Oak decline risk rating for the southeastern United States

Abstract

Oak decline risk rating models were developed for upland hardwood forests in the southeastern United States using data gathered during regional oak decline surveys. Stepwise discriminant analyses were used to relate 12 stand and site variables with major oak decline incidence for each of three subregions plus one incorporating all subregions. The best model for the northern Appalachian subregion included soil depth class, oak basal area, site index, and stand age (R² = 0.65). In the southern Appalachian subregion, significant variables included slope gradient, soil depth class, oak basal area, and clay content (R² = 0.30). The Ozark model included clay content, slope gradient, and oak basal area (R² = 0.32). The composite model included site index/age, clay content, slope gradient, soil depth class, and oak basal area (R² = 0.22). The relatively low R² values and variation in the relationships for some attributes suggest that major oak decline events may be influenced by additional factors.

Citation

Oak, S.; Tainter, F.; Williams, J.; Starkey, D. 1996. Oak decline risk rating for the southeastern United States. Ann. For. Sci., Vol. 53: 721-730