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The basic purpose of this study was to determine a working-day structure and work productivity rate during the process of timber harvesting in mountain conditions. The parameters were determined on the ground of data collected during field studies. The aforesaid working-day structure was defined on the ground of time study observations. The areas included in the survey were typically mountain stands, in which cutting was applied by means of a cutting method IVd. Work teams assigned approximately 50-70% of their work-shift time to technological operations, whose greatest part was taken by delimbing and slashing. A significant portion of the day was taken by preparation of a workstand (approx. 10%), as well as cutting and felling. This was caused primarily by the necessity of snow coat removal. Technological work productivity rates amounted to some 3 to 14 m3 per day per one worker. During the skidding process, a significant percentage of trees remaining along the skidding path was being injured. On the ground of the obtained results and their analyses, an attempt was made to evaluate and suggest possible changes in timber harvesting organization, in order to improve work productivity rates.
The European beech is a major component of central European forests, and the eastern limit of its range lies in Poland. However, the Holocene migration of the beech is not yet finished, especially in NE Poland, so the northern distribution of the beech continues to change. The main goal of this study was to determine if the beech will reach its northern limit in the future. The investigation was carried out in 18 beech stands in Poland. To study the status of the health of the trees, circular plots were established in grids of different sizes. The basal beech stand area ranged from 3.7 m² ha⁻¹ to 31.2 m² ha⁻¹. The density of trees exceeded a hundred trees per hectare in most of the plots (61%), and the average degree of defoliation was not greater than 60% in all of the investigated stands. Environmental conditions influenced defoliation of beech trees (Fisher's test, F = 4.0204; P <0.0001). The vitality of the beech trees varied between stands (Kruskal-Walis test, H = 139.7433, P <0.0001) and was rather good in 56% of the study plots. Seedlings and saplings were observed in all of the investigated stands, and they covered from 5 to 39% and 21 to 80% of the study plots, respectively. Spontaneous beech regeneration was widespread and differed from stand to stand as well as within stands in all of the study plots. The number of tall seedlings in most of the study plots (56%) was greater than 10,000 individuals per hectare. The factors limiting beech regeneration were stand density and herb cover, and the number of beech seed trees influenced the quantity of small seedlings. Beech tree density positively influenced the number of small seedlings, and the strength of the correlation was moderate and statistically significant (Pearson correlation, r = 0.349). Beech tree density influenced the vitality of tall and small saplings (Pearson's correlations, r = 0.673 and r = 0.361, respectively). The spontaneous regeneration and strong vitality of seedlings and saplings suggests that beech can create stable stands in the future and that it is an expansive tree species both within its continuous range and at the limit of its distribution. It is quite possible that beech will reach its north-eastern limit in Poland in the future.
This paper presents results of analysis of the dynamics of growth and development of beech stands in the lower subalpine zone in the Bieszczady National Park from the point of view of size-volume interrelationships of the following three main forest-forming processes: thickness increment, the process of trees dying off in stands and growing of young trees to reach the layer of the manure stand. The obtained results confirmed that the examined beech forests exhibit similarity with multigenerational, complex forests of primeval character. An argument in favour of this includes in particular: high stand volume, good forest health condition and a positive relationship between the process of tree survival (volume increment and ingrowth) and the decrement process. The wide peak distance of culminations of two traits is characteristic too: the number of trees in the lowest diameter subclass and the volume in the diameter subclass several intervals higher.
The study presents the results on the dynamics and structure of the litter fall in the beech stand in two years (1995 - seed year and 1996 - barren year) overgrowing the northern slopes of the "Góra Chełmowa" located in Ojców National Park in two fertility variants. The total litter fall mass during the seed year was on average 4067.3 kg/1 ha and was different by 1260.15 kg from the results obtained during the following year. The greatest part of the litter fall are leaves, which make about 67.6% of the litter fall mass during the seed year and as much as 95.9% in the following year. The fertile habitat had a stimulating effect on the litter fall biomass production such as leaves, seeds, and seed cupules.
Investigations were carried out in series of 6 permanent study areas (5 in forests of prime­val character, and 1 in a managed stand) with the growing stock ranging from 226 m3ha-1 to 593 m3ha-1. These stands were characterized by a considerable differentiation of the tree d.b.h. and a complex storeyed structure, resembling a selection forest. Only two stands reached the growing stock close to the one accepted as the optimum for the beech selection forests. When carrying out a selection cutting in such forests one should take the lowering of the growing stock to about 220/250-300 m3ha-1 into consideration. It would be more correct, therefore, to carry out in managed beech forests a Swiss irregular shelterwood system, rather than a selection cutting system. The latter one may be used in the beech stands of differentiated structure in protection forests or in forests of a special purpose.
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