THE REGROWTH CONSERVATION AFTER SELECTION CUTTING OF FOREST STANDS GROWING IN HYLOCOMIOSA SITE TYPE

Clear cutting and selection cutting are final felling methods. Clear cutting are often used in Latvian forest. The disturbance of biological rhythm in clear cutting areas occurred for several years. Whereas selection cutting is more environmentally friendly, efforts should be made to apply it more in practice. Objectives of this research are to analyse the regrowth conservation after gradual felling in Hylocomiosa forest stands with a different species composition and determine tree health. For dendrometric indicators and gradual selective felling intensity characterization, twelve sample plots with an area of 500 m2 were established in both forest stands. Plots were surveyed before and after the gradual selective felling. In order to perform an analysis of regrowth, 92 small inventory plots with a radius of 2.82 m were evaluated. Regrowth trees were counted (conifers from 0.1 m height and deciduous - 0.2 m) and their height was measured, as well as root rot infection was verified. In the Norway spruce mixed stand (7S3P145) felling intensity was 52% but in the Scots pine mixed stand (5P5S105) respectively – 49%. After felling trees regrowth number of losses account are 53 and 68%. The average height of spruce regrowth trees in both stands after felling was fallen but average height of birch and Scots pine regrowth increased. The differences of regrowth preservation between tree species during selection cutting were significant (p=0.016 α=0.05). Root rot was not detected in the mixed Scots pine stand, but in spruce stand it was found in 33% of cases.