2013 Volume 12 Pages 1-20
This case study analysis examines how overstory and topographic conditions impact regeneration of Abies sachalinensis (Abies) in a selection forest at the University of Tokyo Hokkaido Forest in Northern Japan. The analysis includes 1,382 inventory plots that were regularly surveyed between 1995 and 2004. The density of Abies juveniles and basal area of mature Abies overstory trees were calculated for each plot. Five topographic conditions—elevation, slope angle,curvature, solar radiation, and the topographic wetness index—were examined through spatial analyses using ArcGIS software with 10-m grid digital elevation models. A general linear mixed model analysis was performed to determine site factors affecting the abundance of Abies juveniles. Results indicated that basal area of mature overstory Abies, slope angle, curvature, and solar radiation had positive effects on the abundance of Abies juveniles, while elevation had a negative effect. These factors may be related to the distribution of dwarf bamboo (Sasa senanensis and S. kurilensis) and pathogenic fungus (Racodium therryanum or Herpotrichia juniperi), both of which are recognized as major inhibitors of natural regeneration in Hokkaido.
