Question

In a single tree ecosystem containing smaller birds, trees, insects and larger birds, which will be the second most abundant in number?
(A) Insects
(B) Tree
(C) Small birds
(D) Large birds

Answer 1

Hint: Ecosystem is a vast system that includes the interaction of living components with non-living components that is biotic interaction with abiotic. Graphical representation between relationships of different organisms represents the Ecological Pyramid and this concept is given by Charles Elton.

Complete answer:
Ecological pyramids are of three types: Pyramids of Number, Pyramids of Biomass, Pyramids of Energy. The pyramid of numbers involves the total number of organisms at each trophic level in the ecosystem. Normally it is upright with a wide base which means, higher number of producers at the base and a decrease in the number of organisms as we go towards the top of the pyramid.
In the case of a single tree ecosystem, there is only one tree in that ecosystem and the chain will include a large number of insects depending on that single tree, which in turn are eaten by small birds which are then eaten by large birds.
The pyramid of numbers, in this case, will be spindle-shaped having the least number of trees with the maximum number of insects and then a fewer number of small and large birds than insects. So the insects will be in maximum number, followed by Small birds, followed by Big birds and the single tree will be least in number. So, the second most abundant in number is Small birds.

So, the correct answer is option (C).

Note:
All ecological pyramids of the number are upright means there will be a decrease in number as we go high. Exceptions to this include the Parasitic food chain which is inverted in shape. Pyramids of Biomass can be upright or inverted in shape. Pyramids of biomass in grasslands and forest represent the upright pyramid and Pyramids of biomass in ponds represent the inverted pyramid.