Missouri's Red Oaks Are Dying
Copyright 2001 St. Louis Post-Dispatch
September 3, 2001
By John Curley Of The Post-Dispatch
The tree now dominates forests in this region, but 20 or 30 years from now, the woodlands may be more diverse and drought-resistant.
The big red oak tree in Clayton was just a sapling in the brutal winter of 1918 when the Mississippi River froze so hard you could walk across it with a horse. But the tree survived.
More than 400 people died in 1936 when July temperatures topped 100 for 13 days in a row. The tree endured. In the spring of 1981, wind of 83 mph -- the strongest ever recorded here -- peeled off roofs, tipped tractor-trailers and blew down power lines. The oak stood firm.
But the big tree on the Carrswold subdivision's common ground has finally met its match: a microscopic fungus called hypoxylon. The 70-foot-tall, 3-foot-thick oak was cut down last week and reduced to chips of mulch.
Red oaks, which make up well over half the forests in Missouri and western Illinois, are dying in unprecedented numbers. The generation of oaks that flourished after the land was cleared around the turn of the century is reaching the end of its natural lifespan. A long drought has weakened the trees, making them more vulnerable to insects and diseases. In and around cities, oaks face another deadly threat: man.
"It may be the worst combination of oak-stressing factors we've seen in this century," said Rose-Marie Muzika, a forest ecologist at the University of Missouri at Columbia.
That's a huge concern in southern and central Missouri, where 33,000 people earn their living harvesting timber. And it's a growing problem for property owners here. Oaks represent a valuable asset. When they die, they can become dangerous and expensive to remove.
When Richard and Barbara Lieberman moved to their home on a one-acre lot in Town and Country 10 years ago, they had more than 30 oaks. More than 10 have since died, including all four oaks in front of the house. One tree was scheduled to be taken down this weekend.
Removing those trees cost from $700 to $1,300 each, but that's not the only expense.
"It kills me to take those beautiful trees down," said Barbara Lieberman. "You almost wish they could talk. What a sense of history they'd have."
If trees could talk, they might describe the devastation of the years between 1880 and 1920, when many of the Midwest's pine and hardwood forests were chopped down for lumber and to clear land for farming.
Much of the land wasn't good for agriculture, though. The land was hilly, and the soil was thin. When farming was abandoned, what grew back was oak, mostly red oak.
Of Missouri's 14.7 million acres of forests, about a third are in the red oak group, including red, black, scarlet and other oaks with pointed leaves. About a fifth of the forest is white oaks, bur oaks and others with rounded leaves. One out of six trees is a post oak or blackjack oak.
Like baby boomers, oaks are showing signs of age, and red oaks are dying faster than others. Diseases spread quicker because so many trees are of the same species.
Most tree experts say the oak decline now is at least partly the result of droughts that occurred in the 1950s and 1980s. Add the current three-year dry spell and the fact that many trees are on ridges and slopes with thin soil, and you have a formula for oak failure.
The most dramatic example of oak failure is in southern Missouri and northern Arkansas, where tens of thousands of acres of Ozarks forest have been infested by a beetle called the red oak borer. Four beetles per tree is considered a lot. In June, foresters found 600 beetles per tree in northern Arkansas.
They found about 20 per tree in southern Missouri, and they expect that number to jump. They worry that the state's $3 billion-a-year lumber industry will suffer because the beetle larvae burrow holes, ruining the wood. They also fear that dying trees will fall across roads, hiking trails and campsites in the Mark Twain National Forest.
"We've never seen anything like this," said Ross Melick, who has worked with the U.S. Forest Service for 30 years. "Everyone is amazed."
Red oak borers haven't shown up in big numbers in St. Louis. But people who work with trees here report a steady increase in oak diseases.
Ten years ago, Dan Christie at Metropolitan Forestry Services in Ellisville would see a fungus called oak wilt about once a year. This year, he has seen 30 to 40 cases of oak wilt, which spreads through roots and clogs up trees' circulatory systems. It can kill a red oak in a few weeks. Once you see the signs - leaves that turn brown and drop in the summer - it's usually too late to do anything.
Tim Gamma, head of Gamma Tree Service here and president of the Society of Commercial Aboriculture, said he had seen increases in armillaria root rot and hypoxylon cankers, particularly in older suburbs such as Webster Groves, Kirkwood, Ladue and Clayton.
"In the last three years, we've probably removed two or three times as many oaks as previously," said Gamma, whose company also owns Shield Shade Tree, which was hired to remove the red oak in the Carrswold subdivision.
On Wednesday, he kneeled and pulled bark away from the base of another tree nearby, a huge red oak whose leaves have turned a brownish orange.
"More hypoxylon," he said, pointing to dull gray cankers on the bark. "We may find armillaria here, too. When oaks get stressed, it's rarely just one thing that kills them. It's like someone with cancer getting pneumonia."
Another stress is "contractor blight" - a phrase tree experts use to describe the damage caused by developers. Adding or removing as little as a few inches of soil near a tree can spell its doom. Banging into trees with construction equipment can open them up to insects and infection. Compacting soil around them will reduce their water and air.
"Old oaks and maples are like cranky old men - they just don't tolerate change," said Charles Murphy of Murphy's Tree Service in Wildwood. To protect trees around a construction site, he recommends putting a fence around them as far out as the tree's drip line, where water falls off its canopy.
Nobody knows how long the oak decline will continue here. A lot depends on the weather. Most experts think the decline will get worse before it gets better.
"If you have all these stressful conditions, my prediction is that you're going to see red oak decline," said Bruce Moltzan, forest pathologist for the Missouri Department of Conservation.
Nobody's predicting extinction or anything even close to that. But over the next few decades, there may be significant changes in the make up of the forest. Red oaks may not be as dominant as they are now. Your grandchildren may see more pines, white oaks and other hardwoods.
"We're already seeing more white oak seedlings and maples," said Melick of the U.S. Forest Service. "Twenty or 30 years from now, we'll see a forest that's a little more diverse and drought-resistant."
Missouri's forests
Missouri has about 14.7 million acres of forests -- covering about a third of the state. This includes 4.9 million acres of oaks in the red oak group, 3 million acres of oaks in the white oak group and 2.4 million acres of post oaks and blackjack oaks. The state's forests are 83 percent owned by private parties, 12 percent by the federal government and 5 percent by state and local governments. Missouri's forest industry provides jobs for 33,000 people and generates more than $3 billion a year to the economy.
How to prevent tree decline
Avoid wounding trees with lawn mowers, construction equipment, golf carts, nails and tools.
Never use spikes to climb a tree. Spikes open holes that invite insects and fungus. Spikes also can spread disease from sick trees to healthy ones.
Be careful about using chemicals on or around trees. De-icing salt and lawn herbicides can kill trees.
Don't prune trees just to shorten them or change their shape. And don't prune trees between March and November when their sap will attract disease-carrying insects.
Avoid compacting soil around the tree. Compacting can prevent air and water from reaching the roots.
If you must landscape near trees, contact your local university extension office or conservation agent for brochures and advice or seek professional help from certified arborists. Changing the slope of land around a tree can affect how its roots get water and air.
Study your trees. Know what species are on your property and what they need to stay healthy.