Red spruce stand dynamics, simulations, and restoration opportunities in the central Appalachians

Red spruce (Picea rubens)-dominated forests occupied as much as 600,000 ha in West Virginia prior to exploitive logging era of the late nineteenth and early twentieth centuries. Subsequently, much of this forest type was converted to northern hardwoods. As an important habitat type for a number of rare or sensitive species, only about 12,000 ha of red spruce forests presently remain in the state. In order to assess the prospects for restoration, we examined six northern hardwood stands containing understory red spruce to (1) characterize stand dynamics and regeneration patterns and (2) simulate the effectiveness of restoration silviculture to enhance red spruce overstory recruitment. Stands originated in the late 1800s to early 1900s and are currently in the (late) stem exclusion or understory reinitiation stages. Five of the six stands had even-aged overstories that originated after clear-cutting. Tree-ring chronologies show high initial growth rates consistent with stand initiation. One stand, partially harvested in 1915, was uneven aged with older, legacy residuals in the canopy. Most stands had two cohorts of understory red spruce, with more than 40% of these individuals showing prior release. Our 100-year growth simulation suggested that a 50% basal area thinning from above could double red spruce basal area to support a mixed spruce-hardwood stand in approximately 20-40 years. These results indicate that restoration silviculture could be an effective tool for increasing the amount and quality of this reduced forest type in the central Appalachians.