Old-growth forests are a unique source of information for close-to-nature silviculture. In the National Nature Reserve Dobročský prales (Slovakia), a remnant of mixed old-growth forests of the Western Carpathians, we analyzed changes in tree species composition, stand structure, and creation and closure of canopy gaps. The results were based on data from forest inventories of an entire reserve conducted in 1978 and 2015, extended by detailed measurements in a research plot of 250 × 250 m. We observed the expansion of common beech (Fagus sylvatica L.) at the expense of conifers (Abies alba Mill., Picea abies L. Karst.) in all layers of the stand. Due to a lack of conifers in the category of saplings >130 cm and an abundance of coniferous deadwood, we hypothesize that this development will lead to the dominance of beech. All development stages revealed a reverse J-shaped diameter structure; however, they differed in the majority of basic stand characteristics (e.g., growing stock, basal area, tree density, deadwood volume). Most of the structural indices did not differ between development stages, confirming a relatively high degree of structural differentiation throughout the development cycle. The total gap area reached 18%, with the dominance of small gaps ≤100 m². Nevertheless, only canopy gaps >100 m² formed by the mortality of three or more trees were of higher importance for the extensive establishment of natural regeneration.

Dwarf pine (Pinus mugo Turra) thickets are a substantial land cover in high-elevation mountain ecosystems in Europe, where they fulfill important functions in soil conservation and as wildlife habitat. In many areas across Europe these thickets have rapidly expanded over the past decades because of changing climate and land use, highlighting the need to better understand how species spread relates to growth traits and changing environmental conditions. We quantified changes in dwarf pine cover by elevation on 2 mountains in the Western Carpathians (Central Europe) over 64 years (Babia hora) and 40 years (Pilsko), and we linked them to species growth responses to climate using archival photogrammetry and stem length measurements. We correlated mean growth chronologies with mean monthly temperature and precipitation to assess the main climatic factors driving growth. The total expansion of dwarf pine cover was substantial (28.6% in Babia hora and 57.1% in Pilsko), but the rate of expansion varied with elevation, site, and intra- and interspecific competition. The largest expansion occurred in the open stands of the high elevations (1550–1650 m). Statistically significant positive correlations between growth and temperature were recorded for the most recent growing season and for the preceding growing season. However, despite rising temperatures over time, mean species growth during the last 20 years decreased slightly. The correlation of growth with precipitation was mostly positive but not statistically significant. Thus, the impact of changing climate appeared too weak to overcome other influential factors (eg decline in grazing and intra- and interspecific competition).

Forest–steppe ecosystems represent a heterogeneous small-patch landscape important as a biodiversity hotspot and habitat for many endangered species. In this work, we examine threatened forest–steppe communities using structural indices, browsing intensity and indices that consider herbivorous game preferences. The study aims to assess the abundance of natural regeneration and the browsing intensity in relation to different stand structures and to identify woody species threatened by selective browsing at three study sites on the Krupina Plateau in the southern part of central Slovakia. At each study site, three circular permanent research plots (PRPs), each 500 m² in size, were established for stand structure analysis. Within each PRP, nine circular subplots with a radius of 2 m were established for detailed analysis of natural regeneration. The results of this study suggest that forest patches in the forest–steppe mosaic suffer from a long-term lack of natural regeneration, which is induced mainly by increasing aridity and ungulate pressure. Positive effects on the amount of natural regeneration were noted in association with the aggregated structure of forest patches and the presence of dead wood. Differentiated stand structure influenced the regeneration number in a negative way and at the same time significantly increased browsing intensity. In relation to a more advanced regeneration, shrubs had a protective effect against browsing. The feeding preferences of the animals can positively modulate the species composition and eliminate the imbalances in the regeneration in favor of the increasingly rare Quercus pubescens Willd.

Forest plantations, including those of Norway spruce, are increasingly threatened by drought in Central Europe. One of the measures understating this threat might be the use of drought-mitigative additives at planting. The effects of induced water limitation and the application of hydrogel Agrisorb and commercial ectomycorrhizal fungi (EMF) inoculum Ectovit on the development of 2 + 1 spruce seedlings were estimated in this study. The root systems of 2 + 0 seedlings were treated with the additives, along with their spring transplantation into peat-filled pots. The seedlings were then exposed throughout the entire growing season either to full watering (FW)—volumetric soil water content 70%, reduced watering (RW)—water content 40%, periodic watering (PW)—substrate rehydrated to 70% after drying to the wilting point (21%), or remained non-watered (NW). Survival, growth and chlorophyll fluorescence of the seedlings decreased proportionally to the increased drought intensity, while the highest root-to-shoot ratio and EMF colonization of roots occurred under PW and RW, respectively. NW seedlings died after 9 weeks of desiccation, whereas the EMF inoculum prolonged the survival time by one week. Ectomycorrhizas were formed predominantly with native EMF in all the treatments; nevertheless, compared with the uninoculated control, the formation of a treatment-specific EMF root morphotype and increased EMF colonization under PW and RW were observed on the inoculated seedlings. Both the EMF inoculum and the hydrogel increased survival under PW by approximately 15% but did not significantly affect growth, regardless of the watering regime. These results are limited to the experimental conditions and suggest a more dominant effects of the watering regimes compared with the additives tested.