Leaf changes affected by humid summer and mild fall

Due to a humid summer and a mild fall, Connecticut trees are now being affected during leaf peeping season. (Dustin Phillips/dustinphillips/Creative Commons)

Due to a humid summer and a mild fall, Connecticut trees are now being affected during leaf peeping season. (Dustin Phillips/dustinphillips/Creative Commons)

Leaf peeping season in Connecticut has been affected by the change in climate this year, according to ecology and natural resource professors at the University of Connecticut.

A humid summer, a warm fall, and a drought in the last few months has pushed back and staggered the timing of leaf changes, John Silander, an ecology and evolutionary biology research professor, said.

Weather for the entire season affects when the leaves will change, Silander said. He also stated that the response to the weather depends on the species of tree.

Moderate drought may cause some species to lose their leaves earlier, but at the same time cause other trees to lose their leaves later, Silander added.

“Oak (trees) are pretty drought tolerant,” Silander said. “They’re less sensitive to drought events than, say, maples. Maples tend to be rather drought sensitive. They like water.”

While summer did bring some rain to Connecticut, a drought stretching from August until October have caused more water-dependent trees, such as maples, to drop their leaves early.

“If you go out and look around here, you’ll see that a number of the maples have already lost their leaves. They weren’t very colorful,” Silander said.

A humid summer this year gave way to fungus that infected many of the maples, causing the leaves to fall before they turned, Robert Fahey, an assistant professor in the natural resources and environment department, said. It is still too early in the season for the oaks to normally change color, so it is unclear how those trees have been affected, Fahey said.

“(In Connecticut) we have a huge oak component, the maples and a lot of the other species turn, and then several weeks later the oaks turn,” Fahey said. “So it’s sort of a longer progression, a longer period of coloration.”

A gypsy moth caterpillar outbreak during the summer resulted in large loss of leaves, so full photosynthesis, which allows plants to convert sunlight into energy, could not occur in those cases, Thomas Worthley, an extension professor for forest sustainability, said. The color of the chewed-on or regrown leaves could end up being affected, Worthley said.

“Green colors of some species will remain later and the changes in color will occur in a staggered fashion, rather than all at once,” Worthley said.

Worthley mentioned that how the leaves were affected this year will not be fully visible until the end of the fall because of the different weather.

“As (the green in the leaves) disappears after the first real cold snap... what other pigments and colors might become visible is anyone's guess,” Worthley said.


Nicholas Hampton is a campus correspondent for The Daily Campus. He can be reached via email at nicholas.hampton@uconn.edu.