VPE 511: Environment and Environmental Hygiene (2+1)

PYRAMID OF NUMBERS

(C₂a) Pyramid of Numbers

• It is a graphic representation of number of individual organisms at each trophic level, with producers forming the base and the carnivores at the tip.

POND ECOSYSTEM

(C₂b) Pyramid of Biomass

• The amount of living matter present in an environment is called biomass.
• Biomass of Trophic level depends upon reproductive potential and lonevity of the member.
• Biomass is high in long-lived organisms.

UPRIGHT PYRAMID IN TERRESTRIAL ECOSYSTEM

Inverted Pyramid in Aquatic Ecosystems

• The pyramid of biomass in aquatic ecosystem is inverted. The biomass trophic level depends upon the reproductive potential and longevity of the membrane. In the case of long lived organisms, the biomass is high.
• The biomass of phytoplankton is less than biomass of zooplanktons. The biomass carnivores is higher than the herbivores.

INVERTED PYRAMID OF BIOMASS IN A POND

(C₂c) Pyramid of Energy

• Example: Pond ecosystem
• It is a graphic representation of the amount of energy trapped per unit time and area in different trophic levels of food chain. The producers are at the base and carnivores are at the top.

PYRAMID OF ENERGY