Today's Paper Sports Obits Coronavirus Updates Time Tour Artist Loft Tablet Help HER Classifieds Jobs Crime Puzzles Contact us Newsletters
ADVERTISEMENT

Glorious fall: Where did those colors come from?

OPINION by Jimmy Driggers | November 22, 2021 at 4:00 a.m.
An unidentified woman rides her bicycle past a colorful tree on Whittington Avenue in early November. - Photo by Richard Rasmussen of The Sentinel-Record


What makes one season more colorful than another? Kyle Cunningham, an extension forester with the University of Arkansas System Division of Agriculture, says a lot depends on the weather.

Dry spells and sunny days with cool nights can cause fall colors to be brilliant. This is the weather pattern we experienced in late summer and early fall.

According to the Nov. 11 report from U.S. Drought Monitor, more than half of Arkansas had a drought rating of some sort. Three months ago, only about 19 percent of the state had drought. By Nov. 11, that area grew to more than 61 percent.

The only time drought doesn't help is when prolonged drought stresses trees too far and leaves fall prematurely.

Just like we focus on environmental cues to usher in fall and pumpkin spice season, so do trees. Anything that clues you into knowing that sweater weather is coming -- things like the days getting shorter and the temperature getting colder. We pick up on seasonal changes, and so do trees. Once trees notice these season changes (also known as phenology) it's time to start preparing for the tree to basically hibernate in the wintertime. And that's when the magic happens. This magic revolves around photosynthesis, which is the process of how plants harness energy from the sunlight, water and carbon dioxide to make food for themselves.

The colors change when the green chlorophyll pigments that harvest sunlight for photosynthesis degrade as the days get shorter and temperatures drop. This allows the leaves' other colors to show. These include xanthophylls, which are yellow; carotenoids, which are orange; and anthocyanins, which are red.

The yellow and orange pigments are present during the growing season but are masked by the green chlorophyll.

The anthocyanins occur as the chlorophyll breaks down and are developed by the tree to provide continued protection from excess sunlight so that the tree can continue to obtain and process nutrients and send them to the roots for storage.

As the days get shorter and temperatures begin to drop, the chlorophyll in leaves begins to break down. When the chlorophyll is gone, other pigments present in the tree reflect different colors of light.

Can humans enhance autumn color?

Fertilizing trees may assist in making them vibrant and potentially hold leaves longer, but, the major forces including weather patterns, tree species, and day length will always be the controls of fall color.

In the background of this whole color-changing process, the tree is also entering a sort of hibernation mode -- slowing down the flow of nutrients out to the limbs, hunkering down to conserve energy so it can make it through the winter. After a leaf has cycled through its pigments, it begins to run out of energy and starts to die off. Specifically, the leaf starts to weaken at the stem, making it easy for wind, animals, excited children etc. to drop leaves off the tree. The move from green to yellow and orange, to maybe a red grand finale is a bit like each pigment in each leaf taking a final bow before winter.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit http://www.uaex.uada.edu.

4-H information

There are several 4-H Clubs for Garland County youths who are 5 to 19 years old. For more information on all the fun 4-H activities that are available, call Carol Ann McAfee at the Extension office, 501-623-6841, or email her at [email protected]

Master Gardener information

Master Gardener meetings are held on the third Thursday of each month at the Elks Lodge. They're open to the public and guests are welcome. For more information, call the Extension office at 501-623-6841.

EHC information

The Arkansas Extension Homemakers Council is the largest volunteer organization in the state. For information on EHC or joining an EHC club, call Alison Crane at 501-623-6841 or email her at [email protected]


ADVERTISEMENT

Sponsor Content

ADVERTISEMENT

Recommended for you

ADVERTISEMENT