Abstract:Typhoons are one of the most important natural disturbances, which directly or indirectly have effects on forest stand structure and function. Typhoons disturbance events occur in nearly all forest ecosystems and have profound impacts on forest structure, species diversity and ecosystem functions. Such ecological effects are often complex, subtle, and at small scale relatively unpredictable. Many factors such as tree size, stand density, tree species, stand structure, altitude, gradient, slope location and aspect, affect wind resistances of tree species and the extent of forest damage. The typhoon rarely arrives in temperate regions close to the coastline and in the temperate regions of the interior land. So there is little known about the influence of typhoon on forest in the temperate regions of the interior and even in northeast China. Typhoon "Bolaven" has caused serious damage on forests in northeast China in 2012. In this paper, Typhoon-induced damage has been analyzed at stand level for semi-natural larch-spruce-fir forests of Wangqing Forestry Bureau in Jilin Province. Analysis of variance and correlation analysis are used for examining effects of stand structure and topography on damage severity of trees. Results showed that:(1) Typhoon caused massive damage to semi-natural larch-spruce-fir forests, in some cases reaching over 30% of all trees in the stands. The average percentage of the damaged trees was 14.05%. Major tree damaged types were uprooted, broken, hooked and bending. Among these types, the type of uprooted was the dominant one with a rate of 52%. (2) Tree diameter class had significant effects on the extent of tree damage. The medium and small-class trees were more vulnerable to typhoon damage than the bigger ones. (3) There was no significant correlation relationship between the density and the extent of tree damage. However, the extent of tree damage weakly decreased with increasing stand density. (4) Trees damaged differed significantly among tree species. Broad-leaved tree species were easier to be hurt by typhoon. (5) No significant correlation relationship was found between tree species diversity index and the proportion of damaged trees. (6)The altitude, gradient and slope location had no significant impacts on the extent of the tree damage, while the aspect had, especially the northeast aspect which was more vulnerable with a high damage rate of 18.35%. Therefore, tree size, tree species and aspect were important factors affecting the tree damage of typhoon in this study, and the impact was complicated. We suggested that improving tree quality and mixing tree species enhance stand resistance to wind. The findings presented in this study provide information that can be used to implement silvicultural practices to minimize the risk of those forests and to resist wind damages.