Ecological Pyramid

 Ecological Pyramid

3 types of ecological pyramids based on what it represents are:
1. Pyramid of number
2. Pyramid of biomass and
3. Pyramid of energy

Pyramid of numbers

The number of individuals at the trophic level decrease from the producer to the consumer level. In croplands the crops are more in numbers. The grasshoppers feeding on crop plants are lesser in number. The frogs feeding on grasshopper are still lesser in number. The snakes feeding on frogs are fewer in number.

In grassland the grasses are large in numbers. The consumers decrease in the following order.

Crops  - > Grasshopper  - > Frogs  - > Snakes  - > Hawks.
 

2.Pyramid of biomass

Biomass refers to the total weight of living matter per unit area. In an ecosystem the biomass decreases from the producer level to the consumer level.
In grassland the biomass of grasses is the maximum and it gradually decreases towards the consumer level.
Grass -> Grasshopper  -> Garden Lizard  -> Hawk.
Grass -> Mouse  ->      Snake  -> Hawk.
Crops- > Grasshopper- > Frogs - > Snakes  - > Hawks.
In a forest, the biomass of trees is the maximum and the top consumer is the minimum. The decrease in weight occurs in the following order.
Plants ->    Deer   ->     Fox   -> Tiger.
Plants ->    Rabbit  ->   Fox   -> Lion

 
3. Pyramid of energy 
In an ecosystem, the energy flow from the producer to the consumer level will be decreasing. In grassland, grass plants trap the maximum sun light energy. The energy gradually decreases towards the top consumer level. The chemical energy is transformed into kinetic energy.
Grass -> Rabbit  -> Fox  -> Lion.
Grass -> Grasshopper  -> Garden Lizard  -> Hawk.
Grass -> Mouse  -> Snake

The graphical representation of different trophic levels in an ecosystem is known as ecological pyramid. When it is arranging the number of organisms or the biomass or the energy level of an ecosystem in an order from top to bottom or vice versa, automatically it will form the shape of a pyramid. At the bottom level of the pyramid will be the autotrophs or producers and tertiary consumers at its apex. Pyramid may be represented either in the form of triangle or rectangle. The area of each segment of pyramid will be proportional to the number or biomass or energy level of that ecosystem.