ECOLOGY
                      ECOLOGY 
ANALYTICAL MINDS
- A UNIT OF BHUBAN ENTERPRISES
CONTENTS:-   
1.. ●● ELEMENTS  OF  ECOLOGY
2.. ●● RELATIIONSHIIP--FEEDIING  &  SYMBIIOTIIC
3.. ●● FOOD  CHAIIN  &  FOOD  WEB
4.. ●● BIIOGEOCHEMIICAL  CYCLE
1.ELEMENTS OF ECOLOGY
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’.
1..2--WHAT  DO  YOU  MEAN  BY  
ENVIIRONMENT?
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)
1..3--COMPONENTS  OF  ECOLOGY
1.3.1-INDIVIDUAL:-
     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’.
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.)
1.3.3-COMMUNITY:-
  Several interacting populations that inhabit a 
common environment and are 
interdependent. 
1.3.4-ECO-SYSTEM:-
  Populations in a community and the 
abiotic factors with which they interact 
(ex. marine, terrestrial).
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.  
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
1.3.7-NICHE vs HABITAT:-
Habitat- In ecology the 
Niche – Niche is the role a term ‘habitat’ is used to 
species plays in a denote the place where 
community; its total way of organism or species 
life . A niche is determined 
by the tolerance limitations population live.
of an organism, or a limiting Example-A pond is the 
factor.  habitat of zooplankton 
and fish.
Limiting factor- any biotic or 
abiotic factor that restricts 
the existence of organisms 
in a specific environment. 
Example-amount of water, 
food , etc. 
2.RELATIONSHIP-FEEDING AND 
SYMBIOTIC
2.1-FEEDING 
RELATIONSHIPS:-
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.
2.2-FEEDING RELATIONSHIP CHART:-
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.
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.
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.
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.
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’.
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.
2.3-:-
2.4-TYPES OF SYMBIOSIS:-
SYMBIIO
SIIS
MUTUALIIS
M
PARASIITIISM COMMENSA
LIISM
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.
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.
2.4.3-MUTUALISM:-
‘Mutualism’ is the type of symbiosis which is 
beneficial to both species.
Example- Cleaning birds on Hippopotamus , 
Rhinoceros ,etc.
3.FOOD CHAIN & FOOD WEB:-
3.1-Food Chains
3.2-Food Web
3.3-Tropic Levels
3.1-
 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.
DESERT 
FOOD CHAIN


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’.
MARINE FOOD WEB



MARSH VEGETATION FOOD WEB
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.
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.
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.
4.
4.1-  The Carbon Cycle
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.
The  Carrbon  Cyclle
4.2 – The Phosphorous Cycle
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.

4.3 – The Nitrogen Cycle
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’.

4.4 – The Water Cycle
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’.
Watterr  cyclle
4..5  –  The  Oxygen  Cycle
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.
The  Oxygen  Cyclle
THE END!
PRESENTATION CREDITS
•DR. TATHAGATA DEB
•MR. SHIVAM SAHA
ANALYTICAL MINDS
- A UNIT OF BHUBAN 
ENTERPRISES