Planted forests in dry Mediterranean regions are increasingly threatened by extreme climatic events, making adaptive management strategies such as thinning and underplanting essential. To apply these restoration practices at large scales, it is necessary to understand how different tree species respond to varying thinning intensities. This study evaluated the performance of seedlings from four late-successional, resprouting Mediterranean broadleaf species — Acer monspessulanum L., Quercus pyrenaica Willd Sorbus torminalis (L.) Crantz, and the evergreen Quercus ilex L. subsp. ballota (Desf.) Samp— underplanted along a canopy openness gradient created by thinning treatments in a 50-year-old Pinus pinaster plantation. Four thinning treatments were compared: no thinning (control), moderate thinning from below (20% basal area reduction), heavy thinning from below (35%), and heavy thinning from above (35%), leaving 28.7, 24.9 and 23.2 m 2 ·ha −1 residual basal area, respectively. Thinning significantly increased light availability, throughfall, and soil moisture, with most improvements occurring under moderate thinning. Soil water availability increased at deeper soil layers in all thinned stands, while shallow soil moisture improved mainly under moderate thinning. After five years, seedling survival was high (>80%) across all species and generally increased with greater canopy openness. Quercus pyrenaica and Q. ilex showed the strongest positive response in survival to increased canopy opening, whereas A. monspessulanum and S. torminalis were less affected, likely due to differences in functional traits. Seedling growth was also enhanced by thinning, reaching maximum rates under moderate thinning, with S. torminalis exhibiting the highest growth and A. monspessulanum the lowest. Improved seedling performance under thinning was associated with reduced summer water stress and higher photochemical efficiency during dry periods. Overall, the study demonstrates that moderate thinning creates optimal environmental conditions for the facilitation of underplanted seedlings and provides guidelines for promoting structural and species diversification in Mediterranean pine plantations. • Thinning increases resources and the performance of underplanted seedling. • Seedling water and photosynthetic stress is alleviated under moderate thinning. • Response of underplanted seedlings to canopy openness is species-specific. • Thinning and species mixing speeds the conversion of monospecific pine plantations.

The aims of this study were determining monthly and annual litterfall mass, turnover rates, and the relationship between the litterfall of some tree components (needles, branches, bark, and miscellaneous) and various stand parameters in in afforested coastal sand dunes; nutrient- and water-poor ecosystems, having scarce research. The study was conducted on Stone pine (Pinus pinea L.) and Maritime pine (Pinus pinaster Aiton) afforestation in a coastal sand dune on the Black Sea coast of Istanbul. The total annual litterfall was calculated as 4332kg/ha/year for P. pinea and 4275kg/ha/year for P. pinaster. Among the total annual litterfall, the needle litterfall accounted for 81% in P. pinea and 85% in P. pinaster. Both needle and total litterfall peaks occurred in August, mainly during summer, due to drought conditions from April to September. Biomass-based turnover rates were calculated for needles, branches, and bark. The needle turnover rate was 0.5208 in P. pinea and 0.4258 in P. pinaster, with higher rates observed in smaller diameter classes. Relationships between litterfall mass, turnover rates, and various stand parameters were examined as well. The stand parameters (except tree count per hectare) and tree components showed significant positive correlations with litterfall and turnover rates, excluding needles. In conclusion, monthly litterfall measurements are important for determining the effects of drought and other environmental factors, managing thin fuel loads in forests under changing climate conditions, and monitoring forest ecosystem dynamics. Turnover rates varied depending on species and stand characteristics, and further research is needed in this area.

Conifer-derived essential oils have gained attention as versatile natural additives with potential applications in animal production, including influencing microbial processes and supporting environmental sustainability. This study aimed to characterize the chemical composition of selected conifer essential oils (EOs), evaluate their antimicrobial activity against rumen microorganisms in vitro, and assess the effects of Pinus sylvestris essential oil on rumen fermentation and methane production under in vitro and in vivo conditions. EOs from Thuja occidentalis, Cupressus sempervirens, Juniperus communis, Picea mariana, Pinus sylvestris, and Pinus pinaster were analyzed by GC–MS, and their inhibitory activity against selected rumen bacteria was determined by MIC and IC50 assays. Based on these results, P. sylvestris oil was selected for fermentation experiments. Ninety-two volatile compounds were identified, with monoterpenes as the dominant constituents and α-pinene as the major compound in P. sylvestris oil. In vitro, P. sylvestris oil influenced fermentation in a dose-dependent manner without affecting ruminal pH. In vivo, ruminal pH, ammonia-related parameters, and total VFA concentration were not significantly affected by treatment, whereas several variables showed a significant effect of time. Temporal changes in VFA profiles suggested a transient adaptation of ruminal fermentation. Methane concentration was significantly (p < 0.01) reduced by Pinus sylvestris essential oil supplementation, with a decrease of approximately 28.7% after 14 days. These findings indicate that P. sylvestris EOs may serve as a promising natural modulator of rumen fermentation, although further studies are needed to optimize dosage and confirm long-term effects.

The construction sector’s drive for sustainability has increased the use of Cross-Laminated Timber (CLT), yet its structural reliability is governed by the integrity of the adhesive bond line. This study evaluates the influence of three one-component polyurethane (PUR) formulations (R1, R2, R3) on the adhesion performance of maritime pine CLT. To isolate adhesive-related effects, lamellas were mechanically classified by modulus of elasticity (MOE) and randomly allocated within stiffness classes. Adhesive characterization through ABES, FTIR, and DSC revealed that R3 exhibited slower cure kinetics (t0 = 5482 s) but higher thermal stability. Mechanical testing showed that all formulations developed structurally effective dry bonds with shear strengths exceeding 7.1 MPa, with R3 achieving significantly higher dry shear and interlaminar strength. However, 24 h water immersion caused a catastrophic strength reduction exceeding 95% across all formulations, shifting the failure mode from the wood substrate to the adhesive layer. DSC analysis identified glass transition temperatures between 28 °C and 32 °C, which are consistent with the potential for moisture-induced plasticization near service temperatures. These results indicate that while slower-curing formulations like R3 enhance bond quality in dense softwoods due to improved interphase formation, all evaluated PUR systems showed significant vulnerability to saturated conditions, suggesting that adequate moisture protection is essential for maritime pine CLT applications.

Wood–polymer composites (WPCs) produced through monomer impregnation have attracted increasing interest as a strategy to improve the durability and performance of wood materials. However, the limited permeability of certain wood species often restricts the effectiveness of impregnation treatments. This study investigates the use of microwave (MW) pretreatment as a drying and microstructural modification step to enhance methyl methacrylate (MMA) impregnation and in situ polymerization in maritime pine (Pinus pinaster) heartwood specimens. Wood specimens were subjected to MW treatment of 700 W and 5 min cycles prior to vacuum-pressure impregnation with MMA and subsequent thermal polymerization. Scanning electron microscopy and treatability parameters confirmed that MW pretreatment increased wood impregnability by generating microcracks and improving monomer penetration, thereby resulting in higher polymer retention and a higher weight percentage gain. As a result, the combined MW+MMA treatment produced a more homogeneous distribution of polymethyl methacrylate within the wood structure. The modified specimens showed a substantial reduction in water absorption and the highest water repellence efficiency among the studied groups, while dimensional stability improved to a lesser extent. In addition, the combined treatment significantly increased bending strength and stiffness, indicating an effective reinforcement of the wood structure through polymer loading. These results demonstrate that MW pretreatment is an efficient strategy to improve the treatability of maritime pine heartwood and to enhance the performance of MMA-based WPCs.

Tannin-phenolic hybrid biomacromolecular resins for extrusion-based biocomposite manufacturing.

Delamination remains a critical limitation in the structural application of wood, particularly in adhesively bonded joints. This study investigates the use of a cyclic olefin-based hot-melt film adhesive (Zeon® LS-XU) as a thermoplastic interlayer as a means to delay delamination and enhance joint performance. Single lap joints (SLJs) were tested under quasi-static (1 mm/min) and impact (3 m/s) loading to assess strain-rate effects. Six configurations were examined: two reference, two toughened (with an additional 15 mm of adhesive on each overlap side) and two hybrid configurations combining oak (Quercus alba) and pine (Pinus pinaster Aiton) substrates to improve stress wave propagation. A finite element elastic model was developed to analyse stress distributions and explain the superior performance of hybrid joints. Results revealed that the thermoplastic interlayer delayed delamination onset and increased energy absorption, while hybrid configurations achieved more uniform stress distributions and significantly higher strengths under dynamic loading. The most effective configuration, the hybrid joint under impact conditions, represents a strength improvement of approximately 84% of the peak load compared to the pine reference joints. Overall, introducing a thermoplastic interlayer offers an efficient and lightweight strategy to enhance the toughness and reliability of wood joints exposed to variable loading conditions.

Pycnogenol attenuates oxidative stress and neuroinflammation, enhancing structural and functional recovery after sciatic nerve crush injury in rats.

Rising temperatures and droughts are triggering forest die-off in climate warming hotspots such as the Mediterranean Basin. UAVs equipped with LiDAR and multispectral sensors offer a powerful tool for surveys of tree vigor at landscape level. We used UAV-acquired LiDAR data and multispectral camera imagery to segment individual tree crowns, classify species, and assess the health status in two drought-affected forests in northeastern Spain: a mixed Pinus pinaster–Quercus ilex forest and a Pinus halepensis forest. Individual trees were segmented and classified using object-based image analysis with the Random Forest algorithm incorporating spectral, structural, and topographic variables. Greenness indices (NDVI and EVI) were analyzed in relation to crown height, topography (slope and elevation) and solar radiation, and their interactions. Analyses showed satisfactory crown segmentation (F-Score = 0.85–0.86) and species classification (Overall accuracy = 0.86–0.99), though distinguishing spectrally similar classes remained challenging. Taller P. pinaster trees exhibited higher NDVI, while taller P. halepensis displayed higher NDVI values in dense neighborhoods and on gentle slopes. These findings highlight the potential of high-resolution UAV-based remote sensing for effective near-real-time detection and attribution of forest die-off. Future research should aim to improve algorithm accuracy and better integrate field-based validation across different forest types.

Analyzing the impact of neighbors’ identity and growth rate on individual tree mortality

Impact of resin-tapping on growth, defences and reproduction of 40 yr-old maritime pines in NW-Spain

Context:The hybrid layer integrity is critical for durable resin–dentin bonding and is compromised by activation of matrix metalloproteinases (MMPs).Aims:To evaluate and compare hybrid layer thickness and resin tag penetration depth following pretreatment with maritime pine bark extract, green apple extract, and chlorhexidine in simulated erosive dentin using confocal laser scanning microscopy.Settings and Design:In vitro experimental study.Materials and Methods:Thirty-three extracted intact human teeth were used. After exposing the dentin, samples were treated with 10% citric acid to simulate erosive dentin. After acid etching, the samples were divided into three groups (n = 11): 6.5% maritime pine bark extract, 6.5% green apple extract, and 2% chlorhexidine. A fluorescent dye was incorporated into the adhesive; specimens were restored with composite resin and analyzed under confocal laser scanning microscopy.Statistical Analysis:One-way analysis of variance with post-hoc comparisons was performed. Significance was set at P < 0.05.Results:Hybrid layer thickness (F = 4.477, P = 0.020, standard deviation [SD] =81.621) and depth of resin tag penetration (F = 6.027, P = 0.006, SD = 186.558) in Group 3 (chlorhexidine) as MMP inhibitor showed a statistically significant difference between the groups, with the mean scores being highest in Group 3, followed by Group 1 (maritime pine bark extract) and Group 2 (green apple extract).Conclusion:Hybrid layer thickness and resin tag penetration depth following pretreatment with Group 3 were the highest and statistically significantly compared with Group 1 and Group 2

Fire refugia are critical for post-disturbance recovery, yet microhabitats such as stones remain understudied despite their ubiquity and thermal persistence. This study tested whether the depth- and area-dependent refugial capacity of stones previously demonstrated in Mediterranean oak forests also operates in intensively managed plantations and how forest type and management modulate this capacity. Immediate wildfire effects (1–8 days post-fire) on ground-dwelling macroinvertebrates were quantified under 660 stones across burnt and unburnt native maritime pine and exotic eucalypt plantations following a medium- to high-severity wildfire. Stones acted as thermal refugia in both plantation types, with burial depths greater than 5 cm and surface areas greater than 500 cm2 predicting survival. Despite severe impacts (richness declined by 56% in pine and 63% in eucalypt; overall mortality exceeding 50%), diverse taxa persisted under stones, particularly ground spiders, ants, centipedes, rock bristletails, and harvestmen, while plant-associated and moisture-dependent groups suffered the highest losses. Native pine supported a higher abundance and richness per stone than exotic eucalypt in both burnt and unburnt conditions, reflecting management-driven differences in stone size, depth, and availability. These findings show that retaining sufficiently large, deeply buried stones during plantation establishment can enhance post-fire biodiversity recovery in increasingly fire-prone production landscapes.

Pine turpentine essential oil (PTEO) obtained from Pinus pinaster Ait. is known to be used in many fields such as medicine, cosmetics, agriculture, and art. The medicinal use of essential oils puts pressure on industry to produce high-quality products. Pure essential oils derived from natural sources are mistakenly recognized as safe on the grounds of their natural origin. Unless they meet international standards, their safety remains questionable. Therefore, in this study, it was aimed to evaluate the quality of 14 different pine turpentine essential oil samples purchased from various sources on the Turkish market, based on the legally recognized pharmacopoeia in Türkiye, the European Pharmacopoeia (EP). As stated in the "Turpentine Oil" monograph, appearance, relative density, refractive index, optical rotation, acid value, peroxide value, fatty oils, and resinified essential oils analyses were performed for each sample. Additionally, phytochemical profiles were analyzed by high performance thin-layer chromatography (HPTLC) and gas chromatography-mass spectrometry (GC-MS). The results revealed that none of the samples were compliant with EP standards. With this in mind, it is found necessary to impose strict regulations on the production of commercial essential oils. Nevertheless, pharmacies emerge as preferable options for obtaining such products.

ABSTRACT This study aimed to address the knowledge gap by examining the dynamics of biomass, carbon, and nitrogen pools between foliage and forest floor throughout the development of Pinus pinaster plantations in the restoration site of Durusu coastal dune ecosystem in Istanbul‐Türkiye. Live foliage biomass was determined by destructive sampling, while forest floor sampling was carried out separately from litter + fermentation (L + F) and humus (H) layers. Carbon (C) and nitrogen (N) were determined by CN analyzer. The relationship between all calculated variables and the independent variable (D 2 H), derived to represent stand diameter at breast height (D 1.3m ) and tree height (H), was revealed by regression analysis. Average foliage mass was determined as 8 t/ha, C as 4 tC/ha, and N as 0.08 tN/ha. The mean biomass, C, and N of forest floor were 40 t/ha, 12 tC/ha, and 0.3 tN/ha, respectively. Foliage C, N, and C/N ratio showed high relationships with D 2 H as R 2 adj = 0.779, R 2 adj = 0.798, and R 2 adj = 0.943, respectively. However, the differences between the variables of living and non‐living components showed a linear regression relationship with stand development. The differences in forest floor − foliage values showed lower R 2 values with D 2 H. C and N were stored primarily in living foliage in young maritime pine stands where forest floor accumulation is just beginning. However, in older stands, where forest floor has begun to accumulate, forest floor stores more C and N than live foliage. The average C/N ratio of 42.47 for the entire forest floor indicating decomposition is slow, and C and N storage role shifts to forest floor as the stand develops.

Abstract Soil fungal communities play a key role in multiple ecosystem functions and services within forest ecosystems. Today, forest ecosystems are subject to multiple environmental and anthropogenic disturbances (e.g. fires or forest management) that cause changes in vegetation and in the interactions between plants and soil. In this study, we analyzed the response of soil fungi to forest management in an over 50-year-old Pinus pinaster afforestation site in Guadalajara, Spain. We started from an experimental setting in which silvicultural treatments of thinning and clear-cutting gaps were applied, with different intensities and sizes, respectively. Five years after the treatments, soil was sampled during the spring at a depth of 15 cm along transects (in thinning), in circular subplots (in gaps), and in the control plots. DNA extraction was performed, and for metabarcoding, we used a fungal internal transcribed spacer (ITS2) and high-throughput sequencing with the Illumina platform. The predominant trophic groups (determined by the genus of the fungi) were soil saprophytes, dominated by the genus Mortierella, as well as ectomycorrhizal (ECM) fungi, dominated by the genus Inocybe. Thinning significantly increased the richness and diversity indexes of fungal OTUs (Operational Taxonomic Units) compared to gaps. Moderate low thinning (B20) increased fungal richness without altering community fungal structure. The combination of thinning and coarse woody material (24 m3/ha) increased soil fungal richness but not the other diversity indexes. Thinning treatment increased the ECM genus Russula. The phytopathogen Venturia was highly present in areas with little or no disturbance, while a strong low thinning (B35) reduced Venturia and altered the plant pathogen fungal community. In contrast, a high thinning (A35) did not affect the structure of trophic groups in any case. The diameter of the gaps did not affect the main genera, but large diameter gaps (44 m) increased nonspecific fungal saprophytes. Five years after treatment application, the regeneration of pine and Cistus sp. in the central area of the gaps increased the litter saprophytes and led to a strong replacement of fungal species in this area. We hypothesize that the gaps caused significant changes in the dynamics of organic matter decomposition, although the ECM fungal community was not reduced. Five years after the silvicultural treatments, the soil fungal community has managed to preserve or adapt its trophic functions, even in the center of the gaps.

Modelling Pinus pinaster seedling emergence and early survival after group selection system cuttings

Using a cone calorimeter for small-scale tests as a radiant heat source, the influence of compacting fuel beds on their flammability and combustibility for three different types of dry vegetation (Pinus halepensis and Pinus pinaster needles, and Wheat straw sticks) was experimentally investigated for a wide range of compactness (the degree of densification of the fuel bed) from $$\:3$$ to $$\:50\:\%$$ . While the flaming duration increases monotonically with packing ratio (a quantitative measure of this compactness), ignition time shows at least one minimum value for the fuels studied. Using the mean free path of radiation as the controlling parameter instead of the packing ratio the range with minimum ignition time is significantly narrowed down to a few millimeters, which indicates the importance of radiation in the flammability process as expected for such a mainly radiative heating process. For Pinus halepensis needles, two minimum ignition times for values of packing ratio around 12.6% and 34% were identified both when the fuel bed thickness is varied or maintained constant. For low compactness, before ignition, the mass loss decreases linearly with time with a rate slightly affected by the packing ratio. After ignition, the flame spreads quickly to cover the entire fuel bed (fully developed flame) at the growth time. This marks the beginning of a sharp decrease in the mass corresponding to a sharp increase in the mass loss rate (MLR) towards a maximum value. For high compactness, the linear decrease of the mass still holds before ignition, followed by a long slightly non-linear trend corresponding to the slow flame spreading to cover the whole surface of the bed at the growth time (fully developed flame). This also marks the begining of a sharp mass decrease (MLR increase). The duration between ignition time and growth time is then very short for low compactness, and becomes very large for high compactness and corresponds to a plateau of MLR. The peak MLR is followed by a slow decrease until extinction (decay phase). To analyze the compactness induced combustion, the MLR curve was divided into two widths: the upper width is the Full Width at Half Maximum (FWHM), and the lower width is the duration ( $$\:{x}_{t}$$ ) between extinction time and growth time. The peak MLR, and the FWHM were found insensitive to the compactness (constant behavior within statistical errors for all compactness) whereas the $$\:{x}_{t}$$ was found to decrease for high compactness.

Abstract Genomic offset models are increasingly popular tools for identifying populations at risk of maladaptation under climate change. These models estimate the extent of genetic change required for populations to remain adapted under future climate change scenarios but face strong limitations and still lack broad empirical testing. Using 9,817 single-nucleotide polymorphisms (SNPs) genotyped in 454 trees from 34 populations of maritime pine, a species with a marked population genetic structure, we found substantial variability across genomic offset predictions from different methods, SNP sets, and general circulation models. Using five common gardens, we mostly found positive associations between genomic offset predictions and mortality, as expected. However, contrary to our expectations, we observed very few negative monotonic associations between genomic offset predictions and height. Higher mortality rates were also observed in national forest inventory plots with high genomic offset, but only for some methods and SNP sets. The differing genomic offset patterns produced by the best-validated methods across the maritime pine range hindered drawing definitive conclusions for the species. Our study demonstrates the imperative of employing different methods and validating genomic offset predictions with independent data sources before using them as reliable metrics to inform conservation or management.

This study investigated chemical variations in softwood juvenile wood, focusing on intra-ring variation between earlywood (EW) and latewood (LW) components along the radii. While no radial trends in lignin content and hydroxyphenyl/guaiacyl (H/G) ratio were found, the variation between EW and LW within a single growth ring was highly significant. Analytical pyrolysis demonstrated that earlywood contained, on average, 2.4% more lignin than latewood. Surprisingly, EW exhibited a lower H/G ratio (0.036) compared to LW (0.041), challenging the typical correlation between high lignin content and high H/G ratios. Principal component analysis (PCA) of the pyrolysis products confirmed distinct structural differences in lignin between EW and LW, reflecting their disparate functional roles—transport and mechanical support, respectively. Overall, analytical pyrolysis was highly effective for assessing the significant intra-ring variation in both lignin content and structural composition.