Effects of dietary Scote pine (Pinus sylvestris) essential oil on growth performance, digestive enzymes, immunological and antioxidant responses to Aeromonas hydrophila infection in rainbow trout (Oncorhynchus mykiss).

Multi-component tree biomass approach to estimate litterfall Hg deposition in a warm-temperate coniferous forest in southern Europe.

Role of broad- and needle-leaf morphology in capturing particulate matter and emerging pollutants in urban environments.

Impact of defoliation on tree growth for sessile oak and Scots pine following heat-drought events

How to characterize the decline of natural Pinus sylvestris var. Mongolica forests on sandy land?

Tree retention levels and prescribed burning effects on ectomycorrhizal fungal communities in a boreal Scots pine forest

Scots Pine (Pinus sylvestris L.) establishment success under climate change: Effect of site, stock type and planting time

Determining the optimal intensities for precommercial thinning (PCT) in Pinus sylvestris stands, which hold significant ecological and economic value in Türkiye, is crucial for enhancing growth performance and ensuring well-formed stems. This study investigates the effects of various PCT intensities on the growth parameters of young, naturally regenerated stands located in the Western Black Sea and Central Anatolia regions of Türkiye. A total of 24 experimental plots (4 PCT intensities × 3 replications × 2 sites) were established in thicket-stage stands, and four PCT treatments were applied: T1 (classic), T2 (0.75–1.0 m spacing), T3 (1.5–2.0 m spacing), and a control (unthinned). Diameter at breast height, height, total basal area, and total volume were measured at the end of each growing season for five consecutive years. The results indicated that PCT intensity had a significant effect (p < 0.05) on all measured growth parameters. Both DBH and height increments were positively correlated with increased PCT intensity, with the greatest gains observed in the T1 and T3 PCT treatments. In particular, the relative increment values increased in parallel with the rise in PCT intensity in all measured growth parameters. In conclusion, leaving around 3000–3500 stems per hectare during PCT provides the best outcomes in terms of growth and stand structure. The findings suggest that PCT interventions should be performed on a 3–5 year cycle to maximize growth potential and maintain forest health.

The utilization of photography imagery captured using cameras mounted on unmanned aerial vehicles (UAVs) for aboveground biomass (AGB) inventory has seen rapid growth in recent years. Existing research has predominantly focused on utilizing spectral and textural features for biomass inversion. However, estimating the AGB of trees remains a great challenge using stereoscopic imagery without the help of a digital terrain model (DTM). This study introduces five DTM-independent crown metrics using a digital surface model (DSM) and a canopy height model (CHM) derived from UAV stereoscopic imagery. The accuracy of the five metrics was evaluated against field measurements. The results indicate that the relationship between the crown cross-sectional area (CCSA) and AGB is stronger than that between tree height (TH) and AGB, with R2 = 0.62 and RMSE = 69.22 (kg/tree) for Larix gmelinii and R2 = 0.93 and RMSE = 142.06 (kg/tree) for Pinus sylvestris. Moreover, these DTM-independent crown metrics could be used to estimate the AGB of forests in the Greater and Lesser Khingan Mountain, with R2 = 0.77 and RMSE = 77.10 (kg/tree) for coniferous trees and R2 = 0.78 and RMSE = 72.46 (kg/tree) for all other trees. The results of this study demonstrate that UAV stereoscopic imagery can capture forest canopy information, and DTM-independent crown metrics can be used for AGB inversion where information on terrain under forest is unavailable.

ABSTRACT We assessed soil organic carbon (SOC) stocks and changes across six upland forest sites with 13 replicated plots, spanning bioclimatic regions from the boreonemoral to the northern boreal zone. The sites included three ICP Forests Level II plots in older coniferous stands and three long-term experiments focusing on thinning intensity, tree species effects (Norway spruce, Scots pine, silver birch), and mixtures of Norway spruce and downy birch, the latter two following clear-cutting. Repeated soil surveys spanned 9–34 years. SOC stocks in the organic LFH horizon ranged from 1.4 to 3.6 kg m−2, while total stocks down to 30 cm and 70–100 cm mineral soil depths ranged from 3.0 to 13.5 kg m−2 and 8.5 to 17.5 kg m−2, respectively. Annual SOC stock changes in the LFH horizon ranged from −106 to 111 g m−2 yr−1, with significant changes observed in five plots. Total SOC stock changes down to 15, 18 or 20 cm mineral soil depth ranged from −77 to 154 g m−2 yr−1, with significant increases detected in two ICP level II plots. Sensitivity analyses supported these findings but highlighted inconsistencies in sampling methods, hight spatial variability, and limited replicates, affecting estimates in the remaining 11 plots.

Abstract The nun moth, Lymantria monacha (L.), is one of the most destructive pests of coniferous forests, causing considerable damage during cyclical outbreaks across Eurasian forests. In view of the rising mean temperatures and the associated intensification in pest pressure, it is crucial to implement control strategies that minimize reliance on chemical insecticides. The primary objective of this study was to evaluate the insecticidal efficacy of two formulations containing crystals and spores of Bacillus thuringiensis subsp. kurstaki: Delfin water-dispersible granules (WG) and Foray 76B, which differ in the strain of B. thuringiensis used and in their formulation type. Delfin WG (strain S-11) is a powder for preparing a sprayable aqueous suspension, while Foray 76B (strain A BTS-351) is a liquid concentrate used without diluting with water. Both are intended to reduce the number of Lepidoptera pests. The experiment included three treatments in the 58–72 year-old Scots pine stands threatened by Lymantria monacha: (i) stands treated with a spray solution of Delfin WG, (ii) stands treated with undiluted Foray 76B, and (iii) untreated control stands. Aerial applications were performed using aircraft equipped with Micronair AU 5000 atomizers. Insecticidal efficacy was assessed in two stages: based on (i) 21-days-after treatment monitoring of larval fallout onto canvas sheets placed under the representative trees, followed by (ii) the numbers of alive and dead larvae found in the crowns of representative trees after their cutting. Larval fallout on canvas sheets allowed assessment of early larval mortality, while subsequent crown sampling captured the remaining population, providing a comprehensive evaluation of treatment efficacy. Observed larval mortality reached 97.6% in Delfin WG-treated stands and 95.8% in stands treated with Foray 76B. Statistical analysis confirmed that both treatments resulted in significantly higher mortality compared with the control (P < .05), while no significant difference was found between the two biopreparations. These findings demonstrate that aerial application of Delfin WG is highly effective against L. monacha and supports its use in integrated forest protection strategies in Poland.

Abstract. The effect of climate change on tree growth in boreal forests is likely mediated by local climate conditions and species-specific responses that vary according to differences in traits. Here, we assess species-specific tree growth responses to climate along gradients of mean annual temperature and soil moisture. We assessed growth-climate relationships by using tree-ring width data in Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) from the Swedish National Forest Inventory in relation to climatological data along gradients in mean annual temperature and soil moisture. Trees growing in warmer areas responded more negatively to high temperature and more positively to high precipitation. Site-specific soil moisture only showed an effect on the growth responses in areas of high mean annual temperature. The growth-climate response differed between the species; specifically, the growth response to high temperature varied more along the gradient of mean annual temperature for P. abies than for P. sylvestris. Growth responses to extreme weather events did not deviate from non-extreme events along the climatic gradients. Our study suggests that tree growth responses to climate change will depend on tree species and site-specific climate conditions. In warmer areas, high soil moisture may mitigate the adverse effects of warming on tree growth mainly for P. abies. In colder areas, P. abies is likely to benefit more from warming than P. sylvestris. Although the matching between extreme tree growth and extreme temperature or precipitation years was consistently higher than expected if the two variables were independent, an extreme year is unlikely to cause a tree growth response that markedly diverges from predictions based on linear relationships. Thus, the amplification of negative growth-climate responses during extreme years is likely of limited importance for long-term growth, as such events are inherently rare. Nevertheless, extreme years may influence forest productivity by affecting tree mortality, an aspect that was beyond the scope of this study. In the face of climate change, our results emphasize that forest management should consider site-specific climate conditions and species differences to sustain future forest productivity.

Bark beetles (Coleoptera: Scolytinae) play a dual ecological role in forest ecosystems as disturbance agents and vectors of symbiotic fungi, including blue-stain taxa that affect wood quality and tree health. This study assessed fungal communities specific to four bark beetle species—Ips acuminatus (Gyllenhal, 1827), Ips sexdentatus (Börner, 1776), Ips typographus (Linnaeus, 1758), and Pityogenes chalcographus (Linnaeus, 1761)—colonizing Scots pine (Pinus sylvestris L.) in Slovakia. Fungal DNA was extracted from beetle surfaces and analyzed using ITS2 metabarcoding on the Illumina MiSeq platform to characterize the diversity and structure of associated mycobiota. Alpha- and beta-diversity analyses revealed a taxonomically and functionally rich fungal assemblage dominated by Ascomycota, comprising over one thousand operational taxonomic units. Fungal richness and diversity varied among beetle species: I. typographus and P. chalcographus supported the most diverse communities, I. sexdentatus harbored the least diverse assemblages, and I. acuminatus showed contrasting patterns depending on the index used. Beta-diversity analysis indicated that community composition was primarily structured by beetle species identity, with weaker effects of locality and sampling method. Ophiostomatoid fungi, particularly Geosmithia pallida (G. Sm.) M. Kolařík, Kubátová & Pažoutová, Ophiostoma distortum (R.W. Davidson) de Hoog & R.J. Scheff., and Ophiostoma minus (Hedgc.) Syd. & P. Syd., were consistently prevalent and formed the core mycobiome. Random forest classification and differential abundance analyses confirmed host-specific enrichment of several ophiostomatoid and yeast taxa. Yeasts (e.g., Kuraishia, Candida, Yamadazyma), saprotrophic molds (e.g., Penicillium, Davidiella), and the entomopathogen Beauveria bassiana (Bals.-Criv.) Vuill. also occurred frequently. These findings provide the first DNA-based evidence of host-specific fungal assemblages in Scots pine bark beetles in Slovakia and emphasize their ecological significance for beetle–fungus symbioses and pine forest health.

Seasonal climate warming affects temperate plant phenology differently. Early winter warming can delay dormancy release and budburst due to insufficient chilling, while late winter or spring warming advances budburst. Additionally, the influence of pre-spring non-structural carbohydrate (NSC) availability on leaf phenology remains poorly understood. We explored the effects of previous late-summer defoliation and winter-spring warming on NSC dynamics and spring leaf phenology in two species: deciduous sessile oak with low chilling sensitivity and evergreen Scots pine with intermediate chilling sensitivity. We observed species-specific responses of leaf phenology to warming and defoliation. Winter warming delayed leaf unfolding in pine but not in oak, likely reflecting the greater chilling requirement of the pine. Defoliation significantly reduced pre-spring NSC levels in twigs and roots of both species, and led to earlier needle emergence in pine, with no impact on oak's leaf out date. Our findings indicate a dual dependency of pine leaf unfolding on temperature and internal carbon reserves, suggesting that defoliation, e.g., through herbivory or diseases, affects the following year's spring phenology and leaf growth in evergreen species but not in deciduous trees. These findings are important for understanding the adaptive strategies of different plant functional types under uneven warming conditions.

High-resolution carbon isotope ratio (δ13C) measurements of tree rings have the potential to provide seasonal environmental information. However, due to the complexity of the wood formation processes, the reliability of this method for intra-seasonal reconstruction of growing conditions remains unclear. We therefore investigated the intra-annual variation of δ13C in tree rings of three conifer species (Pinus sylvestris L., Picea abies (L.) H. Karst., Abies alba Mill.) across sites from the Swiss Alps to assess their response to seasonal variation of soil water potential (SWP) and vapour pressure deficit (VPD). Intra-annual δ13C values at a resolution of 10 points per year were assessed using laser-ablation isotope-ratio mass spectrometry. Seasonal δ13C patterns were analysed for synchronicity across trees and species, and their correlation with on-site environmental variables was used to determine the driving factors of δ13C, to reconstruct growing-season dynamics, and to estimate the timings of the growth dynamics and the allocation of carbon to xylem formation. The δ13C patterns showed high synchronicity between species, with characteristic maxima in wet and dry years occurring in the middle of the ring and at the end of the ring, respectively. Seasonal δ13C variations reliably reflected atmospheric dryness. Higher than normal soil dryness hindered the integration of further fresh assimilates into the xylem, thus allowing the identification of species- and site-specific threshold conditions that disrupt wood formation. The δ13C of Scots pine shows the strongest correlations with VPD and SWP, making it an excellent indicator of environmental variability. Silver fir appeared to integrate carbon into xylem structural material over a longer season than the other conifers, whilst Norway spruce shows more plastic, site-specific responses to environmental conditions. In conclusion, we identify how atmospheric and soil drought jointly impact tree growth and intra-annual δ13C patterns across conifer species, offering valuable insights for climate reconstructions and wider applications in forest dynamics.

Abstract Fast-growing wood that imitates colours develops colour differences over time. This shortens its service life. To solve the problems of short colour retention time and insufficient accuracy of colour imitation. In this study, a prediction method for Mongolian scots pine dyeing formulation based on 1D convolutional neural networks (CNN), Bidirectional gated recirculating unit network, linear discriminant analysis and attention mechanism is proposed. First, a large database was established through experiments involving the dyeing of Mongolian scots pine wood chips and multispectral measurements. Then, linear discriminant analysis was used for feature extraction, classification and dimension reduction of multispectral information to reduce the size of data input. Then, the data were fed into a one-dimensional convolutional neural network for feature re-extraction and recipe prediction by a two-way gated recurrent unit network, while an attention mechanism was introduced to highlight key spectral segments and improve the efficiency of the network model. The evaluation results show that the segments and improve the efficiency of the network model. The evaluation results show that the multispectral data input significantly improves the colour difference problem of colour imitation over time, and the present model significantly improves the accuracy of colour imitation. According to the International Commission on Illumination (CIE) 2000 color difference formula (CIEDE2000), the model achieved a minor-difference grade of 99.39% and a no-difference grade of 85.63%, with a coefficient of determination ( R 2 ) of 0.95.

Understanding defoliation of Pinus plantations in the Mediterranean mountains using tree segmentation and ALS time series.

The research assessed the current state of the Mongolian pine forests and revealed the features of their restoration after logging and fires. It was found that the number of Pinus sylvestris L. undergrowth in the cuttings is 15–18 times less than under the canopy of undisturbed stands. Noticeable changes in the cuttings are also observed in the ground cover. So, 5–8 years after harvesting the stand, part of the taiga forest species of the grass-shrub layer disappears in the cuttings and steppe and forest-meadow plant species appear. Changed environmental conditions, intensively developing ground cover and frequently recurring grass-roots fires in cuttings prevent the emergence of seedlings and the formation of undergrowth of the main forest-forming species. The pyrogenic factor is the main anthropogenic factor preventing the natural restoration of forests after their disturbance. Dendrochronological analysis of pine wood samples indicates that fires in the studied area occurred in the past with an average frequency of about 14 years. In the last 20–25 years, during the period of uncontrolled exploitation of forests, forest communities have been exposed to fires once every 7–9 years, and in some tracts much more often. The Scots pine is successfully renewed on burning grounds. The amount of viable undergrowth ranges from 3 to 10 thousand, pcs./ ha. In case of repeated fires in these areas, pine undergrowth and living ground cover are damaged or completely destroyed, shoots in the amount of 4–5 thousand pcs/ha or more appear in places of burnt litter. The age of the undergrowth of the scots pine in the burning is determined, for the most part, by the prescription of the last fire. Haphazard logging of stands and forest fires are most often powerful exogenous factors affecting the formation and development of pine forests in Mongolia.

Abstract Artificial canopy gaps represent an effective tool for promoting natural regeneration, increasing structural diversity in forest ecosystems. However, the influence of specific gap characteristics on regeneration success remains insufficiently understood. This is especially important for the transformation of even-aged, single-layered Scots pine ( Pinus sylvestris L.) stands on oligotrophic sites, where there is a clear need for evidence-based silvicultural recommendations. This study investigated the effects of gap size (0.05 ha vs. 0.30 ha), soil cover type, microtopography, and within-gap position on the establishment and early development of naturally regenerated Scots pine. To assess these factors, generalised additive models were applied to data from a regeneration experiment established in a 98-year-old pine stand during the winter of 2013/2014. Regeneration density was recorded after the 2nd and 8th growing seasons, and in the latter inventory, seedling height and proportions of soil cover types were also measured. Initial findings showed that seedling density in large gaps was over three times higher than in small gaps (3.42 vs. 1.04 seedlings·m −2 ). However, after 8 years, this difference had disappeared, and the gap size no longer significantly affected either seedling density or height. Dwarf shrubs and grasses negatively influenced regeneration density, while lichens and litter had a positive effect on seedling density but were negatively associated with seedling height. The results suggest that both gap sizes may be suitable for regeneration cuttings under similar site conditions.

The adhesion strength was studied for water-based nano-varnishes applied to densified and thermally post-treated beech (Fagus orientalis L.) and pine (Pinus sylvestris L.) woods. Specimens were thermo-mechanically densified at different compression ratios (20% and 40%) and temperatures (110 °C and 150 °C), and subsequently thermally treated at 190, 200, and 210 °C. One-component (OWB) and two-component (TWB) nano-varnishes were applied, and adhesion strength was evaluated using the pull-off test. Results revealed that the modification processes greatly influenced adhesion, with distinct effects depending on wood species. For untreated beech, densification improved adhesion strength, whereas for pine, it either reduced or did not cause a pronounced change. A primary finding was that thermal treatment decreased adhesion strength for all specimens in a temperature-dependent manner; higher temperatures led to progressively lower adhesion. This decline was more pronounced in densified specimens (especially beech wood). The reason was attributed to the cohesive failure within the weakened wood substrate rather than adhesive failure at the varnish-wood interface. Across all treatment conditions, TWB varnish exhibited superior adhesion compared to OWB. The study concluded that densification may have a species-specific effect, while thermal treatment fundamentally reduces wood surface strength and, consequently, varnish adhesion.