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The research article in the Israel Journal of Ecology & Evolution delves into neighborhood competition and spatial patterns of tree species in an evergreen broadleaved forest in Bidoup-Nui Ba National Park, southern Vietnam. A 4-ha plot was established within the park, identifying 7,666 trees of sixty-six species, with the most abundant species showing aggregated distribution at small scales linked to life-history stages. The study uncovered instances of both symmetric and asymmetric competition, shedding light on the ecological processes influencing spatial distribution and competition among broadleaved tree species in the region. [Extracted from the article]

We describe the spider communities collected by pitfall traps from forestry plantations at 16 areas across the UK, primarily planted with conifers, as part of the Biodiversity in Britain's Planted Forests research programme. The large collection of 13,863 identifiable individuals contained 191 species, mainly ones known to be associated with woodlands. The biggest source of variation in the data was a geographical gradient from the southeast to the northwest of the British Isles, presumably reflecting climatic conditions. The far northwestern sites held a relatively homogeneous assemblage typified by Micrargus apertus, while the southeastern sites held a more diverse mix of species. There was some evidence for tree species affecting the assemblage, with differences between the spiders of Sitka spruce and Norway spruce, also between Corsican pine and Scots pine. The age of forest was also influential, with highest diversity in the youngest stands. Overall, we suggest that these artificial plantations contribute to a surprising degree to our forest invertebrate biodiversity and merit further studies to elucidate the factors driving species assemblages within plantations of different tree species and of different ages. [ABSTRACT FROM AUTHOR]

Transcriptomes from stem-inoculated Scots pine saplings were analyzed to identify unique and enriched H. annosum transcripts in the early stages of infection. Comparing different time points since inoculation identified 131 differentially expressed H. annosum genes with p-values of ≤0.01. Our research supports the results of previous studies on the Norway spruce–Heterobasidion annosum s.l. pathosystem, indicating the role of carbohydrate and lignin degradation genes in pathogenesis at different time points post-inoculation and the role of lipid metabolism genes (including but not limited to the delta-12 fatty acid desaturase gene previously reported to be an important factor). The results of this study indicate that the malic enzyme could be a potential gene of interest in the context of H. annosum virulence. During this study, difficulties related to incomplete reference material of the host plant species and a low proportion of H. annosum transcripts in the RNA pool were encountered. In addition, H. annosum transcripts are currently not well annotated. Improvements in sequencing technologies (including sequencing depth) or bioinformatics focusing on small subpopulations of RNA would be welcome. [ABSTRACT FROM AUTHOR]

Wood modification has been explored in various ways to enhance dimensional stability and reduce flammability, with a focus on environmentally friendly treatments to meet market demands. This study aimed to investigate the efficacy of new, potential fire-retardant materials. Specifically, the study examined the combination of tripotassium citrate (TPC), a water-soluble and bio-based fire retardant, with sorbitol and citric acid (SorCA), an eco-friendly thermosetting resin previously studied. While TPC is known to control combustion, its application in wood modification has not been thoroughly researched. To assess the fixation and flammability of these fire retardants, tests were conducted on Scots Pine (Pinus sylvestris L.), including chemical analysis, dimensional stability, mechanical properties, flame retardancy, and leaching tests. The combination of SorCA and TPC showed high weight percent gain (WPG) values; however, leaching and anti-swelling efficiency (ASE) tests revealed challenges in fixation stability. The dynamic mechanical properties were reduced, whereas the static strength values were in the same range compared with untreated wood. While TPC exhibited high flame retardancy prior to leaching, its efficacy diminished post-leaching, underscoring challenges in fixation and the need for improved retention strategies. Bunsen burner tests conducted on leached specimens indicated enhanced performance even under severe leaching conditions as per the EN 84:2020 procedure. However, cone calorimetry measurements showed less favorable outcomes, emphasizing the necessity for further investigation into optimizing TPC retention and enhancing treatment efficacy. [ABSTRACT FROM AUTHOR]

This study investigates lignocellulosic biocomposites' physicochemical properties and strength parameters with varying thermoplastic content. Biocomposites were prepared using wood (Pinus sylvestris) or hemp shives (Cannabis sativa L.) combined with 25% and 50% ABS regranulate. The research focused on evaluating the mechanical energy consumption during the compaction of wood-ABS biocomposites with different pine fractions pretreated with hot water extraction (HWE) and analyzing the relationship between strength and thermoplastic content. Results indicate that the composition of the mixture and the size of the hemp shives fraction did not significantly influence energy consumption during densification. Energy values ranged from 1.234 × 10⁻8 J to 8.296 × 10⁻8 J. While the densification of pine after HWE was unsuccessful without ABS, preheating the mixtures with ABS facilitated the production of a uniform composite. The work required for densification ranged from 1.404 × 10⁻5 J to 2.711 × 10⁻5 J for fractions without ABS. For mixtures with ABS, the work required was 1.954 × 10⁻5 J for fraction 0 ÷ 0.4 (f1) and 0.042 × 10⁻5 J for fraction 0.4 ÷ 0.8. [ABSTRACT FROM AUTHOR]

Pinus sylvestris trees are known to efficiently defend themselves against eggs of the herbivorous sawfly Diprion pini. Their direct defense against eggs is primable by prior exposure to the sex pheromones of this species and their indirect defense involves attraction of egg parasitoids by egg-induced pine needle odor. But it is unknown whether exposure of pine to D. pini sex pheromones also affects pine indirect defense against sawfly eggs. In this study, we investigated the influence of exposure of P. sylvestris trees to the sex pheromones of D. pini on indirect defense mediated by egg parasitoids. Behavioral assays with Closterocerus ruforum, a key parasitoid of sawfly eggs, revealed no significant attraction to odor from egg-free pines pre-exposed to pheromones. Chemical analyses of odor from egg-free pines showed no pheromone-induced change in the emission rates of the known key terpenoids promoting parasitoid attraction. Further comparative analyses of odor from egg-laden pines pre-exposed to the sex pheromones and of odor from egg-laden pines unexposed to pheromones neither revealed significant differences in the emission rates of terpenoids relevant for parasitoid attraction. The results suggest that a pheromone-induced or pheromone-primed, egg-induced pine indirect defense seems to be redundant in addition to the known pheromone-primable pine direct defense against the eggs and the known egg-inducible indirect defense. [ABSTRACT FROM AUTHOR]

This study aims to assess the relationships between SOC content and main soil-forming factors and identify key factors explaining the spatial distribution of SOC. The research was conducted in the Southern Ural Mountains throughout 420 km from north to south in the Republic of Bashkortostan. The predominant soil types are mountainous gray forest (Eutric Retisols (Loamic, Cutanic, Humic)), dark gray forest (Luvic Retic Greyzemic Someric Phaeozems (Loamic)) soils, and gray-humus lithozems (Eutric Leptosols (Loamic, Humic)). Forest stands are mainly composed of birch (Betula pendula), pine (Pinus sylvestris), spruce (Picea obovata Ledeb.), and fir (Abies sibirica Ledeb.). A data set of 306 soil samples taken from the top layer (0–20 cm) was studied using the "random forest" machine learning method. Ninety four spatial environmental covariates were used as explanatory variables, including remote sensing data, climate (temperature, precipitation, cloudiness, etc.), digital elevation model and its derivatives, land uses, bioclimatic zones, etc. The results showed that the SOC content varied widely from 0.8 to 32%. The random forest predictive model explained 55% of SOC variation (R2) with a root mean squared error (RMSE) of 1.35%. Key variables included surface temperature, absolute elevation, precipitation, and cloudiness, which together reflect the Dokuchaev vertical and horizontal zonality laws. The findings emphasize the importance of considering multiple environmental factors in subsequent research focused on assessing the spatial distribution of SOC. [ABSTRACT FROM AUTHOR]

Managing forests for timber yields reduces the amounts of old trees and deadwood, which has profound effects on species that are dependent on them. Retention forestry, where some trees are permanently left unharvested on clear‐cut sites, may enable the formation of deadwood and old trees in managed forests, but it is unresolved how well these practices facilitate the occurrence of species in managed forests, especially in the long term.We studied the capacity of tree retention practices to support the diversity of epiphytic lichens, a key group among threatened forest species. We compared lichen assemblages on retained trees in harvested sites to those on trees in unharvested control sites. The data were collected 21‐year post‐harvest and included living trees, snags (standing dead trees) and logs (fallen trees) of Pinus sylvestris (Scots pine).Living trees, snags and logs each hosted distinct lichen communities. The highest lichen diversity was found on snags.On living trees, species richness was similar in harvested and unharvested sites, but there was slight species turnover. In contrast, deadwood in unharvested sites hosted higher species richness and distinct species assemblages compared to deadwood in harvested sites. These differences were most pronounced on snags. Specifically, unharvested sites contained high‐longevity snags (kelo trees), which hosted unique lichen communities with higher lichen richness than any other studied substrate, including the highest numbers of red‐listed and deadwood‐dependent species.Synthesis and applications. Retention forestry can support lichen assemblages associated with living Pinus sylvestris. However, maintaining deadwood‐associated lichen diversity through retention practices entails significant challenges. Deadwood‐associated lichen diversity relies on high‐longevity snags and is not sustained by the habitats provided in retention forestry. Biodiversity maintenance in forest management requires comprehensive provision of the habitat features of unmanaged forests, such as a qualitatively representative deadwood profile, which can prove difficult. [ABSTRACT FROM AUTHOR]

Climate change means that in many areas in boreal region, the duration and thickness of the winter snow cover is decreasing. Young seedlings are exposed to fluctuating winter temperatures in the absence of protecting snow cover. Responses to winter warm and cold spells were studied with Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth.), and Norway spruce (Picea abies (L.) Karts.) container seedlings in Finland. The frost hardiness of whole seedlings and buds was determined for seedlings sampled directly from outdoor overwintering conditions, after 7-day deacclimation (+5 °C; +7 °C in late March) and deacclimation combined with 7-day reacclimation (− 7 °C) treatments between January and late March. The frost hardiness of buds and whole seedlings in Scots pine was between − 40 and − 30 °C from January to early March. Norway spruces tolerated at least − 50 °C in midwinter, but their frost hardiness in outdoor conditions decreased more rapidly in March than that of Scots pines. Silver birch tolerated − 30 °C in February. During simulated warm spells, the Scots pine and silver birch deacclimated without an ability to reacclimate during simulated cold spells. The buds and whole seedlings of Norway spruces also deacclimated, but they had some ability to reacclimate in February and early March, but not in late March. In Nordic boreal conditions, one-year-old Scots pines and silver birches respond strongly to fluctuating winter temperatures during snowless winters, whereas Norway spruces can tolerate typical winter temperatures in midwinter, but their frost hardiness may reduce during warm spells in March. [ABSTRACT FROM AUTHOR]

ABSTRACT Drought‐related die‐off events have been observed throughout Europe in Scots pine (Pinus sylvestris L.). Such events are exacerbated by carbon starvation that is, an imbalance of photosynthetic productivity and resource usage. Recent evidence suggests that optically measurable photosynthetic pigments such as chlorophylls and carotenoids respond to water stress (WS). However, there is a lack of measurements using imaging spectroscopy, and the mechanisms linking xanthophyll‐related changes in reflectance captured by the photochemical reflectance index (PRI) and chlorophyll changes in red edge position (REP) to WS are not understood. To probe this, we conducted a greenhouse experiment where 3‐year‐old Pinus sylvestris saplings were subjected to water limitation and followed using hyperspectral imaging (HSI) spectroscopy, water status and photosynthetic measurements. Carotenoids (e.g., xanthophyll cycle) and chlorophylls responded to WS, which was observed using the HSI‐derived indices PRI and REP respectively. The spatial‐temporal response in these two pigment‐reflectance groupings differed. The spatial distribution of PRI represented the light intensity around the time of the measurement, whereas REP reflected the daily averaged light intensity over the experimental course. A further difference was noted upon rewatering, where the carotenoid‐related PRI partially recovered but the chlorophyll‐related REP did not. [ABSTRACT FROM AUTHOR]

ABSTRACT Diplodia sapinea causes Diplodia tip blight (DTB) and is recognised as an opportunistic necrotrophic pathogen affecting conifers. While DTB is associated with abiotic stress, the impact of biotic stress in the host on D. sapinea's lifestyle shift is unknown. Observed co‐occurrences of D. sapinea and Melampsora pinitorqua, causing pine twisting rust on Scots pine (Pinus sylvestris), instigated an investigation into their interaction with and influence on the defence mechanisms of the host. We hypothesised that M. pinitorqua infections predispose the trees to D. sapinea by stressing the host and altering the shoot metabolites. Pines in a plantation were sampled over time to study pathogen biomass and host metabolites. Symptoms of both pathogens were consistent over years, and the preceding season's symptoms affected the metabolic profiles pre‐infection and M. pinitorqua's proliferation. Symptoms of M. pinitorqua altered shoot metabolites more than fungal biomass, with co‐symptomatic trees exhibiting elevated M. pinitorqua biomass. Specific phenolic compounds had a strong positive association with the shoot symptom × D. sapinea interaction. D. sapinea's biomass presymptoms was independent of previous disease symptoms and infection by M. pinitorqua. Some trees showed disease tolerance, with delayed rust infections and minimal DTB symptoms. Further investigations on this trait are needed. [ABSTRACT FROM AUTHOR]

The article explores the ancient role of flavonoids in land plants' adaptability to environmental stresses, highlighting their antioxidant properties and multifunctionality. Flavonoids have evolved to serve as defense mechanisms against stressors, modulate plant growth and development, and potentially emerged in response to biotic pressures and UV protection. They also act as signaling molecules, influencing auxin movement and belowground organ growth in angiosperms, while regulating human cell growth and metabolism through protein activities. The document further discusses flavonoids' interactions with hormone signaling pathways, stress responses, and their contribution to plant adaptation in changing environments, shedding light on their diverse roles in plant biology and specialized metabolism. [Extracted from the article]

The impact of chronic radiation exposure on phytohormone content and expression of phytohormone- and stress-related genes of Scots pine in the zone affected by the Chernobyl accident was studied. Needle samples were collected from three plots with contrasting levels of radioactive contamination in the Polesye State Radiation-Ecological Reserve, Republic of Belarus, and two reference plots in the Kozeluzhsky forest in June 2022. The experimental plots were located within the artificial plantations of Scots pine established in 1982, before the accident in 1986. The activity of radionuclides 137Cs, 90Sr, 241Am, 238Pu, and 239+240Pu in soil and needles ensured dose rates ranging from 3.3 to 87 mGy × year−1, while at the reference plots, the range was 0.7‒0.8 mGy × year−1. Concentrations of plant hormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), zeatin, and abscisic acid (ABA) in needles were evaluated using high-performance liquid chromatography (HPLC). We demonstrate that chronic radiation exposure is a significant stress factor that affects both phytohormonal balance and the expression of some important phytohormone- and stress-related genes. We found a tendency toward decreased ABA and auxin concentrations in trees from plots contaminated with radionuclides. The ratio (IAA + IBA + zeatin)/ABA was drastically raised at the most contaminated plots Masany and Kulazhin, reflecting the functional rearrangements of cellular metabolism that ensure plant adaptation under chronic radiation exposure. Changes in gene expression indicated modulation of ABA and Ca2+ signalling pathways, decreased potential of zeatin biosynthesis, and activation of heat shock proteins biosynthesis. [ABSTRACT FROM AUTHOR]

Dendroctonus valens is one of the main invasive pests in China, causing serious economic and ecological damage. Early detection and control of D. valens can help prevent further outbreaks. Based on unmanned aerial vehicle (UAV) thermal infrared and hyperspectral data, we compared the spectral characteristics of Pinus sylvestris var. mongolica in three states (healthy, early-infested, and dead), and constructed a classification model based on the random forest algorithm using four spectral datasets (reflectance, first derivative, second derivative, and spectral vegetation index) and one temperature parameter dataset. Our results indicated that the spectral differences between healthy and early-infested trees mainly occur in the near-infrared region, with dead trees showing different characteristics. While it was effective to distinguish healthy from early-infested trees using spectral data alone, the addition of a temperature parameter further improved classification accuracy across all datasets. The combination of the spectral vegetation index and temperature parameter achieved the highest accuracy at 93.75%, which is 3.13% higher than using the spectral vegetation index alone. This combination also significantly improved early detection precision by 13.89%. Our findings demonstrated the applicability of UAV-based thermal infrared and combined hyperspectral datasets in monitoring D. valens early-infested trees, providing important technical support for the scientific prevention and control of D. valens. [ABSTRACT FROM AUTHOR]

Aims: Vegetation type is one of the most important contributing factors to changes in soil properties during the rehabilitation of mining areas. However, there is still insufficient awareness regarding the relationship between soil properties and the function of soil microbes in C/N metabolism in different revegetation types. Methods: Plots were established in seven revegetation types that were established more than 30 years ago in the Pingshuo opencast coal mine (RP, Robinia pseudoacacia; PS, Pinus sylvestris; PA, Picea asperata; PC, Populus simonii Carr; UP, Ulmus pumila; PT, Pinus tabuliformis; LG, Larix gmelinii). Soil properties and enzyme activity were determined, and a metagenomic approach was used to analyse the potential mechanisms of soil microorganisms involved in carbon and nitrogen metabolism. Results: Total N and soil organic carbon in PT, PS, and UP were significantly higher than those in the other revegetation types. The genes COG0477, COG2133, β-glucosidase (EC 3.2.1.21), and argininosuccinate lyase (EC 4.3.2.1) were prominently present in the soils of all revegetation types, with significantly higher prevalence in RP, PS, and PT. The modification of soil properties owing to revegetation type affects soil microorganisms, thus influencing the C/N metabolism functions of the soil ecosystem. Conclusion: Soil bacteria and fungi play a significant role in maintaining the soil C/N metabolism. Therefore, the impact of revegetation types on the function of soil microorganisms in C/N metabolism must be considered when formulating ecological restoration strategies. Robinia pseudoacacia, Pinus tabuliformis, and Pinus sylvestris could be excellent species choices for facilitating ecological rehabilitation in mining areas. Highlights: • Revegetation species significantly affect soil nutrient levels and enzyme activities. • COG0477, COG2133 and COG0028 are abundant in R. pseudoacacia habitats. • β-glucosidase genes are prevalent in all revegetation habitats. • Soil bacteria and fungi contribute significantly to the regulation of soil C/N metabolism. • R. pseudoacacia, P. tabuliformis, and P. sylvestris are excellent candidates for mining area reclamation. [ABSTRACT FROM AUTHOR]

Scots pine (Pinus sylvestris L.), a keystone species in Eurasian forests, supports diverse fungal communities and thus contributes to forest health and ecosystem functions. The southern marginal populations of P. sylvestris in Türkiye, situated in more arid and warm conditions, offer a unique environment to explore fungal biodiversity. In this study, the authors investigated the fungal assemblages in living (green) and dead (senescent, fallen, and litter) Scots pine needles in Türkiye. Using a culture-based approach coupled with DNA sequencing, distinct fungal communities were identified across different needle types. Frequent isolates included well-known P. sylvestris associates, including Lophodermium pinastri, Sydowia polyspora, and Cyclaneusma minus. Novel findings, such as unidentified Eurotiomycete and Basidiomycete taxa, suggest potentially new species and hidden fungal diversity in this biogeographically important region. Additionally, this study reports the first records of Desmazierella acicola and Phacidium lacerum in Türkiye, further underscoring the region's underexplored fungal biodiversity. Moreover, the biodiversity and community structure analysis revealed the intricate and complex nature of fungal colonization and succession, with significant variations between green, senescent, freshly fallen, and litter needles sampled concurrently. These findings provide new insights into the fungal communities of marginal, understudied Scots pine populations. [ABSTRACT FROM AUTHOR]

The hardness of the wood surface determines its wear resistance and resistance to mechanical damage. This study aimed to determine the effect of walnut tannin used in wood preservation on the surface properties of wood. For this purpose, Scots pine (Pinus sylvestris L.) and walnut (Juglans regia L.) wood test specimens were treated with walnut tannin with a brush. The specimens then were coated with water-based and polyurethane varnishes. After drying, the surface hardness was measured. As a result of the research, it was determined that the highest surface hardness was in the control samples without tannin application and the highest value was in walnut wood. [ABSTRACT FROM AUTHOR]

Graphene was mixed with varnishes at different ratios and applied by spraying method on different cross-sections of various wood materials, and their wear and adhesion performances were determined. Graphene (0.25%, 0.50%, 1%); varnishes (water-based and polyurethane varnish) and wood materials (beech (Fagus orientalis Lipsky), chestnut (Castanea sativa Miller), yellow pine (Pinus sylvestris L.), and spruce (Picea orientalis (L.) Link.)) were used. Adhesion and abrasion tests were performed. A total of 480 test specimens were prepared, 5 specimens for each wood type, cross-sectional direction, graphene ratio, and varnish type for adhesion and abrasion tests. The adhesion of the samples was determined by ASTM D 4541-09E1 pull-off test and abrasion resistance was determined in accordance with ASTM 4060-10. The data obtained were statistically analyzed and the significance values within and between groups were determined. As a result, abrasion resistance and adhesion increased in graphene 2 (0.50%) in both varnish types. [ABSTRACT FROM AUTHOR]

The concentrations of Sr, Tl, and V in soils and plant organs were evaluated at a copper mining site. These are heavy metals that are extremely dangerous and harmful to human and environmental health and, therefore, are on the ATSDR substance priority list. Within the scope of the study, soil samples were taken from different soil depths in the spoil area, the rehabilitation area where planting was performed and adult trees that were at least 20 years old, and the forest area. Soil samples were taken from the rehabilitation and forest areas where Pinus nigra Arnold., Pinus sylvestris L., and Robinia pseudoacacia L. species grow, and leaf, bark, wood, and root samples were taken from trees in the same areas. The study evaluated variations in heavy metal concentrations in soils based on species and soil depth and in plants based on plant species and organs. The study found that the heavy metal concentrations in soils and plant organs generally varied depending on plant species, while these variations were insignificant depending on soil depth. The highest concentrations by species were generally obtained for Sr in Robinia pseudoacacia and for Tl and V in Pinus nigra. [ABSTRACT FROM AUTHOR]

Background: Scots Pine is one of the main forest-forming species in boreal forests; it has great economic and ecological significance. This study aimed to develop and test primers for detecting nucleotide polymorphisms in genes that are promising for detecting adaptive genetic variability in populations of Pinus sylvestris in the Urals and adjacent territories. Objectives: The objects of the study were 13 populations of Scots Pine located in the Perm Territory, Chelyabinsk Region, and the Republic of Bashkortostan. Results: Sixteen pairs of primers to loci of potentially adaptively significant genes were developed, from which three pairs of primers were selected to detect the nucleotide diversity of the studied populations. The indicator of total haplotype diversity determined in the three studied loci varied from 0.620 (Pinus-12 locus) to 0.737 (Pinus-11 locus) and, on average, amounted to 0.662. The nucleotide diversity indicators in P. sylvestris in the study region were, on average, low (π = 0.004, θW = 0.013). Their highest values were found at the Pinus-12 locus (π = 0.005; θW = 0.032), and the lowest were found at the Pinus-15 locus (π = 0.003; θW = 0.002). This indicates that Pinus-15 is the most conserved of the three studied loci. In the three studied P. sylvestris loci associated with adaptation to environmental factors, 97 polymorphic positions were identified. The 13 populations of P. sylvestris are characterized by an average level of genetic diversity (Hd = 0.662; π = 0.004; θ = 0.013). Conclusions: The polymorphic loci of adaptively significant genes of P. sylvestris can help identify the adaptive potential of pine forests in conditions of increasing ambient temperatures. [ABSTRACT FROM AUTHOR]

Scots pine is of greatest importance in northern Germany regarding its cultivation area and expected capability to perform in climate change. However, pine predominantly occurs in monocultures. Therefore, future pine forestry depends on an adaptation to climate change while improving ecological and economic forest functions. Yet future development of pine remains uncertain due to leeway in silvicultural guidelines and future climate. This study questions: (i) what is the range of future pine shares under climate change and different silvicultural management in northern Germany, (ii) how will the current stands develop and (iii) what is the range of uncertainty arising from climate models and silvicultural options? To answer these issues we (i) selected forest development types site- and climate-sensitively to either minimize or to maximize pine shares, (ii) simulated four, now practiced forest management scenarios for 50 years based on the German National Forest Inventory and (iii) analyzed the differences, to be interpreted as uncertainty. Novel to our approach is the site- and climate-sensitive selection of forest development types on large scales which emphasizes the contrasts of the different management guidelines. The results show that growing stock and cultivation area will decrease even if pine is promoted in forestry. The predicted restoration rate ranges from 50 to 72% depending on scenario and previous thinning regime. In conclusion, under the given management concepts and considering today's high proportion of old pine, restoration is alarmingly slow. Amid the rapidly changing climate, we recommend to further adjust the management guidelines to accelerate forest restoration. [ABSTRACT FROM AUTHOR]

Understanding the growth efficiency of individual trees, or growth per unit of resource utilization, can inform silvicultural management strategies to maximize tree and stand growth. Stand structure—the size and spatial distributions of trees within the stand—strongly influences water, light, and nutrient availability, as well as the resource-use efficiency of each tree. Key silvicultural tools for stand management include manipulating tree density, size distribution, and arrangement by controlling natural regeneration, artificial seeding, planting seedlings, and/or subsequent thinning of established trees. We analyzed two sets of plots from even-aged stands of common coniferous species in central Spain, 106 pure Scots pine (Pinus sylvestris) and 92 pure Mediterranean pine (Pinus pinaster), to examine the dynamics of the dominance hypothesis, the relationship between stand structure and growth, and the relationship between structure and growth efficiency. Our main findings revealed a negative impact of size-class uniformity on stand growth in both Scots pine and Mediterranean pine, while the positive effect of tree size on growth efficiency was supported for Mediterranean pine stands but uncertain for Scots pine. At the operational level, our results highlight how thinning intensity is more important than the thinning method in Mediterranean pinewoods and how thinning can benefit the provision of multiple ecosystem services. We also recommend integrating dominance effects on growth into individual tree modelling. [ABSTRACT FROM AUTHOR]

Scots pine (Pinus sylvestris L.) wood is one of the most popular timber export products. However, its low durability can reduce the potential and utilization of the wood. Chemical modification is one of the solutions to overcome this drawback. Chemical modification using non-biocide materials such as glycerol and citric acid was carried out to improve the inferior properties of wood. The study aimed to observe the microstructure and evaluate the surface characteristics of glycerol and citric acid-modified scots pine wood. Scots pine wood was modified using glycerol and citric acid with weight percent gain (WPG) values of 20% and 46%. Surface characteristics were measured, including surface roughness, surface free energy (SFE), wettability, and bonding quality. The results show that chemical modification using glycerol and citric acid resulted in the structure of the pine wood being more filled and denser. The modification could also reduce the roughness of the wood surface, resulting in decreased SFE value, increased contact angle, and decreased wettability on the wood surface. It might cause a decrease in the bonding quality because the wood did not have the strength to mechanically lock with the paint. Glycerol and citric acid modified-scots pine wood can be considered for exterior application. [ABSTRACT FROM AUTHOR]

Prunus serotina is one of the most widespread alien tree species in temperate European forests. Although numerous studies revealed both negative and positive impacts on native ecosystems, only a few assessed the quantitative impacts along a species abundance gradient, based on aboveground biomass of per capita effects. Here we studied how alpha diversity of forest understory changes with increasing aboveground biomass of P. serotina. In Wielkopolska National Park (W Poland) we established 92 plots in both nutrient-rich and poor Pinus sylvestris stands. We assessed the effects of P. serotina proportion on understory species composition using non-metric multidimensional scaling (NMDS). We also assessed the effects of P. serotina proportion on alpha diversity metrics using generalized mixed-effects linear models, accounting also for stand age, soil C:N ratio, and light availability. P. serotina biomass ranged from 0.0 to 34.29 Mg ha−1 (with an average of 5.70 ± 0.83 Mg ha−1), comprising 0% to 17.26% (with an average of 2.93 ± 0.43%) of total woody species biomass. NMDS revealed a lack of P. serotina proportion effects on understory species composition. We found small positive impacts of P. serotina proportion on total species richness (+ 8.8 species along a gradient with a 10% increase of P. serotina biomass proportion) and functional richness (+ 0.08). The positive impacts of P. serotina were mostly related to the confounding effect of two factors: an increase in light availability facilitates both the development of understory plants as well as the growth of P. serotina. [ABSTRACT FROM AUTHOR]

Persistence of standing dead trees (snags) is an important determinant for their role for biodiversity and dead wood associated carbon fluxes. How fast snags fall varies widely among species and regions and is further influenced by a variety of stand‐ and tree‐level factors. However, our understanding of this variation is fragmentary at best, partly due to lack of empirical data.Here, we took advantage of the accruing time series of snag observations in the Finnish, Norwegian and Swedish National Forest Inventories that have been followed in these programs since the mid‐1990s. We first harmonized observations from slightly different inventory protocols and then, using this harmonized dataset of ca. 43,000 observations that had a consistent 5‐year census interval, we modelled the probability of snags of the main boreal tree species Pinus sylvestris, Picea abies and Betula spp. falling, as a function of tree‐ and stand‐level variables, using Bayesian logistic regression modelling.The models were moderately good at predicting snags remaining standing or falling, with a correct classification rate ranging from 68% to 75% among species.In general, snag persistence increased with tree size and climatic wetness, and decreased with temperature sum, advancing stage of decay, site productivity and disturbance intensity (mainly harvesting).Synthesis and applications: The effect of harvesting demonstrates that an efficient avenue to increase the amount of snags in managed forests is protecting them during silvicultural operations. In the warmer future, negative relationship between snag persistence and temperature suggests decreasing the time snags remain standing and hence decreasing habitat availability for associated species. As decomposition rates generally increase after fall, decreasing snag persistence also implies substantially faster release of carbon from dead wood. [ABSTRACT FROM AUTHOR]

Wood ash fertilization remarkably increases tree growth and hence, carbon sequestration in drained boreal peatland forests, particularly in nitrogen (N)-rich Scots pine sites with limited phosphorus (P) and potassium (K). Because ash lacks N, N-deficient ombrotrophic and poor oligotrophic sites are generally considered unsuitable for ash fertilization. In this study, timber production was investigated in six field experiments in N-poor, drained Scots pine dominated peatlands in central Finland, where ash fertilization was applied 15–85 years earlier. Ash significantly increased tree growth in all the study sites. Unfertilized plots showed long-term average mean annual increment (MAI) of 2.01 m3·ha−1·a−1, whereas in fertilized plots MAI was 4.46 m3·ha−1·a−1. An analysis with nonlinear mixed effects model revealed a faster volume yield development and higher asymptote of the mean curve in fertilized plots. Higher amount of K in the ash significantly increased the response. Fertilizations were financially lucrative: on average, the break-even cost surpassed the ash fertilization cost (390 € ha−1) more than two-fold at 5% interest rate. The current nutrient status of fertilized trees was rather balanced. The results proved that the long-term growth response to ash fertilization in poor drained peatland sites is comparable to N-rich sites, but the response time is distinctively longer. [ABSTRACT FROM AUTHOR]

Wood chips and sawdust are used for cultivating Ganoderma lucidum mushrooms. In Northern Europe, side-streams of Pinus sylvestris are highly abundant, however as cultivation substrate they inhibit the growth of G. lucidum. To identify the changes in lignocellulosic composition after fungal degradation, the major lignocellulosic components in P. sylvestris and an optimal substrate for G. lucidum, Populus tremula were analyzed. Populus tremula was evenly degraded while the glucan fraction of P. sylvestris was not degraded and its lignin fraction was consumed almost completely. Despite not being an optimal substrate, P. sylvestris was successfully delignified by G. lucidum. [ABSTRACT FROM AUTHOR]

Eurasian Jays (Garrulus glandarius) typically store seeds on the ground in shallow caches, promoting tree recruitment. However, speculation exists that Eurasian Jays occasionally store a portion of seeds in microhabitats unsuitable for proper germination. Here, we report that unexpected caching sites in Eurasian Jays can be much more widespread than previously considered and despite their accidental character it seems to be a durable aspect of Eurasian Jay's hoarding behavior. Out of 259 removed acorns of Pedunculate Oak (Quercus robur), we localized 31 consumed and 222 stored acorns. Six experimental acorns (3% of stored acorns) were found stored by jays in unexpected caching sites: (i) above the ground on individuals of Scots Pine (Pinus sylvestris), (ii) inside the woody stems of Reynoutria sp. individuals, (iii) in a rotten trunk, and (iv) among ruin debris. Our findings suggest the need to revise our understanding of so-called unexpected caching in Eurasian Jays. This highlights a previously overlooked aspect of oak-jay interactions, offering a valuable piece to the puzzle. [ABSTRACT FROM AUTHOR]

[Objective The aims of this study are to determine the soil desiccation characteristics of a typical plantation in the Baiyu Mountain area, and to provide theoretical basis for reasonable selection and sustainable development of plantation in Baiyu Mountain area. [Methods] The plantations with 40 years of vegetation restoration (PopulusXhopeiensis Hu & Chow. Pinus tabulaeformis and Pinus sylvestris var. mongholica Litv.) were taken as the samples. The barren grassland was taken as the control. Artificial soil drilling method was used to study the drying characteristics and influencing factors of 0-5 m soil in the artificial forest. [Results] (1) The average soil water content of different plantations was in the order: grassland (4.95%) Pinus sylvestris vat, mongholica Litv. (4.49%) >Populus X hopeiensis Hu & Chow (4,39%) >Pinus tabuliformis (2.44%). (2) The soil dry layer existed in different plantations and the formation depth and thickness of the dry layer were basically the same, but the average water content of the soil in the dry layer was different, the lowest value was observed in Pinus tabulaeformis and the highest value was observed in the wasteland. (3) The soil desiccation index of different plantations followed the order: Pinus tabuliformis (69.75%) >PopulusXhopeiensis Hu & Chow (28.83%)> Pinus sylvestris var. mongholica Litv. (26.73%)> grassland (17.05%). (4) Correlation analysis and multiple linear regression model showed that silt. sand and depth were the main factors affecting soil desiccation characteristics of Pinus sylvestris var. mongholica Litv.. Pinus tabulaeformis and Populus X hopeiensis Hu & Chow. respectively. [Conclusion] The soil desiccation degree of Pinus sylvestris var. mongholica Litv, was the lowest after 40 years of planting. Pinus sylvestris var, mongholica Litv. could be used as the best choice for afforestation of typical plantation in Baiyu Mountain area. [ABSTRACT FROM AUTHOR]

The influence of meteorological factors and anthropogenic air pollution on the radial growth of the Scots pine Pinus sylvestris L. was studied as dependent on the distance from the Pechenganickel mining and metallurgical plant (Nikel, Murmansk region). Three (control, buffer, and impact) zones of the pollution gradient were identified based on the contents of main polluting elements (S, Ni, and Cu) in the forest litter. A significant weakening of pine stands was observed in the impact zone and attributed to the combined effect of long-term anthropogenic pollution of the 1970s and unfavorable weather events of the mid-1980s. As the emission decreased from 1988 to 2018, the radial increment of P. sylvestris was observed to increase significantly (by up to 44%) in the impact zone and to remain much the same in the control and buffer zones. More recently, the radial increment of trees in the impact zone reached and even exceeded the values observed in the control zone, although the trees examined were relatively old. The finding demonstrated again the high adaptive capacity of P. sylvestris. [ABSTRACT FROM AUTHOR]

Under a water deficit, the protective proteins known as dehydrins (DHNs) prevent nonspecific interactions in protein and membrane structures and their damage, in addition to playing an antioxidant role. The DHNs of a widespread xerophytic species Scots pine (Pinus sylvestris L.) have been poorly studied, and their role in resistance to water deficits has not been revealed. In this paper, we have expanded the list of DHNs that accumulate in the cells of Scots pine under the conditions of water deficits and revealed their relationship with the effects of water deficits. In this investigation, callus cultures of branches and buds of Scots pine were used. A weak water deficit was created by adding polyethylene glycol to the culture medium. Under the conditions of a water deficit, the activity of catalase and peroxidase enzymes increased in the callus cultures. A moderate decrease in the total water content was correlated with a decrease in the growth rate of the callus cultures, as well as with an increase in the activity of lipid peroxidation. The accumulation of Mr 72, 38, and 27 kDa DHNs occurred in the callus cultures of buds, and the accumulation of Mr 72 and 27 kDa DHNs positively correlated with the lipid peroxidation activity. An increase in the content of DHNs was observed in cultures that differed in origin, growth indicators, and biochemical parameters, indicating the universality of this reaction. Thus, previously undescribed DHNs were identified, the accumulation of which is caused by water deficiency and is associated with manifestations of oxidative stress in the kidney cells of Scots pine. [ABSTRACT FROM AUTHOR]

(1) Background: The present study aimed to assess the antifungal effectiveness of a topical innovative formulation containing the association of an antifungal agent, voriconazole (VCZ), and the essential oil of Pinus sylvestris L. (PSEO). (2) Methods: Pseudo-ternary phase diagram and D-optimal mixture design approaches were applied for the development and the optimization of the o/w nanoemulsion. The optimized formulation (NE) was subjected to physicochemical characterization and to physical stability studies. In vitro permeation studies were carried out using the Franz cell diffusion system. The antimycotic efficacy against Microsporum canis was carried out in vitro. (3) Results: Optimal nanoemulsion showed great physical stability and was characterized by a small droplet size (19.015 nm ± 0.110 nm), a PDI of 0.146 ± 0.011, a zeta potential of −16.067 mV ± 1.833 mV, a percentage of transmittance of 95.352% ± 0.175%, and a pH of 5.64 ± 0.03. Furthermore, it exhibited a significant enhancement in apparent permeability coefficient (p < 0.05) compared to the VCZ free drug. Finally, NE presented the greatest antifungal activity against Microsporum canis in comparison with VCZ and PSEO tested alone. (4) Conclusions: These promising results suggest that this topical innovative formulation could be a good candidate to treat onychomycosis. Further ex vivo and clinical investigations are needed to support these findings. [ABSTRACT FROM AUTHOR]

Irruptions by boreal seed‐eating and frugivorous birds are assumed to be driven by the production of seeds and fruits, crops of which are highly variable between years. Using data from Sweden, we tested whether irruptions of Common Crossbills Loxia curvirostra were correlated with low Norway Spruce Picea abies seed production in the same year as the irruption and/or high seed production in the year prior to an irruption. Similar tests were made for Parrot Crossbill Loxia pytyopsittacus irruptions in relation to Scots Pine Pinus sylvestris seed production. In northern Europe, these conifers represent the key food species of the two crossbill species, respectively. Despite differing times that seeds take to mature and asynchronous seed production between the two conifer species, including a 3‐year cycle for Norway Spruce, the two crossbill species often irrupted in the same year as one another. Analyses showed that irruptions into Britain and other parts of western Europe by both crossbill species were correlated with low seed production by Norway Spruce in Sweden. Low seed production by Scots Pine had a marginally non‐significant additive effect on both crossbill species. In a second set of analyses, the best‐fitting model was one in which low seed production by both conifers in a given year and high seed production in the previous year were each correlated with large numbers of irrupting Common and Parrot Crossbills. The models indicate that the incidental co‐occurrence of low seed production of Norway Spruce and Scots Pine in a given year, after a year of high seed production, may result in an irruption. The seed production of Norway Spruce and Scots Pine in Sweden was correlated with production by the same species in Finland, indicating widespread synchrony of cropping across northern Europe. [ABSTRACT FROM AUTHOR]

Pine stands affected by root and butt rot (Heterobasidion annosum s.l.) contain pines (Pinus sylvestris L.) that can survive for a long time without showing external symptoms of the disease ('conditionally resistant' refers to trees that survive without symptoms despite infection). The establishment of stands from the seeds of such trees can significantly increase the effectiveness of artificial afforestation. Since the growth and development of pine trees is determined to a certain extent by the number of cotyledons after seed germination, this article examines this trait in the progeny of trees that are potentially resistant and those that have already been attacked by root pathogens. The number of cotyledons and the resilience of trees is fascinating and not generally known. Presumably, the number of cotyledons can be linked to disease resistance based on increased vigour. Biologically, a larger area for carbon assimilation leads to better photosynthetic efficiency and the production of more assimilates (sugars) necessary to trigger defence processes in the event of infection. From an ecological point of view, this can give tree populations in areas potentially threatened by root system diseases a chance of survival. The aim of this study was to analyze the potential of using the number of cotyledons and other seedling characteristics to predict the resistance of trees to root and butt rot disease. The collected data show that the seedlings from the group of diseased trees exhibited lower growth rates and vigour. However, the seedlings from the group of potentially resistant trees are similar to the control, meaning the trees that show no disease symptoms because they have not come into contact with the pathogen. Our observations suggest that monitoring germinating cotyledons could serve as an early diagnostic tool to identify disease-resistant pines, although further research is needed. [ABSTRACT FROM AUTHOR]

Insect infestation triggers multiple defense responses in plants, both locally at the infection site and systemically throughout the plant, including the production of feeding deterrents, toxins, defensive proteins, enzymes, and secondary metabolites. Our study aimed to compare the endogenous levels of antioxidative enzymes, photosynthetic pigments, phytohormones, total phenols, and flavonoids in bark-beetle-infested and uninfested trees. We evaluated the surviving trees in bark-beetle-infested stands, assessing both the condition and defense of uninfested and infested beech (Fagus sylvatica), pine (Pinus sylvestris), and fir (Abies alba) trees. Sampling was performed at six affected sites in the Czech Republic, targeting trees that were resilient to significant health deterioration caused by abiotic and biotic factors. The results showed different levels of most of the measured compounds in the three species. Among all the tested species, photosynthetic pigment levels showed the strongest association with infestation status, which was generally lower in the infested plants. For chlorophyll a, extremely significant reductions were observed from 123 ± 20.6 to 101 ± 17.9 μg/g dry weight (DW) in pine, from 231 ± 33.1 to 199 ± 22.2 μg/g DW in beech, and from 60 ± 5.66 to 51.3 ± 6.27 μg/g DW in fir. In contrast, enzymatic activities indicated only isolated instances of significant association, whereas antioxidative properties (total phenolic content, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were not significantly associated with infestation status. There was a statistically significant increase in glutathione reductase activity in infested fir and pine trees. However, this difference was not statistically significant in beech. In contrast, a significant increase in superoxide dismutase activity was detected in infected beech trees. Phytohormones have emerged as the most diverse group of analyzed compounds. Cytokinins were the most distinct, with many of them being significantly increased in infested pines, whereas both beech and fir showed only one significant association. Additionally, derivatives of jasmonic acid also showed a distinct pattern of change associated with bark beetle infestation, with the levels of three out of the four analyzed jasmonates being significantly decreased in infested pines, whereas no effects were observed in beeches and firs. Notably, many phytohormones were significantly elevated in the infested pine, whereas both beech and fir exhibited only one significant association. Overall, the data showed that pines responded differently to bark beetles than to beeches or firs. The greatest changes in phytohormones were observed in pine, whereas the most significant changes in photosynthetic pigments were observed in beech and fir trees. [ABSTRACT FROM AUTHOR]

The editorial "Topicalities in the Forest Ecology of Seeds" focuses on the importance of forest seed farming to ensure a sufficient number of high genetic value fruit/seeds for tree species management. The special issue covers topics such as seed dormancy, desiccation tolerance, complex bioecological studies, and reproductive capacity in forestry. The articles provide valuable insights into the biological and ecological aspects of seeds, offering a scientific basis for forestry and nature conservation practices to enhance forest ecosystem health and biodiversity in the face of environmental challenges. [Extracted from the article]

Research highlights: At the turn of the 21st century, there were more forest territories found disturbed by both natural processes (climate change, wildfires, insect outbreaks, permafrost thawing, etc.) and anthropogenic interferences (air pollution, clearcuts, etc.). Seed collecting, then growing seedlings in forest nurseries, and then planting seedlings over lost forest areas are the forestry measures needed to restore the forest after disturbances. Goals were to construct bioclimatic models of ranges and seed mass of major Siberian conifers (Siberian pine (Pinus sibirica Du Tour), Siberian fir (Abies sibirica Ledeb.), Siberian spruce (Picea obovata Ledeb.), Siberian larches (Larix sibirica Ledeb., L. gmelini (Rupr) Rupr, and L. cajanderi Mayr.) and Pinus sylvestris L.) and predict their potential change in a warming climate by the mid-century. Methods: Multi-year seed mass data were derived from the literature, seed station data, and were collected in the field. Climate data (January and July data and annual precipitation) were derived from published Russian reference books and websites on climate. Bioclimatic indices (growing degree-days > 5 C, negative degree-days < 0 C, and annual moisture index) were calculated from January and July temperatures and annual precipitation for both contemporary and the 2050s (2040–2060) climates using the general circulation model INM-CM5-0 and two climate change scenarios, ssp126 and ssp585, from CMIP6. Our bioclimatic range models (envelope and MaxEnt models) and regression seed mass models for major conifers were built based on these bioclimatic indices. Additionally, their ranges were limited by the permafrost border, which divided the forest area into the permafrost-free zone, where five conifers are able to grow, and the permafrost zone, where only one conifer, Dahurian larch, is able to survive. Results: Under warmed climates, the ranges of all Siberian conifers would expand 1.5-fold due to the decrease in the permafrost zone, except Dahurian larch, which would lose 5–20% of its coverage due to permafrost retreat. Conifers shifting northward would be slower than predicted only by warmed climates because permafrost would thaw slower than climates would warm. Scots pine may expand by up to 60%, covering dryer lands in the south. Future climates were found to favor seed mass increase for major Siberian conifers and for heavier seed to shift northward. Our major conifers differ by the type of seed dispersal mode: zoochoric, animal (Siberian pine) and anemochoric, and wind-dispersed (other five trees). The seed masses of the five anemochoric conifers varied within the range of 1.5–15 g of 1000 seeds, which is about 40–50-fold less than that of zoochoric Siberian pine. Site climate explained about 28–65% of the seed mass variation for the five anemochoric trees and only 11% for Siberian pine (zoochoric tree). This finding needs additional research to explain the reasons. Conclusions: Warmed climates would favor the expansion of the ranges of major Siberian conifers and their seed mass to be heavier, which would support the high-quality seed production for forest well-being and its restoration in Siberia. [ABSTRACT FROM AUTHOR]

Sorting of sawn timber batches is crucial for efficient kiln-drying. This study aimed to verify the hypothesis of different drying attributes of 25 mm thick sapwood and mixed Scots pine boards sawn from a group of butt, second, and top logs and assess the effects of kiln-drying. Three options dry-bulb temperature were taken into account. The drying results were evaluated based on the final moisture content distribution, changes in the cross-sectional dimensions of the sawn timber, drying time, and unit heat consumption. Correlations between sawn timber features, drying temperature, and drying results were analyzed using non-parametric statistical tests. The study proved the dependence of the initial moisture content and wood density variation of Scots pine sawn timber on the log type and the position on the round timber cross-section. The variation of drying attributes of the sapwood and mixed 25 mm Scots boards is insignificant in the final moisture content distribution and cross-sectional dimensions. However, green sorting may have only a beneficial effect on drying time and heat consumption. [ABSTRACT FROM AUTHOR]

The Caledonian pinewoods of northern Scotland represent the remnants of once extensive forests found at the western edge of the natural range of Scots pine (Pinus sylvestris L.). The surviving pinewoods are of international significance and are of high conservation and cultural value. However, for many decades, there has been concern about their long-term future because of a lack of regenerating seedlings and young trees. This problem is thought to be driven by high deer populations resulting in intensive browsing and severe damage to young trees, as well as a lack of favourable micro-sites for seedling germination. An experiment was established on the Mar Lodge estate in 2007–08 adjacent to native pinewood stands to test the effects of protection and site cultivation upon seedling numbers and growth. The experiment was located within a regeneration zone where intensive deer control had reduced numbers to <5 animals km−2. Ten years after initiation, occurrence and numbers of both Scots pine and birch seedlings were substantially increased in cultivated treatments compared with uncultivated controls. There were no effects of protection upon seedling numbers. Protection improved height growth of Scots pine, but not of birch. Cultivation had no effect upon the growth of pine seedlings but did influence the height of birch seedlings due to the rapid growth of some pre-existing seedlings in the uncultivated control. Vegetation cover had increased from ~60%to at least 80% cover 6 years after cultivation. The results suggest that site cultivation may be desirable to boost seedling germination within a Caledonian pinewood, but sustained measures to control browsing pressure are a prerequisite for satisfactory establishment of these seedlings. [ABSTRACT FROM AUTHOR]

Terrestrial laser scanning (TLS) has been adopted as a feasible technique to characterize tree stems while the characterization of trees' branching architecture has remained less explored. In general, branching architecture refers to the spatial arrangement of branches and their characteristics that are important when exploring the eco-physiological functioning of trees or assessing tree biomass and wood quality. Our aim was to develop a point cloud processing method for identifying and segmenting individual branches from TLS point clouds. We applied a Cartesian-to-cylinder coordinate transformation and a simple morphological filtering for stem surface reconstruction and stem-branch separation. Then branch origins were identified as their intersections with the stem surface, and individual branches were segmented based on their connectivity with the branch origins. The method, implemented in MATLAB and openly available, was validated on a 0.4-ha mature and managed southern boreal forest stand. The branch identification performance was assessed based on visual interpretation of 364 randomly sampled stem sections from 100 Scots pine (Pinus sylvestris (L.)) trees that were inspected for branch identification accuracy. The results showed that the branches could only be identified up to the height where the stem could be reconstructed. For 90% of the trees, this threshold ranged between 59.3% and 81.2% relative tree heights. Branches located below this threshold were identified with a recall of 75%, a precision of 92%, and an F1-score of 0.82. Based on our study, it appears that in a managed Scots pine stand, most of the branches can be identified with the developed method for the most valuable stem part eligible for logwood. The findings obtained in this study promote the feasibility of using TLS in applications requiring detailed characterization of trees. The developed method can be further used in quantifying the characteristics of individual branches, which could be useful for biomass and wood quality assessment, for example. [ABSTRACT FROM AUTHOR]

The pressure to plant seedlings in unprepared instead of prepared soil in forest regeneration is increasing, although seedlings' growth in unprepared soil is poorer. One way to improve seedlings' growth could be to add arginine phosphate to the planting hole at the time of planting. In field studies, abiotic and biotic damage normally disturbs studies which seek to determine growth effects, especially in unprepared soil. The study's aims were (i) to clarify whether it was possible to investigate the differences between varying soil layer structures mimicking site preparation methods and seedling treatments in simulated planting places in partly controlled conditions; and (ii) to investigate the effects of arginine phosphate (arGrow® Granulat) on the growth, especially root growth, of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) container seedlings in those simulated planting places. Seedlings of both tree species were planted in 40 l pots sunk partly into the soil in a sandy field. Before planting, pots were filled with soil layers mimicking layers in soil without any site preparation treatment and in spot mounds. After one growing season, the differences in growth parameters between treatments were small in Norway spruce seedlings, and no significant benefits of arginine phosphate were observed. The soil in the spruce pots was fine-textured and contained a thick organic layer. More studies in more common forest soil types suitable for Norway spruce seedlings are needed to be sure about the growth responses. In Scots pine seedlings, adding arginine phosphate granules to the planting holes improved the growth of seedlings at least in the first summer after planting in soil layers mimicking no mechanical site preparation situation, and the growth improvement may even have compensated the mounding effects. In conclusion, mimicking site preparation methods in large pots was a promising method by which the differences between site preparations methods as well as effects of seedling treatments, in our case arginine phosphate, on the growth of conifer seedlings, can be tested. [ABSTRACT FROM AUTHOR]

Genome skimming is a novel approach that enables obtaining large-scale genomic information based on high-copy DNA fractions from shallow whole-genome sequencing. The simplicity of this method, low analysis costs, and large amounts of generated data have made it widely used in plant research, including species identification, especially in the case of protected or endangered taxa. This task is particularly difficult in the case of closely related taxa. The Pinus mugo complex includes several dozen closely related taxa occurring in the most important mountain ranges in Europe. The taxonomic rank, origin, or distribution of many of these taxa have been debated for years. In this study, we used genome skimming and multilocus DNA barcoding approaches to obtain different sequence data sets and also to determine their genetic diversity and suitability for distinguishing closely related taxa in the Pinus mugo complex. We generated seven different data sets, which were then analyzed using three discrimination methods, i.e., tree based, distance based, and assembling species by automatic partitioning. Genetic diversity among populations and taxa was also investigated using haplotype network analysis and principal coordinate analysis. The proposed data set based on divergence hotspots is even twenty-times more variable than the other analyzed sets and improves the phylogenetic resolution of the Pinus mugo complex. In light of the obtained results, Pinus × rhaetica does not belong to the Pinus mugo complex and should not be identified with either Pinus uliginosa or Pinus rotundata. It seems to represent a fixed hybrid or introgressant between Pinus sylvestris and Pinus mugo. In turn, Pinus mugo and Pinus uncinata apparently played an important role in the origins of Pinus uliginosa and Pinus rotundata. [ABSTRACT FROM AUTHOR]

The present research was carried out in stands of Scots pine and black pine, pure or mixed with deciduous trees, installed on degraded lands from the Curvature Subcarpathian area, Romania, in a representative network of permanent research plots and followed the analysis of the structural diversity and stability indicators of these stands at different ages and in different conditions of degraded lands. The relationships between the quantitative variables with reference to the structure were established by analyzing the significance of the Pearson correlation coefficient (r) and also including datasets of slenderness indexes, which were classed into three domains of vulnerability to abiotic factors (like wind and snow). The compositional diversity of pine stands (pure or mixed with deciduous ones) is different in relation to age and is correlated with the structural diversity. The obtained correlation coefficients (r Pearson) express very strong and significant relationships between biometric parameters (h x Dbh, h x Lc%, Dc x Dbh, and Lc% x Dbh) of the structural diversity (r = 0.800–0.930), which is important for the analysis of the stability and vulnerability of pine forests. The strong correlation between the analyzed variables expresses a weak vulnerability to the action of harmful abiotic factors and the increase in the stability and resilience of the studied stands, especially of over 50 years old. In the old pine stands, the low-vulnerability domain (I < 0.80) is the best represented one, with an average of 64.01% from the total number of trees. At this age, trees with DBH > 22 cm fall into the low-vulnerability category. The explanation is that the stands were affected in their youth by the action of snow and wind, which, combined with the silvotechnical works performed, led to their compositional and structural diversification and increased stability. The young (<45 years) and pure-pine stands with higher consistency (>0.8) and even-aged structure are the most vulnerable to abiotic factors due to the fact that a large number of trees are passing gradually into the higher cenotic classes. [ABSTRACT FROM AUTHOR]

Biogenic secondary organic aerosols (SOAs) can be formed from the oxidation of plant volatiles in the atmosphere. Herbivore-induced plant volatiles (HIPVs) can elicit plant defenses, but whether such ecological functions persist after they form SOAs was previously unknown. Here we show that Scots pine seedlings damaged by large pine weevils feeding on their roots release HIPVs that trigger defenses in neighboring conspecific plants. The biological activity persisted after HIPVs had been oxidized to form SOAs, which was indicated by receivers displaying enhanced photosynthesis, primed volatile defenses, and reduced weevil damage. The elemental composition and quantity of SOAs likely determines their biological functions. This work demonstrates that plant-derived SOAs can mediate interactions between plants, highlighting their ecological significance in ecosystems. [ABSTRACT FROM AUTHOR]

Key message: Data acquisition of remote sensing products is an essential component of modern forest inventories. The quality and properties of optical remote sensing data are further emphasised in tree species-specific inventories, where the discrimination of different tree species is based on differences in their spectral properties. Furthermore, phenology affects the spectral properties of both evergreen and deciduous trees through seasons. These confounding factors in both sensor configuration and timing of data acquisition can result in unexpectedly complicated situations if not taken into consideration. This paper examines how the timing of data acquisition and sensor properties influence the prediction of tree species proportions and volumes in a boreal forest area dominated by Norway spruce and Scots pine, with a smaller presence of deciduous trees. Context: The effectiveness of remote sensing for vegetation mapping depends on the properties of the survey area, mapping objectives and sensor configuration. Aims: The objective of this study was to investigate the plot-level relationship between seasonality and different optical band configurations and prediction performance of common boreal tree species. The study was conducted on a 40-ha study area with a systematically sampled circular field plots. Methods: Tree species proportions (0–1) and volumes (m3 ha−1) were predicted with repeated remote sensing data collections in three stages of the growing season: prior (spring), during (summer) and end (autumn). Sensor band configurations included conventional RGB and multispectral (MS). The importance of different wavelengths (red, green, blue, near-infrared and red-edge) and predictive performance of the different band configurations were analysed using zero–one-inflated beta regression and Gaussian process regression. Results: Prediction errors of broadleaves were most affected by band configuration, MS data resulting in lower prediction errors in all seasons. The MS data exhibited slightly lower prediction errors with summer data acquisition compared to other seasons, whereas this period was found to be less suitable for RGB data. Conclusion: The MS data was found to be much less affected by seasonality than the RGB data. Spring was found to be the least optimal season to collect MS and RGB data for tree species-specific predictions. [ABSTRACT FROM AUTHOR]

This study investigates the carbon offset potential in Espoo, Finland, by comparing a construction-impacted deforestation site with a larger conserved forest area. Addressing a knowledge gap in localized forest conservation as a CO2 offset method, our research quantifies the carbon stock and sequestration impacts under both baseline and alternative scenarios for the two study sites. The baseline scenario for offset site reflects standard forest management practices, while the alternative scenario involves complete forest conservation without active management. Our findings reveal that the conserved forest (79 ha), dominated by Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), increased its carbon stock by 26 Mg C ha-1 in soil and 65 Mg C ha-1 in biomass. This enhancement is sufficient to compensate for the smaller deforestation site's (19 ha), also containing a mix of Norway spruce and Scots pine, stock loss of 186 Mg C ha-1 in soil and 43 Mg C ha-1 in biomass. Furthermore, this study illuminates the complexities of CO2 compensation regulation and emphasizes the necessity for robust, transparent carbon accounting practices. The insights offer a valuable perspective on integrating nature-based solutions in urban planning to achieve broader ecological and climate goals. [ABSTRACT FROM AUTHOR]

Understanding why elements are distributed in tree xylem in a particular way is a significant challenge in dendrochemistry. This study explored a hypothesis that metal elements in the xylem interact due to differences in physical properties such as ionic radius and ionization potential. Scots pine in an even-aged stand established during the early 1970s in eastern Siberia was the study species. Increment cores were taken from the north and south sides of trees and scanned with an X-ray fluorescent multi scanner. With the help of X-ray scanning, the following elements were analyzed: aluminum (Al), potassium (K), calcium (Ca), titanium (Ti), manganese (Mn), iron (Fe), copper (Cu), strontium (Sr) and zinc (Zn). Scanning data on the elements were split into early-wood and late-wood data for each year of growth. The following ratios were analyzed: Ca/Sr, Fe/Ca, Fe/Sr, Al/Cu, Al/Zn, Ti/Mn, and Mn/K. Among these, ones having a consistent pattern across tree rings, the ratios show a more or less dependable relationship: that an element shows a larger decrease (relative another element) that has a larger ionic radius and lower ionization potential. Hypothetically, this may be due to the advantage of an ion with smaller ionic radius and higher ionization potential under a deficit of accommodation centers in organic molecules. An experiment approach should be applied to clarify the relationships. [ABSTRACT FROM AUTHOR]

The forest ecosystem in Yuyang District is in the primary succession stage of vegetation construction in the new period. The study of the change characteristics and influencing factors of soil organic carbon storage under different vegetation types is conducive to the restoration of forest ecosystems and the rational use of land. Taking five typical vegetation in Yuyang District as the research object, the content of organic carbon in different soil layers was measured, and the storage characteristics of soil organic carbon in 0-100 cm of different vegetation types and their relationship with soil environmental factors were discussed. (1) Under different vegetation types, the average content of soil organic carbon was Pinus tabulaeformis forest(5.62 g·kgkg–1) > Pinus sylvestris forest(4.13 g·kgkg–1) > Platycladus orientalis forest(3.44 g·kgkg–1) > Hippophae rhamnoides forest(2.75 g·kgkg–1) > grassland(1.37 g·kgkg–1), The average content of soil organic carbon in Pinus tabulaeformis forest was significantly different from that in Platycladus orientalis, Hippophae rhamnoides forest and grassland (P < 0.05). (2) The soil organic carbon storage of different vegetation types ranged from 21.08 t·hm–2 to 76.16 t·hm–2. (3) The correlation between soil organic carbon and soil physical and chemical properties was different in various vegetations. From the perspective of the five types of vegetation, organic carbon and electrical conductivity were extremely significantly positively correlated (P < 0.01), which was related to total porosity and total porosity. The saturated water content was significantly positively correlated (P < 0.05). The storage characteristics of organic carbon under different vegetation types in Yuyang area were different, and the electrical conductivity, total porosity and saturated water content significantly affect the accumulation of soil organic carbon in woodland. [ABSTRACT FROM AUTHOR]

Trees affect the biotic and abiotic properties of the soil in which they grow. Tree species-specific effects can persist for a long time, even after the trees have been removed. We investigated to what extent such soil legacies of different tree species may impact tree seedlings in their emergence and growth. We performed a plant–soil feedback experiment, using soil that was conditioned in plots that vary in tree species composition in Białowieża Forest, Poland. Soil was taken from plots varying in proportion of birch, hornbeam, pine, and oak. In each soil, seeds of the same four target species were sown in pots. Seedling emergence and growth were monitored for one growing season. To further explore biotic implications of soil legacies, ectomycorrhizal root tip colonization of oak, a keystone forest species, was determined. We found no effect of soil legacies of tree species on the emergence measures. We, however, found a clear negative effect of pine legacies on the total biomass of all four seedling species. In addition, we found relationships between the presence of pine and soil fertility and between soil fertility and root tip colonization. Root tip colonization was positively correlated with the biomass of oak seedlings. We conclude that tree species can leave legacies that persist after that species has been removed. These legacies influence the growth of the next generation of trees likely via abiotic and biotic pathways. Thus, the choice of species in today's forest may also matter for the structure and composition of future forests. [ABSTRACT FROM AUTHOR]