Slovakian Forest Research Institute

Zvolen, Slovakia

Slovakian Forest Research Institute

Zvolen, Slovakia
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Stefancik I.,Slovakian Forest Research Institute
Journal of Forest Science | Year: 2017

Crop trees are the main bearers of qualitative and value production of the stands. Although the number and production of the mentioned trees are affected by various factors, crown development by means of the thinning regime can be considered as very significant. The paper aims at the comparison of crop trees in homogeneous beech (Fagus sylvatica Linnaeus) stands, which were managed by three different management or thinning regimes for a long period (ca. 50 years): (i) heavy thinning from below (C grade according to the German forest research institutes released in 1902), (ii) Štefančík's free crown thinning, (iii) without interventions (control). Selection of crop trees was carried out at the beginning of research using the best stem quality, diameter and height dimension and regular spacing). In this paper only the last assessment of crop trees aged from 83 to 105 years including 23 subplots established across the Slovakian territory was analysed. The highest number of crop trees has been reached in forests where Štefančík's free crown thinning was applied. The proportion of these trees on subplots with the mentioned type of crown thinning was 61% out of the basal area at stand age of 100 years. A much lower proportion was found on subplots managed by thinning from below (32%) and on control ones (20%). Crown parameters (crown width, crown ratio, crown projection area, crown surface area and volume) showed the most appropriate values on subplots where Štefančík's free crown thinning was used. It was: 8.36 m (crown width), 0.50 (crown ratio), 56.84 m2 (crown projection area), 289.56 m2 (crown surface area), and 481.75 m3 (volume). Based on the results obtained after almost 50 years of systematic investigations, the mentioned thinning method was recommended for beech forests.

Konopka B.,Slovakian Forest Research Institute | Konopka B.,Czech University of Life Sciences | Lukac M.,University of Reading
Forest Pathology | Year: 2013

A rain shelter experiment was conducted in a 90-year-old Norway spruce stand, in the Kysucké Beskydy Mts (Slovakia). Three rain shelters were constructed in the stand to prevent the rainfall from reaching the soil and to reduce water availability in the rhizosphere. Fine root biomass and necromass were repeatedly measured throughout a growing season by soil coring. We established the quantities of fine root biomass (live) and necromass (dead) at soil depths of 0-5, 5-15, 15-25 and 25-35 cm. Significant differences in soil moisture contents between control and drought plots were found in the top 15 cm of soil after 20 weeks of rainfall manipulation (lasting from early June to late October). Our observations show that even relatively light drought decreased total fine root biomass from 272.0 to 242.8 g m-2 and increased the amount of necromass from 79.2 to 101.2 g m-2 in the top 35 cm of soil. Very fine roots (VFR), that is, those with diameter up to 1 mm, were more affected than total fine roots defined as 0-2 mm. The effect of reduced water availability was depth-specific; as a result, we observed a modification of vertical distribution of fine roots. More roots in drought treatment were produced in the wetter soil horizons at 25-35 cm depth than at the surface. We conclude that fine and VFR systems of Norway spruce have the capacity to re-allocate resources to roots at different depths in response to environmental signals, resulting in changes in necromass to biomass ratio. © 2012 Blackwell Verlag GmbH.

At beginning of the 1980's, the National Science Foundation (USA) came up with the initiation of the program for Long-Term Ecological Research (LTER), which is a program based on long-term comprehensive study of the structure and processes of ecosystems. The Ecological Experimental Station (EES) in the Kremnické vrchy Mountains (Western Carpathians, Slovakia, 1986) was founded for similar purposes. The aim of the research at EES was to evaluate the productivity, carrying capacity and functioning of the beech ecosystem. In February 1989, five plots were established. Four plots were subjected to a regeneration cutting of different intensities (clear-cut, strip shelterwood cut: light, medium and heavy). The fifth plot was left without any management treatments as a control. The second cutting was performed in 2004 followed by the final cutting five years later. Currently, the research is carried out on the EES control plot in the stand comprising 115-120 years old beech trees. In the other stands the research is focused on the development of naturally regenerated beech ecosystems established after different cutting interventions. The future of the EES is in addressing some global issues, particularly the impact of climate change on primary production, as well as on its other consequences for the functioning of the affected ecosystems. © 2015 Milan Barna, published by De Gruyter Open 2015.

Pajtik J.,Slovakian Forest Research Institute | Konopka B.,Slovakian Forest Research Institute | Lukac M.,University of Reading
Trees - Structure and Function | Year: 2011

Biomass conversion and expansion factors (BCEF) which convert tree stem volume to whole tree biomass and biomass allocation patterns in young trees were studied in order to estimate tree and stand biomass in naturally regenerated forests. European beech (Fagus sylvatica L.), Sessile oak (Quercus petraea (Mattuschka) Liebl.) and Scots pine (Pinus sylvestris L.) stands were compared. Seven forest stands of each species were chosen to cover their natural distribution in Slovakia. Species-specific BCEF are presented, generally showing a steep decrease in all species in the smallest trees, with the only exception in the case of branch BCEF in beech which grows with increasing tree size. The values of BCEF for all tree compartments stabilise in all species once trees reach about 60-70-mm diameter at base. As they grow larger, all species increase their allocation to stem and branches, while decreasing the relative growth of roots and foliage. There are, however, clear differences between species and also between broadleaves and conifers in biomass allocation. This research shows that species-specific coefficients must be used if we are to reduce uncertainties in estimates of carbon stock changes by afforestation and reforestation activities. © 2010 Springer-Verlag.

In this paper, a thinning experiment aimed at silvicultural and production issues is analysed. The long-term experiment was established 53 years ago in a beech stand located in the central part of Slovakia. Tending of the stand started at the age of 36 years. Research was conducted in three treatment plots: (i) heavy thinning from below (C degree according to the German forest research institutes from 1902), (ii) free crown thinning, and (iii) control plot (without thinning). The basic stand quantitative parameters (number of trees, basal area, and volume of the timber to the top of 7 cm, diameter and volume increment, total yield) were evaluated from 12 biometric measurements, which were performed during the 53-year-period of investigation. From quantitative production perspective, the best results were almost in all cases obtained in the plot with heavy thinning from below, followed by the free crown thinning. The worst parameters showed the control plot.

Hlasny T.,Slovakian Forest Research Institute | Hlasny T.,Czech University of Life Sciences | Turcani M.,Czech University of Life Sciences
Annals of Forest Science | Year: 2013

• Context: Secondary Norway spruce forests in the Western Beskids are among the most damaged forests in Europe. Although spruce bark beetle (Ips typographus) has been recently causing large-scale damage to these forests, our understanding of I. typographus dynamics in this environment is inadequate for evaluating forest sustainability. • Aim: This study aims to evaluate the patterns of damage caused by I. typographus to spruce forests with compromised ecological stability. • Methods: Forest infestation by I. typographus was inferred from sanitary felling data collected from 1998 to 2004. Stand and site data were obtained from forest management plans. Spatial-dependence analysis, ordinary kriging and neural network-based regression modelling were used to investigate the patterns of infestation and the casual relationships in the studied ecosystem. • Results: I. typographus long-distance dispersal substantially decreased with outbreak culmination. The spread of infestation was only weakly related to stand and site parameters. Infestations spread isotropically at the stand and patch level but directionally at the regional scale. • Conclusions: The large-scale spread of infestation can be explained by the uniform age and species composition of the investigated forests and by the ability of populations to overwhelm suboptimal trees. The observations presented here suggest that secondary spruce forests in Europe may be unsustainable due to unprecedented bark beetle outbreaks, which can be further amplified by changing climate. © 2013 INRA and Springer-Verlag France.

Stefancik I.,Slovakian Forest Research Institute | Stefancik I.,Czech University of Life Sciences
Folia Oecologica | Year: 2013

The paper deals with assessment of the long-term experiment (45 years of investigation) in beech (Fagus sylvatica L.) stand with delayed tending started at stand age of 60 years. The research was performed on four partial plots by different methods of their management: (i) plot with heavy thinning from below (C degree according to the German forest research institutes from 1902), (ii) plot with the free crown thinning (thinning interval of 5 years), (iii) plot with the free crown thinning (thinning interval of 10 years) and (iv) control plot (with no thinning). From qualitative point of view, the best results according to the number of target (crop) trees were found on plots tended by the free crown thinning (thinning interval of 5 years), and the worst on plots with heavy thinning from below and/or plot with no tending (control plot). Consequently, the results showed lower number of target (crop) trees in comparison with our assumption and/or the model developed for beech stands in the past. On the other hand, from quantitative point of view, the best results were achieved on plot tended by heavy thinning from below, followed by the plot with the free crown thinning (thinning interval of 5 years).

Stibig H.-J.,European Commission - Joint Research Center Ispra | Achard F.,European Commission - Joint Research Center Ispra | Carboni S.,European Commission - Joint Research Center Ispra | Rasi R.,European Commission - Joint Research Center Ispra | And 2 more authors.
Biogeosciences | Year: 2014

The study assesses the extent and trends of forest cover in Southeast Asia for the periods 1990-2000 and 2000-2010 and provides an overview on the main causes of forest cover change. A systematic sample of 418 sites (10 km × 10 km size) located at the one-degree geographical confluence points and covered with satellite imagery of 30 m resolution is used for the assessment. Techniques of image segmentation and automated classification are combined with visual satellite image interpretation and quality control, involving forestry experts from Southeast Asian countries. The accuracy of our results is assessed through an independent consistency assessment, performed from a subsample of 1572 mapping units and resulting in an overall agreement of >85% for the general differentiation of forest cover versus non-forest cover. The total forest cover of Southeast Asia is estimated at 268 Mha in 1990, dropping to 236 Mha in 2010, with annual change rates of 1.75 Mha (∼0.67%) and 1.45 Mha (∼0.59%) for the periods 1990-2000 and 2000-2010, respectively. The vast majority of forest cover loss (∼2/3 for 2000-2010) occurred in insular Southeast Asia. Complementing our quantitative results by indicative information on patterns and on processes of forest change, obtained from the screening of satellite imagery and through expert consultation, respectively, confirms the conversion of forest to cash crops plantations (including oil palm) as the main cause of forest loss in Southeast Asia. Logging and the replacement of natural forests by forest plantations are two further important change processes in the region. © 2014 Author(s).

The paper deals with analysis of the results of 38-year-old research on oak stands tended by non-whole-area method. Th e stand originates from natural regeneration, with the age of 50 and/or 53 years, situated in permanent research plot (PRP) Velká Stráž I, located at an altitude of 330 m a.s.l., SW exposure, management complex of forest types 208 - beech-oak forest on loess, management complex 25 - fertile beech-oaks. PRP consists of three partial plots: on the fi rst plot (A I), there are established 156 growth areas calculated per hectare, with square form (3 x 3 m) with area of 9 m2. Th e second plot (A II) numbers 204 growth areas calculated per hectare, with circle form (diameter 4 m), and/or area of 12.57 m2. Th e third plot is control one (without tending). From the viewpoint of qualitative and quantitative production, more suitable results were achieved on plot managed by non-whole-area tending with circle growth areas (diameter 4 m) in comparison with the plot consisted of growth areas of square form (3 x 3 m). Number of target trees per hectare at the age of 50 and/or 53 years found on plot A I was 122 individuals and on plot A II 230 ones, respectively.

Slovakian Forest Research Institute | Date: 2012-04-11

The invention concerns a biologically degradable polymeric composition containing 5 to 95 wt % of polyhy droxyalkanoate and 95 to 5 wt % of polylactic acid or lactide with addition of 2 to 67 parts of plasticizer or mixture of plasticizers per 100 parts of the polymeric blend. The invention covers also composition containing 0.05 to 5 wt % of a reactive additive. Plasticizers are selected from chemicals, such as esters of citric acid, esters of glycerol, esters of phosphoric acid, esters of sebacic acid and other liquid organic low-molecular polyesters. The reactive additive is selected from a group of chemicals such as acrylic polymers, epoxidized acrylic polymers, diisocyanates and their derivatives, epoxidized oils, oligomeric copolymers of various monomers with glycidyl methacrylate and other species.

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