Climate affects fall colors
October usually signals the start of Grand Rapids’ most colorful time of the year, with leaves turning red, orange and yellow before beginning to fall slowly as the month progresses.
This year, however, our time in autumn hues may be severely limited.
The effect of the summer drought may still be visible in the fall season’s trees, as a lack of precipitation in recent months may lead to a dull and short-lived color leaf display this fall.
“I’ve heard that the trees aren’t supposed to be as colorful this fall,” said Jeanette Henderson, program manager at Calvin’s ecosystem preserve. “It makes sense, because trees drop their leaves earlier if they’re stressed.”
While the dry summer will continue to show its effects on tree health, the change in leaf color may not have a drastic impact on the beauty of the season.
“Trees under stress tend to turn color a little faster and a little earlier in the year, but I would be surprised if the differences would be significant enough that we could see those changes,” said biology professor David Dornbos.
From Dornbos’ window, the tops of the trees on Commons lawn are visible. Some of the leaves on those trees have begun to change, while many remain green.
“[The colors] feel pretty normal to me,” he said while surveying the over campus.
Students are also taking note of the trees this year and hoping to enjoy them while they can.
“I love how beautiful campus is in the fall,” said senior Katie Nelessen. “I would be really disappointed if we missed out on the bright colors.”
While many are concerned over the problems with trees, it is difficult to determine the exact causes of leaf-changing speed.
“There is a huge combination of factors at play here,” said Henderson. “Each year is different, and there is a lot of science behind figuring out how it all works together.”
It appears that the dry weather is playing an important role in speeding up the color change this year.
“Color change is largely driven by increasing night length, but the start and rate of color change can in turn be modified by plant stress,” said Dornbos. “It is possible that the dry and hot weather earlier this summer is speeding the progression up.”
Trees also show stress by failing to produce fruit. Watch how many acorns an oak tree produces, suggests Dornbos.
“If you start sensing low numbers of acorns, that’s a sign of a low-energy plant,” he said. “Producing seeds is a secondary need for perennial plants. They only produce fruit if they have extra energy. Otherwise, they are focused on survival.”
In addition to the potential aesthetic issues, trees are facing several other problems because of recent weather patterns. Bugs have become an increasing problem for trees and plants, and not just because of hot, dry summers.
“Warm winters are more problematic than summers because insects exert negative effects when they are not killed in the cold,” said Dornbos. He also said that the survival of more bugs through the winter is one of factors that led to the recent upswing in West Nile virus cases.
Amid the troubles facing trees this season, Henderson remains hopeful.
“There sure are some beautiful trees out there,” she said, looking out at the expansive preserve, with reds and yellows just starting to show. “I hope people get the chance to appreciate it before it’s all gone.”