There are many things that contribute to the demise of a tree, but the top of the list is one that faces all living things.
“I’ve heard people talk about old trees as good friends. It’s hard to see them go, but just like humans they don’t live forever," says Lori Chamberlin with the Virginia Department of Forestry. "Advanced age is a predisposing factor to oak decline.”
But why should so many Virginia oaks be getting old now? The answer, ironically, can be found in the demise of another species, the American Chestnut, which was hit by a blight and began dying out in the 1920’s and 30’s. When chestnut trees fell, there were gaps in the canopy, allowing sunlight to reach the forest floor, and that’s what oaks need to grow.
“A lot of the oaks that we see today were able to take the place of some of our American chestnuts, and mow they’re all reaching advanced age at once,” Chamberlin says.
An old tree is more vulnerable to disease, insect infestation and extreme weather. At Virginia Cooperative Extension, Adam Downing says heavy rains in 2018 and 2019 depleted the oxygen in soil.
“Some roots can tolerate low oxygen environments. Others can’t. When you have continuous rain like we did for that period of time, all the oxygen is pushed out of the soil," he explains. "Trees such as white oak that don’t tolerate (as we say) wet feet, lost their fine root system. Trees that survived that certainly were weakened by it. And that’s sort of the story with a lot of oak trees is they’ve become weakened for various reasons over a period of time, and then become more visibly distressed.”
Oaks may also be stressed by all the development they’ve seen over the last century. Many live alone in yards that are far from forests.
“The soils are more compacted. There’s not the same water availability. Sometimes they’re getting banged up by weed wackers or lawn mowers, and that’s stressful for any tree,” Downing says.
Of course younger trees could be growing up to replace those we’re losing, but at the Department of Forestry, Joe Rosetti says young oaks have problems of their own.
“There’s an over-abundance of white-tailed deer that browse oak seedlings in the winter when there’s not a whole lot to eat, and if they keep eating them, the seedlings will never grow taller than the deer’s mouth.”
At cooperative extension, Adam Downing says fire is another factor. Blazes set by lightning used to take out competing trees, leaving fire-tolerant oak saplings to grow. Now, humans might have to organize controlled burns.
“Smokey the Bear did a great job of stopping wildfires, but Smokey the Bear would probably say we do need some prescribed fires," says Downing. "That would give oak a competitive edge over some of these other species that are becoming the most abundant – in fact the most common tree in Virginia right now is red maple, and it is not as fire tolerant as oak.”
Whatever the reason oaks are failing, Rosetti says we have to bring them back. They are, after all, an important food source, dropping acorns that feed millions of animals.
“Squirrels and chipmunks are usually the first things we think of, but deer, turkey, bear, foxes, raccoons. The native Americans used them as a food source. They would take the shells off and soak them in order to get the tannens out, and then crush them and grind them into a flour.”
And their leaves feed more caterpillars than any other tree’s. Those caterpillars may be a pest to plants, but for birds they are dinner.
In our next report, we’ll tell you what Virginia is doing to save its oaks.
PART TWO:
A hundred years ago, a fungus wiped out many American chestnut trees, and oak saplings that often struggle for light in a forest grew rapidly. Now, experts say oak trees in Virginia are in trouble. Many are old and vulnerable to insects, disease and extreme weather, but the state is stepping up to protect and replace oaks as Sandy Hausman reports.
This is the sound of a coring device which foresters like Joe Rosetti use to study the inside of a tree trunk. It removes a small sample that shows how the tree has grown.
"Trees grow in diameter by putting on another layer of wood around the outside of the tree every year," he explains. And it can tell you about the health of the tree.
“Because the last thing trees put resources to is diameter growth, so if the tree is not growing in diameter very much then the tree may have a health problem.”
And lately, Rosetti says, many of this state’s oak trees are struggling. His colleague at the Virginia Department of Forestry, Lori Chamberlin, is tracking the situation statewide.
"We use different types of data – satellite imagery, ground surveys, aerial survey data to try to map out where there are large forest disturbances."
With that information, Rosetti’s program -- the Hardwood Forest Habitat Initiative, can advise foresters and landowners on where to concentrate their efforts – thinning woodlands so oak seedlings can grow, planting them along river banks and in other places where the odds of survival are best.
“Planting seedlings in a hardwood understory just isn’t very successful, because there is not a lot of light reaching the ground. Planting seedlings is best done in open areas, in riparian areas, reforesting fields that aren’t needed as fields anymore.”
Many of those seedlings will come from one of the state’s two tree nurseries. This one, in Augusta County, will cultivate and sell over 7 million through its website – Buy Virginia Trees.com. Joshua McLaughlin oversees the 189-acre operation – planting seeds gathered by volunteers all over Virginia.
“We get boy scout groups, the girl scout groups, youth groups from church or just individuals who just love to do it.”
The online news service Virginia Mercury profiled one man from Arlington who – each year -- spends six weeks walking the streets near his home, sweeping up acorns. Mike Ortmeier has collected more than 8,000 pounds over the last 13 years.
At the nursery, McLaughlin prepares them for planting.
“When the public gives us acorns we will actually soak them in water, and the good ones will sink, and the bad ones will float, and we’ll scoop the bad ones off, because we don’t need to plant bad acorns.”
One year later, they’ll be ready for harvest and sale – the proceeds used to support an enterprise that gets no tax dollars.
“If you want five seedlings, they’re going to run you $3 apiece. If you want 1,000 seedlings they’re going to run you 35 cents apiece. The more you buy, the cheaper they get, but $3 for an 18-20 inch seedlings is not bad!”
In addition to acorns, a team of 12 is filling pails with black walnuts to be planted by hand. Next year the nursery will offer about 50 different kinds of trees.
“American hazelnut sells out quick. Common persimmons sell out quick. White oak usually sells very well, even though we’ve been increasing white oak numbers dramatically over the past few years. White dogwood, redbud – those sell out very quick as well.”
And, more recently, a tree that produces what is known in Appalachia as the West Virginia banana.
“Paw paw to me tastes like mango custard. It’s something good!” McLaughlin concludes.
