Which ecosystem has the maximum number of producers per unit area?

Given below is an imaginary pyramid of numbers. What could be one of the possibilities about certain organisms at some of the different levels?

Assertion : In a food chain, members of successive higher levels are fewer in number.
Reason : Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.

What are the shortcomings of ecological pyramids in the study of ecosystem?

Ecological pyramids are of

In a marine ecosystem,the biomass pyramid is . . . . . . .