A few weeks before the foliage is supposed to change to brilliant reds and yellows, some trees are looking—brownish. Could there be a link to the rain in August and tropical storm Irene?
Within 100 yards of the shoreline and estuaries, yes.
“That’s something notable. You can’t deny it,” said Chris Martin director of forestry for the Connecticut Department of Energy and Environmental Protection.
The wet weather before July and then in August, capped by Irene, brought out more of a leaf fungus called anthracnose. This causes brown blotching on leaves, and it’s best seen up close.
“Typically it occurs every year,” Martin said. “It’s just more prominent this year than it the past.” People have called DEEP noting brown blotches on sugar maples, but sugar maples represent only 5 percent of the state’s trees.
“People are looking at individual trees up close, they’re going to see that fungus,” Martin said. “From the background, from the scenic outlooks, you won’t be able to notice.”
A hot spell in July, and a bad tropical storm and near-record rainfall in August, did not leave a broad curse on the rest of the state’s foliage.
On individual trees, showing brown leaves where branches broke, tropical storm Irene coincided with the end of the growing season. “The leaves are moving, and about to fall anyway,” said Lloyd Irland, a forestry consultant, Yale research scientist, and author of The Northeast’s Changing Forest.
But the factors that drive fall leaf colors—long droughts and warm, cloudy weather during the fall—aren’t affected by an earlier storm, Irland and other foresters said this week. “The storm itself is a minor factor,” Irland said.
But, “if it’s cloudy, dingy, a lot after the storm, that would be something else again. That would make the colors appear to be less brilliant because none of that sunlight on them.”
Emery Gluck, a state forester who manages Cockaponset State Forest, said he is always reluctant to predict fall colors. But he noted two truths about southern New England’s autumn. “One is that we seem not to have a really defined peak because of the different species turning at different times of the year.” Birches, for instance, turn yellow first. Oak trees—very common in Connecticut—take much longer.
Gluck’s other truth is that fall color vibrancy depends on how healthy the tree is. A diseased or stressed tree will always lose its leaves early.
(I remember hiking on a ridge past trees on a federal Superfund site in Pennsylvania. Zinc smelting had killed most of the vegetation and the government was replanting. The little trees turned red in July.)
A new state map with zingly colors
Last week the state Department of Energy and Environmental Protection unveiled a website about fall foliage. It displays a map that the DEEP said will change colors as the leaves do. See www.ct.gov/dep/foliage. The map turns color based on which areas thypically turn. Click on one of the date ranges, which are listed week by week, staring in early October. The map will change colors. Slow internet connection? Be patient. It takes several seconds for the changes to show.
Another aspect of the website is a helpful discussion of why foliage is bright some years and not others. Mostly, this depends on the weather of the next six weeks or so.
Peak fall colors usually hit in early October and the colors last until around Halloween. If the weather pairs brilliant sunny days with cold nights, that will hasten the colors turning and, some say, even brighten autumn foliage. Cloudy weather appears to dull it.
Studies by foresters in Vermont have linked droughts to leaves turning colors early. It has to do with low nitrogen in the tree. There’s been anything but a drought in Connecticut this year.
Leaves always have color that chlorophyll masks during the warm months. The green dominates during the spring and summer, when the tree is using sunlight to make sugars, feeding itself. When the light diminishes in the fall, chlorophyll is reduced, too, revealing the reds or yellows.
But a second factor is at work in fall leaf color. The brighter the light, the greater the production of anthocyanins, and the more brilliant the colors we see. When the days of autumn are bright and cool, and the nights chilly, but not freezing, the brightest foliage colors will develop. Familiar trees with red or scarlet leaves are red maple, dogwood, red oak, scarlet oak, and sassafras.