In this article we going to discuss about the Ecological Pyramids and it’s types so before we starting this come to the main point, The number, biomass and energy of the organisms in an ecosystem change gradually from producer level to the top consumer level.
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These gradual changes can be expressed in a triangular form. Such representations are called ecological pyramids.
Ecological pyramids are therefore the graphic representation of the number, biomass and energy at successive trophic levels in an ecosystem.
The idea of ecological pyramids was first given by Charles Elton (1927). (Student should note that, while forming an ecological pyramid, producers are always kept at the base. Consumers are always placed above the producer level).
There are three types of ecological pyramids: – (I) Pyramid of number, (ii) Pyramid of biomass and (iii) Pyramid of energy.
(I) Pyramid of numbers
- It shows the relationship among different trophic levels in terms of numberof individual
- in grassland ecosystem, producers are always higher in number and consumers are always lesser than producers. Hence in grassland ecosystem the pyramid of the number is always upright.
- In forest ecosystem also, the pyramid of number is upright as producers. (Trees and shrubs) are higher in number than consumers.
- pond ecosystem also, the producers (phytoplankton) are higher in number than Consumers (fishes etc). Hence pyramid of number in pond ecosystem is also upright.
- In parasitic food chain, the pyramid of number is inverted because producers are usually the host and they fewer in number than parasitic consumers.
(ii) Pyramid of energy
- The energy flows in an ecosystem from producer to Consumer level.
- At each trophic level 80 to 90 % energy 1s lost.
- Hence producers always have more energy than consumers.
- -Therefore, in each ecosystem, the pyramid of energy is always upright.
- SUN IS THE PRIMARY SOURCE OF ENERGY
Before we going to start the pyramid of biomass, first you have to know that, what is biomass? so well, let see
The total mass (dry weight) of all living components 1S called biomass. It can be expressed as)
- total biomass of ecosystem (if all living components of the ecosystem are
- biomass of trophic level (if all individuals of the same trophic leveled
- biomass of species (if the individuals of a particular species are included)
Pyramid of Biomass
- The pyramid that shows their relation among different trophic levels in terms of biomass, is called Pyramid of biomass.
- In grassland ecosystem, the pyramid of biomass is upright because the dry weight of plant and trees (producer) is more than that of consumers.
- In Forest ecosystem, also the pyramid of biomass is upright.
- In pond ecosystem, however, the biomass pyramid is inverted as producers in
- pond are light weighted phytoplankton. But consumers such as large fishes have more biomass.