Grand Avenue by Mike Thompson for November 21, 2013
November 20, 2013
November 22, 2013
Transcript:
I just love all the fall colors. When they're on the trees.
I just love all the fall colors. When they're on the trees.
There are 4 main types of coloring agents in the leaves:Chlorophyl A is dark green, Chlorophyl B is light green, Zanthophyl is yellow, and Carotine is orange-red.
The leaf base is usually grey to black.
These agents die off in that order. Thus, the fall colors.
The amount of “antifreeze” (usually sugar) in the sap and the shape of the leaf — especially the stoma, or respiratory openings, in the bottom of the leaf — determines the precise temperature at which each agent dies, if at all.