High Hopes for Red Oak Regrowth

How our forestry plan is unfolding at the Hope Forest in Danbury

September 3, 2014

After the 2014 timber harvest, the red oak trees still standing at the Hope Forest site are seed trees. Their acorns will fall on ground cleared of competition and prepped to be as amenable as possible for acorn sprouting. Photo by Wendy Weisiger.

One of our more interesting recent timber sales is at the Emily and Theodore Hope Forest in Danbury. We’re using a “seed tree cut” for part of this harvest to encourage red oak to grow.

            The site is very good for red oak, producing a high percentage of quality sawlogs and veneer.  It would be nice to think we could just harvest the red oak and get more back, but that doesn’t usually happen unless you make some effort.  The old timers used to say “Cut pine get oak, cut oak get pine.”  And that certainly is the case when one species populates the understory of the other.  They seem to like the same sites and don’t mind taking advantage of each other.  However, at the Hope Forest we want to have red oak follow red oak.

            Silviculture, the science, art and practice of growing trees, is very specific for each species.   There are many factors to successfully regenerating a tree, and it is likely we don’t know all of them and of the ones we know, we can only control a few.  What we know about red oak is that it needs some shade, that a high percentage of the acorns are rendered unusable every year, that the acorns need to overwinter before they will sprout and that if buried they have a much better chance of becoming seedlings.  We also know that red oak doesn’t fill the air with acorns every year.  In fact, only one of every three to five years is considered a good year, one in which the trees will drop prodigious numbers of acorns.  An acorn has to make it to welcoming ground, then survive a gauntlet of turkeys, deer, insects, fungi, excessive moisture, freezing temperatures, periods of just enough sun and others of just enough shade. Then it might, perhaps, become a tree.  

            So, if we want to have any chance at all of regenerating red oak, we need to make things easier for those acorns.  And that’s what we have tried to do at the Hope Forest.  The first thing we did was to wait!  We waited for a bumper seed crop year. We also waited until the market was strong for the red oak that would be removed, because the high quality deserved good prices.  When those two factors coincided, the seed trees were designated by a forester to remain while the rest of the stand was marked for removal.

            The seed trees will provide additional acorns over the next few years, and their shade will shelter the expected oak seedlings on their journey upwards.  During the operation, the logger skidded logs throughout the harvest area and not just on selected trails.  This disturbs the maximum amount of leaf litter and turns the top layer of soil to loosen it and make it more receptive to acorns.  In the process, acorns are pushed into the soil, hiding them from predators and adding a few percentage points of probability that they will sprout in the spring.

            Now we’ll wait again to see if our efforts produce the desired results.  Mom Nature is not as predictable as we would like. She makes the rules and all we can do is play the game without knowing them all. In a few years we’ll revisit the Hope Forest and do some counting in the harvest areas.  The chances are pretty good we’ll find red oak seedlings during that visit.  But for now it’s only a hope.

           George Frame is senior director of forestry at the Forest Society.