Leaves changing to fall colors early due to stress

Ash tree leaves turn into a yellow color at the Woodland Dunes Nature Center and Preserve

NORTHEAST WISCONSIN, Wis. Leaves on trees are already changing colors for the fall season, but experts say these trees may be under stress from a variety of factors.

One contributing factor to the early color-change of tree leaves is the amount of rainfall this year.

"In a lot of parts of Wisconsin trees are under stress from all the rainfall that we've had this year, especially the northern part of the state, and those trees if they're under stress they tend to turn color and drop their leaves earlier than they normally do," said Jim Knickelbine, Executive Director of Woodland Dunes Nature Center and Preserve.

When roots are inundated with water, trees have trouble getting as much oxygen as they’re used to from soil, which puts stress onto them. The moisture also promotes fungal growth and gives trees in Northeast Wisconsin diseases.

"That's always something that's always present in the environment, this year it's been heightened because of the moisture, probably won't hurt the trees in the long run but it would make them look not quite as nice this time of year," said Knickelbine.

Healthy trees turn yellow, orange and red for the fall season, but diseased trees skip that altogether and turn brown immediately before their leaves fall off.

Knickelbine says peak coloring usually happens close to the first weekend in October. He's confident one bad year isn't likely to turn into two.

"If it happens to be wet one year as long as that's not a long standing condition they'll recover from that- just like drought, they react to drought by being stressed and if that's not long term the trees will recover," added Knickelbine.