The decline of Mongolian Scots pine (Pinus sylvestris var. mongolica) plantations in the “Three-North” shelterbelt region is closely linked to soil degradation. This study compared rhizosphere and non-rhizosphere soils across different stand ages, focusing on nutrient availability, microbial biomass, enzyme activities, and soil particle morphology. Results showed that SOC and TN accumulated with age, whereas AP, AK, and pH declined in older stands, indicating progressive acidification. Results demonstrated that SOC and TN increased with stand age, whereas AP, AK, and pH exhibited a marked decline in the older stands (stands aged ≥ 40 years), reflecting progressive acidification and nutrient depletion. Rhizosphere soils consistently displayed higher SOC, TN, microbial biomass, and enzyme activities than non-rhizosphere soils, largely driven by root exudation and enhanced microbial turnover. The increasing Cmic/Nmic ratio with age suggested a fungal-dominated microbial community, which may exacerbate stand decline by fostering pathogenic fungi. Scanning electron microscopy revealed pronounced particle fragmentation and surface roughness with increasing stand age, particularly in rhizosphere soils, indicating root-driven physical and biochemical weathering. These findings highlight the synergistic effects of stand development and rhizosphere processes on soil structure and fertility, providing a theoretical basis for the sustainable management and restoration of declining plantations.

ABSTRACT In order to understand the dynamic changes of soil organic carbons stocks (SOC-stocks) in Pinus sylvestris var. mongolica plantation of different stand ages, four different ages (young forest, middle-aged forest, mature forest, overmature forest) plantation in Saihanba Machinery Forest Farm were selected as the research object to explore the distribution characteristics of SOC-stocks and discuss its influencing factors. The results reflected that with the increase of forest age, soil organic carbon (SOC) content, and SOC-stocks in different layers generally showed an upward trend, and the same layer in different ages showed a significant difference (p < .05). The SOC content in the 0–60 cm layer showed that overmature forest (27.44 g/kg) > young forest (16.42 g/kg) > mature forest (15.21 g/kg) > middle-aged forest (8.75 g/kg). The SOC-stocks in the 0–60 cm layer showed that overmature forest (223.94 Mg/ha) > mature forest (134.10 Mg/ha) > young forest (126.81 Mg/ha) > middle-aged forest (80.98 Mg/ha). Pearson correlation analysis indicated that stand age, SOC content, above-ground biomass, litter amount, root biomass, soil moisture, catalase activity, invertase activity, and soil bulk density were the key factors affecting SOC-stocks. Results showed that during the growth process from young forest to overmature forest, there was an overall carbon sink effect.

Abstract Root biomass contributes a significant proportion of total biomass and carbon storage in forest ecosystems. Deadwood (including dead roots) is an essential component of the ecosystem carbon (C) balance. Currently there are some shortcomings in the reporting of deadwood regarding the completeness and the level of detail. So far it is not possible to report about dead coarse roots since there is no existing data. Therefore, we assessed wood density and C concentration of excavated stumps and dead coarse roots (≥ 2 cm) of European beech ( Fagus sylvatica L.), Norway spruce ( Picea abies (L.) Karst .) and Scots pine ( Pinus sylvestris L.) in different stages of decay in a case study in Northeastern Germany. In total, 15 rootstocks – three for pine, four for spruce and eight for beech—could be excavated and analysed. The decay class (DC) belowground was found to be less advanced than the one aboveground in 60% of all cases where the DC above- and belowground differed. Significantly decreasing wood densities to a similar level in advanced DCs, i.e. DC 3 and 4, were observed with increasing DC for all tree species. DC has been found to be the main predictor of all variables tested; already explaining 83% of the variation in wood density as a single predictor. C concentration was highest in DC 4 for spruce and pine, but lowest for beech in the same DC. C concentration in beech was generally lower than in spruce and pine. Significantly increasing nitrogen (N) concentrations and decreasing CN ratios were observed with increasing DC for all tree species. Our results indicate that decomposing rootstocks i.e. coarse roots and stumps can be a significant sink (and source) of C. Based on this study—although it needs to be extended to more repetitions and sites in the future—a first estimation of the belowground deadwood C pool as part of the German greenhouse gas reporting can be conducted.

Abstract In Boreal forests, wildfires are common disturbance agents, important for sustaining forest regeneration and ecosystem processes. However, climate warming has intensified fire activity and severity in recent years, and warmer conditions following fire can alter environmental factors affecting tree seedling survival and growth. Management interventions can potentially counterbalance the effects of fire severity and warming. Using a field experiment, we investigated the main and interactive effects of fire severity, experimental warming, understory shrub presence and salvage logging on the growth of different conifer (Picea abies and Pinus sylvestris) provenances, to provide insight about how tree seedlings of various species respond to multiple environmental drivers following fire. Our study shows that low fire severity without salvage logging resulted in poorer seedling above‐ground growth, whereas experimental warming and ericaceous shrubs removal increased seedling biomass regardless of fire severity or logging treatment. Our results suggest that enhanced light availability and reduced resource competition from the understory supports the growth of conifer seedlings following fire. Post‐fire warming further stimulated the growth of conifer seedlings (particularly in high‐severity burn areas) potentially due to increased early colonization by fast‐growing deciduous trees. Moreover, in warmer conditions, northern provenances of P. sylvestris planted in southern locations also showed greater height growth compared to local populations, highlighting the potential for assisted migration under climate change. Synthesis and applications. This study demonstrates that artificial regeneration through planting can support forest recovery following wildfire, especially under high fire severity in sites where natural regeneration is poor. Salvage logging can enhance the growth of P. sylvestris seedlings and indirectly benefit P. abies on low‐severity sites by facilitation by deciduous species that create favourable microhabitats. However, the broader ecological impacts of salvage logging (such as on biodiversity loss and soil and habitat structure) must be considered in management planning. Post‐fire vegetation management, including control of competitive ericaceous shrubs, may further improve seedling establishment. Selecting climate‐adapted seedling provenances can boost reforestation success under future warming. These findings support an adaptive management framework that integrates fire severity, logging intensity, understory control and assisted migration to foster resilient forest landscapes in a changing climate.

The relevance of the research was driven by the necessity for the rational use of the forest resource potential of Scots pine stands in the Volyn Polissya, one of the most forested regions of Ukraine with significant ecological, economic, and social importance. The aim of the study was to examine the stand structure and analyse the utilisation of Scots pine stands in the Volyn Polissya, as well as to explore ways to optimise forest management processes in the region. A comprehensive analysis of the spatial and age structure, as well as the productivity of Scots pine stands in the Volyn Polissya region, was carried out, with an assessment of timber stock utilisation by type of felling. It was found that approximately 64% of forested areas in the study region were covered by Scots pine stands. Artificial pine stands prevailed in terms of area, accounting for over 52%. The most widespread were middle-aged stands, which could be explained by active post-war forest regeneration. The majority of pine stands grew in fresh and moist subor forests, which were optimal for the species' development. The average annual volume of Scots pine timber harvested by forest enterprises in the region amounted to 1.9 million m3, with the majority obtained through principal fellings and sanitary cuttings. Among thinnings, a significant share of timber harvesting came from commercial thinning (age of 41-70). The proportion of other types of felling, both related and unrelated to forest management, ranged from 1 to 2%. The average volume of harvested Scots pine timber per hectare ranged from 2 m3 ha-1 for pre-commercial thinning (age of 11-20) to 173 m3 ha-1 for principal fellings. The results of the study may be used to improve forest management practices and to formulate a strategy for the sustainable development of forestry in the Volyn Polissya

In China, most of the ancient wooden structure mortise and tenon buildings, under the long-term upper load, have columns with surface surfaces that have varying degrees of damage, which need to be repaired and strengthened urgently, but the theory related to CFRP, mortise size, and pre-damage simulation still needs to be deeply studied. To investigate the effects of CFRP reinforcement layers, cross-sectional area of concealed tenons as the projected area after installation, and tenon engagement length as the axial length after installation on the axial compressive mechanical properties of pre-damaged quad-segment spliced Pinus sylvestris var. mongolia composited wooden columns, axial compression failure tests were conducted on 10 specimens following pre-damage simulation and CFRP strengthening. The experimental program yielded comprehensive data, including observations, mechanical analyses, load-displacement curves, load-strain curves, ultimate load-bearing capacities, ductility coefficients, and stiffness values. The results demonstrate that with consistent tenon cross-sectional area and engagement length, increasing CFRP layers from 1 to 3 raises the ultimate bearing capacity from 472.3 kN to 620.3 kN and improves the ductility coefficient from 4.67 to 7.95, clearly indicating that CFRP reinforcement significantly enhances axial compressive performance while effectively mitigating brittle failure. When maintaining constant CFRP layers and tenon cross-sectional area, extending the tenon engagement length from 30 mm to 90 mm elevates the bearing capacity from 494.95 kN to 546.3 kN and boosts the ductility coefficient from 5.58 to 7.95. In contrast, with fixed CFRP layers and engagement length, expanding the tenon cross-sectional area from 360 mm2 to 810 mm2 produces only marginal bearing capacity improvement from 548.2 kN to 556.2 kN with ductility coefficients ranging between 4.67 and 5.56, conclusively revealing that tenon engagement length has substantially greater influence on mechanical properties than cross-sectional area. The optimal axial compressive performance configuration combines 3 CFRP layers, an 810 mm2 tenon cross-section, and a 90 mm engagement length.

Fungal competition in thermally modified Scots pine wood as related to changes in lignocellulosic composition and laccase activity.

The net effect of stress induced by climate change on forest functional dynamics remains uncertain. We monitored the dynamics of wood formation and cambial phenology for 11 consecutive years in two co-occurring tree species with different drought tolerance, Pinus sylvestris and Quercus pyrenaica, providing a unique long-term xylogenesis dataset (2012-2022). To assess the influence of climate on cambial and xylem developmental phases, we analyzed biologically meaningful climatic covariates across different time windows. In pine, late-winter temperatures strongly regulated the onset of cambial reactivation, advancing it 5.5 days per°C of warming, with reactivation occurring between early April and mid-May depending on winter thermal conditions. The onset of cambial reactivation in oaks was influenced both by soil water content and late-winter temperature, although the effect of temperature was weaker and restricted to a narrower time window than in pines. The effect of climate on the end of enlargement was nearly identical in both species, consistent with a turgor-driven regulation: higher maximum temperatures accelerated the process, whereas late-spring precipitation in late spring delayed it. In oaks and pines, the end of wood formation was advanced under hot and dry summers, inducing the early cessation of secondary wall lignification and, thus, reducing the length of xylogenesis. Despite the positive effect of warmer winters on earlier cambial resumption in pines, the duration of the enlargement phase (i.e., radial growth period) remained consistently shorter than in the more drought-tolerant oaks. Yet, the high phenological pasticity of pines to winter temperatures may also increase their growth duration, thereby partially buffering the negative effects of hotter droughts. The long dataset analyzed provided a robust assessment of species-specific phenological plasticity under climate change. Disentangling the net effect of climate on xylogenesis is crucial to understand future growth dynamics in mixed forests where more drought-tolerant species are becoming increasingly dominant.

Non-target and suspect screening of volatile organic compounds from Scots pine and Norway spruce building materials.

Cytochrome P450s from the fungal symbiont of Sirex noctilio, Amylostereum areolatum: characterization, sequence analysis and their response to host terpenoids.

Spent mushroom substrate (SMS) is a promising organic amendment for remediating degraded soils, yet its effectiveness is often limited by poor compost maturity and stability. This study aimed to enhance the quality and functionality of SMS compost through microbial inoculation and to evaluate its impact on soil improvement and plant growth. Three plant growth-promoting strains [Bacillus subtilis (B. subtilis), Azotobacter chroococcum (A. chroococcum), and Paenibacillus mucilaginosus (P. mucilaginosus)] and their combination as a mixed microbial inoculant (MMI) were used in composting. Subsequent pot experiments assessed changes in soil physicochemical properties, nutrient levels, microbial diversity, and the growth of Pinus sylvestris seedlings. Results showed that SMS amended with MMI significantly improved soil porosity, pH, and nutrient content, while enriching beneficial microbial communities dominated by Proteobacteria and Basidiomycota. Moreover, MMI treatment notably enhanced plant height, stem diameter, and chlorophyll content compared to control treatments. These findings highlight the synergistic effect of mixed microbial inoculants in optimizing SMS compost and promoting soil and plant health. The approach offers a sustainable strategy for the circular reuse of agricultural waste and effective restoration of degraded soils.

Influence of drought stress on the seed germination and seedling survival of Pinus sylvestris and Larix decidua

Impacts of winter climate change on northern forest understory carbon dioxide exchange determined by reindeer grazing.

Effects of site preparation on early stage seedling dynamics and performance in pure Scots pine and Anatolian black pine stands

A comprehensive analysis of shelterbelts located within the territory of the State Enterprise «Research Farm ’Skvyrske’ of the Institute of Agroecology and Environmental Management of the National Academy of Agrarian Sciences of Ukraine» has been carried out. The aim of the work is to clarify the floristic composition, symphytosozological and ecological characteristics of shelterbelts, as well as to establish the degree of participation in the conservation of biodiversity. The species composition includes 237 species of higher vascular plants, distributed among 162 genera and belonging to 55 families. The syntaxonomic structure of the shelterbelts of the Left-Bank Forest-Steppe of Ukraine is represented by plant communities of the class Robinietea, with a dominance of the order Chelidonio–Robinietalia. Several alliances and associations have been identified, involving Robinia pseudoacacia, Acer negundo, Pinus sylvestris, Quercus robur, Ulmus spp., Fraxinus spp., Tilia cordata, and others. For the first time, new associations and subassociations have been proposed for typical phytocoenoses that form under anthropogenically transformed agro-landscape conditions, taking into account both alien and native species. The width of the forest belts is from 5 to 25 meters. In terms of vertical stratification, two-layered stands prevail (particularly with the participation of Populus alba and Robinia pseudoacacia), although single-layered shelterbelts also occur. The ecological and floristic diversity of vascular plants is relatively low; however, these belts perform crucial functions as biological corridors, buffer zones, and habitats for pollinators, entomophages, and small mammals. The presence of shrub species such as Crataegus monogyna, Sambucus nigra, and Ligustrum vulgare ensures ecological stability and enhances the biotic attractiveness of shelterbelts for fauna. The findings obtained can be applied to improve design solutions for the establishment of new shelterbelts, the restoration of degraded areas, and the implementation of eco-network principles within agro-landscapes. Moreover, this research is of practical significance for shaping national agricultural adaptation programs to climate change, since it highlights the importance of shelterbelts as naturebased solutions that increase ecosystem resilience and sustainability in agricultural territories.

Digital Volume Correlation (DVC) was used to study the hygroscopic shrinkage in lignocellulosic tissues. For this, small tissue segments of only a few cells were prepared from the endocarp of Hura crepitans fruits, the sclereid cell layer of Pinus jeffreyi pine cone scales, the sclerenchyma fiber sheath of peripheral vascular bundles in Marantochloa leucantha and latewood of Pinus sylvestris. The cells were imaged in a wet and dry state using X-ray nano-holotomography. Subsequently, a DVC analysis was conducted using Avizo™, elastix and MBS-3D-OptFlow, to visualize and quantify their hygroscopic shrinkage and to compare the accuracy of the approaches. The results reveal an anisotropic shrinkage behavior (1) along the cell length compared to radial shrinkage and (2) a greater radial than tangential shrinkage within the cell wall. The accuracy of the DVC results was validated and compared using two artificially deformed datasets (linear and sinusoidal) for controls. A (sub-)voxel accuracy for both controls could be demonstrated for each software with the image registration toolkit elastix performing best. In addition, the abundance of structural features in the cell walls leads to an improved DVC accuracy. Overall, DVC proved to be a viable approach to study the hygroscopic deformation of lignocellulosic tissue samples.

This study investigates the diversity and distribution of Suillus fungi in Pinus sylvestris var. mongolica (PSM) forests across Inner Mongolia, with a focus on understanding the environmental factors influencing fungal communities. High-throughput sequencing was utilized to analyze soil fungal communities across 12 PSM forest sites, alongside assessments of meteorological variables and soil enzyme activities. Thirteen Suillus species were identified, with S. clintonianus being the dominant species. The diversity of Suillus fungi exhibited significant geographical variation, with diversity decreasing from east to west. Precipitation and leucine aminopeptidase activity were identified as key drivers of fungal distribution. The soil fungal community was predominantly saprotrophic, playing a crucial role in nutrient cycling and ecosystem stability. The findings provide a deeper understanding of the role of ectomycorrhizal fungi in sustaining forest health and offer valuable insights for sustainable forest management and restoration efforts in semi-arid regions.

The industrial production of conifer seedlings in nurseries uses large amounts of fertilizers to ensure their proper growth and accurate nutrient status. However, inorganic nitrogen fertilization leads to nitrate leaching, which has negative environmental consequences. An alternative solution could be the use of controlled-release fertilizers that supply nutrients over longer periods and hence have a lower environmental impact. This study analysed the performance of a novel arginine-iron-hexametaphosphate complex on Scots pine (Pinus sylvestris) seedlings. The complex was characterized using a wide range of analytical tools, indicating that it is a precipitated complex rather than a crystalline compound. Plant growth on arginine-iron-hexametaphosphate was comparable to a commercial inorganic nitrogen controlled-release fertilizer but with significantly lower nitrate leaching. A nitrogen budget of seedlings and growth substrate showed that seedlings had acquired nitrogen in excess of the amount of nitrogen present at the start of the experiment, and this excess nitrogen was smaller in seedlings grown on the inorganic fertilizer. Measurements of acetylene reduction in seedlings indicated low but measurable rates of nitrogen fixation, potentially contributing to the excess nitrogen. Together, the results showed that the arginine-iron-hexametaphosphate complex is a good alternative to commonly used fertilizers and can contribute to sustainable seedling production.

In this paper, a combined modification method using thermal modification and wax impregnation was investigated. The advantage of this method is that the two modification steps are completed in one step. Two different wood species, beech (Fagus sylvatica) and Scots pine (Pinus sylvestris), were investigated. The effects of the treatments were tested regarding the wax uptake, mass loss, density, equilibrium moisture content, swelling, water contact angle, strength properties, and durability. Through the synergistic effect of the combined modification, it was possible to significantly improve the dimensional stability and decrease the hygroscopicity and equilibrium moisture content, while swelling anisotropy was not affected. It was proven that the wax uptake during this method is highly dependent on the treatment temperature, resulting in a large density increase. The treatment resulted in an obvious color change as well. Bending strength was not affected by the combined treatment, while impact bending, compression strength, and Brinell hardness were improved. High durability was observed after the combined modification method, indicating that lower treatment temperatures are enough to efficiently protect the wood.

Scots pine wood represents one of the important tree species used by the wood processing industry in many countries for both interior and exterior applications. It is well known that thermal treatment alters the color of wood. To protect wood from outdoor environmental conditions, certain chemicals are applied to its surface. These protective chemicals also influence the color of thermally treated wood. In this study, the color-altering effect of picture varnish (refined linseed oil), commonly used as a protective chemical in the field of painting, was investigated on both thermally treated and untreated wood materials. In this study, Scots pine (Pinus sylvestris L.) wood samples were subjected to thermal treatment at 212°C for 2 h. Following this, varnish made from refined linseed oil was applied to these samples with different treatments and controls. Color and whiteness index (WI*) values were analyzed on the resulting 4 different materials, and the results were compared among them. Significant variance analyses were obtained for the factors of heat treatment, picture varnish application, and their interactions on WI* (║ and ⊥), a*, L*, ho, b*, and C* values. In the non-heat-treated samples, the application of varnish resulted in reductions in WI* values in both directions and in L* values, while increases were observed in ho, b*, C*, and a* values. Additionally, the application of varnish on the heat-treated samples resulted in an increase in a* values,while reductions were observed in WI* values in both directions, as well as in ho, L*, b*, and C* values.