Soil scarification effects on oak reproduction in two mixed-oak bottomland stands of southern Illinois

This study investigated whether soil scarification during the presence of oak mast could increase oak seedling establishment and decrease poison ivy cover in two mixed-oak bottomland stands that lacked adequate advanced oak reproduction. Study sites were located along the Saline River in southern Illinois and designated as Cherrybark Bottoms, with an overstory dominated by cherrybark oak (Quercus pagoda Raf.), and Post Oak Flat, which contained an even mixture of post oak (Q. stellata Wang.) and cherrybark oak. Scarification was completed in November of 1999 using a small farm tractor with a pull-behind field disk to incorporate acorns into the soil. One growing season after scarification, Cherrybark Bottoms had significantly more oak seedlings in the scarifled plots (7,243 ha(-1)) than in controls (453 ha(-1)). Likewise, Post Oak Flat had a significantly greater density of oak seedlings in scarified plots (8,715 ha(-1)) when compared to control plots (679 ha(-1)). In addition, scarification decreased poison ivy [Toxicodendron radicans (L.) Kuntze] cover in both stands. Results suggest that, in the presence of abundant acorns, scarification may increase the establishment of new oak seedlings in mixed-oak bottomland forests.