Ecological Pyramids

Ecological pyramids are also called 'Eltonian pyramids' after C. Elton.

Charles Elton (1927) developed the concept of ecological pyramids who noted that "…the animals at the base of a food chain are relatively abundant while those at the end are relatively few in number…"

Ecological pyramids can be defined as,

"a geographical representation of an ecological parameter like number of individuals or amount of biomass or amount of energy present in various trophic levels of a food chain with producer forming the base and top carnivores at the tip".

Graphical representation of the trophic structure is done by drawing ecological pyramids, where the basal, mid and top tiers show the parameter values for producers, herbivores and carnivores in the ecosytsem.

An ecological pyramid may be upright (tapering towards the tip), or inverted (widens towards the tip) or spindle shaped (broader in the middle and narrow above and below).

On the basis of the parameters used, ecological pyramids are of three types.

• Pyramid of Numbers

• Pyramid of Biomass

• Pyramid of Energy