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Igor Štefančík

Vplyv výchovy a poškodenia snehom na zmeny drevinového zloženia, porastovej výstavby, kvalitatívnej a kvantitatívnej produkcie zmiešanej smrekovo-jedľovo-bukovej žrďoviny na výskumnej ploche Stará Píla

Práca je príspevkom k výskumu problematiky prebierok v zmiešaných (SM-JD-BK) porastoch 5. lesného vegetačného stupňa v oblasti stredného Slovenska. Výskum sa uskutočnil na dvoch sériách trvalých výskumných plôch založených v roku 1972. Na každej zo sérií sú tri čiastkové plochy, pričom na jednej sa aplikuje úrovňová voľná prebierka v rámci celoplošnej výchovy. Na druhej ploche sa uskutočňuje neceloplošná výchova, resp. tretia plocha sa ponechala bez úmyselného zásahu ako kontrolná. Na prelome rokov 1993 a 1994 boli výskumné plochy postihnuté snehovou kalamitou. Vyhodnotili sa dynamické zmeny drevinového zloženia, porastovej štruktúry, kvantitatívnej a kvalitatívnej produkcie vrátane pestovnej analýzy ôsmych zásahov za obdobie 34 rokov. Osobitná pozornosť sa venovala vývoju budúcich cieľových stromov, ktoré sú hlavnými nositeľmi kvalitatívnej i kvantitatívnej produkcie porastu. Zistené zmeny sa porovnali z hľadiska rozdielov medzi dlhodobo celoplošne i neceloplošne vychovávanými plochami a kontrolnou plochou (bez zásahu). Doterajšie výsledky naznačujú priaznivý vývoj porastov na vychovávaných plochách aj napriek ich poškodeniu snehom v minulosti.

Open access

Igor Štefančík

Abstract

In this paper, a beech thinning experiment aimed at qualitative production issues was analysed. Two beech stands (93- and 105-year-old), growing at acid sites with similar ecological conditions were compared. The stands differ in the stand age, when their tending started (at the age of 40 years in one experiment versus 60 years for the second one). In the first stand, the thinning interventions were carried out during last 45 years, while in the second stand a 53-year-long period of investigation was recorded. The research was conducted in four treatment plots: (i) heavy thinning from below (C degree according to the German forest research institutes from 1902), (ii) free crown thinning with thinning intervals of 5 years, (iii) free crown thinning with thinning intervals of 10 years, and (iv) control plot (without thinning). The stand qualitative parameters (stem and crown quality, proportion of the best quality assortment and share of crop trees) were evaluated. From the point of qualitative production, the best results were most frequently obtained at the plots with the free crown thinning followed by heavy thinning from below. The worst parameters were found at the control plot

Open access

Igor Štefančík

Abstract

Impact of tending on dvelopment of beech (Fagus sylvatica L.) pole timber stands was analysed using different variants of the free crown thinning, i.e. the original method developed in Slovakia at the end of 1950s. Four variants of this method were compared: (i) - the free crown thinning on the whole area, the method of promising trees, later the method of target trees at stand age of 58 years. (ii) - the free crown thinning on non-whole area, tending realised inside of growth space of target trees only, the method of target trees, salvage cutting on the whole area. (iii) - the free crown thinning on non-whole area, the method of promising trees (the method of target trees at stand age of 58 years) realised on circular plots with diameter 4 m and spacing 8 m (distance between centre of circular plots). (iv) - combined selective method, thinning from below and the free crown thinning by method of target trees was used by the first thinning, in next thinning only the free crown thinning on whole-area was used, method of target trees. The structure (diameter and height) of the stand, the quantitative production parameters had been observed for a period of 30 years. Small differences were found in diameter and height structure between the variant (iv) and other three ones. Comparison of quantitative production pointed out minimum differences in favour of the variant (iv) compared to the other ones. The same results were also obtained in the qualitative production, especially for selective quality (target trees).

Open access

Igor Štefančík, Stanislav Vacek and Vilém Podrázský

Abstract

This work summarizes the history and development of the research on silviculture in the former Czechoslovakia. A different approach of the silviculture research reflecting various site conditions was presented separately for the Bohemian area (later Czech Republic) and Slovakia (later Slovak Republic). The research focused especially on spruce forests in the Czech Republic, and on pure and mixed beech stands in the Slovak Republic. The attention was also paid to the history of research institutions before and after the dissolution of Czechoslovakia. The results achieved so far have been analyzed with particular focus on silviculture of the two most significant tree species in the former Czechoslovakia, namely the Norway spruce and the European beech. At present, the two species dominate the tree species composition of both countries. The spruce comprises 50.5% of the forests in the Czech Republic, and 23.1% in Slovakia. The share of beech is 33.5% in Slovakia, but only 8.3% in the Czech Republic. In both countries, the share of these tree species has changed, in comparison with their original proportion. It is more evident in the Czech Republic than in Slovakia, especially in the case of spruce. For the two tree species, the most important results of a long-term research (including developed original thinning methods) were evaluated separately for each country.

Open access

Tomáš Klouček, Igor Štefančík, Rudolf Petráš, Julian Mecko and Martin Slávik

Abstract

The models of height curves were derived from repeated measurements at six permanent research plots in the experimental object of Komárnik situated in the Eastern Carpathians. During more than 50 years of investigation, the heights of 1,346 beech and 1,208 fir trees were measured. Tree heights had a great variability, but the stage-shift of height curves was not confirmed. The non-linear regression models of height curves for beech and fir were derived, where tree height is a function of tree diameter and model height for a selected diameter class. They are based on the Korf growth curve with three parameters. The models explained 90% and 94% of beech and fir height variability, respectively. The models confirmed the actual knowledge that fir had higher tree height increment than beech especially for trees with greater diameters. The comparison of our models to those developed by other authors showed that the shape of height curves slightly differed. Beech curve was characterised by greater, while fir curve by lesser curvature in comparison with other published models. Our models have only local validity due to the limited scope of experimental data. They can be applied under the local conditions in order to perform valuation and simulation of growing stock development and increments of uneven-aged and multistoried fir-beech stands.

Open access

Martin Slávik and Igor Štefančík

Abstract

The paper analyses the influence of auxiliary trees species on selected qualitative characteristics of the parent oak stand aged 100-120 years from the tending aspect point of view. Stand structure described by relative height position, and stem straightness and branchiness as the main qualitative parameters were studied on 162 trees in three different forest stands: (i) without woody understorey, (ii) with understorey dominated by European hornbeam with an admixture of small-leaved linden and field maple, and iii) with understorey dominated by small-leaved linden. The results showed a positive effect of auxiliary tree species on the oak quality (straightness and branchiness of stems) in the lower part of the stem. Under the assumed elimination of genetic influences, better qualitative parameters of oak could be explained by the occurrence of auxiliary trees in the understorey.

Open access

Igor Štefančík, Michal Bošeľa and Rudolf Petráš

Abstract

Value production is one of the most important information for comparing different management strategies in forestry. Although the value production of forest stands is affected by various factors (stem and assortment quality, stem dimension, stem injury, price of assortments), thinning can be considered as one of the most important one. This paper aims at the evaluation of qualitative and value production in homogeneous beech stands, which were managed by two different thinning types for period of 45 to 55 years: (i) – heavy thinning from below (C grade according to the German forest research institutes released in 1902) and (ii) – Štefančík´s free-crown thinning. The third variant was control (iii) – subplot with no interventions. Silvicultural quality characteristics of the lower half of the stem were assessed using a 4-class scale (A – the best quality, D – the worst quality). Assortment structure (commercial quality) was estimated for each stem by an assortment model developed in the past. Nearly 3,000 individual trees aged from 83 to 105 years from 23 subplots established across the Slovakia territory were assessed. The highest volume of the best silvicultural quality of stems (A class) has been reached in forests where Štefančík´s free-crown thinning was applied (57 – 85%) while the lowest (22 – 56%) on subplots with no management. The proportion of two best commercial quality assortments (I + II) was highest in forests managed by heavy thinning from below (21 – 29%) and the lowest when no treatment was applied (7 – 19%). The highest value production (expressed in € ha−1) was reached in the forests treated by free-crown thinning. Results suggested the overall positive impact of thinning on the increase of value production in beech forests. Particularly, the free-crown thinning focusing on selection of best quality trees should be preferred as it leads, besides its sufficient value production, to a higher vertical differentiation of the beech forests.

Open access

Robin Ambrož, Stanislav Vacek, Zdeněk Vacek, Jan Král and Igor Štefančík

Abstract

The paper presents the results of the study of the current and simulated structure of beech forests in the Lány game preserve, which is situated in the Křivoklátsko Protected Landscape Area in the Czech Republic. The research was conducted at two permanent research plots (PRP) of 0.25 ha in size in a mature beech forest using the FieldMap technology. Typological, soil and phytocoenological stand characteristics and the history of management of both PRP are comparable; however, they differ in the protection against wildlife. The results demonstrated that deer species including red deer (Cervus elaphus L. - 300 head), sika deer (Cervus nippon nippon Temm. - 300 head), mouflon (Ovis musimon Pallas - 250 head) and fallow deer (Dama dama L. - 300 head) is a limiting factor for successful development of natural regeneration of European beech (Fagus sylvatica L.). Natural regeneration on PRP 1 with wild boar herd (Sus scrofa L. - 150 head) is sufficient in relation to site and stand conditions. On the contrary, there is no regeneration on PRP 2 with the occurrence of deer species. The results of biometric measurements and subsequent predictions by the SIBYLA forest biodynamics simulator indicate that the stands are insignificantly structured, mature, productive beech stands with the absence of individuals in the lower tree layer.

Open access

Jan Král, Stanislav Vacek, Zdeněk Vacek, Tereza Putalová, Daniel Bulušek and Igor Štefančík

Abstract

The structure and health status of waterlogged or peaty spruce (Picea abies [L.] Karst.) forests in the summit parts of the Krkonoše Mts. in the Czech Republic were studied in 1979–2014. The objective was to evaluate the stand structure, dead wood, trend of the health status and productivity on four permanent research plots (PRP) in relation to air pollution (SO2 and NOx concentrations) and climatic conditions (temperatures and precipitation amounts). Stand structure was evaluated on the base of the measured parameters of individual trees on PRP. The health status of trees was evaluated according to foliage, and their vitality was assessed according to their radial growth documented by dendrochronological analyses. The radial growth was negatively correlated with SO2 and NOx concentrations. Stand dynamics during the observation period was characterised by increased tree mortality, the presence of dead wood and reduction of stand density from 1983 to 1992, while the most severe impairment of health status and stand stability occurred in 1982–1987. The foliage mass of living trees has been gradually increasing since 1988, but no pronounced improvement of tree vitality was documented after the decrease in SO2 concentration. However, particularly physiologically weakened spruce trees were attacked by the European spruce bark beetle (Ips typographus). The process of forest damage is manifested not only by foliage reduction but also by symptoms of various necroses on the assimilatory organs. In terms of climatic data, the weather in April had the most important effect on radial growth. Diameter increment showed positive statistically significant correlation with temperature in growing season, but the precipitation effect was low.

Open access

Tereza Putalová, Zdeněk Vacek, Stanislav Vacek, Igor Štefančík, Daniel Bulušek and Jan Král

Abstract

The negative effect of air pollution on mountain spruce stands culminated in the 70s – 90s of the 20th century, when an extensive dieback and disturbance of stands occurred in the Krkonoše Mts., the Czech Republic. Dendrochronological analysis was used on ten permanent research plots established in 1976–1980 to document the dynamics of radial increment of Norway spruce (Picea abies [L.] Karst.). The objective was to determine the effect of SO2, NOX and O3 concentrations and precipitation and temperatures on spruce radial growth in climax forests, waterlogged forests and cultivated forests. The results document the strong depression of diameter increment in the period 1979–1991 caused by synergism of climatic extremes and high SO2 pollution in the 80s and 90s of the 20th century. After 2000 climate had prevailing effect on radial growth. Spruce increment was in positive correlation with temperature, particularly with temperature in the growing season and annual temperature of the current year. In general, temperature had a more significant effect on increment than precipitation, mainly in climax and peaty spruce stands. Diameter increment was in significant negative correlation with SO2 and NOX concentrations in all types of stands. Overall, peaty spruce stands were the most vulnerable to air pollution stress. Low radial increments were caused also by climate extremes, historically by strong frosts and winter desiccation in early spring, nowadays in time of climatic changes by extreme drought. Spruce stands have the ability of quickly responding by tree-ring width to both negative and positive impulses related with air pollution and climate.