October 07, 2002
Nebraskans Will Still Enjoy Fall Tree Color Despite Drought
LINCOLN, Neb. — Contrary to predictions that this year's drought would dim fall's colors, it appears trees will be showing off their vibrant colors as usual.
University of Nebraska forester Jon Wilson said he initially thought trees would be duller this year and drop their leaves earlier than usual. However, in the last week, he's seen ash trees turning brilliant yellow and Virginia creeper vines changing into a bright red.
"With day length shortening and not getting a killing frost to stop the breakdown, we're going to see an average fall out here," the forester at NU's West Central Research and Extension Center at North Platte said.
David Mooter, NU program leader for community forestry for the Nebraska Forest Service in Omaha, agreed, saying the green ash were spectacular.
"They're the brightest gold I've seen in a while. With drought, you might think they'd be duller," Mooter said.
"But in years of drought, you'll see impressive colors," said Doak Nickerson, district forester at NU's Panhandle Research and Extension Center at Scottsbluff.
"It's been incredible this fall," he said. "This is some of the most impressive fall color and grandeur in trees that I've ever seen."
Trees react differently to drought – some trees actually taking on better fall color, Mooter said. Each tree has a different level of health and vigor. Genetics also plays a role, Mooter said.
"There is no formula to predict fall color for a given area of the country," Mooter said. "The intensity of fall color and time of peak color vary and are determined by complex environmental factors, as well as the genetic makeup of the plants themselves. These factors vary from plant to plant and from region to region."
Tree color is the result of the replacement of chlorophyll, the manufacturer of food for the tree, slowing down due to a variety of factors, Mooter said.
Eventually the flow of water and minerals into the leaf stops and the chlorophyll dies. With the death of the chlorophyll, other pigments in the leaf are unmasked and begin to show through.
One pigment, carotenoids, is responsible for the brilliant yellows and oranges and are conspicuous in ash, maple, aspen, birch, black cherry, cottonwood, tulip tree and sycamore.
Anthocyanins, another pigment, are responsible for reds, purples and blended combinations of these colors. Unlike the carotenoids, these pigments have not been present in the leaf all season. They develop in late summer in the sap of the leaf cells.
Wilson said any drought damage in trees will be seen during leaf-out and leaf formation next spring.
"The bottom line is we can all sit around and make little guesses, but all of us should know that nothing in nature is for certain," Mooter said.
For more information on fall color in trees, visit the USDA Forest Service Web site at USDA Forest Service or visit Warnell School of Forest Resources.
10/7/02-SA
David Mooter
Nebraska Forest Service
Forester
(402) 444-7804
Doak Nickerson
Nebraska Forest Service
District and Extension Forester
(308) 632-1238
Jon Wilson
West Central Research & Extension Center
District Forester
(308) 532-3611 - Ext. 139
Sandi Alswager Karstens IANR News and Photography (402) 472-3030
Department: Nebraska Forest Service
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