Tom Wessels, MA
Department of Environmental Studies
Sixteen plots were surveyed in a rich northern hardwood forest which was logged using group selection cuts during the winters of 1998-99 and the summer of 2000. Eight plots were placed in patch cuts while the remaining eight plots were placed in the unlogged forest matrix as controls. Each plot was sampled in August 2000 and again in late May or early June, 2001. Sampling at each plot consisted of estimates of percent cover for all herbaceous species in each of 20 1x1 m sub-plots. Comparisons of alpha diversity and cover were made between forest matrix samples and patch cut samples and between summer-harvest areas and winter-harvest areas. Plots cut in the winter showed significantly higher alpha diversity and cover than their corresponding control plots while both measures were significantly lower in summer cut plots than in the surrounding forest. Summer logged areas were also significantly lower in alpha diversity and cover than winter logged areas. Control plots at each of the two areas showed no significant difference in either measure. As a group, ferns appeared to be especially sensitive to logging disturbance with Botrychium virginianum, Adiantum pedatum, Cystopteris bulbifera, and Dryopteris marginalis showing significant declines in harvested areas. Winter-harvesting appears to create the least immediate negative impact on vernal herbs.