Question

Which of the following representations shows the pyramid of biomass in the aquatic ecosystem and can also be attributed to the pyramid of numbers of a single large tree in the forest ecosystem?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

In the case of aquatic systems, the biomass can increase at higher trophic levels. For example, in oceans, the food chain typically starts with phytoplankton and ends with predatory big fishes which have the largest biomass, making the pyramid itself inverted.

The representation of the forest ecosystem in the pyramid of numbers is always upright because the producers are large sized trees which make the base of the pyramid. The herbivores such as birds, deer, elephants etc. make up the primary consumers and are less than primary producers; gradually the higher trophic levels consisting of secondary and tertiary consumers is generally smaller than that of the lower trophic levels.

But, the pyramid of number is inverted in the case of a single tree because as a producer, it can provide nourishment to several herbivores such as birds which can further support a larger population of ectoparasites.