Long-Term Seedling Height Growth and Compositional Changes Following Logging and Wildfire in a Central Pennsylvania Oak Forest

Overstory and understory data were collected over a 15-year period (1996–2011) before and after seed tree logging in 1996 and an accidental wildfire in 2006 in a young developing mixed-oak forest in central Pennsylvania. The mature forest overstory was dominated by chestnut oak (Quercus montana) followed by northern red oak (Quercus rubra), black oak (Quercus velutina), scarlet oak (Quercus coccinea), and red maple (Acer rubrum). Logging reduced the stand basal area by 76% and the tree density by 80%. Tree regeneration was dominated by red maple and mixed-oak species with 32,956 stems per ha prior to logging, which increased to 47,170 stems per ha eight years later. Wildfire reduced tree regeneration to an average of 22,511 stems per ha over three sample periods, with the largest reduction in red maple (−60%), followed by red oak species (−36%) and chestnut oak (−17%). The mean maximum height of plot-dominant regeneration for red maple and the four oak species increased significantly during the eight years after logging (from 0.14 to 1.29 m), but was reduced by 27% after wildfire (most in red oak, −56%). The maple and oak species again had rapid height growth for four years after wildfire, by which time they exceeded their preburn heights. The success of oak species in this study is related to their ability to produce a relatively large number of seedlings (before and after logging and after fire) and match or exceed the height growth of red maple after these disturbances.