Some plants (grasses) tend to contain a greater concentration of chlorophyll than others (pines). can you develop a hypothesis to explain this? would it be testable?

I would hypothesize that plants (such as grasses) that are lower to the ground, and thus more likely to be somewhat shielded from sunlight, contain higher concentrations of chlorophyll to assist in the growth and energizing process than do other vegetal organisms (such as pines) which are not blocked from the light of the sun.