Energy Pyramid

The four main trophic levels in an energy pyramid are:

1. Producers

Producers or autotrophs (grasses, green plants) occupy the first level or at the bottom of the energy pyramid.

2. Primary Consumers

The second trophic level is occupied by primary consumers or herbivores like grasshoppers that feed on primary producers for food and energy.

3. Secondary Consumers

The organisms occupying the third trophic level are known as secondary consumers. These organisms include carnivorous animals like frogs that feed on grasshoppers.

4. Tertiary Consumers

It is the last level of the energy pyramid consisting of organisms like owls, hawks, and foxes that consume both primary and secondary consumers for food. Only a mere 0.1% of the solar energy absorbed by producers reaches this level.

Quaternary Consumers

In some food chains, above the tertiary consumers are quaternary consumers or apex predators. They reside at the top of a food chain or an energy pyramid. Such organisms as humans, wolves, polar bears, lions, and tigers do not have natural predators of their own.

Sometimes a tertiary consumer is also the apex predator in the food chain.

Decomposers

Finally, decomposers also play an essential role in the ecosystem. They decompose the dead organic matter, wastes, and faces, thus helping to clean the environment. The breaking of organic matter provides nutrients to the soil that primary producers use to prepare food. It is the process of recycling energy in the ecosystem.

Grass, the primary producer, utilizes solar energy to produce their food, which grasshoppers, the primary consumer, eat. The grasshopper then transfers its energy to frogs, the secondary consumers. Frogs are eaten by snakes, the tertiary consumer in this food chain.

Upon death, the organic matter of the hawk is mineralized by decomposers, returning the nutrients to the soil. The producers can utilize the nutrients to continue the food chain.