Step 1: Read the diagram:
The figure has two bars. The lower bar is PP (primary producers) and it is short. The upper bar is PC (primary consumers) and it is wider.
Each bar shows the standing crop, which is the biomass, at that trophic level. The base is smaller than the next level, so the pyramid is inverted.
Step 2: Part (i): identify the pyramid:
This is an inverted pyramid of biomass.
Step 3: Part (i): example and condition:
A sea (marine) ecosystem is a good example. The producers are tiny phytoplankton.
They have a small standing crop at any time, but they grow and divide very fast. The zooplankton and fishes that feed on them have a larger biomass.
So an inverted biomass pyramid is possible when producers have a very short life span and a fast turnover.
Step 4: Part (ii): limitations:
1. A pyramid assumes a simple food chain. It does not show food webs, where one species feeds at many levels.
2. It does not give a place to saprophytes (decomposers), even though they are vital.
(Another valid point: it does not consider the rate of production or the time factor.)
Final Answer:
(i) Inverted pyramid of biomass, as in the sea. (ii) It ignores food webs and it ignores decomposers.
