1. Environment,
Ecology and Ecosystem
Environmental Studies
UNIT-1

2. Environment
• Environmental science is an interdisciplinary field
that includes both scientific and social aspects of
human impact on the world.
• The word environment is usually understood to
mean the surrounding conditions that affect
organisms.
• In a broader definition, environment is
everything that affects an organism during its
lifetime.
• In turn, all organisms including people affect
many components in their environment

3. Environmental Science
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4. Classification of Environment
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5. Components of Environment
• The two major Components of environment are :
Abiotic components : Air, Water, and Land etc
Biotic components: All living organisms around us viz. plants, animals,
and microorganisms
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6. Components of Environment
• Earth’s environment can be further
subdivided into the following four segments:
(1) Atmosphere
(2) Lithosphere
(3) Hydrosphere
(4) Biosphere
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7. Atmosphere
 It is the gaseous envelope surrounding the earth and
extends upto 500 kms above the earth’s surface.
Constituent Volume %
– Nitrogen 78.1
– Oxygen 20.9
– Water vapour 0.1–5
– Argon 0.9
– Carbon dioxide 0.03
– Trace constituents* Balance
– *The trace constituents include Helium, Neon, Krypton,
xenon, SO2, NO2, Ammonia, Ozone, and
– Carbon monoxide etc.
 The atmosphere, which is a gaseous cover, protects the
earth from cosmic radiations and provides life sustaining
Oxygen, the macronutrient Nitrogen and Carbon dioxide
needed for photosynthesis.
 The atmosphere screens the dangerous UV radiations from
the sun and allows only radiations in the range of 300 nm –
2500 nm (near UV to near IR) and radio waves.
 The atmosphere plays a major role in maintaining the heat
balance of the earth by absorbing there-emitted radiation
from the earth.
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8. Five Layers of the
Atmosphere
Troposphere : lowest layer – extends up to 10km; contains 99% of the water vapor and
75% of the atmospheric gases
• The troposphere is the first layer above the surface and contains most clouds and half of
the Earth's atmosphere.
• Weather occurs in this layer
Stratosphere – directly above troposphere, extending from 10 km to about 50 km above Earth’s
surface
• Portion of the upper layer contains high levels of a gas called ozone
• Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs
harmful rays from the Sun
Mesosphere – extends from the top of the stratosphere to about 85 km above Earth
• Coldest layer with little ozone
• Meteors or rock fragments burn up in the mesosphere.
• Ionosphere here – layer of charged particles

9. Thermosphere – thickest atmospheric layer found between 85 km and 500 km above Earth’s
surface
• The thermosphere is a layer with auroras, known for its high temperatures.
Warms as it filters out X-rays and gamma rays from the Sun
Ionosphere here, too – help carry radio waves
Exosphere - The atmosphere merges into space in the extremely thin exosphere. This is the
upper limit of our atmosphere.
• Outer layer where space shuttle orbits.

10. Lithosphere
• The earth’s crust consisting of the soil
and rocks is the lithosphere. The soil is
made up of inorganic and organic
matter and water.
• The main mineral constituents are
compounds or mixtures derived from
the elements of Si, Ca, K, Al, Fe, Mn, Ti,
O etc. (Oxides, Silicates, and
Carbonates).
• The organic constituents are mainly
polysaccharides, organo compounds of
N, P and S.
• The organic constituents even though
form only around 4% – 6% of the
lithosphere, they are responsible for
the fertility of the soil and hence its
productivity
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11. Hydrosphere
 This comprises all water resources both surface and
ground water.
 The world’s water is found in oceans and seas, lakes
and reservoirs, rivers and streams, the Polar Regions in
addition to ground water below the land areas. The
distribution of water
 among these resources is as under
– Oceans and Seas 96–97 %
– Glaciers and polar icecaps 2–3 %
– Fresh water < 1%
 The water locked up in the Oceans and Seas are too
salty and cannot be used directly for human
consumption, domestic, agriculture or Industrial
purposes.
 Only less than 1% of water resources are available for
human exploitation. Water is considered to be a
common compound with uncommon properties.
These uncommon properties (e.g. anomalous
expansion of water) are mainly responsible for
supporting terrestrial and aquatic life on earth.
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12. Biosphere
• The biosphere is a capsule encircling the earth’s
surface wherein all the living things exist.
• This portion extends from 10000 m below sea level to
6000 m above sea level.
• Life forms do not exist outside this zone.
• The biosphere covers parts of other segments of the
environment viz. Lithosphere, Hydrosphere and
Atmosphere.
• Life sustaining resources like food, water and
oxygen present in the biosphere are being withdrawn
and waste products in increasing quantities are being
dumped.
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13. Types of Environment
• Natural Environment
– The environment that comes in
its existence by its own or
naturally.
– Without interference of humans
– It operates through self
regulating
mechanism(Homeostasis)
• Man-made
Environment(Anthropogenic)
– Env. Is modified by human activity
– Scientific technology which is result
of human brain is decorating the
natural environment.
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14. Objective of Environmental education
• Awareness:
• Knowledge
• Attitudes
• Skills
• Participation

15. Importance of Environmental science
• Solving the issues related to environment
– Pollution
– Over exploitation of non-renewable sources
– Food problem
– Sustainable development
– Maintain the ecological balance
– Eco friendly product
– Conservation of natural sources
– Understand the food chain
– Inculcating attitude and value
– Encouraging Environment protection

16. Scope of Environmental Science
• Natural Resources
• Ecology
• Biodiversity and its conservation
• Environment pollution and control
• Natural disaster
• Development
• Social issues in relation to development and
environment
• Human population and environment 13

17. Learning to Live More Sustainably

18. Man and Environment
• Natural Conservations
– Sacred Groves of India
– Water storage : Water reservoir
• Traditional methods of Agricultures
• Traditional Methods of fishing
• Ecosystem Balance

19. Traditional Man and environment
relationshipSacred Groves of India
• Traditional uses:
– Ayurvedic medicines.
– Replenish able resources like fruits and honey.
– The vegetation cover helps reduce soil erosion and prevents
desertification,
– Water requirements of local communities.
• Modern uses:
– biodiversity hotspots,
– Sacred groves often contain plant and animal species that have
become extinct in neighboring areas.
– sacred groves in urban landscapes act as "lungs" to the city as
well, providing much needed vegetation cover.
• Threats
– Urbanization, over-exploitation of resources
– Environmental destruction due to religious practices.
– Other threats to the sacred groves include invasion.
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20. Traditional Method of Farming
• Traditional Use
– Planting were coordinated with the
movement of plant and stars
– Harmony with the local Environment
and Seasons
– Cultivate large no of Crops varieties.
– Rotation of crop and Soil fertility
– Mixing sand, Slit and clay in right
proportion.
• Modern Use
– Heavy use of chemical and pesticides
– Local biodiversity affected
– Use of Vehicles.
• Treats
– Food security
– GMO Food
– Pesticides
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21. Traditional method of fishing
• Traditional
– Fishers have extensive knowledge
of oceans and fisheries
– Mesh size of the nets was
designed to catch only a particular
species, and among them only the
adult fish
• Modern
– Mechanized boats and later big
trawlers.
– Outsiders entered in the business
with the aim of cating as much fish
as possible
• Threats
– No regards for conservation of
resource.
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22. Impact of Science and technology on
the environment
• Invention of Engines and Automobiles
• Efficient machines were made for sawing and
felling trees.
• Cutting down the trees
• Invention of concrete building of dams, and
diversion of rivers water for agriculture and
power production
• Chemical fertilizer and pesticides
• Huge amount of ground water is extracted with
pumps

23. Environmental Degradation
What is environmental degradation? Let us understand it.
 It is the process by which our environment i.e., air, water and land, is
progressively contaminated, over- exploited and destroyed.
 When the environment becomes less valuable or damaged,
environmental degradation is said to occur.
 In specific term, environmental degradation is the deterioration of the
environment through depletion of resources such as air, water, soil and
forest; the destruction of eco-systems and the extinction of wildlife.

24. Causes of Environmental Degradation
Social factors
 Growing Population
 Poverty
 Urbanization
 Changing life style
Economic factors
 Agricultural Development
 Industrialization
 Economic Development

25. Growing Population
 Population is the greatest resource of any country and a major
contributory factor for development, and yet it is a major cause of
environmental degradation.
 As we find, the rapid pace of population growth has led to the excessive
utilization of natural resources.
 Huge population also leads to huge production of wastes.
 The resultant outcomes are loss of biodiversity, pollution of air, water and
soil and increased pressure on arable land. All these have been putting
great stress on the environment.

26. Poverty
 Poverty is said to be both the cause and effect of environmental
degradation.
 You may have seen that the poor people use natural resources more than
the rich.
 They use these for building their huts, for cooking, for their food and for
meeting many other needs.
 In this way they deplete these resources faster as they have no
opportunity of gaining access to other types of resources that are primarily
exploited by the rich.
 As we know, the more the resources are utilized, the more degraded the
environment becomes.
 The more the environment deteriorates, the more impoverished the poor
will be.

27. Urbanization
 You may have observed a large number of poor people from villages
moving to towns, cities and mega cities to earn their livelihood. This has led
to unplanned and rapid expansion of cities, creating enormous pressure on
the infrastructural facilities.
 If you live in a city, you may be experiencing these pressures on housing,
water and electric supply and sewage.
 You would be aware of the growing slums.
 Urban slums are major sources of pollution and suffer from the worst kind
of unhygienic conditions.
 The fast pace of urbanization has also been responsible for the depletion
of forests and irrational use of other resources.

28. Changing Life Style
 There has been a remarkable change in the style of living of people.
 This change is visible not only among the people living in cities and towns
but also among those who live in villages.
 The changing life style of people has enormously increased their level of
consumption.
 It has also resulted in the increase of human activities that are causing
serious damage to environment in many ways.
 It has contributed to air, water, sound, vehicular and industrial pollution.
 The fallout of the fast increasing use of modern gadgets like refrigerators
and air conditioners is the release of harmful gases in the atmosphere.
 This has been causing global warming which is very dangerous. In fact, due
to overuse of modern gadgets, harmful gases like carbon monoxide and
carbon dioxide
are released which lead to global warming

29. Agricultural Development
Agricultural development is so important for a country
like ours. But this has been affecting the environment adversely.

30. Biological interactions are the interactions
between organisms in a community.
In the natural world no organism exists in
absolute isolation, and thus every organism
must interact with the environment and other
organisms.
Inter relationship amongst living organisms
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31. There are six possible combinations, ranging from
mutually beneficial through neutral to mutually
harmful interactions.
The level of benefit or harm is continuous and
not separate, such that an interaction may be
trivially harmful through to deadly,
for example. It is important to note that these
interactions are not always static. In many cases,
two species will interact differently under
different conditions.

32. • There are six types of symbiotic relationships.
Parasitism +/-
Mutualism +/+
Commensalism +/0
Neutralism 0/0
Competition -/-
Predator/Prey +/-
• Each relationship can
be shown using + - or
0.
Effect on X Effect on Y Type of interaction
0 0 Neutralism
- 0 Amensalism
+ 0 Commensalism
- - Competition
+ + Mutualism
+ - Predation or Parasitism

33. Mutualism
• Mutualism—mutually beneficial
interaction between individuals of two
species (+/+).
• The contact between the two
organisms may be intimate or it may be
occasional or periodic.
• The best example for mutualism
relationships between animals, can be of
Egyptian plover and the crocodile. In the
tropical African jungles, the crocodile lies
keeping its mouth open.
• The plover flies in to the mouth of the
crocodile and eats the decaying meat
stuck in its teeth. The crocodile does not
eat the plover, but appreciates the free
dental care. This way, both of them are
benefited from each other.
Plover and Crocodile
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34. • Commensalism: Individuals of one species
benefit, while individuals of the other species
do not benefit and are not harmed (+/0).
• example is of a birds nest in a tree. The bird is
benefitting because the tree is giving the bird
shelter and the tree is not getting anything in
return.
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35. Parasitism: Parasitism is the
situation where one organism
benefits while the other is
harmed. A + / - relationship.
For example, mosquito is a
parasite, feeding on a human
while transferring the disease
called Malaria.
 Similarly, lice are an
example of parasitism
because they feed on blood
from the humans head.
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36. • Neutralism: is the situation where both species remain
unaffected A 0 / 0 relationship.
• A Bactrian Camel and a Longtailed Tadpole Shrimp, both living
in the Gobi desert
•
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37. • Amensalism: is a relationship in which a product of one
organism has a negative effect on another organism.
• The bread mold penicillium is a common example of this;
penicillium secrete penicillin, a chemical that kills bacteria.
• This antibiotic compound inhibits the growth of many species
of bacteria (in this picture, it's Staphylococcus aureus) by
interfering with the normal formation of peptidoglycan in the
cell wall.
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38. • A second example Allelopathy, in which some plants produce
chemical compounds that inhibit the growth of nearby would-
be competitors, is one type of amensalistic interaction is the
black walnut tree (Juglansnigra), which secrete juglone, a
chemical that harms or kills some species of neighboring
plants, from its roots.
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39. • Competition: can be defined as
an interaction between
organisms or species, in which
the fitness of one is lowered by
the presence of another.
• Limited supply of at least one
resource (such as food, water,
and territory) used by both is
required.
• Competition is one of many
interacting biotic and abiotic
factors that affect community
structure.
Male-male
interference
competition in
red deer.
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40. References/Sources
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43. Book/Web Resources
• Environmental Studies by R. Rajagopalan