ENVIRONMENTAL STUDIES

Notes 68 Pages

Bengaluru City University

Bachelor of Business Administration

Contributed by

Prajwal Hallale

1

SMT DIVYASHREE D V, MESIOM

NOTES ON
ENVIRONMENTAL STUDIES

SMT DIVYASHREE D V
LECTURER
MESIOM

COURSE OBJECTIVE
The objectives of environmental studies are to develop a world in which
persons are aware of and concerned about environment and the problems associated
with it, and committed to work individually as well as collectively towards
solutions of current problems and prevention of future problems for Environmental
growth
COURSE OUTCOME
By the interactive sessions, diagram, and illustrations the Environmental
Studies major prepares students for careers as leaders in understanding and
addressing complex environmental issues from a problem-oriented,
interdisciplinary perspective on the ethical, cross-cultural, and historical context of
environmental issues and the links between human and natural systems.

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SMT DIVYASHREE D V, MESIOM

Unit 1: INTRODUCTION TO ENVIRONMENT

Environment can be defined as something that surrounds us. Though our primary interest
is the environment of man, we cannot exist in isolation. Human activity has to be
understood in relation to other forms of life that exists in both animal and plant kingdom.
Therefore it is necessary to deal with the environment of all life forms.

Environment consists of three domains. viz, gaseous – air (atmosphere), liquid – water
(Hydrosphere), and solid – land (lithosphere). These three domains meet at a common
interface on the surface of the earth. This interface, a shallow life-bearing layer is the
‘Bio-Sphere’. Structure and functioning of the bio sphere is essentially dependent on the
exchange of matter and energy that takes place continuously amongst the land surfaces,
water bodies and atmosphere.

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Sustainable Development

Sustainable development has been defined in many ways, but the most frequently quoted
definition is from Our Common Future, also known as the Brundtland Report:
"Sustainable development is development that meets the needs of the present without
compromising the ability of future generations to meet their own needs."A characteristic
which has set human beings apart from other species is their ability to control many
aspects of the environment. Throughout the recorded history, man has struggled to
manage his natural environment in order to improve his well being.

The quality of our environment is determined by the intricate processes of the human race
making a living and enjoying life. In that process water, food, land and air are used. The
changes produced during this use affect the health, comfort, aesthetic senses, efficiency
and capacity of people to attain a satisfactory social adjustment. Use of essentials for life
affects the dynamics of all plant and animal life on earth by altering the ecological
balance. Another aspect - use of land and air as waste disposal sinks is impairing their
quality. The disturbance has reached such levels that these resources are no longer usable
for their designated purposes in many instances. The rapid increase in world’s
population and the accelerated rate of use of all natural resources are making the
consequences of misuse more drastic and more widespread. While living on the resource
offered by the ecosystem it is necessary to maintain the sustenance levels of the
ecosystem. This becomes very important while taking up developmental activities.
Assessment of ecological changes and implementing preventive and corrective measures
is an essential step in making the developmental activity ecologically sustainable.
A developmental scenario in which no damage is done to the ecosystem can be ideally
termed as sustainable development. But this is not easy to achieve. Hence the
developmental activity can be assumed to be sustainable when irreversible damage is not
done to the environment; even if a stress is developed it can be overcome by adopting
suitable corrective measures.
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UNIT 2: ECOSYSTEM

The bio-sphere is made up of the living system consisting of plant and animal kingdom,
and the non-living components including minerals, water etc., The entire system is
sustained by the source of energy, the Sun. Organisms belonging to different species
either of plant kingdom or animal kingdom interact among themselves as well with the
physical environments they occupy. This system is called ecological system or
ecosystem.
ECOSYSYTEM
Living organisms and their non-living systems of the environment are
inseparable, inter-related and interact upon each other. Any unit that includes all the
organisms in a given area interacting with the physical environment so that a flow of
energy leads to clearly defined trophic structure, biotic diversity and material cycles,
exchange of materials between living and non-living components within the system is
known as ‘ECOSYSTEM’. The term eco-system was coined by Tansley in 1935. He
defined it as “the system resulting from the integration of all the living and non-living
factors of the environment”.

The two major aspects of eco-systems are
(i) structure and
(ii) function

Structure comprises of,
• The composition of biological community including species (plants, animals and
microbes), biomass, life cycles and distribution in space, tropic standpoint.
• The quantity, distribution and cycling of the non-living materials such as major and
micro nutrients, trace elements and water.
• The range or gradient of conditions like temperature, light, rainfall, relative
humidity, wind and topography.
Function involves,
(i) the rate of biological energy flow i.e., production and respiration rates of the
community
(ii) rate of materials or nutrient cycles
(iii) Biological / ecological regulation which includes regulation or organism by
environment (photo periodism) and regulation of environment by organisms
(nitrogen fixation by organism).
Thus, in any ecosystem, the structure and function are studies together.
From the trophic stand point, an ecosystem has two components.
(i) Autotrophic Component
(ii) Heterotrophic Component

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SMT DIVYASHREE D V, MESIOM

Autotrophic Component
The fixation of light energy, use of simple inorganic substances like carbon and
water, synthesis of hexose sugars to complex substances such as polysaccharide
carbohydrates (starches) and further fat and protein synthesis predominate here.

Heterotrophic Component
Utilization, rearrangement and decomposition of complex substances is
predominate here. These are macro consumers such as herbivores, carnivores and
omnivores and micro consumers such as decomposers, osmotrophs and saprotrophs.

From the functional stand point an ecosystem may be conventionally analyzed in
terms of,
(i) Energy Circuits
(ii) Food Chains
(iii) Diversity Patterns in Space and Time
(iv) Nutrient Cycles
(v) Development and Evolution
(vi) Control (Cybernetics)

For descriptive purpose the various components of an ecosystem can be
conveniently arranged in the following manner.
(i) Producers – they are autotrophic organisms, largely green plants which are able
to produce the required food materials from simple inorganic substance.
(ii) Macro Consumers – Heterotrophic organisms, chiefly animals which ingest
other organisms or particulate organic matter. They are three types, viz., primary
consumers (herbivores), secondary consumers (carnivores) and tertiary consumers
(carnivores / omnivores).
(iii) Micro Consumers – Heterotrophic organisms, chiefly bacteria and fungi which
break down complex compounds of dead organic matter, absorb some of the
decomposition products and release inorganic nutrients that are usable by the
producers together with organics. These are called composers.

The two ecological processes of energy flow and mineral cycling involving
interaction between physico-chemical environment and the biotic community is
considered as the ‘heart’ of ecosystem dynamics. In an ecosystem, always energy flows
in non-cyclic manner from sun to the decomposer via producers and macro consumers
whereas the minerals keep moving in a cyclic manner.

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Components of Ecosystem
As discussed above, an ecosystem has three distinctive components that can be identified
as :
• non living or abiotic component including climate regime
• living or biotic component
• source of energy – light and heat
Abiotic Substances
These comprise of inorganic and organic compounds present in the environment. The
inorganic components of an ecosystem are oxygen, carbon dioxide, water, minerals etc.,
whereas carbohydrates, proteins, lipids, amino acids etc., are examples for organic
material. The predominant source of energy in the earth’s biosphere is sun. The aboitic
substances are circulated in the ecosystem through material cycles and energy cycles.

Biotic Substances
Living organisms in the ecosystem – various species of plants and animals including
microbes are termed as biotic components. They can be classified as producers
(autotrophs) and consumers ( heterotrophs).

Producers ( Autotrophs)
Autotrophs produce their own food from inorganic substances, using light or chemical
energy. Green plants including the unicellular algae which contain the pigment
chlorophyll are producers. They take up simple substances such as water, carbon di-
oxide, and oxygen, as well as inorganic nutrients and produce biological molecules
needed for life from the inorganic substances. This production activity is vital for the
existence of the ecosystem as the products of photosynthesis support the life on earth.
The overall effect of photosynthesis is to unite the hydrogen atoms of water with the
atoms of carbon di-oxide to form carbohydrate. In the process oxygen gets released. A
generalized photosynthesis reaction can be represented as :

H
2
O +CO
2
+ light energy Chlorophyll Carbohydrate + 0
2

Energy obtained from solar radiation plays the key role in this process. Hence the
photosynthetic activity is essentially brought about during day time, although some
insignificant amount of photosynthesis takes place during night time utilizing the faint
light emitted from the heavenly bodies.

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Consumers ( heterotrophs)

The heterotrophs do not have the ability to produce their own food. All these species are
consumers. Bacteria, although belong to plant kingdom are not capable of production
and are classified as consumers. The animals which feed on plants are called herbivores.
They are primary consumers. Those feeding on animals are called as carnivores which
are secondary consumers. Another category of consumers which feed on both plants and
animals are called as omnivores.

ECOLOGY
An ecosystem is a vast and complex natural system. It consists of large pools of material
resources and living organisms supported by sources of energy. There is a constant
exchange of materials and energy in the ecosystem. The dynamics of such systems in
which we live has to be properly understood so that we live happily, at the same time
keeping the health of the whole system in good condition. Study of the ecosystem in all
aspects is called ‘ecology’. The definition of ecology is in the Greek words ekos, “ the
house”, and logos “knowledge of”. It is knowing what makes our dwelling place
function.

Classification of Ecosystems / Ecology: Ecosystems are broadly classified as :
Terrestrial Ecosystems – which encompass the activities that take place on land, and
Aquatic ecosystems - the system that exists in water bodies
These ecosystems can be further subdivided as :
Terrestrial ecosystem - Forest ecosystem,
Mountain ecosystem
Desert ecosystem
Grassland ecosystem
Urban ecosystem
Aquatic ecosystem - Marine ecosystem
Fresh water ecosystem
Esturine ecosystem

Engineered ecosystem : An ecosystem which is fully designed and controlled by man is
called ‘Engineered ecosystem’. A paddy field or a fish pond can
be quoted as an example for this ecosystem.

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Environmental impacts of human activities

All living beings including man are dependent on their environment for existence. But
every manmade activity has some impact on the environment. More often it is harmful
than benign. But human beings cannot live without taking up these activities for their
food, shelter, comfort, security and many other needs. The following activities cause
major impacts on the environment:

- Agriculture
- Housing
- Transportation
- Industries
- Water resources projects including irrigation projects
- Power Generation
- Mining
- Tourism
- Socio-Economic activities
- Defence related activities
- Petroleum processing
- Urbanization
- Commercial deforestation
- Providing public amenities such as water supply, sanitation, electricity, telephone,
transportation etc.,
- Religious places – public activities

BIO-GEO-CHEMICAL CYCLE
Nutrients, unlike energy are recycled in the ecosystem. There are about 40
chemical elements considered to be essential for living organisms. Materials are in
limited quantity in the earth’s system and to keep the system going continuously the only
possibility is to regenerate the materials. The unique method evolved in nature is
recycling materials continuously is by linking them in cyclic changes.

The macro-nutrients are C, H, O, P, K, I, N, S, Mg, Ca, etc., which have cycles
with atmosphere while micro-nutrients like Cu, Fe, Co, etc., are soil based form edophic
cycles.
The bio-geo-chemical cycles are of two varieties
• sedimentary cycles
• Gaseous cycles.

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The sedimentary cycles the main reservoir is the soil, the sedimentary and other
types of rocks of earth’s crust.
The gaseous cycles have their main reservoir of nutrients in the atmosphere and
oceans.
Examples are the oxygen, carbon, nitrogen, sulphur, etc. Both are driven by the
flow of energy and both are tied up with the water cycle or the hydrologic cycle. In
nutrient cycle, various chemical compounds of the main element are transferred while in
hydrologic cycle a compound i.e., water is circulated as solid liquid and vapour phase.

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SMT DIVYASHREE D V, MESIOM

UNIT 3: NATURAL RESOURCES

Resources are needed for the development of civilization. Natural resources are
the materials provided by the nature that are required to sustain life and livelihood. They
include air, water, land, food, timber, paper, medical plants, minerals, fuel, etc.
Everything that human beings use is drawn from the nature. Due to increased standards
of living results in excessive utilization of natural resources. However, the natural
resources are limited. They should be properly and optimally used for a comfortable
living. The entire living system will collapse when the utility exceeds the regeneration
capacity.

Forest Wealth
Forests are valuable source of biodiversity from which we derive various benefits
like medicines, domesticated plants, animals, etc. Forest reduces the impact of raindrop
by covering the surface of the land with litter and leaves. This results in reduction of soil
erosion, in turn floods in rivers. It moderates climate. Forest provides livelihood for
large sector of tribal people. It also fulfills timber, fuel-wood, fruits, fibre, recreation
and other benefits. These are self managed ecosystems by way of managing and
maintaining themselves in the absence of human interference. It maintains the natural
ecological balance by providing habitat for various species of plants and animals.

They provide shelter to large number of animals and birds. Infact tropical rain
forests are the best sources of diversity of animals. These animals are not only
aesthetically valuable but represent a tremendous store of genes. These genes have been
evolving over millions of years, so when one species of animals or plant become extinct,
a very valuable source of genetic information is lost. Our wheat, rice, ragi, sugar cane,
etc., are also descendants of once wild grasses.

Many forests have been damaged by cutting them to provide space of
urbanization / agriculture / industry. Deforestation is the curse of modern civilization.
Large reservoirs submerge land / forest along with upstream course of river and valuable
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ENVIRONMENTAL STUDIES

ENVIRONMENTAL STUDIES

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