While trees are not the largest level in the pyramid of numbers, they are still the base for both the pyramids of biomass and pyramids of energy.
true or false? ?

It is true because A pyramid of biomass is a representation of the amount of energy contained in biomass, at different trophic levels for a given point in time . The amount of energy available to one trophic level is limited by the amount stored by the level below. Because energy is lost in the transfer from one level to the next, there is successively less total energy as you move up trophic levels. Tree is a base as it provides food and energy.