News Release
Expert Says Drought May Affect Fall Color Across the State
Media Contact(s)
Dr. Robert Bardon, (919) 515-5575
Lauren Gregg, News Services, (919) 515-3470
Sept. 5, 2007
FOR IMMEDIATE RELEASE
The drought that has plagued most of North Carolina this summer will probably have an adverse effect on fall foliage across the state this fall.
Dr. Robert Bardon, associate professor of forestry and extension forestry specialist at North Carolina State University, says that because of the severe drought, trees are going to look for ways to lose their leaves instead of retaining them, so leaves will turn brown and fall from trees more quickly than usual.
Bardon says moisture helps drive the process that produces color change in leaves. Drought makes leaves shut down, which speeds up the color changes, as well as the rate at which the trees will lose their leaves.
"Weather conditions that create the most vibrant fall color are cooler evening temperatures -around 40 degrees - and daytime temperatures of around 70 degrees," Bardon says. "In addition, rain is needed to ensure plenty of soil moisture.
"With the lack of rain, the trees cannot produce enough energy to maintain the leaves. They'll quickly go dormant and detach from the tree."
During the spring and summer, leaves manufacture most of the food necessary for a tree's growth. The food-making process occurs in cells that contain the pigment chlorophyll, which gives the leaves their green color. The leaves also contain other pigments that are masked most of the year by the greater amount of chlorophyll.
In the fall, partly because of the changes in the period of daylight and changes in temperature, the leaves stop their food-making process. As the chlorophyll breaks down, the green color disappears and yellow colors surface. Other chemical changes create additional pigments that vary from yellow to red to blue.
Drought conditions stop the food-making process prematurely and hasten the breakdown of chlorophyll, resulting in a quick and early color change.
Bardon says there may be some localized pockets of areas in the state that did get enough rain to produce vibrant fall color. However, the location of those areas is very difficult to predict.
Leaves at higher elevations in North Carolina, such as Mt. Mitchell, will be the first to change, probably around the end of September or first of October, Bardon says. Then the trees in the lower elevations will begin to change.
Even though the fall foliage in the mountains and across the state might not be the most vibrant this year, Bardon says taking a trip to see the leaves is always worth it.
"Nature always gives us something to see," Bardon says. "The leaves may not be the brightest this year but with the landscape changing there is always something new and different to observe."
- gregg -