“Dull falls” may be added to the string of detriments climate change may bring, according to a 2018 report by the Pennsylvania Department of Conservation and Natural Resources. “Climate change is disrupting the timing of natural cycles, such as trees’ emergence from dormancy, leaf development and blooming,” the agency said in a recent statement highlighting the problem.
“It can get very complicated, and it can have negative impacts to the vibrancy of the foliage,” added Kerry Campbell, environmental manager for the state’s Department of Environmental Protection energy office.
Leaf color is affected by an interplay of conditions, including excess rainfall or drought, high or low temperatures and frost. Climate change is expected to have an influence on all of them. Among the changing conditions that could lead to a fall foliage letdown: a dry, hot summer caused by rising temperatures and disrupted rainfall patterns that can result in browning or early leaf drop.
Climate change also is expected to make conditions more hospitable for diseases and invasive insects, which can further stress trees and lead to more muted colors.
Also, scientists are predicting that the dominate range of some tree species will move northward to escape warming temperatures. Among the likely candidates are sugar maples, which provide one of the most brilliant autumn displays.
“In ecology, everything is connected,” said Chris Firestone, a plant botanist with DCNR. “Climate change can impact small things that we don’t think about, and we don’t always know how those things may play out.”
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