The aim of this thesis is to analyze damage to forest stands due to natural disturbances. The study was carried out at two spatial levels. At the landscape level it analyzed, based on the amount of salvage logging for the period 1973-2011, the volume, structure and dynamics of the causes of salvage logging as well as the impact of site and stand factors on the salvage logging for the Brezova reber forest management unit (the area of 1.722 ha). It was found that the probability of damage occurrence due to natural disturbances is significantly higher during the first three years after logging. Damage due to snow was more likely to occur in younger stands, while damage caused by wind and insects was more likely to occur in older stands. Natural disturbances are more strongly influenced by site than by stand factors. Interaction between the different natural disturbances was confirmed using multiple linear regression. At the stand level in the Brezova reber research site (departments 25c and 26c, the area of 0.81 ha) the 2012 snow damage of stand trees was analyzed. The stands in research sites were divided into three treatments: A) classical selective thinning, B) selective thinning with fixed crop trees and C) control plots for natural development. The highest percentage of damaged trees and crop trees was recorded in treatment A. Differences in the percentage of damaged forked trees were found between treatment B and treatment C. Using the binary logistic model it was found that crop trees that were more released (the number of felled competitors per crop tree) were less damaged. In treatment A damaged trees appeared on the entire surface, mostly near crop trees. In treatment B damaged trees were also inside the clusters of indifferent trees, but less near crop trees. In treatment C the damage was most severe in the part with the highest stand density.
|