ENVIRONMENTAL STUDIES(ES)

ENVIRONMENTAL STUDIES

Lesson 12: Food chains, food webs and ecological pyramids

Ecological/food pyramids

All trophic levels together form the ecological pyramid. The graphical representation of the trophic structure and also trophic function is referred as “Ecological Pyramids”. In this, the first or producer level forms the base and successive levels make up the apex. A large number of organism’s i.e green plants from the most basic or first trophic level of the food pyramid. The herbivores that eat plants are at the second trophic level and are called primary consumers. The predators that feed on them form the third trophic level and are known as secondary consumers. Only a few animals form the third trophic level consisting of the carnivores at the apex of the food pyramid. Ecological pyramids may be of 3 general types

• Pyramid of numbers

• Pyramids of biomass

• Pyramids of energy