Modeling sprout-origin oak regeneration in the central Appalachians

We describe the development of individual-tree models to estimate, before overstory removal, the contribution of common central Appalachian oak species (northern red oak (Quercus rubra L.), black oak (Quercus velutina Lam.), chestnut oak (Quercus montana Willd.), and white oak (Quercus alba L.)) to stand stocking in the third decade (20-30 years) after harvest. The models incorporate three aspects of sprout-group development: (1) the initial sprouting of overstory oaks (≥5 cm DBH) following cutting, (2) sprout-group survival, and (3) sprout-group size at the end of the regeneration period. Logistic regression was used to model initial sprouting as a function of parent tree species and diameter using measurements on 1173 stumps. Sprout-group survival was extrapolated from 4 year remeasurements on 321 stumps. Sprout-group size, expressed as a percentage of stocking, was estimated from measurements on 429 third-decade sprout groups. Predicted sprout-origin stocking values calculated for mature oak stands compared favorably with stocking values observed in third-decade stands. The models provide forest managers with essential information on stand development following planned regeneration treatments. A similar modeling approach may be useful in other plant communities where sprouting plays an important role in post-disturbance stand development.