Effects of Phellinusweirii gaps on early successional vegetation following timber harvest
A 65-year-old stand in northwestern Washington dominated by Pseudotsugamenziesii (Mirb.) Franco was harvested by clear-cutting in 1987. Before harvest, canopy gaps caused by the root-disease fungus Phellinusweirii (Murr.) Gilbn. covered about 22% of stand area. Five years after harvest, overall plant species composition of former gaps differed significantly from adjacent areas of previously intact forest. Forbs and trees were more abundant, and ferns less abundant, in areas of previously intact forest than in former gaps. In contrast, total cover, species diversity, and the abundance of plant species groups (defined by distributional and life history characteristics) did not differ significantly between areas of previously intact forest and former gaps. Plant species responded individualistically to timber harvesting in gaps and intact forest. These results show that development of root-disease gaps may influence understory patterns during early succession following harvest.