Archive for Thursday, November 3, 2005

Maple leaves are baffling with change

November 3, 2005

Don't be troubled if this year's maple leaf displays aren't like you remembered. Even the experts are baffled by the color changes this year.

It's one thing for the trees not to change color by Maple Leaf Festival time, always the third full weekend in October, but this year the change has been more gradual, almost as if the colors on many trees are just fading in. But, on others, they're in full color. And, even odder, there are instances were side-by-side trees are doing each.

"I don't know what's up," said Roger Boyd, a biology professor at Baker University who has been a long-time watcher of trees in general, but Baldwin's maples in particular. His dad, the late Ivan Boyd, was the one who suggested celebrating Baldwin's abundant supply of maples and that how the festival came about almost 50 years ago.

Normally, the trees are in full color when the festival rolls around. But, Boyd pointed out that "we've missed the peak several years in a row" at Maple Leaf time. But, this year is just different.

"My take is that it has been nice and warm, so the process of turning has been delayed," said Bruce Chladny, a horticulturist at the Douglas County Extension Office. "Temperature as well as day length play important roles in the leaves turning. When temperatures are cool, the leaf colors are more vibrant. When the temps are warm, the colors are faded."

That's all fine and good. It's well established that the whole leaf turning process is determined by those factors. Scientifically, it goes like this:

"I think that nighttime temperatures stayed too high to trigger the breakdown of Chlorophyll and the production of the red pigment, Anthocyanin," Boyd said around festival time. "Daytime highs probably weren't the problem as much as it didn't cool off enough at night."

However, the real baffler is the "patchiness" that's occurring in trees, even those next to each other. The "graying of the temples" has long been noted as a few limbs in trees, mostly at the top, would change color, but not the rest of the tree. But, eventually, the rest of the tree followed suit.

This year, some trees have that "patchiness" throughout, even this late into the change of season.

"All I can say is that generally night-time temperature and daylength are usually the determining factors, but I don't know enough about the physiology of the leaves well enough to explain what we are seeing," Boyd said.

"I have noticed some patchiness and attributed it to a slower rate of turning and not having consistently cooler weather at night," he said. "But, I'm guessing."

What the experts do know is that now is the time to enjoy the colors, whether there's patchiness or not.

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