Question

Identify the type of the given ecological pyramid and give one example each of pyramid of number and pyramid of biomass in such cases

Answer 1

This pyramid is an inverted pyramid.

Inverted pyramid of biomass in a lake: Phytoplankton -> Zooplankton -> Fishes.

Inverted pyramid of number: Trees -> Insects -> Birds.

Answer 2

Answer:

An ecological pyramid can be defined as a graphical representation of different ecological parameters, namely the number of individuals found at each tropic level, the energy quantity or the biomass found in each tropic level. These pyramids depict the producers at the base whereas the apex depicts the top level consumers found in the ecosystem.

Pyramids are of three types:

• Pyramid of numbers – it gives the graphical representation of the number of individuals found at each tropic level in a food chain of an ecosystem. This pyramid can be inverted or upright depending on the crowd of producers. Example – In a Greenland ecosystem, this pyramid is upright where in the food chain, the number of producers is followed by the number of herbivores, which in turn is followed by number of secondary and tertiary consumers. Therefore, the number of individuals at the level of producers will be maximum, whereas the number of individuals at the top are carnivores will be the least. The pyramid of numbers in a parasitic food chain is inverted, where in the food chain, producers provide food to fruit eating birds which in response support few species of insects.
• Pyramid of biomass – it is a graphical representation of the total quantity of living matter found at each tropic level of an ecosystem and can either be inverted or upright. In grasslands and forest ecosystems it is upright as the quantity of biomass at the producer level is higher than at the carnivore level, at the top. This pyramid is inverted for a pond ecosystem as the biomass of fishes far surpass the biomass of zooplankton on which they feed.
• Pyramid of energy.