STRESS CATCHES UP WITH SOME TREES; OLD OAKS FELLED BY HEAT, STRESS AND AGE

The "Mighty Oak" is still mighty.

Despite some people's concerns that more than the normal number of oak trees are dying, foresters and other tree specialists say it's no more than usual.

A giant oak tree crashed into a Cape Girardeau home earlier this year.

There was no wind, the tree looked healthy except for some bark peeling away from the trunk. But, the big tree uprooted, crashing into the house.

There were no injuries.

In another section of town, a monstrous white oak failed to produce leaves this summer. The tree service company which removed the giant trunk reported that the tree appeared to have been dying over the past few years.

Three or four pin oak trees in Sikeston no longer produce leaves.

Oak trees can appear to be healthy one year and die the next, say spokespeople of the Missouri Department of Conservation Forestry Division and lawn and garden specialists.

"We don't know exactly what happens," said Paul Schnare, of Cape Girardeau, who has been in the lawn and garden business for more than 20 years and is an adjunct professor in horticulture at Southeast Missouri State University, "They're calling the problem at Sikeston ~~`pin oak decline.'"

Keith Wright of Wright Service of Cape Girardeau, and Susan Burks, a forestry pathologist with the Missouri Department of Conservation's Forestry Division, Jefferson City, say that some of the oak tree problems can be attributed to stress, caused by weather conditions over the years.

"We have received a couple of calls concerning dying oak trees," said Wright. "There are a number of factors that could lead to the dying tree -- lightning, stress created by drought and heat, and plain old age."

All trees have a certain amount of reserve, said Burks.

"Oak wilt is common, especially in white oaks," said Burks. "This disease can move into a healthy tree and kill it. It doesn't need any tree stress."

And, the wilt can move from one tree to another among trees within close proximity, said Burks.

Meanwhile, oak decline is created by a group of complex problems, said Burks.

"Trees are subject to a lot of stress," she said. Each time the trees are stressed they're weakened, making way for secondary problems -- armillary root rot and chestnut bore.

"These secondary diseases take advantage of a tree while it's down, or stressed," said Burks.

It may take time for the stress and disease to show up, she added.

"Oak trees, which live long lives, can handle most stress," said Burks. "But, eventually they may wear down. We're seeing trees die now that have suffered stress over the past four or five years."

Burks attributed a lot of the oak problems to especially wet springs over the past few years.

"We've had wet springs four of the past five years," she said. "White oaks don't handle the wet springs well."

This is especially damaging to white oaks. And, when the oaks get stressed, the armillary disease moves in the roots.

A lot of trees, not only oaks, are victims of crowded root conditions.

"A tree may be near a parking lot, driveway, or building, and while it grows, the root system can't expand, and the tree is stressed," said Rocky Hayes, an urban forester who works out of the Cape Girardeau Regional conservation office.