BDN quotes Birkel in article on early fall foliage

The Bangor Daily News quoted Sean Birkel, Maine’s state climatologist and a research assistant professor at the University of Maine Climate Change Institute, in the article, “Maine’s fall foliage is popping up early this year.” Some trees in Maine are already changing color, which could be the result of drought putting the trees under stress, especially those at the edges of roads, forests and in yards that have more shallow roots. However, most tree varieties have not been affected by the drought and the foliage is expected to remain mostly on schedule. Maine’s fall foliage season usually lasts from mid-September to mid-October, the BDN reports. Birkel said rising fall temperatures may cause fall foliage to come later in the year over the long term. Birkel’s recent research entails gathering temperature and precipitation records for the state of Maine dating back to 1895. According to Birkel’s research, Maine’s average September temperature has been steadily increasing, with a higher rate of increase over the past 20 years. But foliage is difficult to predict because it is affected by many factors aside from temperature, the article states. “It’s a complex process because it involves the daylight length, overall precipitation, and it could also link to nighttime low temperature versus daytime high temperature,” said Birkel.