What are ecological pyramids?

Ecological pyramids are used to compare the trophic levels in a food chain.

Pyramid of numbers

• Allows us to compare the number of organisms present in each trophic level at a particular time.

http://upload.wikimedia.org/wikipedia/en/thumb/9/9d/Pyramid_of_numbers.png/400px-Pyramid_of_numbers.png

Pyramid of biomass

• Allows us to compare the mass of organisms present in each trophic level at a particular time.


• Constructed based on the standing mass (dry mass of organisms in each trophic level at any one time ) of organisms.

http://www.botany.uwc.ac.za/sci_Ed/grade10/ecology/images/pyra6.gif