Vplyv vychovy a po kodenia snehom na zmeny drevinového zlo enia, porastovej vystavby, kvalitatívnej a kvantitatívnej produkcie zmie anej smrekovo-jed ovo-bukovej r oviny na vyskumnej ploche Stará Píla

The paper is a contribution to the research on problems of thinning in mixed (spruce-fir-beech) stands situated in the 5th altitudinal vegetation zone (beech with fir) in the central part of Slovakia. The research was carried out on two series of permanent research plots established in 1972. Each of the series consists of three partial plots. Free crown thinning was used for tending one plot as a part of whole-area tending. On the second plot a non whole-area tending was realised and/or the third one was left without planned silvicultural treatment as control. At the turn of years 1993 and 1994 research plots were affected by snow break disaster. Dynamic changes of tree species composition, stand structure, qualitative and quantitative production including silvicultural analysis of eight thinning interventions were evaluated for the period of 34 years. Special attention was paid to the development of future crop trees, which are the main bearers of stand quality and quantity. The changes were compared with respect to differences between the plot with whole-area and non whole-area long-term silvicultural treatment and the control plot (without treatments). Preliminary results showed favourable development of tended plots despite the damage by snow in the past.