The document defines environment and its components, including biotic elements like plants and animals and abiotic elements like air and water. It then discusses key concepts like ecosystems, which are communities of interacting living and non-living things in an environment. Ecosystems have biotic components like producers, consumers, and decomposers, as well as abiotic factors like temperature, water, and nutrients. Energy and matter flow through food chains and webs in ecosystems. Common ecosystems like forests, grasslands, deserts, ponds, and oceans are also outlined.

1. Definition
Environment can be defined as a sum total of all the living and non-living elements and their effects that
influence human life. While all living or biotic elements are animals, plants, forests, fisheries, and birds, non-
living or abiotic elements include water, land, sunlight, rocks, and air.
The Environment can be divided into four segments:
Atmosphere
Hydrosphere
Lithosphere
Biosphere
Ecology is the study of organisms and how they interact with the environment around
them.
Ecosystem :
The simplest definition of an ecosystem is that it is a community or group of living
organisms that live in and interact with each other in a specific environment.
Ecosystems can be small-scale, covering a small area such as a pond or large-scale
covering a large area such as a tropical rainforest.
The world is divided up into ten major ecosystems.
An ecosystem is a community of living organisms in conjunction with the nonliving
components of their environment things like air, water and mineral soil interacting
as a system.

2. • All the populations in a specific area at a given time a community includes populations of organisms of
different species.
• These biotic and abiotic components are regarded as linked together through nutrient cycles and energy
flows.
• As ecosystems are defined by the network of interactions among organisms, and between organisms and
their environment, they can be of any size but usually encompass specific, limited spaces although some
scientists say that the entire planet is an ecosystem.
• An ecosystem can be destroyed by a stranger.
• The stranger could be the rise in temperature or rise in sea level or climate change.
• The stranger can affect the natural balance and can harm or destroy the ecosystem.
• It is a bit unfortunate but ecosystems have been destroyed and vanished by man-made activities like
deforestation, urbanization and natural activities like floods, storms, fires or volcanic eruptions.

3. Structureofan Ecosystem
Living(Biotic) Components
Producers
Consumers
Decomposers
Non-living(Abiotic)Components
Physical factors
Chemical factors
Limiting factors

4. BioticComponentsof Ecosystems
Producers(or autotrophs)
Green plants and some bacteria which manufacture their ownfood.
Consumers(or heterotrophs)
Animals which obtain their food from producers
Primary consumers
Secondary consumers
Tertiary consumers
Decomposers
Bacteria and fungi that decompose dead organic matter and convert it
into simpler parts

5. AbioticComponentsofan Ecosystem
PhysicalFactors Rainfall
Sunlight
Humidity
Temperature
Nature of soil
Water currents
ChemicalFactors Salinity of Water
Nutrients present in soil
Oxygen dissolved in water
Percentage of water and air insoil
Food, water, shelter and space are
Limiting Factors
limiting factors for the growth of
population of human and
animals.

6. Classification of ecosystem

7. Kindsof Ecosystems
Natural Ecosystems Man-made Ecosystems
Terrestrial Ecosystems Aquatic Ecosystems
Fresh water Ecosystems Marine Ecosystems
Lentic Ecosystems
(Static water)
Lotic Ecosystems
(Running water)

8. Foodchainandfood web
Energy flow
Ecological pyramids
Functionsofan
Ecosystem(concepts)

9. FoodChain
The transfer of food energy from the source (plants) through a series of
organisms by repeated eating and being eaten up is referred to as food
chain.

10. FoodWeb
The interlocking pattern formed by several food chains that are linked
together is called a food web.

11. FoodChain
A series of organism
by repeated eating
and being eaten up
is referred as food
chain.
Types:
Grazingfoodchain-a
commonchain
Detritus food chain-
chain derived by the
organic wastes and
dead matter from
grazingfood chains
Theprocess ofeatingandbeing eaten

12. GrazingandDetritusFood Chain
Detritus (Deadorganicmatter)Food Chain
Grazing Food Chain

13. You will see the terms food chains and
food webs. They describe the same series
of events that happen whenone organism
consumesanotherto survive.

14. THEPRODUCERS
Producersarethebeginningofa
simplefoodchain.Producersareplants and
vegetables.

15. THEPRODUCERS
All energy comes from the
Sun and plants are the
ones who make food with
that energy. They use the
processof photosynthesis.
Plants
nutrients
also make
for other
organismsto eat.

16. Consumersarethe nextlink inafood
chain.Therearethreelevels of
consumers.

17. FEEDINGRELATIONSHIPS
Afood chain shows a simple feeding relationship.
Sun → grass → rabbit → fox
Note:All food chains start with the sun

18. All food chains start with
ENERGY from the sun

19. Foodweb
Intermixing of food chains

20. EnergyFlowin Ecosystems
First Lawof Thermodynamics: energy can neither be created nor
destroyed but only is transformed from one form toanother.
Second Law of Thermodynamics: the second law of
thermodynamics states that no energy transformations are 100%
efficient.
10 PercentRuleof Energy
As a rule of thumb, 90 percent of the energy involved is degraded
at each trophic transfer and only 10 percent of the energy is
conserved inthe organism's tissue.

21. EnergyFlowin Ecosystems

22. Energyflowinecosystem

23. Ecological Pyramid
The graphical representations of different trophic levels in an
ecosystem where producers occupy the base and the top
consumer occupy the apex of the pyramid, is known as ecological
pyramid .

24. Pyramidof Number
Pyramid of number is used to show the number of individuals in
each trophic level.
It is upright in case of grassland and pond ecosystems.

26. EcologicalPyramids
tertiary
consumers
secondary
consumers
primary
consumers
producers
75 g/m2
150g/m2
675g/m2
2000g/m2

27. Pyramidof energy
Pyramid of energy is used to show the amount of energy
transferred between trophic levels. It provides the best
representation of the overall nature of anecosystem.
The pyramid of energy flow is always upright because there is
always loss of energy while moving from lower trophic level to
higher trophic level.
The energy reaching the next trophic level is always less
compared to that in the previous trophic level.

28. EnergyPyramid
is

29. Ecological Pyramids
energy
lost
energy transferred

30. Studyofsomecommon ecosystems
Terrestrial ecosystem
Grasslandecosystem
Desertecosystem
Forestecosystem
Aquatic ecosystem
Pondecosystem
Oceanecosystem

31. Forest Ecosystem
A forest ecosystem consists of several plants, particularly trees, animals and microorganisms that live
in coordination with the abiotic factors of the environment. Forests help in maintaining the
temperature of the earth and are the major carbon sink.
AbioticComponents
Inorganic and organic substances found in the soil, climatic
factors, e.g., temperature, humidity, rainfall, and light.
BioticComponents
Producers
Different kinds of trees depending upon theclimate
Consumers
Different kinds of primary, secondary, and tertiary consumers, e.g.,deer, elephant, moles, snakes, lizards, lion,
and tiger
Decomposers
These are various kinds of bacteria andfungi

32. Grasslandecosystem
In a grassland ecosystem, the vegetation is dominated by grasses and herbs. Temperate grasslands and
tropical or savanna grasslands are examples of grassland ecosystems.
All grasslands in the world are categorize into the following two types:
Tropical grasslands- closets to equator and are hot throughout the year.
Temperate grasslands- farther from the equator and have both hot summers and harsh winters.

33. GrasslandEcosystem
Abiotic Components
climatic components, temperature, rainfall, light, etc.
BioticComponents
Producers
Mainly grasses with a few scatteredtrees
Consumers
Deer, rabbit, giraffe, etc., are herbivores,
while wolf, leopard, etc., are carnivores
Decomposers
Mainly bacteria and fungi

34. DesertEcosystem
Deserts are found throughout the world. These are regions with little rainfall and scarce vegetation.
The days are hot, and the nights are cold.
AbioticComponents
Low rainfall, high temperature, and sandy soil
BioticComponents Producers
Predominantly thorny shrubs, cactus, etc.
Consumers
Different insects, lizards, reptiles, nocturnal rodents, birds, etc.
Decomposers
Various bacteria and fungi

35. PondandOcean Ecosystem
AbioticComponents
It includes organic and inorganic substances, atmospheric gases
dissolved in water, minerals found in dissolved state, etc.
BioticComponents
Producers
Submerged floating and emergent aquatic plants For example, nelumbo,
hydrilla, chara, etc.
Consumers
Maybe primary, secondary, or tertiary, e.g.,small fishes, beetles, mollusca, crustaceans, etc.
Decomposers
Chiefly bacteria, actinomycetes, fungi,etc.

36. Aquatic Ecosystem
Aquatic ecosystems are ecosystems present in a body of water.
These can be further divided into two types, namely:
Freshwater Ecosystem
Marine Ecosystem
Freshwater Ecosystem
The freshwater ecosystem is an aquatic ecosystem that includes lakes, ponds, rivers, streams and
wetlands. These have no salt content in contrast with the marine ecosystem.
Marine Ecosystem
The marine ecosystem includes seas and oceans. These have a more substantial salt content and greater
biodiversity in comparison to the freshwater ecosystem.

37. Effects of human activities on environment
Humans are mainly responsible for the destruction of the environment.
The impacts of human activity on the environment are from the time of our very earliest ancestors.
Since then we have all been modifying the environment as per our convenience, and at this point, today,
we are losing all the valuable natural resources which cannot be gained back.
The human effects or the factors contributing to the loss of the environment are:
Pollution
Deforestation
Overpopulation
Disposal of wastes
Water Pollution:
Air Pollution
The exploitation of Marine Life:
Overuse Of Harmful Pesticides And Fertilizers:
Wastage of natural resources