Why are there always more members on the lower trophic levels than the higher trophic levels?
As energy moves from one trophic level to the next, more and more energy is available for the next level limiting the number on the next level.
The members of the lower trophic levels are always small in size so there can be more of them.
As energy moves from one trophic level to the next, less and less energy is available for the next level limiting the number on the next level.
The members of the lower trophic levels pass on all of their energy to the next trophic level.