Cooler temperatures signal deciduous trees to stop producing chlorophyll, the green pigment responsible for photosynthesis, he explains. The chlorophyll breaks down and disappears, unmasking other leaf pigments. After chlorophyll production stops, trees also produce another pigment in their leaves called anthocyanin, Abrams explains. The anthocyanins create the brilliant reds and purples seen in maple, sassafras, sumac, black gum and purple oak. The amount of anthocyanin produced each year is related to starch levels in the tree.
Trees often produce less starch during droughts.
All predictions aside, Abrams says not to worry. All systems are go if the weather cooperates. To read previous months' news releases, click on this link.