1. Number of organisms (Pyramid of Numbers): This pyramid shows the number of individual organisms at each trophic level. It can be inverted in some cases, like in a forest ecosystem where there are fewer large trees but many insects feeding on them.
2. Biomass (Pyramid of Biomass): This pyramid depicts the total dry weight of organisms at each trophic level. It is usually upright, as a significant amount of energy is lost as heat during each trophic level transfer.
3. Energy (Pyramid of Energy): This pyramid represents the amount of energy flowing through each trophic level in a given time. It is always upright, as the second law of thermodynamics dictates that energy transfer is never 100% efficient, resulting in a decrease in energy at each higher level.
