■ PYRAMID OF NUMBERS
◇ Pyramid of numbers represents the total number of individuals of different species (population) at each trophic level.
◇ Depending upon the size, the pyramid of numbers may not always be upright, and may even be completely in verted.
◇ It is very difficult to count all the organisms in a pyramid of numbers and so the pyramid of number does not completely define the trophic structure for an ecosystem.