Why are trees different shades of green?
It’s dependent on the level of chlorophyll in teh leaves plus any other pigments that are present to give natural colouring that evolution has deemed good for the longevity of the species. Evergreens tend to be darker as the needles (rather than leaves) are deisgned to reduce water loss through transpiration, so they have a smaller area through which to photosynthesise. trees ‘retract’ the cholorophyll in autumn before the leaves fall off, as it is expensive to make so they draw it back into the plant before teh rest of teh leaf falls off – that’s why leaves go brown.
