Trophic Pyramid

In order to visualize the available energy and biomass at each trophic level, ecologists use the pyramid model. At each trophic level, beginning with the primary producers on the bottom, a rectangle is made proportional to its value in that ecosystem. In terrestrial ecosystems, the energy and biomass pyramids decrease as each trophic level progresses. The primary producers have the most of both and the tertiary consumers are at the top with the least of both values. Aquatic ecosystems share a similar energy pyramid where the primary producers have the greatest amount and the tertiary consumers have the least. However, the biomass pyramid shows a different pattern. At the lowest trophic level, the primary producers, there is the least amount of biomass and as the trophic levels increase the biomass increases. This is known as an inverted pyramid. A pyramid such as this one occurs in aquatic ecosystems because the turnover rates of the primary producers are much higher. In terrestrial ecosystems, a lot of the biomass is inedible so the turnover rates are slower.