Stand recovery of a temperate hardwood forest 60 years after a stand-replacing windthrow based on a permanent plot study

Abstract: We examined the dynamics of stand structure and composition over a 60-year period in two permanent plots in a deciduous hardwood forest in Hokkaido, Japan, which were severely disturbed by a stand-replacing windthrow, to reveal trends that could be valuable to the development of a model of forest recovery after a severe windthrow. We analyzed temporal trends in tree density, species richness and diversity, successional composition, and stand development stage in the plots. Both plots recovered as hardwood stands. Tree density and species richness increased, peaking 35‒40 years after the windthrow, and then decreased in both plots. Based on these results, we concluded that both plots were in the stand-initiation stage for 35‒40 years after the windthrow, and then transitioned into the stem-exclusion stage. Species diversity increased with an increase in species richness during the stand-initiation stage, and then decreased slightly in both plots. In both plots, successional composition did not fluctuate greatly in the 60 years after the windthrow, and both returned to pre-disturbance composition during the stem-exclusion stage. The temporal trends observed in this study were remarkably similar to those in a previous study of permanent plots located near the plots used in this study. Therefore, this study provides valuable information that can be useful in the development of a stand recovery model in temperate forests after stand-replacing windthrows