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Th e growth response of trees to changing climate plays a key role in the effi cient management of forest ecosystems. Th e case study analyses long-term growth trends and reactions of conifer tree species (Norway spruce, silver fi r, Scots pine) on climate characteristics in mixed selection forest of the Volovské vrchy Mts. in eastern Slovakia. Th e collection of data for the analysis of stand structure was carried out in 2016 on a series of 41 circular sample plots (size 500 m2). From the selected trees in diff erent vertical layers of forest stand we collected totally 152 cores. Sampled cores were processed with standard dendrochronological methods. Based on the data acquired from the tree cores, silver fi r was confi rmed as the tree species with the best growth during the last three decades. As the only one tree species, fi r showed a positive trend of diameter growth in this period. Regarding the infl uence of climate change, the most endangered tree species was Norway spruce. Its diameter growth was limited mainly by higher summer temperatures of current and previous year and by drought. According to the acquired results we assume that silver fi r can be one of the tree species, which will replace Norway spruce in many localities. Nevertheless, questionable is how the fi r will react on the gradual increase of climate extremes and the growing competitive pressure of European beech. Regarding the diff erences between stand layers, the results confi rmed a lower sensitivity of middle layer trees to the impact of drought in comparison with the upper layer trees. [ABSTRACT FROM AUTHOR]

The study presents the changes of structure in three Norway spruce-dominated forest stands with different soil type and aspect in demonstration object Pro Silva Donovaly-Mistríky (the Low Tatra Mts., Slovakia). In surveyed stands, the conversion to single-tree selection system using the current generation is being applied for the period of 40 years. Based on the data from the full calipering in 1979 and the stand inventory (stems and natural regeneration) in 1999, 2013 and 2021 on the series of permanent research plots (0.25 ha) in investigated stands, a relatively rapid advancement in the conversion process was observed. An appropriate model of selection forest is characterized by the optimal stand volume 320 m³ ha-1 and target dbh 66 cm in protection forests on ranker soil and by stand volume 385 m3 ha-1 and target dbh 66 cm in stand with dominant production function. Under the ongoing climate change, the high proportion of Norway spruce in the stands on nutrient-poor soils and the southern aspect could lead to their fast disintegration and gradual loss of differentiated structure. Research objects of this study were three forest stands with dominant proportion of Norway spruce in demonstration object Pro Silva DonovalyMistríky in orographic unit Nízke Tatry (Slovakia). Forest stands with different soil type and aspect have been converted to selection forest using the current generation for more than 40 years. The results of full calipering in 1979 and the stand inventory in 1999, 2013 and 2021 on the permanent research plots (0.25 ha) confirm that the stands have reached the stage of structuration (compartment 1606 and 1632c) or the stage of structure achievement (compartment 1631). In the compartment 1606 with southern aspect, despite the enhanced conditions of ranker soil, we observed a rapid dieback of spruce in the upper tree layer of the converted stand. In this phase, the stability of the upper tree layer is guaranteed by silver fir, as its vitality in these ecological conditions is acceptable. During the investigated period, dynamics of regeneration processes (individuals in height range 50–130 cm) was adequate, with balanced representation of spruce (58%) and fir (42% – Tab. 3). On the other hand, a significant decrease of tree density was registered in the category of ingrowth (height ˃ 130 cm, dbh ≤ 8 cm), with the reduction from 4480 ha-1 in 2013 to 1560 ha-1 in 2021. Despite the decrease of fir proportion (77%) in favour of spruce (23%), the dominance of fir in the lower tree layer is maintained (Tab. 3). In compartment 1632c, the ranker soil played a significant role in differentiation of diameter structure and natural regeneration of spruce and fir in clusters (Fig. 1 and 2; Tab. 3). The dynamics of regeneration processes during the investigated period was continuous, with the spruce proportion in natural regeneration (height 50–130 cm) reaching 53% and the fir proportion of 38% in 2021. The decrease to the density 1720 ha-1 was observed in the category of ingrowth. Reduction of the trees in this category that provides the individuals for the diameter class 10 cm resulted from the high tree density in the diameter class 10 cm. In compartment 1631, the dynamics of regeneration processes during the surveyed period was adequate, with balanced proportion of spruce and fir. The significant decrease (by 200%) in the ingrowth category was registered also in this compartment (Tab. 3). In the investigated stands, the reduction of the annual volume increment with the gradual approaching to the selection structure was observed. On the permanent research plots in compartments 1606 and 1632c that represent the stage of structuration, the annual volume increment reached 4.5 m³ ha-1 and 4 m³ ha-1. Compartment 1631 that is in the stage of structure achievement has the annual volume increment of 7 m3 ha-1. According to the ongoing continuity of regeneration processes and the differentiation of stand structure, the model with optimal stand volume of 320 m³ ha-1 and target dbh of 66 cm proposed for the protection stands (compartments 1606 and 1632c) was confirmed as appropriate. Model with such parameters is able to maintain the sustainable fulfilment of the non-production functions as well as the high-quality timber production (resonance wood). In the stand with dominant production function (compartment 1631) it is possible to set the target diameter to 66 cm and the optimal stand volume to 385 m³ ha-1 (Tab. 3; Fig. 1). The results confirmed that on such high-productive site even in the case of significant exceeding of the optimal stand volume this does not represent the risk for the regeneration processes. [ABSTRACT FROM AUTHOR]

Forest management mimicking natural processes represents an approach to maintain mixed, uneven-aged stands at small spatial scales. The reliance on natural processes, especially on natural regeneration leads to the use of gap-based regeneration as a fundamental silvicultural technique. As a baseline for such management, we investigated mixed forest in unmanaged National Nature Reserve Sitno in the Western Carpathians, which harbours extraordinary diversity on a rather small scale. To quantify the impact of gaps on gap-filling processes and to assess the role they play in recently observed changes in tree species composition we established a large (2.5 ha) permanent research plot and surveyed the status of natural regeneration, forest structure, tree species composition, and disturbance regime. Our research highlights the long-term and contemporary difficulties in the establishment of Quercus petraea (Matt.) Liebl and Fagus sylvatica (L.). Based on the provided evidence, the native tree species diversity in one of the few preserved old-growth multi-species beech-oak forest remnants is not likely to persist, what could have many implications for future ecosystem functioning. Our results suggest that variation in gap size is an important factor contributing to composition of tree species composition of natural regeneration. The recent intermediate-scale disturbance pattern dominating the old-growth beech-oak forest is beneficial to canopy recruitment of species less shade-tolerant than Fagus sylvatica, as Acer pseudoplatanus (L.), Acer platanoides (L.), and Fraxinus excelsior (L.). We discuss possible factors behind observed shifts in tree species composition and limitations for application of gap dynamics to forest practice in managed beech-oak forest systems. Overall, results of this study may help to design silvicultural measures promoting mixed-species forests to deliver a range of desired ecosystem services. [ABSTRACT FROM AUTHOR]

The increasing probability of Taxus baccata (L.) decline given climate change brings forth many uncertainties for conservation management decisions. In this article, the authors present the effects of applying regeneration cuttings since the year 2000 on the viability of the understory yew population. By collecting data from a stand located at the centre of the largest population of European yew in Slovakia, containing approximately 160,000 individuals, and analysing tree-ring records from 38 sampled trees, the improved performance of yews, including stem growth, seed production, and number of regenerated individuals, was revealed. Thinning the canopy by removing 15% of the growing stock volume per decade, combined with the subsequent irregular shelterwood cuttings, was assessed as a useful strategy. Moreover, lower radial growth of females compared to males, but simultaneously their similar response to climate, suggests a possible trade-off between reproduction and growth. Release cuttings of up to 30% of the standing volume in the vicinity of the female trees, executed in the rainy summers following warmer winters, and consistent elimination of deer browsing, can further enhance the positive effects of applied cuts on yew viability. Overall, the suggested active measures could be considered as an effective option to preserve the unique biodiversity of calcareous beech-dominated forests in Central Europe. [ABSTRACT FROM AUTHOR]