THINNING OF SCOTS PINE STANDS AND SNOW DAMAGE

Effect of thinning on snow damage in Scots pine (Pinus sylvestris L.) stands was studied in three long-term experiments located in Polabi Lowland in the Eastern Bohemia. High snowfall occurred in January 2010 and damage in differently thinned (and planted with different spacing) 25-, 48- and 80-year-old pine stands was analysed. It was confirmed that h/d ratio is good indicator of individual stability of tree against snow damage. Values of h/d ratio over 100 were found for all damaged trees. Results showed that lower initial density itself is not a guarantee of stand stability without subsequent thinning. For studied sites, early thinning (to the top height 5 m) is applicable as a measure to reduce the risk of snow damage. In middle-aged pine stands, the effect of thinning on stability has decreased. Furthermore, this effect is minimal in mature pine stands.