I am currently undertaking an investigation regarding Copper Beech tree leaves. Basically i have collected results which have shown that the leaves of a copper beach become less transparent the further away from the trunk you go (the leaves at the edge of the tree let least light through). I would be ever so greatful if anyone could tell me why this is? and what is in the leaf that cause less light to be passed through. I assume it is some sort of pigment but i dont know, there appears to be little information regarding this on the internet, i assume as it is quite a specific question. Any help is appreciated. Tom Curtis
perhaps the concentration of chlorophyll is strongest where the most light exists (outside canopy of the tree / plant) to make the photosynthetic function most efficient?
Thanks, i think that must be why. Also do you know the name of the pigment that makes copper beech trees leaves the golden brown colour? i dont think this can be chlorophyll. Many thanks for your help. Tom
Its not, its probably a carotenoid. Most plant leaves have more than one pigment in them, of which the green chlorophyll(s) is just one. These accessory pigments, such as carotenoids (fucoxanthin, a carotenoid apparently gives brown algae its colour), xanthophylls etc. don’t actually photosynthesize but absorb different wavelengths of light to chlorophyll (hence producing a different colour) and pass their absorbed energy to the chlorophyll. These dark pigments mask the chlorophyll, but if you look a copper beech leaf that has grown in the shade, where these pigments are less useful, you can often see the chlorophyll showing through making them look less brown.
Purple pigments called anthocyanins. Jimmyq is right in the explanation that they're strongest on the most brightly lit parts of the tree; the leaves are also physically thicker there, too.
