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The aim of the study was to compare growth and survival of plug and bare−root seedlings planted at different dates. The experiment was established in 2003 in the Oleśnica Forest District (south−western Poland). Seedlings were planted at four dates: the end of August, September and October 2003 and the beginning of April 2004. The two−factorial experiment comprised eight treatments. It was established in the randomized complete block design in five replications. In each plot a total of 390 seedlings were planted. The objects were measured in the years 2004−2008 and 2013. At first height of all trees was measured using a scaled rod. In 2013 diameter at breast height was measured on all trees and height was measured for some randomly selected individuals. The ANOVA was supplemented with with Tukey's multiple comparison test. The height and diameter distributions in analysed variants were compared with Kolmogorov−Smirnov test. Treatments were found rather not to vary in terms of their survival rates (fig. 1). No variation was found for mean diameters at breast height (tab. 1). The difference between the treatment with the maximum (August planting, bare−root seedlings) and minimum (April planting, bare−root seedlings) tree height equaled 69 cm. No significant differences were recorded between mean heights of trees planted in August, September and October regarding the planting material type. Variation in basal area results both from survival rates and diameter at breast height. Only spring planting of bare−root seedlings was found significantly different from all other variants (tab. 1). Differences in height between the control and the mean for the experiment increased continuously (fig. 4). Scots pine seedlings may be successfully planted in late summer and autumn. Under relatively advantageous conditions, particularly moisture levels, 1 year old bare−root pine seedlings are not inferior to plug seedlings. Plug seedlings tolerate soil drought conditions better than bare−root seedlings. The effect of stress connected with drought after planting, measured by mean height, rather than disappearing, is continuously increasing with age.
The study assesses the effect of applied cuttings on the transformation of the species composition, structure and development of the forest towards selection forest type. The described control unit was established in 2000 in the Krucze Mts. (southern Poland) within the programme of silver fir restoration in the Sudety Mts. The working hypothesis was based on the advantageous effect of the selection management system on fir trees. 46 permanent circular sample plots of 0.05 ha each were established and diameter at breast height measured on all trees along with height of 2−3 trees growing closest to the plot center. Measurements were repeated in 2004 and 2013. The greatest share in the growth increment was recorded for the most numerous species (spruce and fir). Only spruce and beech were important in the group of young trees (recruitment), which did not include fir or larch. The timber resources increased from 339 in 2000 to 381 m³/ha in 2013, which indicates that not whole current increment was harvested. The increase in the growing stock follows the reduction in the number of trees per hectare from 361 to 317. Thus the number of young trees did not compensate for the losses. As a result the investigated unit is not in the state of equilibrium and in the future more work and care should be devoted to the regeneration. Fir turned out to be a species with the greatest production potential. In the first period growing stock of this species amounted to 17%, while the increment was over 26%. In the latter the increment reached 34%. The most important objective of the selection cuttings in this concrete unit should be to tend for regeneration and trees at low diameter sub−classes at the expense of use of trees with target values of diameters at breast height and disturbing the selection cutting structure. It is advisable to increase the share of fir in the structure of analysed unit.
The study objective was to verify the hypothesis on ecotypic variation in beech and ineffectiveness of transferring its reproductive material over larger distances. Beech nuts were collected in the autumn of 1990. Experimental sites were established in the Baligród and Oleszyce forest districts (SE Poland). On single plots of 18.00×13.75 m (247.5 m²), a total of 110 three−years−old seedlings were planted in a 1.50×1.25 m spacing in autumn 1993. Single row of mountain ash was left between the plots. In the period of 1994−2016 a series of analyses was conducted concerning adaptation, growth, phenological and qualitative traits. Height was measured on all trees using a measuring stick, except for the year 2016, when hypsometer was used to measure approximately 20 heights and remaining ones were determined based on the height curve. Results were analysed using univariate analysis of variance based on the random model, followed by Duncan’s multiple range test for each experimental site and year of the study. For 2016 ordering of populations in each of the experimental sites was compared using Spearman’s rank correlation test. In terms of survival rates in Oleszyce site the local provenance from Oleszyce proved to be superior. In all the years of the measurements it was characterised by the highest survival rate. In this respect the Komańcza and Lutowiska provenances from the Bieszczady Mountains turned out to be the worst ones. In the experimental site in Baligród, the Barlinek and Połczyn provenances outranked the others in terms of their survival rates, while in 2016 it was the population from Komańcza. Tree height effects in Oleszyce site showed that the local population from Oleszyce grows best, while the Pomeranian population from Jamy was also exceptional. The Bieszczady populations (Komańcza and Lutowiska) are characterised by the worst growth traits. In the experimental site in Baligród, the local Baligród population is characterised by poorest growth, similarly to the other ones from the Bieszczady. In terms of growth, the Western Pomeranian population from Gryfino is exceptional. As far as all the evaluated traits are concerned the investigated populations exhibit considerable variability, as no geographic ordination could be found. It was confirmed that imported populations, even from long distances, may exceed local populations in terms of their adaptation traits and growth rates.
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