Global warming expected to damper leaf colors this fall

North Carolina scientists have begun to express concerns over fall leaf color, with some warning the leaves will not be as vivid as in previous years.

Beverly Collins, an associate professor in the Department of Biology at Western Carolina University, said recent gradual climatic warming has contributed to trees continuing to photosynthesize later than usual, thereby delaying color change.

“This means that the colors will not start appearing as early or all at once, as they would if the weather did what it often does, and gets colder faster,” she said.

Collins said the main changes people will notice is in color vibrancy and consistency.

“Colors would normally be brighter because of how completely and quickly the chlorophyll degrades,” she said.

Howard Neufeld, a professor of physiological plant ecology at Appalachian State University, said the development of yellow and orange leaves in autumn usually occurs around the same time every year, but red leaf development is subject to variability.

Yellow and orange leaves contain pigment present year-round, but the pigment in red leaves is produced in response to cool and sunny weather conditions in August through September, he said.

He said, if anything, there may be a slight delay in leaf color development this year, with drought-sensitive trees being the most affected.

“What we’ve had this fall has been a prolonged period of above-normal temperatures and below-normal rainfall,” Neufeld said.

Regardless of the potential environmental implications global warming holds, both Neufeld and Collins said the change in leaf color itself should not concern people.

“The leaves are still healthy,” Collins said.

Neufeld said even with all of the delaying factors, trees in places with high elevations, like Grandfather Mountain, have already begun to experience leaf change.

“The fall color starts at the highest elevation, and about every 10 days, it works its way about a thousand feet lower,” he said.

The predictions of leaf color change are not a concern for North Carolina tourism, said Beth Carden, the executive director of the Henderson County Tourism Development Authority.

Carden said the hotels in her district have booked up completely.

“I don’t think that people are going to cancel because it may not be reported as being as vibrant of a year,” she said.

Carden said the leaves will look spectacular to tourists regardless.

“I’ve read several different reports this year — they’re gonna be pretty.” she said. “I grew up here, they’re pretty no matter what they say.”

state@dailytarheel.com