By Rebecca Roberts • Updated Mar 24, 2022
A biomass pyramid visualizes the distribution of living organisms across an ecosystem’s trophic levels. At the base sit the producers—autotrophic plants that convert sunlight into chemical energy. Above them are primary consumers (herbivores), followed by secondary consumers, and so forth. In a typical system, each successive level contains fewer organisms, creating a triangular shape. An inverted pyramid occurs when higher trophic levels outnumber the lower ones, often reflecting limited primary production or high predator abundance.
Begin by cataloging the plants and animals that inhabit the system you wish to represent. Knowing which species occupy each trophic level will guide the size of each section.
Sketch the widest base of the pyramid to represent producers. Use shading or a label to indicate plant biomass.
Place the second layer directly above the base. This section should be smaller, illustrating the reduced biomass of herbivores.
Continue upward with a slightly narrower third level for secondary consumers.
The topmost, smallest section represents tertiary consumers—carnivores that feed on the animals below.
Include quantitative data—such as organism counts or biomass estimates—for each level to give the pyramid analytical depth.
