Editing Biomass (ecology) (section)

==Ecological pyramids==
{{Main|Ecological pyramid}}
[[File:Ecological Pyramid.svg|thumb|upright=1.4|An [[energy pyramid]] illustrates how much energy is needed as it flows upward to support the next trophic level. Only about 10% of the energy transferred between each trophic level is converted to biomass.]]

An ecological pyramid is a graphical representation that shows, for a given [[ecosystem]], the relationship between biomass or [[primary production|biological productivity]] and [[trophic level]]s.
* A ''biomass pyramid'' shows the amount of biomass at each trophic level.
* A ''productivity pyramid'' shows the [[Primary production|production]] or [[Trophic dynamics|turn-over]] in biomass at each trophic level.

An ecological pyramid provides a snapshot in time of an [[biocoenosis|ecological community]].

The bottom of the pyramid represents the primary producers ([[autotroph]]s). The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called [[primary production]]. The pyramid then proceeds through the various trophic levels to the [[apex predator]]s at the top.

When energy is transferred from one trophic level to the next, typically only ten percent is used to build new biomass. The remaining ninety percent goes to metabolic processes or is dissipated as heat. This energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, with more biomass at higher levels.