Search Results (254)

Historical vegetation resurveys provide valuable insights into long-term forest dynamics and the legacy effects of past land use. We resurveyed 45 quasi-permanent vegetation plots originally recorded in 1942 in acidophilous Pinus sylvestris forests of central Slovenia to assess vegetation change after nearly nine decades of secondary succession. We analysed changes in species composition, vegetation structure, tree regeneration, taxonomic diversity across spatial scales, functional and phylogenetic diversity, ecological indicator values, and diagnostic species. The formerly relatively homogeneous pine-dominated vegetation underwent a pronounced compositional shift and differentiated into three distinct successional pathways, characterised by increasing dominance of Fagus sylvatica, Castanea sativa, or Picea abies. Although total tree-layer cover remained largely stable, P. sylvestris declined in dominance and was almost absent from the regeneration layers in 2025, indicating limited capacity for persistence under current stand conditions. Vegetation change was accompanied by a shift towards shadier, more mesic, and nutrient-richer conditions, and the replacement of stress-tolerant pine-forest specialists by more competitive forest species. Diversity responses were strongly scale-dependent: plot-level species richness and phylogenetic diversity declined, whereas regional species richness and compositional differentiation increased. These results show that secondary acidophilous P. sylvestris forests should not be interpreted as stable vegetation types, but as dynamic land-use legacy systems whose future development depends on local site conditions, stand development, and historical management legacies. Full article

Advances in imaging and fabrication technologies offer new opportunities to develop tools that support the visualization and understanding of complex biological materials. This contribution presents a comprehensive methodological framework for generating anatomically representative, species-specific 3D models of wood microstructure, intended to enhance student comprehension in wood science and related fields. The workflow integrates micro-X-ray computed tomography (micro-CT) scanning, image segmentation, STL model preparation, and additive manufacturing. Using micro-CT, we captured high-resolution, non-destructive 3D datasets of four wood species—European beech (Fagus sylvatica), oak (Quercus robur L.), Norway spruce (Picea abies), and Scots pine (Pinus sylvestris). The resulting volumetric data were processed with dedicated software to isolate and reconstruct key anatomical features, which were subsequently converted into printable STL models. These models were fabricated at a 1:400 scale using filaments composed of 40% wood particles and 60% biodegradable polylactic acid (PLA), underscoring the relevance of sustainable materials in educational tool development. The primary aim of this work is to document and justify each stage of the technological process, thereby providing a replicable pathway for producing detailed, pedagogically useful representations of wood microstructure. The resulting models are publicly available on the Sketchfab platform as part of the “3D Wood Micro Structure Collection.” Full article

Climatic variation is inherently linked with tree phenology; however, phenological triggers depend on species and habitat. We analyzed key climatic factors for the onset of secondary growth for Scots pine (Pinus sylvestris L.) at the southern limit of its distribution in Siberia. From direct observations of developing tree rings, seasonal curves of the number of cells in the cambial zone, in the cell-expansion zone, and the total number of xylem tracheids were developed over seven years with a wide variety in the phenological dates. We found that later and shorter intervals of these stages of xylogenesis were compensated by higher maximums of kinetics curves, probably due to higher temperatures and daylengths during the respective phenophases. Air temperature and soil temperature at a depth of 20 cm converged to values (mean ± SE) 6.6 ± 0.9 °C (air) and 3.7 ± 0.4 °C (soil) for a 15-day interval prior to cambial activity onset. Date of Tsoil ≥ 3.5 °C was most closely related to cambial activity onset (r = 0.99) and preceded it by 9.6 ± 1.1 days. Cumulative temperature sums were less reliable. Apparently, both air and soil temperature thresholds have to be reached for cambial division to start in this species-habitat combination. Late abundant snowfall can yield divergence between air and soil temperatures and delay the onset of xylogenesis. Full article

As a society, we are facing an environmental crisis, and as a result, nature-based and environmentally friendly solutions are gaining increasing popularity. The development of environmentally friendly wood-protection systems is an important challenge in materials science. In this study, lanolin-based emulsions were systematically evaluated as natural agents for improving the hydrophobicity and biological durability of wood. Scots pine (Pinus sylvestris L.) samples were treated with four types of lanolin emulsions, including variants containing boric acid, and subsequently analysed in terms of contact angle, resistance to wood-decay fungi (Coniophora puteana and Pleurotus ostreatus), and susceptibility to mould and microfungi growth (Chaetomium globosum; and mixture of: Chaetomium globosum, Aspergillus niger, Penicillium, Paeciliomyces variotti, Alternaria tenuis, and Trichoderma viride). This study investigates whether, and to what extent, the application of lanolin affects surface hydrophobization and thus improves its resistance to fungi. The results demonstrate that lanolin treatments, like paraffin or carnauba wax, significantly increase surface hydrophobicity, with contact angles rising from approximately 58° for untreated wood to 85–105° for treated samples. This effect is associated with reduced biological degradation, as evidenced by lower mass loss in treated samples compared to controls. Depending on the formulation, mass loss was reduced by up to approximately 30 percentage points for Coniophora puteana and up to approximately four percentage points for Pleurotus ostreatus. The incorporation of boric acid further enhanced resistance to wood-decay fungi, while slightly reducing contact angle values. The results indicate that lanolin-based emulsions can effectively improve both the moisture resistance and the biological durability of wood. The study provides a comprehensive experimental assessment of lanolin as a sustainable alternative to conventional hydrophobic agents and demonstrates its potential for application in wood-protection systems. Full article

The increasing frequency and intensity of hotter droughts are driving widespread forest dieback, yet the role of tree nutritional status in drought-induced growth dieback remains poorly understood. We investigated how nutrient composition across tissues (leaves, wood) relates to water use patterns and growth resilience in rear-edge populations of Scots pine (Pinus sylvestris L.) in Northeastern Spain. Using a multi-proxy approach, we combined analyses of foliar and sapwood nutrient concentrations, stable isotopes (δ¹³C, δ¹⁸O), and dendrochronological indicators across contrasting tree vigor classes. Defoliated trees exhibited pronounced shifts in elemental composition, including depletion of foliar K and increased concentrations of Ca, S, and Fe, alongside higher intrinsic water use efficiency and reduced growth resistance to drought. In contrast, the sapwood elemental composition was less responsive to defoliation but showed stronger associations with isotopic signals and drought resilience, suggesting its integrative role in tree functioning. Coordination of nutrient concentrations between tissues was limited, suggesting organ-specific regulation of nutrient allocation under drought stress. Our results reveal that nutrient imbalances are linked to water–carbon dynamics and drought responses and emphasize the importance of considering multi-organ nutrient dynamics to improve our understanding of long-term nutritional imbalances during drought-induced forest dieback. Full article

Soil- and plant-associated fungi and bacteria are an important part of many ecosystems as they can affect plant health, growth and stress tolerance. However, it remains poorly understood whether the microbiomes differ between conifer species growing in the same site conditions and between tree ecosystem compartments. The main aim of the study was to describe and compare the microbiomes of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.), growing in a boreal forest common garden experiment on adjacent forest plots, to analyse the tree species effect on the composition of the needle and surface soil organic-mineral horizon microbiomes. The needle and surface soil organic-mineral horizon bacterial and fungal microbiomes were simultaneously analysed by full-length 16S and ITS sequencing on a long-read sequencing platform; however, the bacterial analysis was restricted to soil samples. The highly abundant bacterial phyla in both pine and spruce soil were Actinomycetota, Pseudomonadota, Planctomycetota and Acidobacteriota. The dominant fungal phyla in pine and spruce surface organic-mineral soil was Basidiomycota, while the needles were dominated by Ascomycota. The results showed an effect of tree species on the soil bacterial and fungal microbiomes and needle fungal microbiomes based on alpha diversity, which was higher for Norway spruce compared to Scots pine. The results indicated that Norway spruce might be able to support higher microbial diversity, which could potentially be due to differences in needle longevity, root exudates, litter input and its degradation, between pine and spruce. Furthermore, the results indicated distinct microbiomes between the soil and needle compartments. Full article

Glued-laminated timber (GLT) and cross-laminated timber (CLT) panels are increasingly used as exposed structural elements in representative buildings. These structures are often part of public-use areas, which require the application of restrictive fire-safety measures without significantly affecting the color of exposed wooden surfaces during the service life of these building elements. The effect of fire-retardant treatments on the color of Scots pine (Pinus sylvestris L.) wood was evaluated using five impregnation agents with different active substances. Changes in gloss and color characteristics—lightness (L*), green-red coordinate (a*), and blue-and-yellow coordinate (b*)—were measured sequentially directly after impregnation, after exposure to variable humidity conditions and after exposure to UV radiation. The total color difference (ΔE*) ranged from 2.82 to 17.76 after impregnation and increased to 6.31–20.71 after aging, indicating a risk of aesthetic deterioration of fire-retardant-treated wood surfaces under typical service conditions for timber structures in representative buildings. The most pronounced color changes were observed for the fire retardant containing potassium and copper compounds (FR4) and the combination of 2-aminoethanol with boric acid (FR5). Full article

Global climate change is reshaping Central European conifer forests, affecting growth and ecosystem dynamics. At the same time, tree species differ in their productivity and responses to climatic conditions. Across mid-elevation monocultures of European yew (Taxus baccata L.), Norway spruce (Picea abies [L.] Karst.), Scots pine (Pinus sylvestris L.), silver fir (Abies alba Mill.), and European larch (Larix decidua Mill.), we quantified stand structure, volume, biomass carbon sequestration, and growth–climate responses (1971–2023). Silver fir reached the highest stand volume (711 m³ ha⁻¹), with lower productivity in pine (−17.0%), larch (−22.9%), spruce (−26.0%), and yew (−70.6%). In contrast, larch maximised biomass carbon sequestration (267.7 t ha⁻¹), whereas yew had the lowest value (87.7 t ha⁻¹), but the greatest stand diversity (except high differentiation), while pine showed the lowest diversity. Radial growth was most constrained by warm Junes and dry Julys; an early-season multi-month drought compounded by heat further suppressed radial increments, and severe winter frosts added stress. Among the studied species, spruce was the most climate-sensitive, whereas fir and pine showed comparatively more resilience. From a practical forestry perspective, promoting structurally diverse stands with high production potential and prioritising climate-resilient tree species, especially fir, can help sustain production and stability at mid elevations under climate warming. Our results provide species-specific benchmarks for adaptive silviculture and identify the seasonal windows when growth is most vulnerable. Full article

Scots pine (Pinus sylvestris L.) spans most of Eurasia, yet southern and mountainous populations may retain distinctive genetic components shaped by long-term isolation and complex postglacial dynamics. We genotyped 186 trees from four Scots pine stands in Armenia (AM1-AM4) and reference stands from Germany, Russia and Montenegro with the PiSy50k SNP array and integrated these data with published European array datasets from Finland, Poland and the Baltic region. After quality checks and conservative SNP filtering, 627 individuals from 47 populations and 3659 SNP loci were retained. Within-population diversity was generally high; Armenian stands AM2–AM4 were among the most diverse, whereas AM1 showed reduced diversity and the highest differentiation relative to the remainder of the dataset (FST vs. rest = 0.0047). Direct pairwise F_ST and hierarchical AMOVA confirmed pronounced heterogeneity among Armenian stands, with AM1 the most differentiated stand, AM2 and AM4 closest to the broader Eurasian background, and AM3 intermediate. Principal component analysis (PC1 = 1.42%, PC2 = 0.76%) again separated AM1 strongly from all non-Armenian samples, while AM2 overlapped with the central/eastern European cluster and AM3 and AM4 combined continental-like and AM1-like individuals. Structure-like inference with LEA/sNMF showed a broad cross-entropy plateau from approximately K = 4 to K = 6; we therefore use K = 5 as a practical summary, which highlighted a dominant AM1-associated ancestry component and variable continental admixture in AM2–AM4. KING kinship estimates provided little evidence for within-stand family clustering in Armenian stands; no second-degree-or-closer pairs were observed in AM1–AM4. Together, the results reveal pronounced heterogeneity among Armenian Scots pine stands and identify AM1 as a highly differentiated but unresolved genomic component, providing a genomic baseline to support conservation planning, provenance evaluation and the management of forest reproductive material in the Lesser Caucasus. Full article

(1) Research Highlights: This study provides the first integrated assessment of Scots pine (Pinus sylvestris L.) growing in the urban forests of Karaganda, Kazakhstan, a city consistently ranked among the most air-polluted cities globally. We examined the adaptive phyto-chemical response of needles to extreme technogenic stress and evaluated their dual potential as biological filters and renewable sources of bioactive compounds. (2) Background and Objectives: Urban forests are critical for mitigating air pollution; however, the biochemical responses of trees in heavily industrialized environments remain poorly understood. Karaganda faces severe atmospheric pollution from mining, metallurgy, and energy sectors, with particulate matter (PM) levels exceeding permissible limits by up to 20-fold. This study aimed to evaluate the state of Pinus sylvestris, a key component of local protective plantations, by studying heavy metal accumulation, anatomical localization of secondary metabolites, and the phytochemical profile and biological activity of needle extracts obtained using different extraction techniques. (3) Materials and Methods: Needles were collected from 15 trees across three sites in Karaganda’s industrial green zones. Heavy metal content (Pb, Cd, As, and Hg) was determined using atomic absorption spectroscopy and voltammetry. Anatomical–histochemical analysis localizes major metabolite classes. Liquid extracts were prepared using four methods, percolation (PER), vortex-assisted (VAE), microwave-assisted (MAE), and ultrasound-assisted (UAE) extraction, and analyzed by GC-MS. Antimicrobial activity was tested against S. aureus, B. subtilis, E. coli, and C. albicans using the disk diffusion method. The antioxidant capacity (water- and fat-soluble) was measured amperometrically. Statistical analysis was performed using one-way ANOVA with Tukey’s HSD test (p < 0.05). Results: Despite extreme ambient pollution, heavy metal concentrations remained below pharmacopoeial limits (Pb < 0.1, Cd < 0.05, As < 0.01, Hg < 0.001 mg/kg), indicating effective biofiltration without toxic accumulation. Histochemistry confirmed the active synthesis of protective phenolics, flavonoids, and essential oils in the mesophyll, epidermis, and schizogenic cavities. GC-MS identified 72 compounds in the PER extract, 70 (the VAE), 72 in (MAE), and 46 in (UAE). The PER extract exhibited the highest relative abundance of bioactive terpenoids: α-cadinol (5.24%), α-muurolene (4.32%), and caryo-phyllene (2.20%). UAE extracts exhibited elevated 5-hydroxymethylfurfural (6.90%), indicating degradation. Antimicrobial testing revealed that PER produced the largest inhibition zone against S. aureus (15.0 ± 1.0 mm), significantly exceeding that of the other methods (p < 0.001). PER extract also demonstrated the highest water-soluble antioxidant capacity (3600 ± 0.40 mg quercetin equiv./dm³) and substantial fat-soluble activity (1633 ± 0.23 mg gallic acid equiv./dm³). (4) Conclusions: Pinus sylvestris in Karaganda exhibits remarkable adaptive resilience, maintaining safe heavy metal levels while accumulating a rich repertoire of stress-induced secondary metabolites. Classical percolation optimally preserves this native phytocomplex, yielding extracts with superior antimicrobial and antioxidant properties. These findings support a dual-use model wherein urban pine plantations simultaneously serve as living biofilters and renewable sources of standardized bioactive extracts, a concept with direct implications for circular bioeconomy strategies in industrial regions worldwide. This supports the strategic importance of coniferous plantations for bioremediation and sustainable resource use in industrial regions. Full article

Wind disturbance is the major driver of forest damage in Northern Europe, particularly during late autumn and winter when cyclonic activity might coincide with unfrozen soil conditions. We quantified the thermal regime of periodically waterlogged mineral soils in relation to snow cover thickness (SCT) in hemiboreal forests of Latvia. The study was conducted in 15 forest stands dominated by birch (Betula spp.), Scots pine (Pinus sylvestris L.), and Norway spruce (Picea abies (L.) H. Karst.) during two contrasting winters (2023/2024 and 2024/2025) across two regions differing in local climatic conditions. Soil temperature was monitored at 0, 10, and 20 cm depths, while SCT was measured at five points per plot. Linear mixed-effects models were used to assess the effects of air temperature, precipitation, region, season, and species composition to snow cover thickness (SCT) and effect of the other parameters to soil temperatures. SCT varied strongly between regions and seasons. Snow accumulation was lower in pine- and spruce-dominated stands compared to birch stands. Formation of snow layer increased soil temperatures at the surface, whereas SCT had a more pronounced insulating effect at depths of 10–20 cm, especially during prolonged snow cover (F = 15.43 − 54.25, p < 0.001). Heat transfer from deeper layers further enhanced thawing under waterlogged conditions. Snow cover significantly insulates soil in a depth-dependent manner, with its magnitude varying across regions and seasons. Promoting mixed-species stands and selecting deep-rooted species, such as birch, can enhance the formation of frozen soil, and thus soil–root anchorage, reducing wind damage risk on periodically waterlogged soils. Full article

Old-growth forests provide a key biodiversity reservoir due to their high amount of deadwood and abundance of tree-related microhabitats (TreMs). This research investigates the abundance and diversity of deadwood and TreMs in old-growth Caledonian pine forests located in the Cairngorms National Park, Scotland. The study area is a Scots pine (Pinus sylvestris L.)-dominated forest. A field survey campaign was conducted in 15 sample plots to collect data on stand and deadwood characteristics, and TreMs by category. Within circular plots of 531 m², the diameter at breast height, height, and insertion height of the canopy of all the living trees were measured, and the three deadwood components (snags, fallen deadwood, and stumps) and TreMs were recorded. The results showed a total deadwood volume of 37.53 ± 32.39 m³ ha⁻¹, mostly in the form of snags (68.9% of total volume) and in the lowest degree of decay (first decay class equals 36.8%). The average number of deadwood elements is 217 ha⁻¹, distributed to 127 snags ha⁻¹, 64 fallen deadwood ha⁻¹, and 26 stumps ha⁻¹. The results showed an average of 89.1 TreMs ha⁻¹ on snags and 26.4 ha⁻¹ on living trees. The abundance and diversity of TreMs are significantly related to the volume of snags (R² = 0.712), the deadwood diversity (R² = 0.664), and the degree of decomposition (R² = 0.416). Full article

Long-term observations of the seasonal growth of Scots pine (Pinus sylvestris L.) tree rings in the arid conditions of the Khakass-Minusinsk Basin (southern Siberia) revealed that in 2024, trees had formed a tree ring with a typical intra-annual density fluctuation (IADF) in the transition wood. An analysis of the timing and causes of this wood structure anomaly was conducted using a combination of three approaches: (1) analyzing images of cross-sections of the forming tree ring throughout the season; (2) comparing the timing of anomalous cells’ differentiation with daily climate data; (3) comparing seasonal growth observations with calculated characteristics of the modeled growth rate and its derivatives: soil moisture and transpiration. We found that during the most severe heat wave and drought (from 22 June to 9 July), the last normal earlywood cells were yet expanding, IADF cells were being produced in the cambial zone, and the first of them began expansion, while normal cells began being produced again immediately after the subsiding of environmental stress. Apparently, low soil moisture and very high temperatures mainly impacted cells in the cambial zone, marking it as the primary target of external factors influencing tree-ring formation and structure, which is important for dendroclimatology and digital wood anatomy. This result is supported by both indirect and limited direct evidence from other sources. Full article

Understanding how climatic variability affects growth and water relations of Scots pine (Pinus sylvestris L.) is essential for assessing stand sustainability in hemi-boreal regions. Linear mixed-effects models were used to quantify the effects of climatic variability and tree characteristics on stem volume increment (ZV), sap flow (SF), and water-use efficiency (WUE) of Scots pine growing on highly oligotrophic soils in Curonian Spit National Park. Annual ZV was strongly controlled by tree size and seasonal temperature conditions. Higher temperatures in late winter and mid-summer enhanced growth, whereas elevated temperatures in April–May reduced increment. June moisture availability, expressed by the hydrothermal coefficient, had a positive effect, highlighting the sensitivity of growth to early-summer drought and heat waves. Sap-flow density during May–October was primarily driven by climatic factors, with temperature stimulating and relative humidity reducing SF, while tree size played a minor role. Random-effects analysis showed that unexplained variability in ZV was mainly associated with persistent differences among trees and sites, whereas SF variability occurred largely at the within-tree level. In contrast, WUE was dominated by climatic drivers, with no detectable site- or tree-level random effects. Higher June precipitation increased WUE, while warmer growing-season conditions reduced it. Overall, Scots pine growth and WUE are mainly regulated by intra-annual climatic conditions, particularly summer water availability. Despite rapid climatic change, no critical physiological thresholds or growth collapse were detected during the study period, indicating substantial adaptive capacity of Scots pine even under the observed exceptional conditions. Full article

The distribution of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.), similar to other tree species, depends on habitat conditions (climate, soil, and location), which are further affected by forest management. The analysis of forest ecosystems utilizes the link between the knowledge of habitat requirements of forest trees and their share in plant communities described via the phytosociological method. There is a significant knowledge gap in this regard, namely the lack of plant communities with the natural participation of pine and beech. In this context, the aim of this study was to identify the variability of plant communities involving Pinus sylvestris and Fagus sylvatica within its northeastern range. Our research resulted in the identification of two new phytosociological units described as a Fago–Pinetum association and a subassociation within the existing Leucobryo-Pinetum plant community (Leucobryo-Pinetum fagetosum). Leucobyro-Pinetum fagetosum is characterized by the constant presence of beech in the herb and seedling layer or by a share of beech in the shrub and small-tree layer up to 10% cover. Fago–Pinetum is characterized by a greater share of beech in the shrub and small-tree layer (covering 10%–30% area) and by the presence of beech in the lower understory. Full article