Differences Among the Three Types of Ecological Pyramids

The concept of the ecological pyramids, also known as the Eltonian pyramids, was originated by ecologist Charles Elton. There are three ecological pyramids, each with three levels. Each pyramid is a pyramid-shaped diagram that depicts the number of organisms, total biomass and energy productivity at each level of the food chain.

Trophic Levels

• Each level of each pyramid represents a trophic level. Trophic levels are the levels of the food chain. The food chain, and therefore each ecological pyramid, begins with the lowest trophic level, the producers. Producers are grass and other plants that are fed upon by the next trophic level, the herbivores, which are in turn fed upon by carnivores.

Pyramid of Number

• The ecological pyramid of number concerns the number of each trophic level in an ecosystem. It begins with the most abundant organisms: the producers. The levels of the food chain continue up the pyramid, through each trophic level, as the total number of organisms decreases.

Pyramid of Biomass

• The pyramid of biomass plots the total mass of organisms in an ecosystem. Much like the pyramid of pyramid of numbers, it begins at the bottom with the producers (plants) and continues up through the food chain as the total mass of organisms decreases.

Pyramid of Energy

• As with the other ecological pyramids, the pyramid of energy begins at the bottom with the producers and works its way up the food chain. This pyramid, however, plots the total energy of an ecological system. Its purpose is to show the loss of energy in an ecosystem as the food chain progresses, with energy decreasing as the tropic levels progress.