The Minnesota Department of Natural Resources forecast for fall foliage colors calls for a drab year.

Sometimes a drought can mean more vibrant colors. However, this year’s severe drought is having an opposite effect.

The source of the vibrant colors, called carotenoids, break down when a tree experiences stress from a lack of water. This leads to premature leaf shedding and duller colors, according to the DNR.

The drought conditions across the state over the summer will result in duller colors as trees begin to shed their leaves for the winter, DNR officials said.

Fall colors are just beginning to arrive in Southeast Minnesota. This corner of the state — especially closer to the Mississippi River — was spared the worst of the drought.

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Does that mean the colors here will be more vibrant? Possibly. Only time will tell, naturalists said.

However, so far, it’s not looking great.

Sara Holger, interpretive naturalist at Whitewater State Park said signs so far point to a drab year there.

“Colors are pretty poor here so far,” she said. “Everything seems to be turning brown or yellow and then dropping.”

One of the usual bright spots of the fall season in the park hasn’t been very colorful, she added.

“Even the big maple by the Nature Store, which usually turns bright orange, is dull yellow and already lost half its leaves,” Holger said.

Further east, fall colors are starting to creep in at Beaver Creek Valley State Park in Houston County.

At Great River Bluffs State Park in Winona County, few leaves are turning, but fall wildflowers — sunflowers, goldenrod and blazing star —are in full bloom, park officials there report.

How leaves get their colors

Carotenoids are antioxidants in leaves that protect chlorophyll, which is what turns sunlight into food and gives leaves their green color. When leaves stop producing chlorophyll, the carotenoids show through with as orange and yellow.

Some trees produce blazing red colors in the fall. That color comes from anthocyanin pigments. Those pigments intensify once chlorophyll production stops and when days are sunny and nights are cool. The cool off causes sugars to get trapped in the leaves. Trees such as maples, cherry and some oak that produce a lot of sugar can end up showing vibrant red and purple colors in the fall, according to the DNR.

People can follow the fall colors as they peak around Minnesota at the DNR’s fall color finder page at www.dnr.state.mn.us/fall_colors.

John Molseed is a tree-hugging Minnesota transplant making his way through his state parks passport. This column is a space for stories of people doing their part (and more) to keep Minnesota green. Send questions, comments and suggestions to life@postbulletin.com.