Stochasticity of species assemblage of canopy trees and understorey plants in a temperate secondary forest created by major disturbances

Detrended canonical correspondence analysis (DCCA) was applied to explore the species assemblage of plants in a temperate secondary forest that was created by major disturbances. The DCCA showed vague relationships between species dominance and environmental factors for canopy tree species even when rare species were excluded from the analysis. For the highest dominant species of the understorey, the scores of the first axis, which correlated with the species richness of overstorey trees, decreased. This fact showed that the assemblage of canopy trees affects, through the differences in leaf phenology or leaf characteristics of canopy trees, the life history of dominant understorey plants. The study's results suggest that competition colonization might be more important for canopy trees during the developing stage of the forest if the disturbance occurs on a large scale, and that colonization from the local species pool determines species assemblage on a landscape scale.