………………………………………………………………………………………

The term biodiversity is a contraction of the term “Biological Diversity.” The term
biological diversity was coined by Walter G. Rosen in 1965. The contracted term
“Biodiversity” was coined by biologist by name E.O. Wilson in 1985.
DEFINITION & MEANING OF BIODIVERSITY
The term biodiversity is defined as the variety & variability among living organisms
and the ecological complexes in which they occur.
Biodiversity is defined as “Genetic variability & diversity of life forms such as
plants, animals & microbes living in a wide range of ecosystems.”
According to IUCN Biodiversity is defined as “Variety & Variability within species &
their populations, the varieties of species & their life forms.”
Various definitions of biodiversity emphasize the fact that biodiversity is not just
confined to species but even extends to distinct population within species that
contribute to biodiversity.
IMPORTANCE OF BIODIVERSITY
➢ Biodiversity is important for proper functioning of organisms & ecosystems.
➢ Biodiversity plays an important role in the formation & enriching the soil.
➢ Biodiversity influences water cycle & biogeochemical cycles in the ecosystem.
➢ Human population depends on the varieties of plants & animals for food,
clothing etc. Biodiversity influences human life.
(I) TYPES OF BIODIVERSITY / LEVELS OF BIODIVERSITY
Biodiversity refers to the variety & variability of plants, animals & micro organisms
of the world. It is the totality of genes, species & ecosystem in a region. The
biological diversity include three hierarchial levels; (A) GENETIC DIVERSITY (B)
SPECIES DIVERSITY (C) ECOSYSTEM DIVERSITY
(A) GENETIC DIVERSITY
❖ It refers to variation of genes within a species.
❖ Gene is the basic fundamental unit of hereditary character which forms the
chromosomes which is found in the nucleus of the cell.
❖ The number of genes present in a species differs from the genes present in
other species.
❖ The genetic information is stored in the form of genes are transferred from
generation to generation. Eg: Man belongs to the species Homo sapiens. All
UNIT-4
BIODIVERSITY AND CONSERVATION

human beings form one human population. There are different races around the
world which differs in skin colour. These differences in human race are due to
genetic diversity.
❖ A species with more genetic diversity can adapt better to the changed
environmental conditions.
❖ The genetic diversity plays a vital role in maintaining ecological balance.
❖ Genetic diversity is brought by natural process but man has capacity to
manipulate the gene causing genetic diversity.
❖ Genetic diversity contributes for economic benefit. Gene manipulation
results in increased agricultural yield.
(B) SPECIES DIVERSITY
➢ It refers to the variety of species within a region. It includes full range of
species in the region from micro-organisms to multi-cellular plants & animals.
➢ Species are the group of organisms which interbreed among themselves to
produce fertile offspring and that reproductively isolate from other species.
➢ Genetic diversity is the major root cause for species diversity.
➢ Species are commonly unit describing biodiversity. There are 3 types.
1) α-INDEX DIVERSITY:- It is the relative richness of different species in an area.
2) β-INDEX DIVERSITY:- It is the relative richness of different species along a
gradient from one habitat to another habitat within the community.
3) γ-INDEX DIVERSITY:- It is the richness of different species in a range of
habitats within the geographical area.
(C) ECOSYSTEM DIVERSITY
➢ It refers to the variation in different ecosystems of a geographical area.
➢ Variety & variability among different ecosystems in the biosphere is
Ecosystem diversity.
➢ In ecosystem, living organisms are continuously interacting with the non-
living component of the environment.
➢ Ecosystem differs from one another by its physical, chemical & biological
structure.
➢ Variation in the trophic structure, nutrient cycles, energy flow etc is found in
this type of diversity. Eg: Forest ecosystem is having different character than the
desert ecosystem in both abiotic & biotic components.
➢ Ecosystem diversity is characterized by different types of ecosystem which
represent different parts of biosphere.

TERRESTRIAL ECOSYSTEM AQUATIC ECOSYSTEM
Forest Ecosystem Ocean Ecosystem
Grassland Ecosystem River Ecosystem
Desert Ecosystem Pond Ecosystem
Garden Ecosystem Lake Ecosystem
Caves Ecosystem Aquarium Ecosystem
(II) BIOGEOGRAPHICAL CLASSIFICATION ZONES OF INDIA
India has different types of climate and topography. It has a rich heritage of
biological diversity. it has large variability in flora and fauna. India is divided into
ten bio-geographical zones. These zones are;
(I) TRANS-HIMALAYAN REGION:- This region includes Ladakh mountains in
Jammu and Kashmir & Himachal Pradesh. This region is cold and arid, extensive
areas of base rocks and glaciers.
FLORA:- The flora of this region comprises trees like Pine and Deodar.
FAUNA:- The animals of this region are Wild Sheep, Yak, Tibetian Ass, Snow
Leopard, Wolf etc,.
(II) HIMALAYAN REGION:- It covers North-West Himalayas, Western Himalayas,
Central Himalayas & Eastern Himalayas.
FLORA:- Flora of Himalayan region are Pine, Cart Tree, Sal, Castor etc,.
FAUNA:- Wild Bear, Sambar, Leopard, Deer etc,.
(III) GANGETIC PLAINS:- It comprises the upper ganga plains and lower ganga
plains. This region stretches from eastern Rajasthan, through Uttar Pradesh to
Bihar and West Bengal. These Gangetic plains are most fertile regions.
FLORA:- Acacia, Sal, Mango etc,.
FAUNA:- Black Chinkara, Rhinoveros, Turtle, Alligator etc,.
(IV) NORTH-EASTERN REGION:- It comprises Brahmaputra valley and eastern
hills or Assam hills. This region is rich in ever-green and semi-evergreen rain
forest, moist deciduous forest, swamps and grasslands.
FLORA:- Bamboo, Sal, Jackfruit, Castor.
FAUNA:- 390 species of fauna, Elephant, Rhino, Buffalo, Deer, Porcupine etc,.
(V) DESERT ZONE:- Desert zone comprises salt desert of Kutch in Gujarth &
sand desert of Thar in Rajasthan. The natural vegetation of this region consist of
tropical thorny forest & salt marshes.

FLORA:- Acacia, Grass.
FAUNA:- Wolf, Chinkara, Desert Cat, Indian Bustard.
(VI) SEMI-ARID ZONE:- West of India is the area between deserts, deccan plateau
including Aravalli range. This zone includes Punjab plains, Rajasthan & Gulf of
Kutch & Kathiwar peninsula of Gujarath.
FLORA:- Tropical thorny forest, Date, Palm, peepal.
FAUNA:- Lion, Blackbuck, Sambar.
(VII) DECCAN PENINSULA:- South & South Central Plateau of river. The Deccan
Peninsula covers about 43% of India’s total land surfaces.
FLORA:- Deciduous forest & Tropical forest.
FAUNA:- Tiger, Leopard, Sloth bear, Elephants, Wild buffaloes.
VIII) WESTERN GHATS:- These are the hill regions flows across Karnataka,
Tamilnadu, Kerala & Andhra Pradesh which covers 5% of Indian land resources.
FLORA:- Different plant species, Monsoon forests etc.
FAUNA:- Niligiri Langur, Lion-tailed macque, hornbill, Tortoise, Frog, Lizards,
Snakes etc.
IX) COASTAL ZONE:- Comprises of the west coast & east coast.
FLORA:- Sea grasses, Coconut, Banana, Cashewnut etc.
FAUNA:- Crocodiles, Dolphin, turtles, tortoises etc.
X) ISLANDS:- It comprises of Andaman & Nicobar Islands on the Bay of Bengal &
the Lakshadweep islands in the Arabian Sea. Lakshadweep Islands consists of 30
major islands.
FLORA:- Jack fruit, coconut, Cardamom, Clove etc.
FAUNA:- Dolphin, Alligator, Water Snake, Turtles, Crabs, Sponges etc.
(III) BIODIVERSITY PATTERNS & GLOBAL BIODIVERSITY HOT SPOTS
➢ Every country is characterized by its own biodiversity depending mainly on
its climate. India has a rich biological diversity of flora and fauna.
➢ Overall 6% of global species are found in India.
➢ It is estimated that India ranks 10th among the plant rich countries of the
world.
➢ 11th rank in terms of number of endemic species of higher vertebrates.
➢ 6th among the centers of diversity and center of agricultural crops.
➢ The total number of living species identified in our country are about
1,50,000.
➢ Out of a total of 25 biodiversity hotspots in the world, India posses two, one
is north-east region of India and one is western ghats.

➢ India is also one of the 12-mega diversity countries of the world.
➢ Some major groups of flora and fauna in India are – Algae, Lichen, Fungi,
Bryophytes, Pteridophytes, Flowering plant, Fishes, Amphibians, Reptiles, Birds
and Mammals.
HOTSPOTS OF BIODIVERSITY
➢ A biodiversity hotspot is a region of the earth which is extremely biologically
diverse and also under severe threat due to habitat loss, climate change or
extensive species loss.
➢ Around 25 sites worldwide are recognized as biodiversity hotspots, and
several organizations have made efforts to protect these sites. Guarding such
regions from further damage is considered environmentally and culturally
important, as a biodiversity hotspot hosts organisms which are not found anywhere
else on earth.
➢ Hotspots have been identified based on three criteria, they are;
(a) On the number of species present.
(b) On the number of those species found exclusively in an ecosystem.
(c) On the degree of threat they face.
➢ British ecologist Norman Myers created the biodiversity hotspots concept in
two scientific papers published in 1988 and 1990.
➢ There are 25 hotspot of biodiversity at the global level. India has two
hotspots and they are;
EASTERN HIMALAYAS:- It occupies the total area of 7298 sq km which include
4250 plant species which are endemic. This region shows a varied topography
which includes orchid flowers, bryophytes and lichens etc., which are endemic to
this region. The endemic animals in Himalayan region are snow leopards, yak,
birds, etc.
WESTERN GHATS:- It occupies the total area of 1,89,611 sq km includes the
western strip regions of Karnataka, Kerala and Tamilnadu. This regions shows a
high endemic in reptilian, amphibian species and has 10 species of endemic
threatened species, 14 species of endemic threatened mammals, 87 species of
threatened amphibians and 405 species of endemic plant species.

(IV) INDIA AS A MEGA-DIVERSITY NATION
➢ India is one of the 19 mega biodiversity countries of the world. So far about
70% of the total area of the country has been surveyed for biodiversity. Till to date
45,000 wild species of plants and 81,000 wild species of animals have been
identified.
➢ There are also 45,000 species of wild plants found in India. About 18%
including many flowering plants are endemic.
➢ Indian forest covers 64.01 million hectares having rich biodiversity of plant
in the trans-himalayan, North-west, west central and eastern Himalayan forests,
western, coasts etc.
➢ India’s World Heritage sites are Khaziranga National Park in Assam,
Keoladeo Ghana National Park in Rajasthan, Manas Wild life Sanctuary in Assam,
Nanda Devi National Park in Uttar Pradesh, Sundarban National Park in West
Bengal.
➢ Besides the above facts, the following facts clearly indicates that India is a
mega diversity nation.
➢ Out of the 12,28,183 life forms in the world reported till now, India has
about 89,451 or 7.28% and more likely to be discovered.
➢ Nearly 5,10,000 insects have been identified in India.
➢ Out of 35,000 described species of crustaceans about 3000 are found in
India.
➢ India’s fish fauna is very rich with more than 2,500 fish species known to
occur in India.
➢ India has also recorded 64 gymnosperms, 1,135 pteridophyta, 2850
bryophytes, 2021 lichens, 6500 algae and 14500 fungi.
➢ India has the major population. For instance nearly 60% of the world’s tiger,
80% of the world’s one-horned rhinoceros, 100% of the Asiatic lion, 65% of the
Asian elephant are found in India.
➢ More than 3000 species have been recorded for use in fibre, fodder, gum,
dyes, colours, essential oils, scents and also for religious purposes.
(V) ENDANGERED & ENDEMIC SPECIES OF INDIA
ENDANGERED SPECIES
➢ A species is said to be endangered when its number are reduced severely
and it faces the danger of becoming extinct.
➢ EXTINCT:- A species is said to be extinct when there are no more
individuals of that species alive anywhere in the world.

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