Pinus Sylvestris Research Articles

Sensitivity of long-term productivity estimations in mixed forests to uncertain parameters related to fine roots

Forest growth models are increasingly being used in forestry and ecology research as predictive tools to help developing practical guidelines and to improve understanding of the drivers of forest ecosystem functioning. Models are usually calibrated using parameters directly obtained or estimated from empirical field observation, and hence are subject to uncertainty. Thus, output accuracy depends on input parameters precision and on how influential is each parameter on model behaviour. Hence, it is important to analyse parameter-related uncertainty and its effects on model outputs. This can be done by performing sensitivity analyses, which allow to explore the influence of one or several calibration parameters on model outputs. As studies on tree root parameters are particularly scarce, the aim of the present work was to evaluate the influence of parameters related to fine roots on estimations of long-term forest growth patterns in pure and mixed forests, using FORECAST (a hybrid forest growth model) as a virtual lab. The fine root parameters assessed were biomass, turnover rate, and nitrogen content. The analysis was performed by simulating monospecific stands of two contrasting species (Pinus sylvestris L. and Fagus sylvatica L.), and mixed stands formed by both species. In all cases, FORECAST showed good capability to contain uncertainty propagation during the first and middle stages of stand development (<40 years). After that moment, model output uncertainty steadily increased, but it reached different maximum uncertainty levels depending on stand type. Simulations of the less nutrient demanding P. sylvestris manifested very little sensitivity when growing in monospecific stands. However, F. sylvatica monospecific stands showed intermediate sensitivity, but significant species interactions occurred in mixed stands that determined the biggest impact detected of uncertainty related to fine root parameters over model outputs. All things considered, FORECAST displayed an interesting capability to capture some of the interspecific interactions that are key in mixed forests functioning. Our results suggest an acceptable model performance under uncertain parameterization but also caution against expecting accurate quantitative estimations of forest growth, especially when considering long-term scenarios in complex mixed stands.

A study of annual tree-wise LiDAR intensity patterns of boreal species observed using a hyper-temporal laser scanning time series

This study introduces the annual tree-wise intensity patterns of three boreal tree species, silver birch (Betula pendula Roth.), Scots pine (Pinus sylvestris L.), and Norway spruce (P,icea abies H. Karst.), observed from a long-term hyper-temporal point cloud dataset collected with a permanent laser scanning (LiDAR) station. An annual LiDAR intensity pattern refers to the trend of variations of tree-wise calibrated LiDAR intensity values over the course of a year, primarily linked to species-specific phenological characteristics. Such pattern was discovered from hyper-temporal (76 observations between April 2020 and April 2021) high resolution (0.01 m 3D point spacing at 100 m distance) point cloud observations acquired using a single wavelength (1550 nm) static LiDAR system installed on a climate monitoring tower at the Hyytiälä forest research station in central Finland. A set of experiments was designed to explore the interactions among tree-wise calibrated LiDAR intensity, species, data quality, and observation dates. Thus, to provide practical suggestions for expectable accuracies of tree species classification using diverse types of LiDAR systems and data acquisition strategies. It was revealed that by combining high spatial resolution (up to 100,000 points/m2) with bi-weekly observations (two scans per week except winter period), the average tree species classification accuracy reaches 96.8% for the three boreal tree species in the study area, where the few misclassified cases are attributed to inaccurate individual tree segmentation. This suggests that the annual tree-wise LiDAR intensity patterns, which reflects the tree-wise phenological dynamics, are robust and species-specific. When the spatial resolution was reduced to 5 points/ m2, the average accuracy of species classification among the three studied species reached 85% when using bi-temporal data from spring and autumn. Our analysis further indicates that arranging data acquisition with a two-week variability in late autumn and late spring could yield higher accuracy in species classification. Furthermore, our study revealed the importance of subcanopy information for species classification, specifically in distinguishing different coniferous species. When limited to upper canopy data (as in simulated airborne LiDAR scenarios), achieving a tree species classification accuracy of over 80% required either high point density (e.g. 8000 points/m2) combined with bi-temporal collection in a year, or low point density (5 points/ m2) with a dense time series (e.g., 76 time points within a year), which showcased the possibility to compensate low spatial resolution with high temporal resolution, and vice versa, in capturing species-specific phenological characteristics of trees.

Afforestation-Induced Shifts in Soil Bacterial Diversity and Community Structure in the Saihanba Region.

Afforestation plays a pivotal role in ecosystem restoration, exemplified by the Saihanba Mechanized Forest Farm, the world's largest planted forest; however, the assembly mechanisms and interactions of soil microbial communities in such forests remain inadequately understood. This study aimed to elucidate the impact of different afforestation tree species, namely Larix gmelinii var. principis-rupprechtii, Picea asperata, and Pinus sylvestris var. mongolica, on soil bacterial diversity and community structure in comparison to grassland. Sixty soil samples were collected at a 20 cm depth, and high-throughput sequencing was employed to identify bacterial communities and assess their interactions with environmental factors. A total of 6528 operational taxonomic units (OTUs) were identified, with Solirubrobacter, Conexibacter, Bacillus, Massilia, Gaiella, Acidibacter, and Vicinamibacter being the dominant genera. Afforestation significantly impacted soil bacterial alpha diversity, with notable influence from key soil chemical properties, including available phosphorus (AP), cation exchange capacity (CEC), and the carbon-to-nitrogen ratio of soil organic matter (SOM-C/N). The Mantel test highlighted pH, the Normalized Difference Vegetation Index (NDVI), and spatial variable (dbMEM) as primary environmental factors influencing dominant bacterial genera. The bacterial community structure demonstrated deterministic homogeneous selection, wherein SOM-C/N emerged as a significant factor influencing the dissimilarity of soil bacterial communities. Furthermore, plantation soils exhibited a more complex network structure than grassland soil, highlighting the crucial role of bacterial communities in vegetation changes and providing valuable insights into their response to environmental factors during the reforestation process.

Diversity and distribution of Phytophthora species across different types of riparian vegetation in Italy with the description of Phytophthora heteromorpha sp. nov.

Riparian formations encompass a diverse suite of transitional zones between terrestrial and aquatic ecosystems. During the last decades, these formations have been impacted by several emerging diseases. The first outbreaks were detected on alder formations, but have progressively also been observed on other plant species such as Betula pubescens, Nerium oleander, Populus alba, Salix alpina, Salix purpurea and Tamarix gallica. Declining plants showed a plethora of symptoms (leaf spot, shoot blight, bleeding cankers and root rot) indicative of Phytophthora infections. Since there is little information about the aetiology of these pathosystems, from November 2019 to March 2023, an in-depth study was conducted in 46 riparian ecosystems spanning from the Mediterranean to Alpine regions. Overall, 744 symptomatic samples (stem bleeding cankers and root with rhizosphere) from 27 host species were collected for Phytophthora isolation. Based on morphology and DNA sequence data, 20 known Phytophthora species belonging to seven phylogenetic clades have been identified: P. plurivora (202 isolates), P. gonapodyides (156), P. pseudosyringae (84), P. lacustris (57), P. acerina (31), P. idaei (30), P. alpina (20), P. pseudocryptogea (19), P. cambivora (13), P. pseudotsugae (13), P. cactorum (9), P. honggalleglyana (6), P. pseudogregata (6), P. debattistii (4), P. multivora (4), P. cinnamomi (3), P. bilorbang (2) P. crassamura (2), P. ilicis (2) and P. inundata (2). In addition, 26 isolates of a new putative species obtained from Alnus incana and Pinus sylvestris are described here as Phytophthora heteromorpha sp. nov. The new species proved to be pathogenic on grey alder causing symptoms congruent with field observations. This study represents the most comprehensive investigation on the Phytophthora species associated with declining riparian vegetation in Italy and highlights that the polyphagous pathogen P. plurivora represents a growing threat to Mediterranean, temperate and alpine ecosystems.

DAMAGE TO PINE PLANTATIONS BY THE APICAL BARK BEETLE AND STEM PESTS IN THE BRANCH «KOROSTYSHIV FORESTRY»

The treetop bark beetle (Ips typographus) is the main pest of Scots pine (Pinus sylvestris L.) in Europe in general and in Ukraine in particular. It affects the phloem (inner bark) of trees, disrupting the supply of nutrients, which can lead to the death of pine plantations, especially young or weakened ones [1].

Long-term nitrogen addition modifies fine root growth and vertical distribution by affecting soil nutrient availability in a Mongolian pine plantation

Fine roots are the primary organ of tree species in water and nutrient acquisition, and are the major contributor of forest soil organic carbon (C). However, it remains largely unknown how fine root growth dynamics and vertical distribution respond to long-term nitrogen (N) enrichment, which prevents us from accurately evaluating forest C sequestration potential under N deposition. Here, we investigated the effects of nine-year N addition (0 and 10 g N m−2 year−1) on fine root nutrients, biomass, production, turnover rate and vertical distribution in three soil layers (0–10, 10–20 and 20–40 cm) of a Mongolian pine (Pinus sylvestris var. mongolica) plantation in the Keerqin Sandy Lands, Northeast China. We found that soil inorganic N was increased and Olsen-P was decreased by N addition. N addition increased fine root N, C:P and N:P ratios, but reduced fine root P and C:N ratio across all soil layers. N addition reduced fine root biomass in 0–10 cm soil layer but increased it in 20–40 cm soil layer. N addition accelerated fine root turnover rate in 0–10 cm soil layer, and increased fine root necromass across all soil layers. Moreover, N addition significantly enhanced biomass of ectomycorrhizal extraradical hyphae in the 0–10 cm soil layer. Redundancy analysis showed that variations of fine root traits were well explained by soil NO3−-N in 0–10 and 10–20 cm soil layers, and by soil NH4+-N and Olsen-P in 20–40 cm soil layer. Collectively, our results highlight the shift from N limitation to P limitation of Mongolian pine plantations under long-term N addition, and suggest that changes in fine root growth and vertical distribution induced by N addition could accelerate belowground C allocation in Mongolian pine plantations.

Low formaldehyde-emission particleboards with the addition of Scots pine wood waste derived activated carbon

ABSTRACT Free formaldehyde released after particleboard production poses significant risks to human and environmental health. This study investigated the impact of adding activated carbon produced from pine wood waste to particleboard on formaldehyde emissions to lessen this risk. In the first stage of the study, pine wood waste was activated with zinc chloride (ZnCl2) at 600°C for 90 min to produce activated carbon. The activated carbon was examined by scanning electron microscope, thermogravimetric analysis, Brunauer–Emmett–Teller (BET) analysis, fourier-transform infrared spectroscopy and X-ray diffraction. BET surface area of the produced activated carbon was 1102 m2/g. In the second stage of the study, activated carbons (0.5%, 1.0% and 1.5%) were added to a commercially preferred three-layer particleboard to enhance its mechanical, thermal and physical properties. In addition, the effects of the activated carbon on the free formaldehyde emissions of particleboard at 0 and 6 months were investigated. It was found that the free formaldehyde emissions of particleboards with activated carbon addition decreased by 24% at 0 months- and 6 months by 27% compared to the control group. Thus, waste material that has become a more valuable product as activated carbon will minimize harm to the environment and humans.

Twenty years of irrigation acclimation is driven by denser canopies and not by plasticity in twig- and needle-level hydraulics in a Pinus sylvestris forest.

Climate change is predicted to increase atmospheric vapor pressure deficit, exacerbating soil drought, and thus enhancing tree evaporative demand and mortality. Yet, few studies have addressed the longer-term drought acclimation strategy of trees, particularly the importance of morphological vs. hydraulic plasticity. Using a long-term (20 years) irrigation experiment in a natural forest, we investigated the acclimation of Pinus sylvestris morpho-anatomical (stomatal anatomy and crown density) and hydraulic traits (leaf water potential, vulnerability to cavitation Ψ50, hydraulic conductivity Ks, and tree water deficit TWD) to prolonged changes in soil moisture. We found that low water availability reduced twig water potential and increased TWD during the growing season. Still, the trees showed limited adjustments in most branch-level hydraulic traits (Ψ50 and Ks) and needle anatomy. In contrast, trees acclimated to prolonged irrigation by increasing their crown density and, hence, the canopy water demand. This study demonstrates that despite substantial canopy adjustments, P. sylvestris may be vulnerable to extreme droughts because of limited adjustment potential in their hydraulic system. While sparser canopies reduce the water demand, such shifts take decades to occur under chronic water deficits and might not mitigate short-term extreme drought events.

Nitrogen uptake, retranslocation and potential N2-fixation in Scots pine and Norway spruce seedlings

Nitrogen uptake, retranslocation and potential N2-fixation in Scots pine and Norway spruce seedlings

Pine-Oil-Derived Sodium Resinate Inhibits Growth and Acid Production of Streptococcus mutans In Vitro.

S. mutans is a key pathogen in dental caries initiation and progression. It promotes oral biofilm dysbiosis and biofilm acidification. Sodium resinate is a salt of pine-oil-derived resin which has antimicrobial properties. Pine-oil-derived resin consists of terpenes, diterpenes, and abietic acids. The aim of this study was to determine the effects of pine (Pinus sylvestris) oil resinate (RS) on growth and acid production of cariogenic S. mutans strains in planktonic form and biofilm. The S. mutans type strain NCTC10449 and clinical isolate CI2366 were grown on 96-well plates for testing of RS effects on growth and biofilm formation, and on plates with integrated pH-sensitive optical ensors for real-time measurements of the effects of RS on bacterial acid production. We found that even short-time exposure to RS inhibits the growth and acid production of S. mutans in the planktonic phase and biofilms. In addition, RS was able to penetrate the biofilm matrix and reduce acid production inside S. mutans biofilm. RS thus shows potential as a novel antibacterial agent against cariogenic bacteria in biofilm.

Лесоводственная эффективность проведения несплошной лесозаготовки древесины в сосняках после гидротехнической мелиорации в Сокольском районе Вологодской области

In the Sokolsky district of the Vologda region of Russian Federation, the influence of continuous harvesting of&#x0D; wood in drained pine forests on the taxation and macrostructural parameters of common pine trees (Pinus sylvestris L.)&#x0D; was determined. The objects of the study are represented by pine forests: the main species is Scots pine (P. sylvestris L.)&#x0D; with an admixture of common spruce (Picea abies (L.) H. KARST.) and birch (Betula pendula Roth). The drained forest&#x0D; objects were selected after the continuous harvesting of wood and a control stand (without logging), temporary test areas&#x0D; (runway) were delimited. Drainage measures in experimental forests were carried out in 1972. Continuous logging was&#x0D; carried out in 2005 when skidding technological drags were attached to the main corridor at an angle of 45 degrees. The&#x0D; distribution of the number of P. sylvestris L. trees by thickness steps within the boundaries of the runway in 83% (p &lt;&#x0D; 0.05) of cases tends to normal. Average periodical growth of late wood P. sylvestris L. on the runway after drainage&#x0D; increased in the channel position by 30 % (tfact ≥ tst; 4.51 &gt; 2.70; p &lt; 0.01), and after intermittent logging increased by&#x0D; 19 % (tfact ≥ tst; 1.99 &gt; 1.71; p &lt; 0.1). Carrying out continuous complex harvesting of wood in drained pine forests has a&#x0D; positive effect on increasing the stock (by 38%), while in stands without logging – by 28 %.

О лучших геоэкотипах сосны обыкновенной (Pinus sylvestris L.) для искусственного лесовосстановления

The basis for adjusting the previously established boundaries of forest seed areas for forest-forming species are the results of studying the condition, growth intensity and productivity of their offspring in the form of forest geographical crops, which were created in the 60-70s of the XX century in different regions of the USSR. The best geoecotypes are identified by comparing the morphometric parameters achieved by the test geographical offspring by the age of “ripening”, or on the basis of multifactor analysis with their comprehensive assessment based on a set of criteria. In 2018-2021 In order to identify and select the best geoecotypes of Scots pine (Pinus sylvestris L.), moved to the Central Black Earth Region (Voronezh region), based on their potential economic suitability for sustainable forest reproduction in the European part of the Russian Federation, comprehensive studies were carried out in 59-61-year-old tree stands that are seed trees offspring of different forest-steppe and steppe geoecotypes. On 32 trial plots, promising, medium and unpromising P. sylvestris geoecotypes were determined using a unified methodology and 12 evaluation criteria. It has been reliably established that among the 18 forest-steppe ecotypes studied, only 4 are the best. To introduce them into silviculture production, it is necessary to optimize the logistics of procuring seeds of the best ecotypes, growing standard planting material from them and planting them in appropriate forest conditions. According to forecasts, the use of seeds and planting material, identified selectively the best geoecotypes of P. sylvestris during the implementation of plans for the sustainable reproduction of future forests in the European part of the Russian Federation, will provide an accumulative silvicultural and economic effect that grows over time and high economic efficiency.

Изучение спектрометрических особенностей лесных семян для улучшения посевных качеств: ретроспективный кластерный анализ направлений научного ландшафта

Forest seeds spectral data in the visible and infrared regions of electromagnetic radiation lengths quite effectively&#x0D; differentiate the origin, viability, types of seeds, their infestation with pests and diseases, the ability to absorb and lose&#x0D; water. The search for a method of seed testing that is both experimentally simple, fast and effective for predicting germination is necessary to increase the energy efficiency of forest nurseries in the production of planting material. The retrospective references systematization (N = 55, 1998-2023, terms [Scholar Query = seeds* AND (spectr* OR optic*) (properties OR features) AND analysis]) into clusters was carried out on the basis of eight performance criteria represented by&#x0D; rank variables. The level of similarity and difference between clusters is determined by the method of the most distant&#x0D; neighbors with the grouping of data by the square of the Euclidean distance. The most distant criterion from other criteria&#x0D; is the level of invasiveness of testing (the square of the Euclidean distance is 25, p &lt; 0.05). Correlation analysis of nonparametric criteria indicates a direct strong interaction between the level of financial and organizational costs (Spearman&#x0D; coefficient ρ = 0.77; p = 0.0008), time costs and low machine learning capability (ρ = 0.725; p = 0.0008). In the future, it&#x0D; is planned to periodically supplement the set of systematic data to obtain an objective assessment of seed testing methods,&#x0D; as well as using a seed passport to evaluate the relationship of RGB spectral data of more than 1 000 individual seeds&#x0D; with early growth of seedlings in a post-pyrogenic experimental site of the forest landscape of the Voronezh region by&#x0D; example (Pinus sylvestris L. var. Negorelskaya).

Влагопроводность ядровой древесины сосны, поврежденной сильным низовым и беглым верховым пожаром

The forest fire has an effect on the tree trunk. Of the total number of fires in the forest-steppe zone of Russia, strong grass-roots fires prevail. As a result of this type of fire, the undergrowth burns out, which contributes to the most prolonged exposure to high temperature on the lumpy, economically valuable part of the trunk. The effect of high temperature affects the structure of the anatomical elements of wood, its integrity is violated. In the standing timber of the Scots pine (Pinus sylvestris L.) destructive processes occur after fire damage, which have a significant effect on its physico-mechanical properties and are accompanied by intensive tar formation. One of the primary processes in wood processing technology is its dehydration, as a result of which wood is transformed from a natural material into a technological raw material. Therefore, the application of existing technological drying modes to wood damaged by fire is impractical. It is impossible to carry out the processes of dehydration or humidification of wood without information about the value of its moisture conductivity. The moisture conductivity of wood is determined by the moisture conductivity coefficient. The value of the moisture conductivity coefficient of samples of fire-damaged and undamaged P. sylvestris heartwood&#x0D; extracted from the stemwood was determined by the method of stationary moisture flow in the radial and tangential directions. In comparison with the intact Scots pine wood, wood damaged by fire has an inverse dependence of the intensity of the moisture current – in the tangential direction it is higher than in the radial direction. There is a general decrease in the moisture conductivity coefficient of pine wood: in the radial direction – by 40.2 ± 1.58% (p &lt; 0.05), in the tangential direction – by 14.5 ± 0.92% (p &lt; 0.05) compared with intact wood. Patterns of changes in the value of the heartwood coefficient of moisture conductivity in standing pine, damaged by fire, will allow to adjust the existing drying modes and improve the quality of the dried wood and the efficiency of the softwood kiln drying technology.

Модель образующей древесного ствола сосны обыкновенной (Pinus sylvestris L.), произрастающей в Костромской области

Models of the stem taper have become widespread in forestry research. Models of the stem taper based on the equations of the stem taper are capable of determining with sufficient accuracy the assortment potential of forest stands. For the Kostroma region, no work has previously been carried out aimed at modeling the stem taper of trunks. Therefore, the goal of the study was to search and justify models of the stem taper of a tree trunk with one equation that most correctly describe the change in tree diameter with height in Scots pine stands growing in the Kostroma region. As experimental data, 10064 measurements of the diameter of 692 pine trees were obtained. To carry out the analysis, 19 models of tree stem taper with one equation were selected. Calculations were carried out in the Python environment. The calculated values of quality metrics, graphical analysis of residuals and errors made it possible to establish that the four-parameter model most adequately describes of the stem taper of pine forest stands in the Kostroma region. The stem diameter predicted using the model at any height makes it possible to analyze the assortment structure without resorting to tree felling. Further research is required aimed at developing standards for the assortment structure of trunks based on the proposed stem taper model.

Investigating Water Storage Dynamics in the Litter Layer: The Impact of Mixing and Decay of Pine Needles and Oak Leaves

Little is known about how the degree of mixing various forest-forming species affects forest floor hydrology. We evaluated the water storage capacity of the resulting litter layer by mixing the litterfall of Scots pine and sessile oak and studying their decomposition time. We prepared 90 artificial samples containing pure pine litter, pure oak litter, and mixed pine–oak litter with varying shares of pine needles. These samples were subjected to 15 months of decomposition in soil. After every three months of decay, some samples were removed from the soil, and their water storage capacity, bulk density, and C:N ratio were evaluated. Our findings indicate that samples with the greatest water storage capacity had a low C:N ratio and a predominant share of oak leaves. Conversely, samples with a high C:N ratio and a predominant share of pine needles had the lowest water storage capacity. After 12 and 15 months of decomposition, the water storage capacity increased by more than 52% compared to the initial water capacity of the samples. The highest increase in water storage capacity (&gt;40%) was observed in samples with a predominant share of oak leaves, while the lowest (approximately 28%) was recorded in samples with 80 and 100% of pine needles. Our findings suggest that introducing mixed-species stands, with deciduous species as the predominant component, can yield several ecological benefits, such as an increased ability to store water in forest floor.

Выращивание культур кедра сибирского в условиях повреждаемости дикими животными

The research of 26-year-old mixed plantations of Siberian spruce and Siberian stone pine cultivated by biogroups of about 300 pcs/ha (2–5 stone pine seedlings alternating 4–9 spruce seedlings in a row) has shown that the damage rate by moose to them is much lower than to pure stone pine plantations or the mixed ones of Siberian stone pines and Scots pines we have studied before. The share of biogroups containing damaged stone pine trees is 18 %. A third of this number is plantations with damage to all the trees. This is most pronounced in biogroups of 4 to 5 stone pines as well as in case of frequent alternation of biogroups in a row. 76 % living stone pines have been preserved (89.3 % of them without damage to the stem). About two thirds of them (about 500 pcs/ha) grow in the crown of spruce trees adjacent to stone pine biogroups. Prolonged exposure to growing in a spruce tree crown negatively affects the growth of a stone pine’s central shoot and crown. We are the first in the Middle Urals to propose a scheme for cultivating sustained productive mixed plantations of Siberian stone pines and Siberian spruce trees (or Norway spruce trees). Stone pines are planted in biogroups of 2–3 seedlings, beginning the planting strictly on one side of the site. The first biogroup in odd-numbered rows (1, 2, 3, 5, etc.) is planted after 3 spruce seedlings from the beginning of the row, the second and subsequent biogroups in these rows – after 9 spruce seedlings. The first biogroup in even-numbered rows (2, 4, 6, 8, etc.) is planted after 9 spruce seedlings from the beginning of the row, maintaining this sequence until the end of the row. Every row in mixed plantations is concluded with planting no less than 3 spruce seedlings. During silvicultural treatment procedures natural regeneration is completely removed: softwoods – by mechanical means, and hard woods – by ringing or injection of environmentally friendly water-based chemicals. These measures reduce or eliminate the appearance of coppice and, accordingly, food reserve for wild animals. Spruce trees adjacent to stone pine biogroups are cut down while lightening and thinning, which creates the possibility for the growth of stone pines. The proposed method for cultivating plantations of Siberian stone pines and Siberian spruce trees has been patented. It can be introduced into silvicultural practice in the taiga zone where stone pines are grown.

Морфологическая изменчивость ассимиляционного аппарата Pinus sylvestris L. в пределах Тебердинского национального парка

Pine forests are widespread in the Karachay-Cherkess Republic, in particular, in the Teberdinsky National Biosphere Reserve, mainly in its northern part. The variability 0 of pine morphological parameters is associated with the ecological and geographical features of the species’ habitat, which is especially important for the Caucasus Mountains. The purpose of this research has been to study the morphological variability of pine in the mountainous conditions of the Karachay-Cherkess Republic based on the morphometric parameters of needles and shoots. The collection of needles and shoots has been carried out using the standard methods. According to the data obtained, the longest pine needles are found in the gorge of the Gonachkhir River (1671 m above sea level), and the shortest – in the gorge of the Daut River (1900 m above sea level). A decrease in the length of the needles with altitude has been recorded. No change in the width has been observed. The needle packing index, on the contrary, increases with altitude. The length of the shoot in the samples of Pinus sylvestris ranges from 22.00 mm (Arkhyz and Daut-2 samples) to 28.94 mm (Teberda and Daut-1 samples) and correlates with the altitude of the habitats. The weight of the freshly collected pine needles in the study area has varied from 4.43 g (Teberda) to 6.06 g (Daut-1); when dried, the weight of 100 pairs of needles has decreased in all the samples by 2 times and has ranged from 2.23 g (Teberda) to 2.00 g (Gonachkhir). No correlation of the weight with the terrain altitude has been found. The lifespan of pine needles growing at different altitudes in the Karachay-Cherkess Republic is on average 2–3 years; 4–year-old needles have been found in small quantities in Teberda (1 %) and Dzhamagat (4 %).The results of this research are the first data on the morphological variability of the needles and shoots of Pinus sylvestris L., growing at different altitudes for the Western Caucasus, in particular for the Karachay-Cherkess Republic. The obtained data on the variability of the pine assimilation apparatus in the Western Caucasus complements and confirms the conclusions of other scientists about the increase in the size and weight of needles, as well as a decrease in their life expectancy when moving from north to south. They will be useful in assessing the phenotypic variability of coniferous forests.

Utilizing pyrolysis cleavage products from softwood kraft lignin as a substitute for phenol in phenol-formaldehyde resins for modifying different wood species

AbstractPhenol-formaldehyde resins can be used for wood modification through an impregnation process and subsequent curing within the wood cell wall. Phenol is gained from non-renewable resources, and its substitution by renewable chemicals has been a research goal. A promising example for renewable phenol substituents are lignin-derived organic chemicals. Phenol-formaldehyde resins with such substitutions have been studied, however, knowledge of their application for wood modification is deficient. While there are attempts to modify pine and beech wood with this method, studies on other wood species are scarce. Considering the increasing use of different wood species in wood industry, determining the influence of the wood species on the modification quality is an important research goal. Therefore, in this study, vacuum-pressure impregnation of five wood species – Scots pine sapwood (Pinus sylvestris), Norway spruce (Picea abies), European beech (Fagus sylvatica), Silver birch (Betula pendula), and European aspen sapwood (Populus tremula) – with phenol-formaldehyde resins is described. Here, up to 45% of the phenol in the synthetic resin is substituted by vacuum low-temperature microwave-assisted pyrolysis cleavage products from commercial softwood kraft lignin. The solution uptake, weight% gain, leaching, and anti-swelling efficiency of the modified wood are analyzed and compared. The results indicate that up to 30% of the phenol can be substituted without significant decreases in the performance of the modification. The method gives comparable results for most of the wood species described herein, with exception of beech wood, for which the modification had a lower quality. The results could help to develop more environmentally friendly wood modification methods for several common European wood species.

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan (Siberia)

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan (Siberia)