When you hike through the woods in Nashville, you don't expect to encounter wolves. If you keep your eyes open, though, you may see some wolf trees.
Foresters used the term 'wolf tree' to indicate a very large tree with a broad crown and a short main stem. These trees were considered wolves because they were so large that they devoured sunlight that other trees might need. These trees were often killed because they had no market value.
Today, we have a changed opinion of these huge trees. They are now understood to be very important as wildlife habitat and also in regenerating a new forest after harvesting or damage. Harvesting rules, especially on state and federal forest land, often require that wolf trees be left in place.
Wolf trees serve another important purpose: they can tell us a lot about the history of a forest. On a recent walk through the Warner Parks of Nashville, I noticed something striking. Throughout these hilly, dense woods were many huge wolf trees. A closer inspection showed that these were species typical of the woodland pasture habitat: chinkapin oak, Shumard oak, blue ash, and kingnut (I have not yet seen any bur oak).
Their enormous size and low, spread branches tell us that these trees did not grow up in a forest, but in either an open woodland or woodland pasture. The level ground surrounding the Warner Parks has a large number of woodland pasture tree species and several intact woodland pastures. I suspect that this part of Nashville represented a continuum from woodland pastures on level ground to open woodlands and the slopes and denser forest on the upper slope.
The Warner Parks are about to lose their large population of white ash to emerald ash borer. I made a quick estimate of the stocking (timber density) of white ash in the Warner Parks and estimated it to be more than 20%. As these trees die over the next few year, conditions may favor the ability of the wolf trees to reproduce.
I look forward to learning more about this beautiful area.