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In the period of ongoing global climate change, ecosystems, including Central European forests, face significant challenges such as summer droughts and heat waves, which increase the climate risks also for the European beech (Fagus sylvatica L.), an important and dominant broadleaved tree species in this region. This article provides a comprehensive review of current knowledge on the adaptation strategies of European beech in response to changing climatic conditions, highlighting its ecological demands, development of taxonomy, ecological and economic importance and exploring its resilience, growth characteristics, and challenges such as water regime, pests, diseases, and the impact of climate change. A key finding is that despite the various stressors affecting European beech, adaptive management and the use of mixed forest stands can significantly contribute to its conservation and sustainable use. The importance of integrating the genetic diversity and adaptive capacity of European beech into forestry practices is emphasised. The review of 203 studies highlights the need for further research focused on understanding the interactions between European beech and a changing climate in order to develop more effective strategies for its conservation and sustainable management in the future. [ABSTRACT FROM AUTHOR]

Although the ongoing global climate change elicits a shift in tree species composition along the vertical gradient, very extensive areas of pure Norway spruce [Picea abies (L.) Karst.] stands still occur out of their ecological optimum in the Czech Republic and Central Europe. Adaptive measures should be applied in these stands to promote productivity and stability. All measurements were performed in the 2018–2021 period on three permanent research plots located in the North-East part of Bohemia (Czech Republic). Based on the results, the most favourable way to increase solar radiation use efficiency expressed by canopy production index (CPI) and leaf area efficiency (LAE) is in-time heavy pre-commercial thinning application. Th e highest CPI and LAE values were observed in the Norway spruce stand aft er heavy pre-commercial thinning application (CPI = 2.00 and LAE = 1.59). In contrast, CPI = 1.26 and LAE = 0.99 were observed aft er the mild one, and CPI = 0.73 and LAE = 0.60 were reported in the control treatment with no silvicultural intervention. Overall, the presented results indicate a positive effect of heavy pre-commercial thinning on CPI and LAE in pure young Norway spruce stands. However, more eff ort should be devoted to studying the impact of different pre-commercial thinning intensities on solar radiation use efficacy across a broader gradient of site conditions, and future work should also be extended to other tree species. [ABSTRACT FROM AUTHOR]

Scots pine has been considered a resistant tree species not only to adverse habitats but also to drought for a long time for its pioneering character, enabling it to thrive at significantly nutrient-poor and dry sites where the competitive pressure of other tree species is reduced. It has also some physiological properties adapted for the increased efficiency of water management. However, the increased and cumulated drought stress in Central Europe after 2013, which has accelerated significantly since 2015, showed the limits of the Scots pine´s sustainable prosperity in many sites of its present occurrence. The research analyses 101 studies published in the period from 1975 to 2022, representing basic properties, ecophysiological aspects, health status development, growth and fertility of Scots pine related to drought stress. It also deals with the influence of the tree species mixing effect and silvicultural management on the health status of Scots pine stands. The review aims to provide comprehensive material for understanding the development of Scots pine´s health and growth, as well as optimising its use under ongoing global climate change conditions characterised by an increase in annual air temperatures and by irregular distribution of precipitation, leading to the increasing frequency of drought periods. Methodological recommendations for silviculture in pine forests are also mentioned here. [ABSTRACT FROM AUTHOR]

Heavy thinning is supposed to be helpful for maintaining more favorable water balance in forest stands, and thus mitigate impact of drought episodes. To investigate impact of thinning on topsoil (10–13 cm) moisture conditions, a two-year soil sampling campaigns were conducted in 2019 and 2020. The soil moisture was calculated using a water-weight loss approach based on dry/fresh sample weight ratio. The samples were collected using metal capsules of known weight from totally 8–9 experimental series monthly during growing seasons of 2019 and 2020, respectively. Each series included thinned and un-thinned young growth stands of Norway spruce monoculture, spruce mixed with broadleaved tree species and mixture of sycamore maple with rowan. However, the statistically significant differences were not found in topsoil moisture between thinned and un-thinned young growth stands, thinned ones showed slightly better water balance conditions during both investigated years. Reduced number of trees and canopy closure had not depleted water throughout evaporation from upper soil profile. Therefore, thinning of young growth should be recommended especially at drought-endangered sites. Forest health decline and following die-off are exhibited in large areas of monospecific stands of Norway spruce and Scots pine in the Czech Republic. This development is attributable to shifts of conditions such as high air temperatures in growing seasons and different distribution of precipitation amounts over year, which resulted in hydrological drought in 2015–2019. Thinning is a deliberate measure that helps us control future stability, health and resilience of young forest stands and also impacts on species composition, environment and nutrient cycle in the stands. Heavy thinning is supposed to affect hydrological balance as interception is reduced (lower LAI) and more soil water is expected to be available for the trees left on site. On the other hand, such thinning intensity can increase evaporation from inside the stands and it also increases temperature amplitudes. The drought stress is even attributable to increased transpiration rates from released trees in case the soil below canopy has been dry for a long time. If true frequently, one can doubt a usefulness of heavy thinning at drought-endangered forest sites. This article deals with topsoil moisture below thinned thickets of tree species that were compared with moisture conditions below unthinned thickets. The objective of the study addressed a research question whether the thinning affected availability of water in soil, and thus proved a beneficial effect of the heavier thinning on the young drought-endangered forest stands. The sampled stands were monospecific spruce, spruce mixed with other, mainly broadleaved tree species and sycamore maple with rowan (Table 2). The thinning aimed at releasing crop trees of better quality and removal of both the unhealthy ones and wolf broadleaves; the thinned treatment was always accompanied with the unthinned one. 10–13 cm mineral topsoil samples (20 per thinned-unthinned series i.e. 10 per the treatment, see Table 3) were taken monthly in May-September periods in 2019–2020. Larger stones were excluded from the samples, and each sample was placed into metal capsules (of known weight) and covered with lid. The closed capsules were then delivered to laboratory where a water weight loss was measured as ratio of dry (dried at 105 °C) and fresh sample weights; this allowed us to determine a soil sample moisture. Arithmetic means were calculated from 10 values representing thinned and unthinned moisture conditions. The differences were tested using a pair t-test and 95% confidence intervals of difference were computed using R 3.6.3 (R Core Team 2020). In 2019, topsoil moisture was affected negatively by low precipitation at depth of 10–13 cm; minimum values were shown in July. Following 2020 showed more favorable conditions with maximal values in May and July. Soil moisture showed also higher variability in 2020 compared to 2019 (Fig. 1). The differences between control and thinned treatments were very small and even negligible. In 2019, the sites benefited from thinning slightly except for May values when 0.4% higher soil moisture was found below unthinned canopy. No statistically significant (α = 0.05) differences excepting for the thinned treatment in September (1.5% higher moisture, p = 0.02) were found in 2019. The topsoil moisture was 0.6% higher insignificantly (p = 0.27; 95% confidence interval 0.6 ± 1.1 %) under thinned treatments in 2019. Next year, the soil moisture values exhibited small differences reflecting also benefit from thinning; the only zero difference was shown in August. The highest moisture attributable to removal of trees amounted 1.8% higher moisture compared to control in July. No statistically significant (α = 0.05) differences were found significant though July values were at limit of significance (p = 0.05). The topsoil moisture was 0.9% higher insignificantly again (p = 0.16; 95% confidence interval 0.9 ± 1.3 %) under thinned treatments in 2020. Based on the two-year measurement campaign and data analysis it can be concluded: • More favorable precipitation conditions of 2020 affected 10–13 topsoil moisture values positively compared to precipitation-poorer 2019. • The topsoil moisture below thinned thickets showed slightly higher values compared to conditions without thinning; the differences were found insignificant mostly. • Removal of trees and following broken canopies, however, did not show depleted topsoil water due to higher evaporation from exposed forest floor surface. The early thinning of the thickets should not, therefore be ignored at drought-endangered sites. [ABSTRACT FROM AUTHOR]

Topsoil contents of cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn) and related soil properties such as pH and carbon (C) and nitrogen (N) contents were studied in the two main forest types of the Archbishopric forests in the area of the Jeseníky Mts., Czech Republic. Statistical comparisons were carried out between mature Norway spruce (NS) and European beech (EB) stands, separately for the forest floor (horizons FH) and the mineral (0–2 cm depth) soil. The FH horizons under EB showed higher contents of Zn, as compared to NS. In comparison, potentially higher contents of Cd were found under NS. The mineral topsoil under EB showed higher contents of Pb and Zn as compared to NS. In contrast, the pH was higher and the C:N ratio lower under EB, as compared to NS in both soil layers; the latter due to higher C under NS in organic horizons, while higher N under EB in the mineral soil. The results indicate that the species composition of managed forests may have conflicting impacts on soil quality and the accumulation and persistence of heavy metals in forest soils. [ABSTRACT FROM AUTHOR]

The paper deals with the first results from thinning experiments in the forest stands with both mixed and unmixed Douglas-fir. Douglas-fir reaction, expressed by diameter at the breast height (DBH) and height (H) increment 4-6 years after thinning application was evaluated. Five experimental series were established in 2010-2012. The age of the experimental stands at the time of experimental plot establishment ranged from 8 to 25 years. The plots are situated in Eastern and Southern Bohemia on acidic sites. Thinning led to accelerated diameter increment, whereas relationship between height increment and thinning remains unclear. Thinning also improved development of slenderness ratio (H/ DBH), although in some plots the slenderness ratio continuously increased even after thinning, but slowly compared to control plots. [ABSTRACT FROM AUTHOR]