Why is the energy pyramid not a smooth geometric shape like a triangle but, rather, looks like narrow blocks stacked on top of wider blocks?

Question

Responses

A triangular pyramid would reflect a food pyramid rather than energy flow.
A triangular pyramid would reflect a food pyramid rather than energy flow.

The sizes of each shape show how much is consumed (or produced) at each level.
The sizes of each shape show how much is consumed (or produced) at each level.

Energy decreases at each level, and only 10% remains from the previous level.
Energy decreases at each level, and only 10% remains from the previous level.

Lower levels have far more individuals, so the shape reflects their population size.

Answer 1

The energy pyramid is structured with narrow blocks stacked on top of wider blocks primarily because energy decreases at each trophic level, and typically only about 10% of the energy is passed from one level to the next. This concept is often termed the "10% Rule" in ecology.

Thus, the correct response is:

Energy decreases at each level, and only 10% remains from the previous level.

This structure effectively illustrates the significant loss of energy as it moves up the trophic levels, which is why the upper levels are narrower compared to the wider and more energy-rich lower levels.