In 2009 was carried out the second measurement on research plots inside young beech forests on plateau Mežakla, which were designed and first measured in 2005. Three types of thinning treatments were used. First treatment which was used was a conventional selective thinning with normal intensity of cutting (Treatment 60), second treatment had a 50% lower density of crop trees, but with normal thinning intensity (Treatment 30), and the third treatment had 75%lower density of crop trees and strong thinning intensity (Treatment 15). For all crop trees were determined tree species, measured the diameter, height, length of trunk without branches, were counted the branches at first 4m of a trunk and defined asymmetry of crown and its place to grow. After fourvegetation seasons only minor differences between treatments were significant, but it should be noted that the results are preliminary. Method 15 has proved to be favourable if we want to increase the diameter of the trunk, the volume of the canopy and provide a better stability of crop trees. Treatment 30 has proven best for improving length of the trunk without knots and the number of thin branches on the first 4 m of trunk. If we want a bettercleaning of thick branches or more growing space for crop trees we will decide for Treatment 60. However, if the stands are left to natural development, this will positively influence the height growth and decrease thenumber of thin branches. Treatment 15 with high thinning intensity also postpones next interventions to the future. With Treatment 30 we can reduce the ratio of h/d and increase the crown, which is in the area with frequent natural disturbances very important. The Treatment 60, which represents the classical selective thinning and is in current practice most often applied, produces good results and does not require substantially more work load than those required by other methods of thinning which were tested.
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