The study describes an experiment with the Swiss irregular sheltherwood system. A 40-year period of research and development allows to regard it as a new method which clearly bridges the gap between the Swiss irregular sheltherwood system and the selection cutting system. A new classification was proposed: — an irregular sheltherwood and selection cutting system.
In connection with the decline of spruce stands on the Krynica plots of IPTNS-IUFRO 1964/68, observed in the last decade and attributed to the so-called spiral disease, an attempt was made to determine whether the current health condition of trees is influenced by genotype (provenance). As shown by preliminary observations, the spruces differed in the degree of survival depending on provenance. The inventories of died or broken trees to be removed during the sanitary cutting, made in the years 2000, 2003, 2004 and 2008, yielded also information about the number of spruces that remained in the blocks of the experiment for each provenance and provenance region by Krutzsch (1968). Analysis of variance showed that genotype (provenance) has a statistically significant effect on the survival of trees. In the years 1999-2008, spruces from region 21 (Bohemian Forest) displayed the poorest survival rate in the conditions of the Beskid Sądecki Mts., while those from region 80 (Eastern Siberia) survived best.
The aim of this study was to determine the productive potentiality (stand volume, basal area, and their increments) of the natural little leaf linden stand 26.68 ha in area. This stand is a part of the Obrożyska nature reserve of the total forest area of 98.25 ha. Measurements were carried out in 1995 and 2005 on 26 4-are sample plots established according to the statistical-mathematical system of forest inventory and control, and in 1999 and 2000 on three permanent sample plots which represented different developmental stages and phases of the virgin forest. Between 1990 and 2005, the mean volume of the entire stand increased from 538 to 567 m3/ha. In the growing up stage it increased from 554 to 584 m3/ha, while in the optimum stage from 510 to 541 m3/ha. The volume increment in these two stages was 66 and 51 m3/ha/10 years respectively. Volume of the stand representing the growing up stage in transition to the optimum stage (Obrożyska I classical permanent sample plot) increased during the 10-year period from 700 to 768 m3/ha, while in the stand representing the initial phase of the optimum stage (Obrożyska II) it increased from 797 to 861 m3/ha, and in the stand representing the growing up stage (Obrożyska III) from 696 to 761 m3/ha. The volume increment in these three plots was almost 80, 96, and 82 m3/ha/10 years respectively. The stand volume per hectare of the little leaf linden forest in the Obrożyska reserve is one of the highest among stands of natural character in the Polish part of the Carpathians. A very high productive potentiality of the investigated little leaf linden stand permits to accept this tree species as the main species in stands of the submontane zone as well as in the lower part of the lower montane zone in the Poprad river valley and in the climate close to that of the surroundings of the town of Muszyna.