<abstract><title style='display:none'>Abstract</title> The paper proposes and justifies an alternative concept of aggregation of forest site types in higher units for purposes of differentiation of forest management. Analysis of variance was performed for both: the natural occurrence of tree species in reserves, as well as the production potential of tree species measured on the representative plots according to Zlatnik´s altitudinal vegetation zones and edaphictrophic series. Based on the results of this analysis, an aggregation of forest site types was suggested along the elevation gradient of climatop, and along the edaphic-trophic and the edaphic-hydric gradients of edaphotop. By intersection of such created 32 categories of geotope with the basic formation groups of forest habitats by Braun-Blanquet geo-botanical school, 53 reconstructive geo-biotopes were formed. The proposed unit was compared using the F-test, Akaike information criterion (AIC), and the index of classification efficiency (EQ) with current typological units in terms of its ability to describe the variability of the analyzed parameters. Finally, the qualitative association of the compared classification models with the European classification systems was assessed. Based on the results obtained, it can be concluded that the site unit geo-biotop is at least comparable with currently used unit MGFT, with the number of categories lower by 72%.</abstract>

The concept of geo-biotope as a possible superior site unit for
differentiation of forest management

Národné lesnícke centrum-Lesnícky výskumný ústav Zvolen, Stredisko lesníckej ochranárskej služby, Lesnícka 11, SK-969 23 Banská Štiavnica

Technická univerzita vo Zvolene, Lesnícka fakulta, T. G. Masaryka 20, SK-960 53 Zvolen

Parasitic wasps (Hymenoptera) of the European oak bark beetle larvae (<italic>Scolytus intricatus</italic> Ratz., Coleoptera: Scolytidae)

Národné lesnícke centrum - Lesnícky výskumný ústav Zvolen, T. G. Masaryka 22, SK - 960 92 Zvolen

Národné lesnícke centrum - Ústav lesných zdrojov a informatiky Zvolen, Sokolská 2, SK - 960 52 Zvolen

Odvodenie 3-D modelu povrchu korún lesného porastu a detekcia korún stromov z leteckých snímok s vysokým rozlíšením

<abstract xml:lang="en"><title style='display:none'>Results of harvesters and forwarders operations in Slovakian forests</title>Paper deals with performance, consumption of fuel and negative effects of harvester technologies on remaining stand at some workplaces in Central Slovakia.Measurements were performed at OZ (affiliated state forest enterprise) Beňuš, Kriváň, Čierny Balog and ProPopulo Poprad Ltd. Harvester and forwarder Valmet 911.1/6 + Valmet 840.1/8, John Deere (JD) 1070 D + JD 810 D, JD 770 D + JD 810 D and JD 1270 D + 1110 D were used. The results show that during wheeled harvesters operation on the slopes with inclination to 40% it is possible to reach that number of mechanically damaged trees could be on average below 10%. Using statistical verification it was found that treatment intensity influences significantly damage to remaining stand.Harvester JD 1070 D operating in tending felling reached an average performance only 2.3 m3.h-1 with average volume of tree 0.14 m3 and slope inclination within 10%. We found that it is possible to reduce to a half the costs of the production of 1 m3 of wood by proper technological preparation of the workplace and modifying the technical parameters of machine according to the parameters of stand where harvesters would operate.</abstract>

Results of harvesters and forwarders operations in Slovakian forests

The dynamics of vegetative phenophases observed at the autochton population of Norway spruce (<italic>Picea abies</italic> [L.] Karst.) in Slovakia

Effect of tending and snow damage on changes in tree species composition, stand structure, qualitative and quantitative production of mixed spruce, fir and beech pole-stage stand on Stará Píla research plot

<abstract>
<title style='display:none'>Abstract</title>
This article deals with the possibility of reducing greenhouse gas emissions and fuel consumption in machines using cut-to-length (CTL) technology with the help of electro-hybrid systems. The text discusses the individual components of these systems. Furthermore, the article contains technical solutions for current electro-hybrid drive systems of harvesters, forwarders and forwarding trailers, including their description and available parameters. The current technical and technological development of electro-hybrid drive systems and their components leads to a significant improvement in the performance of drives of the new generation of CTL machines and to higher energy efficiency. Thanks to this, the use of electro-hybrid drive systems in these machines could significantly reduce greenhouse gas emissions as well as operating costs.
</abstract>

Advancing sustainability in forestry machinery: Electro-Hybrid drives for greenhouse gas reduction and enhanced energy efficiency

<abstract>
<title style='display:none'>Abstract</title>
The paper deals with the identification of the long-term potential of forest stands with the prevailing Norway spruce representation and the elaboration of a forecast of the development of spruce growing stock and felling possibilities until 2050. The analysis of historical data has confirmed a decrease in the area of spruce by 13.2% since 2010 and its growing stock by 16.4% over the same period. These developments indicate a reduction in felling possibilities in the coming decades. The evaluation of spruce felling since 2012 showed that the planned felling volume was exceeded by 11.3 mil. m3, i.e. annually at average by 1.25 mil. m3. This exceeding was caused by incidental felling, which accounted for an average of 84% of total felling. The forecast of spruce growing stock and felling until 2050 was derived differently for two scenarios based on the development of growing stock and actual cutting percentages in the decade 2012–2020 (scenario A) and cutting percentages according to planned felling (scenario B). In the case of scenario A, there would be a significant reduction in spruce growing stock from the current volume of 114.8 mil. m3 by 36% in 2040. In the case of scenario B, a decrease in spruce growing stock would be more modest. Ten-year felling volume of spruce under the scenario A forecast will result in the amount of 42.6 mil. m3 (first decennium), 32.0 mil. m3 (second decennium) and 25.7 mil. m3 (third decennium).
</abstract>

Sustainable development: Evaluation and forecasting of Norway spruce production and growing stock in Slovakia in the context of bioeconomy

<abstract>
<title style='display:none'>Abstract</title>
In Europe, <italic>Xyleborinus attenuatus</italic> Blandford is considered an invasive bark beetle native to East Asia. We used the results of many local surveys and data from private and museum collections to get information on the distribution and abundance of <italic>X. attenuatus</italic> Blandford in the Czech Republic. The ambrosia beetle <italic>X. attenuatus</italic> Blandford is probably widespread throughout the territory of the Czech Republic, from the lowlands to the mountains, and has one generation per year in Central Europe. The flight activity lasts from mid-March to May, F1 adults emerge in August and September and overwinter in wood or in the ground under an infested tree. <italic>X. attenuatus</italic> Blandford predominantly occupies soft deciduous trees and so far there economic damage have not been reported yet. However, <italic>X. attenuatus</italic> Blandford is a vector of ambrosia fungi <italic>Ambrosiella</italic> spp. and <italic>Raffaelea</italic> spp., and therefore this ambrosia beetle should be monitored.
</abstract>

Distribution of the invasive ambrosia beetle <italic>Xyleborinus attenuatus</italic> Blandford, 1894 (Coleoptera: Curculionidae: Scolytinae) in the Czech Republic (Central Europe)

<abstract>
<title style='display:none'>Abstract</title>
The spatial distribution of the epigeic fauna of floodplain ecosystems (willow-poplar floodplain forest, regenerated poplar forest), in the conditions of the natural environment of the Dunajské luhy Protected Landscape Area (PLA, hereinafter) and agrarian landscape was studied. The Dunajské luhy PLA, hereinafter (Slovak Republic) is the part of the system of protected areas of the European Union. During the three years 2020–2022, 24,169 individuals belonging to 19 taxa at 6 locations using the pitfall traps method were recorded. Through spatial modeling, the preference of most taxa for floodplain forests located in the Dunajské luhy PLA was found. We also observed a significant difference in number of individuals of epigeic fauna in floodplain forests betvween Dunajské luhy PLA area and agrarian landscape during all three years 2020 (p = 0.0070), 2021 (p = 0.0077) and 2022 (p = 0.04624). Thus, agroecosystems in the neighborhood of alluvial forests had a negative impact on the taxonomic diversity and abundance of epigeic fauna. In order to maintain a balance between the production of food, wood and the preservation of natural forest stands, it is important to optimally allocate areas and set up their management. For example, by creating forest islands in agricultural crops, to increase the epigeic fauna.
</abstract>

Comparison of spatial dispersion of epigeic fauna between alluvial forests in an agrarian and Dunajské luhy protected landscape area, southern Slovakia

<abstract>
<title style='display:none'>Abstract</title>
Ongoing coniferous monocultures decline in Beskydy Mts. Slovakia, emerged into establishment of Demonstration object of reconstruction of spruce forests (DORS) Husárik, focused on various technological processes of regeneration of economically important tree species. For Norway spruce (<italic>Picea abies</italic> [L.] Karst.) assessment of less frequently used artificial regeneration technologies, including planting of containerized transplants (CRT) or direct seeding procedures (direct seeding DS, seeding into vegetation cell VCS) and commonly used planting of bareroot transplants (BRT) was carried out. Seven years after experimental plot establishment, the lowest survival rate was recorded for DS treatment with 42% survived seedlings, the highest for CRT treatment with 79% survived transplants. For germinated seedlings, average seeding spot occupation rate recorded for DS (72%) was significantly lower than for VCS (98%) one year after seeding and remained significantly lower also over further consecutive years. Average survival recorded for planted transplants over monitored period did not differ markedly and gradually decreased to 76% for BRT and 79% for CRT. Reflecting different ontogenetic stage of individuals assigned to selected treatment average height 134.6 cm for DS, 134.1 cm for VCS and 182.0 cm for CRT, 215.0 cm for BRT was recorded seven years after establishment. The results suggest that for spruce, less frequently used artificial regeneration technologies (VCS, CRT), that markedly curtail time period required for target tree species installation on planting sites, with survival and growth rate of plants recorded in this study, could provide reasonable alternative to commonly used planting of BRT.
</abstract>

Comparison of Norway spruce artificial regeneration techniques tested in the area destroyed by spruce bark beetle in Kysuce Region (Slovakia)

<abstract>
<title style='display:none'>Abstract</title>
Resistance of horse chestnut <italic>Aesculus hippocastanum</italic> ‘Mertelík’ to <italic>Cameraria ohridella</italic> was proven in the trial under semi-field conditions. Seedlings of vulnerable and resistant trees were grown together in rearing cages and were exposed to the strong attack from <italic>C. ohridella</italic> larvae. Significant differences in leaflet injuries were observed between susceptible and insect-resistant trees. Variety ‘Mertelík’ showed almost none or very small damages compared to high defoliation level in case of standard trees. The results confirmed that this resistant clone could be suitable for use under field conditions.
</abstract>

Resistance of horse chestnut tree (variety ‘Mertelík’) to <italic>Cameraria ohridella</italic> Deschka &amp; Dimić, 1986 (Lepidoptera: Gracillariidae)

<abstract>
				<title style='display:none'>Abstract</title>
				 The paper presents information on the projected drought exposure of Central Europe, describes the anticipated dynamics of the regional forests, and identifies measures facilitating the adaptation of forests to climate change-induced drought risk. On the basis of an ensemble of climate change scenarios we expect substantial drying in southern Slovakia and Hungary, while such trends were found to be less pronounced for the Czech Republic and Austria. In response to these climate trajectories, a change in species composition towards a higher share of drought tolerant species as well as the use of drought resistant provenances are identified as paramount actions in forest adaptation in the region. Adaptation to aggravating climate change may need to use artificial regeneration to enrich local gene pools and increase the drought tolerance of stands. Increasing risks from pests, pathogens and other disturbances are expected as a result of more frequent and severe droughts, underlining the need to put a stronger focus on risk management principles rather than on indicators of productivity in silviculture and forest planning. A consolidation of disturbance monitoring systems and a broader use of pest dynamics and hazard rating models are paramount tools to facilitate this adaptation process in forest management. The effectiveness of all the suggested measures needs to be controlled by efficient forest monitoring systems, the consolidation of which seems to be a timely task. Systematic and long-term implementation of the presented measures should increase forest stability and resilience, and further secure the sustainable provision of ecosystem services under climate change.
			</abstract>

National Forest Centre - Forest Research Institute Zvolen, T. G. Masaryka 2175/22, SK – 960 92 Zvolen, Slovakia

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129

University of West Hungary, Institute of Environmental and Earth Sciences, Pob. 132, H – 9401 Sopron, Hungary

University of Natural Resources and Life Sciences, Institute of Silviculture, Peter-Jordan-Straße 82, 1190, Vienna, Austria

Technical University Zvolen, Forestry Faculty, T. G. Masaryka 24, SK – 960 53 Zvolen, Slovakia

Eötvös Loránd University, Department of Meteorology, Pázmány P. s. 1/A, H – 1117 Budapest, Hungary

Climate change increases the drought risk in Central European forests: What are the options for adaptation?

<abstract><title style='display:none'>Abstract</title>In time of climate change, close-to-nature silviculture is growing in importance as a tool for future forest management. The paper study the tree layer and natural regeneration of monospecific Norway spruce (<italic>Picea abies</italic> [L.] Karst.), trough mixed spruce-beech to dominant European beech (<italic>Fagus sylvatica</italic> L.) forests in Jizerské hory Mts., the Czech Republic. In the locality, shelterwood and selection system have been applied since 2000. The research objectives were to evaluate production parameters, structural diversity, species richness, natural regeneration dynamics and radial growth of individual tree species in relation to climatic factors and air pollution. The stand volume on permanent research plots amounted to 441 – 731 m3 ha−1 in initial stage of transformation. Natural regeneration showed high expansion of beech and decrease of spruce compared to mature tree species composition. Radial growth of spruce was in significant negative correlation with SO2 and NOX concentrations compared to no effect on beech increment. Moreover, spruce was more sensitive to significant years with extreme low radial growth. Beech was more stable in radial growth. Spruce was more resistant to air pollution and climatic stress in mixed stands. Low temperature was limiting factor of radial growth together with climate extremes (such as strong frosts and more frequent droughts) and biotic factors (bark beetle, beech scale). Close-to-nature management supporting admixed tree species should lead in future to diversification of stand structure toward higher species, spatial and age structure to mitigate negative effect of climatic change.</abstract>

Adaption of Norway spruce and European beech forests under climate change: from resistance to close-to-nature silviculture

<abstract>
<title style='display:none'>Abstract</title>
The structure and health status of waterlogged or peaty spruce (<italic>Picea abies</italic> [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 (<italic>Ips typographus</italic>). 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.
</abstract>

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, CZ – 165 21 Prague, Czech Republic

Structure, development and health status of spruce forests affected by air pollution in the western Krkonoše Mts. in 1979–2014

<abstract><title style='display:none'>Abstract</title> Knowledge of the structure and dynamics of near-natural mixed forests is a key factor for ecologically oriented management of forest ecosystems. The development of these model forests mostly takes place continually without any pronounced disturbances. Natural regeneration can be locally limited by ungulate browsing. The paper was focused on the structure and development of forest stands with emphasis on natural regeneration in relation to ungulates in Černý důl Nature Reserve and Trčkov National Nature Reserve situated in the Orlické hory Mts., Czech Republic. The case study was conducted in a spruce-beech-fir forest stand on four permanent research plots (PRP) of 0.25 ha in size. PRP are situated in the same stand and in comparable site and stand conditions, but two PRP has been protected against game by fencing since 1985-1989. The stand volume ranged from 478 to 565 m3 ha−1 in age 143 - 156 year. The results showed that the diversity of tree layer was higher by 19.8% (48.0% in species richness) in the stands protected by fence. In the phase of natural regeneration, the species composition, stand structure and number of recruits were poorer on unfenced PRP (7,990 recruits ha−1) compared to fenced PRP (13,160 recruits ha−1). Admixed silver fir and rowan were completely eliminated by browsing (to 94 - 100% of individuals). Growth analyses statistically confirmed that ungulates were a significant limiting factor for successful forest development (P &lt; 0.001).</abstract>

Structure and dynamics of spruce-beech-fir forests in Nature Reserves of the Orlické hory Mts. in relation to ungulate game

<abstract><title style='display:none'>Abstract</title>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 (<italic>Picea abies</italic> [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.</abstract>

Tree-ring widths as an indicator of air pollution stress and climate conditions in different Norway spruce forest stands in the Krkonoše Mts.

<abstract><title style='display:none'>Abstract</title>Norway spruce (<italic>Picea abies</italic> [L.] Karst.) and silver fir (<italic>Abies alba</italic> Mill.) are main tree species of Central Europe that are currently highly vulnerable in times of global climate change. The research deals with the effect of climate and air pollution on radial growth of silver fir and Norway spruce in mixed age-varied (56 – 146 years) forests in the Jeseníky Protected Landscape Area, the Czech Republic. The objectives were to evaluate biodiversity, structure and production, specifically interaction of radial growth of fir and spruce to air pollution (SO2, NOX, tropospheric ozone) and climatic factors (precipitation, air temperature). Concentration of SO2 and NOX had negative effect on radial growth of fir, while radial growth of spruce was more negatively influenced by tropospheric ozone. Fir showed higher variability in radial growth and was more sensitive to climatic factors compared to spruce. On the other hand, fir was relatively adaptable tree species that regenerated very well when the pressure of stress factors subsided (air pollution load, Caucasian bark beetle, frost damage). Low temperature was a limiting factor of radial growth in the study mountainous area, especially for fir. Fir was significantly sensitive to late frost, respectively, spruce to winter desiccation and spring droughts with synergism of air pollution load. Generally, older forest stands were more negatively influenced by air pollution load and climatic extremes compared to young trees.</abstract>

Effect of climate and air pollution on radial growth of mixed forests: <italic>Abies alba</italic> Mill. vs. <italic>Picea abies</italic> (L.) Karst.

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