This document provides information about ecosystems and natural resources. It defines ecosystems as interacting systems consisting of organisms and their environment. It discusses different types of ecosystems like terrestrial and aquatic ecosystems. It also explains key ecosystem functions like photosynthesis, energy flow, and material cycling. Additionally, it covers topics like food chains, ecological pyramids, renewable and non-renewable resources, and the importance of conserving natural resources for future generations.

1. Environment Management
ecosystem

2. Name Of Members
Shivam
Ravi
Jai
Simarpal
Jaskaran
Himanshu
Roy
Navil
Vikas
Petrick
Imran
Pranav
Shikha
Poonam
Vignesh
Nilofer

3. Meaning Of Ecosystem
• The term ecosystem was first used by A.G.Tansley in 1935. He defines the term
‘ecosystem’ as “a particular category of physical systems consisting of organisms and
inorganic compounds in a relatively stable equilibrium, open of various sizes and
kinds.”It is comprised in two major parts i.e. Biome (the whole complex of plants and
animals of a particular spatial unit) & Habitat (physical environment)
• The example of a fish in the lake or a tree in the forest indicate clearly that if we want to
understand the living of different organisms and their habitats properly, then we must
not considered them in isolation. We must consider them as a part of an interacting
system.
• The examples of natural ecosystems are ponds, lakes, grassland, desert, etc. In these
ecosystems the biotic and the a biotic environment interact in different ways and work
like a system. Biosphere in other words is said to be the parts of Earth where
atmosphere, the hydrosphere and lithosphere have met through which life has become
possible.

4. Kinds of Ecosystem:
Ecosystems
Natural Ecosystem
Terrestrial
Aquatic
Fresh water
Marine
Artificial Ecosystem

5. •

6. Functions of Ecosystems:
• Functions of any ecosystem mainly refer to the interaction between biotic
and a biotic components.The primary interactions between these two
components are influenced by the ultimate source of energy i.e. Sunlight.
Functions of
Ecosystems
Photosynthesis Energy Flow Material Cycling

7. Energy Material Flow:
• The most important feature of all ecosystems is the flow of energy because
ecosystems depend on a steady and regular supply of energy to maintain
structural organization and carry out all life preserving activities.
• The most important step to provide energy for all the organisms in the
ecosystem is the ultimate source of energy i.e. Sun.The average energy
reaching on the earth surface is about 2 cal/ Out of this huge solar energy
only about 5% solar energy is converted into chemical energy by plants.

8. Continued…….
• The initial conversion of solar energy into chemical energy by the primary
producers is the most important step in providing energy for all other living
organisms in any ecosystem.The movement of energy is through the
process of eating. No energy can be created or destroyed.
• The energy from the sun is used up by plants.This energy is transmitted to
the herbivores, and further is transferred to carnivores.Then the dead
bodies are consumed by the scavengers and microorganisms present in the
soil.The dead organic matter is consequently released into the soil in the
form of nutrient pool.The matter provided by nutrient pool is used by
plants in the manufacture of food. Hence, it can be seen that energy flow is
unidirectional but material flow is cyclic in nature.

9. Food Chain and FoodWeb:-
• The point where food energy is transferred from one group of organisms to
the other group is known as tropics level.
• A simple sequence of organisms such as a plant, an insect, etc. which feed on
one another, form a food chain.
• Plants form primary tropics level, the insects form the herbivore tropics level,
the snake eating frog form the carnivore tropics level and a bird eating a
snake form the top order tropics level.
• Many food chains operate simultaneously. Many times these food chains are
connected to each other. Example plant may form food for many herbivores,
which in turn may form food for carnivores and so on. Hence, these food
chains are interconnected to form a food web. It is very complex.
Plants Herbivore Carnivore (first) Carnivore (second)

10. Ecological Pyramids:
• It refers to the representation of trophic level and functions of an ecosystem
graphically. These are three types of ecological pyramids:-
Pyramid of Numbers Pyramid of Biomass Pyramid of Energy
It depicts the number of
organisms at each trophic
level. The pyramid may be
inverted or upright.
It is based on total biomass at
each trophic level in a food
chain. The pyramid may be
inverted or upright
It depicts the amount of
energy present at each trophic
level. This pyramid is always
upright.

11. Characteristics of Resources:
• A substance is merely part of nature until a society has a use for it. Consequently a natural
resource is defined by three elements of society:
a) A society’s cultural values influence people’s decision that a commodity is desirable and
acceptable to use.
b) A society’s level of technology must be high enough to use the resource.
c) A society’s economic system affects whether a resource is affordable and accessible.
• Let us consider petroleum as an example of a natural resource in North America:
• CulturalValues: North Americans ant to drive private automobiles rather than public
transports.
• Technology: Petroleum is the preferred fuel in private automobiles because these are easily
powered by gasoline engines.
• Economic system: North Americans are willing to pay high enough prices for gasoline.
• The same elements of society apply to the study of any example of a natural resource i.e
Rice to the Japanese, Diamonds to the South Africans, Forests to the Brazilians, and air
quality to Los Angeles. A combination of three factors is necessary for a substance to be
valued as a natural resource. Differences in these three factors help geographers to
understand why a resource may be valuable in one place and ignored elsewhere.

12. Types of Resources:
• A natural resources can be of the following types:
i. Biotic and A biotic resources.
ii. Renewable or Flow and Non-Renewable resources or fund.
Biotic Resources Abiotic Resources
A biotic resource is the resource which is
directly or indirectly derived from
photosynthetic activity of green plants. For
example Food fruits, wood, fibre, milk and
milk products, fish meat, leather,etc.are termed
as biotic resource. Coal, oil and natural gas
are also biotic resource as they were produced
by photosynthetic activity of plants which
occurred millions of years ago.
Mineral material, fresh water, rocks, salts, and
chemical, etc. are termed as abiotic resources
as biological activity is not involved in their
formation.

13. Continued………..
Renewable or flow resources Non-renewable resources
They are replaced continually at least
within a human lifespan and can be
regenerated. These resources have the
capacity to replenish or renew by
themselves. Solar energy, air, wind, water,
trees, grain, livestock are some examples.
They form so slowly that for practical
purposes they cannot be replaced when
used i.e they cannot be regenerated once
they are exhausted. Coal, oil, gas and ores
of uranium, aluminium, lead, copper iron,
etc. are some examples.

14. Limitations of Renewable resources:
• Most of the biotic resources which are developed as a result of only recent
photosynthetic activity of green plants are renewable in nature. The biosphere
constitutes an excellent life support system which can fulfill all human needs. But
its size and productivity is limited by availability of water, nutrients and
environmental conditions.
• Though an enormous quantity of water is present on our planet, for fresh water life
depends largely on precipitation, which too is available only in a finite quantity
annually. Its uneven distribution over earth’s surface has caused large surface area
to become deserts. A large part on earth’s surface is too cold or rocky for any
productive use, whereas a large area has to be devoted to forests and wildlife which
due to their obvious importance cannot be curtailed beyond certain limits.This
leaves only a limited area at our disposal for agriculture and pastures.
• Growing more and more from the same crop fields involves expensive use of
fertilizers, energy input, irrigation and high yielding varieties. Global livestock and
fisheries resources can also not be expanded beyond certain limits. It is only upto a
limited extent that resources of biosphere can be safely exploited. Over exploitation
tends to damage the biotic system and thereby the overall productivity. It could
cripple the very resource base which is so important to our existence.They cannot
be stretched beyond a certain limit. With careful management this limit can be
enlarged.

15. Finite Nature of Natural Resources:
• Neither energy nor matter can be created or destroyed. No one, howsoever
advanced technology, can create something out of nothing nor can anything be so
discarded as to become nothing. A constant flow of materials is needed to maintain
living beings, a society, or an economy which must come from somewhere, whereas
a continuous stream of wastes discarded has to go somewhere.The total amount of
matter present on our planet is fixed except for cosmic particles entering and some
gases leaving from outer atmosphere.This has been so throughout the known
history of our planet the elemental composition of earth’s atmosphere, hydrosphere
and the lithosphere is fixed, stable and known.
• The enormous changes which take place everyday involve changes in the state,
mix and distribution of materials on earth.Volcanoes erupt, emit lava, ash and
gases, create new islands or bury cities. Each year man extracts billions of tons of
materials and fuels from earth, transforms them chemically creating new molecular
combinations which never existed before. All these activities require energy, which
comes only from just two sources – the incoming solar radiations and the residual
heat of earth’s core. Fusion energy is the only source of energy which man has not
been able to harness till date.

16. Continued………
• In other words, as far as matter is concerned, our planet is nearly a closed
system – nothing enters or leaves it. It regularly receives large amounts of
energy from sun, much of which has to be re-radiated back to space in order
to maintain a heat balance. Therefore, mankind’s immediate environment,
the planet earth, is limited in size and space as well as in its material
resources.There is a constant entry of energy into the system as solar
radiation, however, material resources of our planet are fixed in quantity
and have to be used again and again in a cyclic fashion.

17. Conservation of Resources:
• Conservation may be defined as “careful and rational use of resources and their
preservation from reckless exploitation and destruction. It means judicious use of
resources to preserve for future needs. It includes control and management of
resources in such a way that they will be useful to man forever.”
• Excessive exploitation, high rate of consumption and misuse, etc. are considered as
dangerous as it would lead to their depletion. Rapid growth of population during
the last 100 years and rising standard of living and per capita income are likely to
increase the rate of exploitation and consumption of many natural resources.
Conservation of exhaustible resources is very urgent need of the time.
• For example “power resources like coal or oil, once we burn, it vanishes. It cannot be
used again. Conservation of such resources therefore, is must, otherwise within next
few hundred years, there would not be any coal or oil, left for the future economic
development.Such resources must be used only when their use is most essential, or
we must find out substitutes for them so that we can use them for longer time.”

18. Methods of Conservation of Some Resources:
Soil
Natural Vegetation
Minerals
Water

19. Wealth:
• Wealth is goods and services owned. In popular usage “wealth” can be described as
an abundance of items, usually in the form of money, real estate and personal
property. An individual who is considered wealthy, affluent, or rich is someone who
has accumulated substantial wealth relative to other in their society or reference
group.
• In economics, wealth refers to the value of assets owned minus the value of
liabilities owned at a point in time.Wealth can be categorized into three types i.e
Personal property, including homes or cars, money savings and the capital wealth of
income producing assets, including real estate, stocks, bonds, etc.
• Wealth refers to accumulation of resources ‘Richness’ refers to abundance of such
resources.A rich individual or community or country, thus has more resources
than a poor one The concept of wealth is relative. For example a person with US
$10,000 in USA may not be considered as wealthy person but “a person with same
amount in countries like Bangladesh will be considered as wealthy person.”

20. Man and Global Resources:
• Systematic exploitation, modification and destruction of natural
ecosystems began right from the time when man learned to use fire,
domesticate animals and grow plants for food. Man’s interaction with the
environment can be divided into three phases.These are the phases:
I. The phase of food gathering and hunting.
II. The phase of plant and animal domestication, pastoralism and settled
agriculture.
III. The phase of science, technology and industrialization.