Question

Why are the pyramids referred to as 'upright' or 'inverted'. Explain.

Answer 1

Pyramids are referred to as upright or inverted based on the number, biomass or any other factor that show gradation from producer to consumer level.

In an upright pyramid, producer occupies a broader base while successive trophic levels decrease in width or size due a decrease in the fact of under consideration. Like a pyramid of energy shows gradation with a broader base having a large amount of energy at producer level decreasing gradually towards successive levels.

Likewise, as in a pond ecosystem, the pyramid of biomass is inverted because biomass of fishes far exceeds the biomass of phytoplanktons. Producer this occupies a smaller base and consumers are more in biomass. The pyramid is inverted.