The document provides an extensive overview of ecology, defining key concepts such as organisms, populations, communities, ecosystems, and biomes, as well as discussing symbiotic relationships among species. It outlines various feeding relationships and the roles of different groups of organisms, including producers, consumers, and decomposers. Additionally, it describes essential biogeochemical cycles including the carbon, phosphorus, nitrogen, water, and oxygen cycles, highlighting their significance in ecosystem functioning.

1. ECOLOGY
ANALYTICAL MINDS
- A UNIT OF BHUBAN ENTERPRISES

3. 1.ELEMENTS OF ECOLOGY

4. 1.1-WHAT IS ECOLOGY?
Ecology- the scientific study of interactions
between “organisms and their environments”,
focusing on energy transfer
Ecology is a science of ‘relationships’.

5. 1.2-WHAT DO YOU MEAN BY
ENVIRONMENT?
The environment is made up of two factors:
 Biotic factors- all living organisms inhabiting the
Earth
 Abiotic factors- nonliving parts of the environment
(i.e. temperature, soil, light, moisture, air
currents)

6. 1.3-COMPONENTS OF
ECOLOGY

7. It is the lowest level of
organization.
Any unicellular or multicellular form
exhibiting all of the characteristics of
life, an individual is known as an
‘Individual’ or ‘Organism’.

8. 1.3.2-POPULATION:-a group of organisms of ‘one species’ living
in the same place at the same time that
‘interbreed’.
Produce ‘fertile’ offspring
‘Compete’ with each other ‘for ‘resources’
(food, mates, shelter, etc.)

9. 1.3.3-COMMUNITY:-
Several interacting populations that inhabit a
common environment and are interdependent.

10. 1.3.4-ECO-SYSTEM:-
Populations in a community and the abiotic
factors with which they interact (ex.
marine, terrestrial).

11. 1.3.5-BIOME:-
 A ‘Biome’ is a specific area characterized by the
animals and plants that live within it , the climate
conditions , the amount of water available , the
soil conditions , and the location of the area.

12. 1.3.6-BIOSPHERE:-
 ‘Biosphere’ is the life supporting portions of
Earth composed of air, land, fresh water, and
salt water.
• The highest level of organization

13. 1.3.7-NICHE vs HABITAT:-Niche – Niche is the role a
species plays in a
community; its total way of
life . A niche is determined
by the tolerance limitations
of an organism, or a limiting
factor.
Limiting factor- any biotic
or abiotic factor that
restricts the existence of
organisms in a specific
environment.
Example-amount of water,
food , etc.
Habitat- In ecology the
term ‘habitat’ is used to
denote the place where
organism or species
population live.
Example-A pond is the
habitat of zooplankton and
fish.

14. 2.RELATIONSHIP-FEEDING
AND SYMBIOTIC

15. The relationship in the
feeding mechanism
of the living
organisms is known
as the feeding
relationship.
The main type of feeding
relationship is of
Producer & Consumer.

16. 2.2-FEEDING RELATIONSHIP
CHART:-

17. 2.2.1-TOP CARNIVORES or
TERTIARY CONSUMERS:-
 Those organisms that feed on the primary
consumers and can be purely carnivorous and
occupy the topmost position in the feeding
relationship of the eco-system is known as ‘Top
carnivores’ or ‘Tertiary Consumers’.
 Example-Tiger , Lion , etc.

18. 2.2.2-CARNIVORES or
SECONDARY CONSUMERS:-
 Those organisms that feed on the primary
consumers and can be purely carnivorous and
occupy the position right below the ‘Top
Carnivores’ in the feeding relationships of the
eco-system is simply known as the ‘Carnivores’ or
‘Secondary Consumers’.
 Example-Polar Bear , Hounds , etc.

19. 2.2.3-OMNIVORES or
SECONDARY CONSUMERS:-
 Those organisms which feed on both plants and
animals are known as the ‘Omnivores’.
 Example-Bear , lizards , small fish , etc.

20. 2.2.4-HERBIVORES or
PRIMARY CONSUMERS:-
 Those organisms that feed directly on green
plants and are purely Herbivorous are known as
‘Herbivorous’ or ‘Primary Consumers’.
 Example-Cow , Buffalo , Deer , etc.

21. 2.2.5-PRIMARY PRODUCERS:-
 All ‘autotrophs’ i.e. Plants , that trap energy from
the sun and by the help of a green pigment
‘chlorophyll’ found in them produces food is known
as ‘Primary producers’. The method of producing
food (consumable energy) from the sun’s energy is
known as ‘Photo-synthesis’.

22. 2.2.6-
DECOMPOSERS:-
The organisms that is
responsible for the
breakdown of the
complex compounds of
dead and decaying
plants and animals into
simpler molecules that
can be absorbed by the
‘Primary Producers’ is
known as ‘Decomposers’.
In other words they
breakdown the dead
producers and
consumers and release
the energy back into
circulation in the
environment.

23. 2.3-:-

24. 2.4-TYPES OF SYMBIOSIS:-

25. 2.4.1-COMMENSALISM:-
‘Commensalism’ is the type of Symbiosis in which
one species benefits and the other is neither
harmed nor helped.
Ex. Epiphytes(A plant, such as a tropical orchid or a
bromeliad, that grows on another plant upon which
it depends for mechanical support but not for
nutrients. Also called xerophyte, air plant. ),
orchids on a tree , etc.

26. 2.4.2-PARASITISM:-
‘Parasitism’ is the type of symbiosis in which one
species benefits (parasite) and the other is
harmed (host).
 Parasite-Host relationship.
 Example-Tapeworm found in Human body, leeches
found in animals body , etc.

27. 2.4.3-MUTUALISM:-
 ‘Mutualism’ is the type of symbiosis which is
beneficial to both species.
 Example- Cleaning birds on Hippopotamus ,
Rhinoceros ,etc.

28. 3.1-Food Chains
3.2-Food Web
3.3-Tropic Levels

29.  A food chain shows the
feeding relationship between
different living things in a
particular environment
or habitat.
 Plants are the bottom of a
food chain because they are
autotrophs that make their
food from the non-living
environment. Organisms that
can make their own food are
called ‘Producers’.
 ‘Consumers’ are animals that
eat producers or other
animals. So they come
second in the chain.

30. DESERT
FOOD
CHAIN

33. 3.2-FOOD WEB
 Food Web is a
representation of
interconnected food
chains of a certain
biome.
 The adjacent figure
shows the ‘soil food
web’.

34. MARINE
FOOD WEB

38. WEB

39. 3.3 -
TROPIC LEVELS
 Each link in a
food chain is
known as a
tropic level.
 Tropic levels
represent a
feeding step in
the transfer of
energy and
matter in an
ecosystem.

40. TROPIC LEVELS-IT’s CONNECTION WITH
FOOD CHAINS & FOOD WEB
 Food chain- It is a
simple model that
shows how matter
and energy move
through an
ecosystem and it’s
each stage simply
defines a tropic
level.
 Food web- It shows
all possible feeding
relationships in a
community at each
tropic level.

41. ENERGY TRANSFER IN
TROPIC LEVELS:-
Biomass- It is the amount
of organic matter
comprising a group of
organisms in a habitat.
 As you move up a food
chain, both available
energy and biomass
decrease.
 Energy is transferred
upwards but is
diminished with each
transfer.

42. 4.

43. The ‘Carbon Cycle’ is the biogeochemical cycle
by which carbon is exchanged among the
biosphere , pedosphere , geosphere ,
hydrosphere and atmosphere of the earth.
It simply describes the movement of carbon as
it is recycled and reused throughout the
biosphere including carbon sinks.

44. The Carbon Cycle

45. The ‘Phosphorous Cycle’ is the biogeochemical cycle
that describes the movement of phosphorous
through the lithosphere , hydrosphere and
biosphere.
Unlike many other biogeochemical cycles , the
atmosphere does not play a significant role in the
movement of phosphorous , because phosphorous and
phosphorous based compounds are usually solids at
the typical ranges of temperature and pressure
found on earth.
Soil microorganisms act as both sinks and sources of
available P in the biogeochemical cycle and locally the
transformations of P are chemical , biological and
microbiological.

47. The nitrogen cycle is the biogeochemical
cycle by which nitrogen is converted into
various chemical forms as it circulates
among the atmosphere and terrestrial and
marine ecosystems.
The conversion of nitrogen can be carried
out through both biological and physical
processes.
Important processes in the nitrogen cycle
include ‘fixation’ , ‘ammonification’ ,
‘nitrification’ and ‘denitrification’.

49. The water cycle also known as the
hydrological cycle or the hydrologic
cycle , describes the continuous
movement of water on , above and below
the earth surface.
The physical processes carrying out
water cycle are ‘Evaporation’ ,
‘Condensation’ , ‘Precipitation’ ,
‘Infiltration’ , ‘transpiration’ ,
‘Condensation’ , ‘Percolation’ and
‘Surface runoff’.

50. Water cycle

51. The oxygen cycle is the biogeochemical
cycle of oxygen with its three main
reservoirs : the atmosphere(air) , the
total content of biological matter within
the biosphere(the global sum of all
ecosystems) , and the earth’s crust.
The main driving factor of oxygen cycle
is photosynthesis , which is responsible
for the modern earth’s atmosphere and
life on earth.

52. The Oxygen Cycle

53. THE END!

54. •DR. TATHAGATA DEB
•MR. SHIVAM SAHA
ANALYTICAL MINDS
- A UNIT OF BHUBAN ENTERPRISES