Regeneration Dynamics on Treefall Mounds and Pits for 10 Years after a Windfall in a Natural Mixed Forest

The treefall mounds and pits resulting from uprooting caused by strong winds is an indispensable microtopography for the regeneration of many tree species through improved light conditions mineral soil exposure. These microtopographies are expected to become more important because global warming predicted increase windstorm frequency. This study aimed clarify characteristics that contribute early establishment major in a natural mixed forest northern Japan. 39 tip-up simultaneously typhoon September 2004 were selected. In 2006, intensity moisture contents measured each mound pit. Seedlings all counted, 2014, height saplings was measured. initial seedling density, regardless species, significantly higher than on mound, but density at 10-th growing season decreased comparable between two locations. Intense favor Betula sp. (Betula platyphylla B. ermanii). contrast, Abies sachalinensis Picea glehnii, had negative effect, so it concluded conifers would be limited under condition where form large gaps.