Question

In a tree ecosystem, the pyramid of number is
(a) Upright
(b) Inverted
(c) Both A and B
(d) None of the above

Answer 1

Hint: In a tree ecosystem, the tree is the primary producer and occupies the base whereas microparasites occupy the top consumer level. Pyramid of numbers depicts this data according to increasing or decreasing numbers in trophic levels.

Complete answer:
Ecological Pyramids: It is the graphical representation of number, biomass and energy of the successive trophic levels of an ecosystem.
It represents the gradual decrease or increase of number, biomass and energy from the producer level to the consumer level in an ecosystem.
Pyramid of number – It is an ecological pyramid which is formed on the basis of the number of primary producers, primary consumer and top consumers in an ecosystem.
The pyramid can be Upright in which there is a tapering decrease of the parameters.
For example- Pyramid of energy is always upright.
It can be inverted in which the parameters increase as we go from producer to top consumer.
For example- Pyramid of biomass in a pond ecosystem
The pyramid can also be intermediate, where the primary consumers exceed in number or biomass as compared to the primary producers as well as top consumers.
A tree ecosystem is a parasitic ecosystem.
Here the primary producer is the tree which occupies the base level.
Small herbivores like birds and small animals that live on the tree are the primary consumers.
The top consumers or the secondary consumers are the parasites on these small animals.
Based on numbers, in a tree ecosystem, the primary consumer or the tree is single in number, primary consumers are more in number and the parasites are greatest in number.

So the correct answer is ‘Inverted’.

Note: -The pyramid of numbers is inverted for a parasitic tree ecosystem.
-The pyramid of numbers for a tree ecosystem can also be spindle-shaped in the case of a non-parasitic ecosystem. Where the base is occupied by the tree as primary producers.
-Small herbivorous birds and animals are the primary consumers and are more in number.
-Top predators like Eagles occupy the top of the pyramid and fewer in number than the herbivores.