2012 Volume 94 Issue 1 Pages 17-23
Thirty-years data at the Mt. Naeba Experimental Beech Forest were analyzed to suggest criteria for successful natural regeneration after clear-cutting of the cool temperate forests in Japan. In this forest, partial logging of canopy trees was conducted with different intensities (0, 30, 50, 70, and 100%) and removal of shrub, herb and dwarf bamboo were conducted by different methods (weeding or herbicide with or without soil scarification, and control) in 1968 (totally 25 treatments), and the remnant canopy trees were harvested in 1978. The stem length of the tree saplings and the coverage and the maximum height of the vegetation (for each species) were investigated repeatedly in the quadrats. The probability of trees regenerating successfully (the coverage of tree species >50%) in 2008 was modeled based on the density and the mean height of the saplings and vegetation height in 1982. The probability was primarily determined by the density of saplings within the quadrat in 1982. For example, it exceeded 80% when the density of saplings of 50-cm height were >200,000 per hectare. Thus, current criteria (ca. 30-cm height, >5,000 per hectare) should be too optimistic. For successful regeneration, it is highly recommended to establish much more seedlings by weeding before cutting.