Management History-What We Did
Overstocked oak savanna before thinning
When my husband, Bill and I moved to our farm, Timberhill, we had no idea that we would be restoring an oak savanna. We just wanted to be improve our woodlands. Over half the property that we had purchased was overstocked oak and hickory woodland. The understory was so thick with elm, honey locust, prickly ash, multiflora rose, and other woody invasives that one couldn’t walk through the woodlands without a machete. Since we knew nothing about timber management we consulted our Iowa district forester, Randy Goerndt. (Iowa provides a forester to assist landowner woodland management in each of thirteen forestry districts.) After compiling a complete inventory of our woodlands Randy recommended thinning the pole timber and clearing the understory.
Thinned oak savanna
We began thinning the woodland in 10-15 acre units, one unit each year. However, it didn’t long for shingle oak grubs, coralberry and other scrub to take advantage of the dappled sunlight in the newly opened woodland. Bill and I could see that it wouldn’t take long for the thinned woodland to become crowded with woody invasives again. We consulted an ecologist who told us that our property was a rare oak savanna. She pointed out the large spreading oak trees which she called “wolf trees.” Presettlement these had been the only trees in our woodlands. Cessation of fire after European settlement caused the woodlands to become overstocked. The ecologist explained that oak savanna is a fire dependent ecosystem, and we would have to restore fire in order to restore the woodlands.
Same oak savanna after five annual burns
Bill and I began burning our woodlands in 1995. We began in small units, gradually increasing the size of our burns as we became more experienced in managing controlled burns. Since 2003 we have burned the entire restoration each year. These annual burns are spotty leaving a patchwork of burned and unburned ground. They are much less destructive than less frequent burns because there is less fuel. Instead of parboiling and scorching the ground as periodic burns do they scud over the ground leaving the rhizome layer intact. (A report studying the effects of various management regimens at Timberhill and adjacent unmanaged property is attached.)