ZingPath: Flow of Energy in an Ecosystem

Name and describe three types of ecological pyramids.

~ Energy pyramids - Each level of an energy pyramid shows the energy that is available within that level, called a trophic level. The energy decreases from the lowest trophic level to the highest.

Pyramids of numbers - Each level in a pyramid of numbers represents the number of organisms consumed by the level above it.

Biomass pyramids - Biomass pyramids show the total amount of mass of the organisms in each trophic level. The amount of biomass decreases from the lowest trophic level to the highest.

How are all the ecological pyramids similar?

~ In all the ecological pyramids, producers (organisms that produce their own food) are found at the lowest trophic level. This trophic level contains the highest amount of energy.

The energy in each trophic level of an energy pyramid is just 10 percent of the energy in the level below it. What accounts for the decrease in energy from the lowest level to the highest level of an energy pyramid?

~ All living things use some of the energy they get from nutrients to carry out life processes such as respiration and movement. In addition, some of this energy is lost as heat. As a result, the energy in ecosystems decreases from the lowest level to the highest level. This is also the reason why the number of levels in an energy pyramid is limited.

What is biomass, and how does the amount of biomass change in each level of a biomass pyramid?

~ Biomass is the total amount of mass of the organisms in a trophic level of a biomass pyramid. Each level of a biomass pyramid contains just 10 percent of the biomass found in the level below it. Therefore, the amount of biomass decreases from the lowest trophic level to the highest.