What We Can Do About Diminishing Oak Forests
While participating in an online seminar about oak forest regeneration this past January, I learned some good news and some bad news about oak trees in the USA.
The bad news? Oak forests are on the decline.
The good news? Those of us who own forest land can help do something about it.
Why We Need Oaks
The seminar was sponsored by the Ohio State University Extension and led by Natural Resources Specialist David Apsley, who began by discussing why oak trees are so important to our nation and our ecosystem.
As a Nation
Because of their toughness and longevity, oaks are a symbol of strength. As such, they have been our national tree since 2004.
Oaks are also integral to our economy, their wood quality making them a sawmill staple.
Moreover, oak trees have long dominated the central hardwood forests of the eastern USA. They are also vital to the ecosystems of northern USA hardwood forests as well as the hardwood forests of Appalachia.
About 58 oak species are native to the USA.
As Part of the Ecosystem
Oaks have high wildlife value. In other words, a large number of animals use oak trees for food, shelter, nesting material and as cover from predators.
According to Apsley, acorns alone are a food source for over 90 species, from bears to song birds. Moreover, insects and other animals feed on oak bark, oak wood and oak leaves. These species attract additional creatures, which feed on the feeders.
In turn, oaks depend on wildlife to distribute and plant their seeds (acorns).
Simply put, oaks are the linchpins of their ecosystems, with myriad wildlife depending upon them for survival.
Over 90 species eat acorns as a regular part of their diets.
Why Oak Forests Are Declining
To regenerate, oak forests must produce as many new oak trees as the total number of trees that either die or are harvested by landowners and the lumber industry. Unfortunately, that's not happening. The reasons? As the demand for oak wood continues unabated, so does the harvesting of oak trees. Meanwhile, oak forests experience fewer fires.
Fewer forest fires sounds like a good thing, right? But not for oak trees, which rely on fires for their regeneration.
Forest Fires and Oak Trees
Oaks are more likely to survive a forest fire than other trees.They have thick, fire-resistant bark and leathery, fire-resistant leaves. Oak seedlings also have inordinately large root balls, so they are more likely to survive a fire. They are also among the first seedlings to appear after a fire.
Forest fires destroy plants that would otherwise shade out young oaks.
What oak seedlings and saplings can't tolerate is shade, which is why natural oak forest regeneration relies upon periodic forest fires. The periodic fires destroy underbrush and under-story plants that would otherwise shade oak trees out.
Without occasional forest fires, oaks fail to regenerate due to excessive shade. And as a result, shade-loving trees with less wildlife value, such as maples, fill the forest, further shading out young oaks.
What We Can Do
To encourage oak regeneration, landowners can clear shading plants from around oak seedlings and saplings, allowing them the light they need to survive and grow.
Professional foresters do this in several ways, two of which are unsuitable for most landowners.
Foresters may use chemical herbicides to burn away underbrush. In a world already full of pollutants, this seems unconscionable to me.
They also sometimes use controlled fires to burn away shading plants, a practice too dangerous for the majority of property owners.
The third method for removing shade plants, however, is very doable for most of us: manual clearing.
Manual clearing means just that— manually cutting back the area around oak seedlings and saplings to allow more light to reach the plants.
For best results, this should be done twice, once when oaks are seedlings and again when they are saplings.
When oaks are seedlings, remove the underbrush and other mid-story plants nearby to ensure plenty of sunshine reaches the young plants.
When the seedlings develop into saplings, remove some of the surrounding forest canopy, cutting branches from nearby trees to allow more light to reach the forest floor.
If those of us with woods on our properties took the time to perform these two tasks, we could dramatically increase the oak population in our woods and slow down the decline of one of our nation’s most beneficial native trees.
Will you reduce shade in your forest property to encourage oak regeneration?
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© 2017 Jill Spencer