All About Different types of Ecological pyramid

1. Ecological
Pyramids
A Key To Understanding The Structure And Function Of
Ecosystems

2. - Prof. Dayanjali Thakkar Jay Bhosle [ 17MECH013 ]
 Shethwala Mohd Shafi M.Shoeb [17mech014]
 Jayesh Nakiya [ 17MECH015 ]

3. Contents…….

4. ►Ecological pyramids are graphical representation of the
trophic of the trophic structure of ecosystem.
►Trophic Levels are the feeding position in a food chain
such as primary producers, herbivore, primary
carnivore, etc.

5. Types of Ecological Pyramid
 Three types of ecological pyramid can usually be
distinguished namely :-
1 ) Pyramid of Numbers
2 ) Pyramid of Biomass
3 ) Pyramid of Productivity

6. ► Is The Graphic Representation Of Number Of Individuals Per
Unit Area Of Various Trophic Levels.
► Large Numbers Of Producers Tend To Form The Base.
► Lower Numbers Of Top Carnivores Occupy The Tip.

7. Evaluation of Pyramid of Number
ADVANTAGES
• Simple easy method (number
counting) of giving an overview
• Good for comparing changes to
the ecosystem at different times of
year e between seasons
DISADVANTAGES
• Numbers of a specific species can be
too great to measure accurately
• Does not take into account juveniles'
or immature forms
• All organisms are included regardless
of size, hence inverted pyramids

9. Pyramid of Numbers - Example
Θ The shape of the pyramid of numbers vary from
ecosystem to ecosystem.
Θ In aquatic ecosystems and grassland
communities, autotrophs are present in large
numbers per unit area.
Θ They support a lesser number of herbivores,
which in turn support fewer carnivores.

12. Evaluation A Pyramid Of Bio-mass
ADVANTAGES
 Overcomes the problems of
Pyramids of number
DISADVANTAGES
 Only uses samples from populations,
so difficult to measure biomass
exactly.
 Time of year that biomass is
measured influences result e.g. trees
in summer.
 Organisms of the same size do not
necessarily have the same energy
Content

13. Pyramid of Biomass
 Is the graphic representation of biomass
present per unit area of different trophic
levels, with producers at the base and
top carnivores at the tip.
 Biomass is calculated by the mass of
each individual x number of individuals
at each trophic level.

15. Inverted Pyramid of Biomass
In an aquatic habitat the Pyramid of biomass
is inverted or spindle shaped where the
biomass of trophic level depends upon the
reproductive potential and longevity of the
members

17. Pyramid of Productivity
Pyramid Of Productivity Is A Graphic Representation Of
The Flow Of Energy Through Each Trophic Level Of A
Food Chain Over A Fixed Time Period. The Input Of
Solar Energy May Be Indicated As An Extra Layer At
The Base.

19. Only 10% of the energy is available to next trophic
level ( as per Lindeman's ten percent rule)

20. PYRAMID OF
PRODUCTIVITY
Advantages
No inverted pyramids
are obtained.
Shows actual energy
transferred and allows
for rate of production
Disadvantages
It is difficult and complex
to collect energy data
(rate of biomass
production over time).
Problem always exists in
assigning a species to a
specific trophic level.

21. Bioaccumulation :- when plants animals
take up a chemical from the environment
and do not excrete it The chemical builds
up in the organism over time to a
potentially lethal level.
Consequences of Ecological Pyramids and
Ecosystem function

22. Bio-magnification :- refers to the sequence of processes
that results in higher concentrations of the chemical in
organisms at higher levels in the food chain (at higher
trophic levels). In this way the chemicals
concentration is magnified from trophic level to
trophic level. The concentration of the chemical may
not affect lower levels of the food chain but the top
levels take in so much it can cause disease or death.
Consequences of Ecological Pyramids and
Ecosystem function

23. There are many pollutants like the DDT
that are not bio- degradable. These
accumulate in the organisms and cause
serious health problems. The
contamination of water with these
pollutants results in their entry into the
microscopic plants and animals. These
organisms are fed upon by higher aquatic
life like the fish. The fish in turn are fed
upon by the land animals including man.
Thus, the pollutant reaches the body of man. At each step in the
food chain, the contaminant increases in quantity. This is because a
fish feeds on large quantity of smaller plants and man eats fish.
These contaminants like DDT remain in the fats and are not
degraded in the body. Over the years the amount of DDT increases
in the body. This is called bio-magnification.