When landowners see big oak trees, maybe accompanied by some oak seedlings on the ground, it’s natural to assume that the oak in their woods is doing just fine.
But as people learned at the “Oak in the Driftless” workshop held in Cashton, WI, on Oct. 1, the future of oak in southwest Wisconsin is facing two great challenges.
Timing Is Everything
Oak is an economically valuable timber species with many potential markets, including building materials, furniture, and veneer.
Oak markets naturally wax and wane over time. But even at the height of these markets, harvesting too many oak trees is not the problem that oak faces. It’s the events before and after harvest that can either make or break oak’s future.
“In a perfect world, oaks would be harvested in the fall, in a year with a bumper crop of acorns, and at the peak of that bumper crop,” said Kevin Schilling, a Wisconsin Department of Natural Resources forester who presented at the oak workshop.
Under this scenario, he explained, plenty of acorns would be present to sprout into seedlings after the mature oaks were removed. But, just as important, the disturbance created by the logging operation would work the acorns into the soil before deer and other wildlife had the chance to eat them.
In reality, though, such ideal timing is extremely hard to pull off, given the unpredictability of the acorn crop and the busy schedules of loggers.
“We don’t live in a perfect world,” Schilling said, “which is why we recommend oak harvests be done in stages.”
Stage One: Laying the Groundwork for Regeneration
The first stage of the harvest lays the ground work for oak regeneration. Many trees are removed, providing space for oak seedlings on the ground and allowing needed sunlight to reach them. At the same time, the best acorn-producing trees are purposefully left behind to promote regeneration.
It’s almost impossible to predict when the next bumper crop of acorns will occur, Schilling said. So it might take a few years to reach the goal of this first harvest stage: hundreds of oak seedlings per acre carpeting the ground.
Once this needed carpet of seedlings is present, it’s time to move on to stage two: The mature oaks that so dutifully established the conditions for regeneration must also be harvested. And that brings us to the next challenge facing oak.
Stage Two: Creating the Full Sun Conditions for Regeneration
Young oak saplings need full sunlight to survive. While oaks as seedlings tolerate some shade, saplings do not. This is why you will likely see oak seedlings growing under your oaks, but not oak saplings. You just won’t.
This fact makes the second harvest stage absolutely critical to renewing your oak woods. The second stage removes the remaining, mature oaks so that seedlings get the full sun they need to mature into saplings.
While the basics concepts of the two-stage oak harvest are fairly easy to understand, the technical details of these harvests are not. A professional forester can help you make key decisions, such as which trees to leave behind as seed trees and how many; and when to cut your mature oaks after seedlings have become established.
A Listen-In on the Oak Workshop Field Trip
After lunch at the workshop, participants toured the property of local landowner, Jim Moede, which he and his family are actively managing for oak. Jim, along with his forester, have “picked their battles” across the property, Jim said, selecting areas where oak regeneration has the greatest potential for success.
Rather than simply pointing out these areas and telling participants what to do to manage them, tour guide Scott Walter, a wildlife biologist with the Ruffed Grouse Society, encouraged participants to “read the land” and think through possible actions for themselves.
Prompting them through a series of questions, Scott first asked, “What types of trees do you see?”
“Oak trees,” the participants answered.
“Are there any oak seedlings on the ground?” Scott asked. “No,” came the answer.
“What could we do about that?”
“We need to clean out some of this brush,” the group said.
“That is a good start: The brush will out-compete young oak seedlings. Is that all?” Scott probed.
“No, we would have to cut some trees,” said the group.
“How many?” Scott asked.
Amid chuckles of understanding and reluctance, the participants replied, “A lot of them.”