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WCU's resident fall forecaster calls for 50-50 chance of good leaf color |
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Autumn in Western North Carolina is typically host to a fiery display of color, especially during peak leaf viewing season of mid-October to late November.
But this year, Western Carolina University's sought-after fall foliage forecaster and biology professor, Dan Pittillo, advises leaf-lovers to simply flip a coin when trying to decide whether to color this coming leaf season "drab" or "dazzling." Due to scattered and sporadic drought conditions, this year's fall color will be spotty across the entire Southeast region. Dry conditions during trees' primary growing season typically leads to the best fall color, Pittillo said. "The Southern Appalachian Mountains in Eastern Tennessee and Western North Carolina have about a 50-50 chance of seeing good fall color this season," said Pittillo, an expert in Appalachian plant ecology. "In these areas, drought conditions have only been severe enough to affect small shrubs and grass, but not trees." Alabama, Florida, Georgia and Southern Mississippi - areas that have faced a significant lack of rainfall - should expect to see the region's sparse population of deciduous trees turn more dramatic fall colors, he said. However, if there is too little moisture for trees to remain healthy until cool weather sets in, these areas could see only dead brown leaves, he said. Pittillo predicts that the Northeast should see approximately average fall colors. Chlorophyll, the chemical that gives trees their green color in spring and summer, begins to break down in the fall, exposing the underlying pigments - brick red anthocyanins and sunny yellow xanthophylls. When the two pigments are present together, pumpkin orange leaf color can result. Tree growth, occurring mostly in early summer, is highly affected by the amount of rainfall an area receives, Pittillo said. When a water shortage or severe drought hinders the growth process, the green leaves remain functional, and the energy that would normally being used to expand the tree's trunk and stem length is instead converted to other organic forms, including the color changing pigments, he said. Although this summer has been unusually dry, there has been adequate rainfall for good tree growth in the Southern Appalachians, he said. "However, the processes are complicated by the interaction of many factors and the results can vary," said Pittillo. "Predicting fall color is an inexact science." A hard, early frost will produce poor color for all but the hardiest trees, such as scarlet and pin oaks, black gum or tupelo, beeches, some hickories and Bradford pears, he said. North Carolina's red and sugar maples, the brightest and most colorful species, may have exceptionally good color if early frosts are 25 degrees Fahrenheit or above and are followed by bright, sunny days, Pittillo said. Other stresses, such as the application of herbicides that place high amounts of stress on shrubs and trees, can add to the fall colors, he said. However, as herbicide-sprayed vegetation continues to degenerate, it gradually turns brown and will become distracting as the season progresses. Pittillo encourages leaf-lovers to remember that whether classified as "spectacular" or simply "average," this year's leaf display will nonetheless be pleasing to the eye somewhere along the route. "So take heart and enjoy the color as the cool fall weather returns," he said. |
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