Hur ska tall- och gran bestånd i Götaland gallras för att minska risken för vindskador?

Abstract: With knowledge of how the southern Swedish forests have been affected by storms the past years, this study intended to find out which factors affect the storm firmness of a stand the most. The study was based on data from stands in the, by the storm Gudrun, affected area. The results of the analyses that tested the stand factors that influence the amount of storm damage to the greatest extent showed that the storm sensitivity of Norway spruce stands were largely due to previous management actions. The factors that could be controlled by thinning and had relevance of storm damage standpoint, according to the results were; the dominant height, volume, basal area weighted mean diameter and stand age at last thinning. In this study, these results are not as clear for Scots pine. Common for both tree species wass that the stands position in relation to a storm advance is a clearly mattering factor. From the results that the analyse gave, a number of thinning programs for spruce have been simulated. The simulations were made for a thinning of 23.6% thinning strength, two thinnings of 22%, three thinnings of 45% and a thinning of 60% thinning strength. An unthinned control was also simulated.