Wpływ sposobu pielęgnowania uprawy na wzrost dębu

We examined growth of oaks after cleaning carried out in a 11−year−old stand in Kolumna Forest District (central Poland). The purpose of the treatment was to remove naturally regenerated species mainly birch. Four different cleaning variants were applied. They differed in time of application and height of unwanted trees i.e. spring cleaning at ground level in every second oak row (W1) or over the entire surface (W2), breaking at a height of 1 m in spring (W3) or in summer (W4) and control (K) where trees were not removed. We analyzed height and its increment, dbh and its increment as well as slenderness, i.e. h:d ratio, in 4−year−long period after treatment. The study reviled that the cleaning, regardless of the applied method, significantly improved oak growth, while lack of cleaning led to increased competition of birch. The pressure from the other species firstly reduced diameter increment and later the height increment (tab.). As a result, the h:d ratio of oaks increased. The 4−year height and dbh increment were similar in all the applied treatments but in the last year of study the dbh increment in variants W2 and W4 was significantly higher than in W1 and W3 due to greater competition of birch in these variants (figs. 1 and 2). Cleaning done on a limited area provides satisfactory growth and stability for young oaks, but it is probable that such a stand needs more frequent intervention than the one from W2 cleaning variant.