Black Oak Site Quality in Relation to Soil and Topography in Southeastern Ohio

Abstract

Abstract Site quality for black oak ( Quercus velutina Lam.) was studied in 135 well‐stocked, even‐aged, undisturbed stands located in the unglaciated hill country of southeastern Ohio. Multiple regression analysis showed the following, for medium‐textured, well‐drained soils: (i) site index increases with increased depth of surface soil (A1 + A2 horizons); (ii) site index decreases with increased amounts of stone in the subsoil (B1 horizon); (iii) better site index occurs on lower slopes and in coves while poorer sites are generally found on upper slopes and ridges; and (iv) better sites occur on north‐ and east‐facing slopes while poorer sites occur on south‐ and west‐facing slopes. For fine‐textured soils with restricted internal drainage: (i) site index increases with increased depth of surface soil (A1 + A2 horizons); (ii) poorest sites occur in areas having the finest textured subsoils; and (iii) site index increases with increased steepness of slope. Multiple‐regression equations accounting for about 80% of the variance in tree height are presented for each of these soil groups. Site‐prediction tables based on these equations are given for estimating the site index of black oak on the forested uplands of southeastern Ohio.