Pyramid of Biomass

A pyramid of biomass is used to indicate or represent the flow of energy between different organisms (Producers and consumers) or to indicate the total biomass present at different trophic levels in an ecosystem. It represents the relationships between numbers, biomass, energy, and bio productivity of different trophic levels. It is also known as the ecological pyramid or the Eltonian pyramid.

Biomass is the amount of organic matter present in any living organism. It is calculated as the mass of living organisms present at each trophic level in a given sample size. Biomass is calculated by multiplying the biomass of the organisms with the number of living organisms present at each trophic level. Biomass is expressed in two ways, either in Dry weight in grams or calories per unit area.

Biomass decreases with an increase in trophic levels because the biomass of green plants is much higher than that of primary consumers. The biomass of primary consumers is higher than that of secondary consumers, and the same goes for tertiary consumers. To create an ecological pyramid, you need to follow some basic concepts of it:

• The producers will always be at the bottom of the pyramid. Tree, grass, phytoplankton, shrubs are the producer or primary producers. The producers only consume air and sunlight to make the energy. They do not depend on any other living organism; instead, they depend on the dead organisms and gain nutrition and necessary minerals from their dead bodies.
• The primary consumers lie between the producers and the secondary consumers in the pyramid. The herbivores animal (insects, deer, cows, goats, rabbits, and many more) are the primary consumers. They eat or consume green plants to make energy for their living.
• The secondary consumers lie between the primary and tertiary consumers in the ecological pyramid. Frogs, birds, foxes, snakes are the secondary consumers and consume primary consumers to make energy.
• The tertiary consumers lie at the top of the pyramid. The carnivore animals are the tertiary consumers. Lion, Bear, Tiger, Leopard, cheetah are some examples of tertiary consumers. The tertiary consumers completely depend on the numbers of primary and secondary consumers. If primary and secondary consumers disappear from the ecosystem, then the tertiary consumers will also disappear soon.

Pyramid of Biomass Examples

As we know, the biomass of the pyramid represents the energy flow between different trophic levels. In the pyramid of the grassland ecosystem, the biomass decreases with the increase in trophic levels, but for the marine ecosystem, it is not true. The pyramid of biomass for the marine ecosystem is inverted or upright as the biomass increases with the increase in trophic levels. We need to understand the behaviors and differences between the marine and grassland ecosystems. To understand the reason for the inverted pyramid of the marine ecosystem.

Let's see the example of the pyramid of biomass for the grassland ecosystem.

As we have already discussed, the plants or the producers occupy the base of the pyramid. Then primary consumers (rats, rabbits, goats, etc.) take second place in the pyramid, followed by secondary consumers (snakes, birds, lizards, etc.) and then followed by tertiary consumers (Lions, tigers, bears, etc.)

As we know, biomass is calculated by multiplying the mass of the organism and the number of organisms present at each trophic level. It gives the pyramidical shape for the representation of energy flow. We can observe the biomass of producers is much higher than that of primary consumers and decrease further sequentially from secondary to tertiary consumers.

Example of a Pyramid of Biomass for the marine ecosystem:

The pyramid of Biomass of Marine Ecosystem or Aquatic Ecosystem is inverted shows the oppositive behavior from the grassland ecosystem. This is due to the biomass of producers (phytoplankton)being much less than that of primary consumers. The biomass of primary consumers is much less than secondary and tertiary consumers.

One question that arises from this is how the producers in fewer quantities can provide sufficient energy flow in the marine ecosystem?

This is due to high reproducibility and less lifespan of producers and primary consumers. At any point in time, their biomass is much less than the biomass of primary consumers. Still, they can reproduce them in a shorter period, and a larger quantity is required for primary and secondary consumers and balance the energy requirement of the marine ecosystem.