Soil C:N:P stoichiometry in rhizosphere and non-rhizosphere of Pinus sylvestris var. mongolica forests.

The aim of this study was to reveal the stoichiometric characteristics of carbon, nitrogen and phosphorus in rhizosphere and non-rhizosphere soils of Pinus sylvestris var. mongolica in the Hulunbuir desert. We investigated the contents and stoichiometry of organic carbon, total nitrogen, and total phosphorus contents of rhizosphere and non-rhizosphere soils across different stand ages (28, 37 and 46 a) of P. sylvestris var. mongolica plantations, with P. sylvestris var. mongolica natural forest as the control. We analyzed the correlation between soils properties and soil stoichiometry. The results showed that rhizosphere effect significantly affected soil N:P, and stand age significantly affected soil organic carbon content in P. sylvestris var. mongolica plantation. Soil organic carbon content in plantation was significantly lower than that in natural forest. Soil organic carbon and total nitrogen contents of plantations in both rhizosphere and non-rhizosphere soils firstly decreased and then increased with increasing stand age, while total phosphorus firstly increased and then decreased in rhizosphere soils, and firstly decreased and then increased in non-rhizosphere soils. There was significant positive correlations between C:N and C:P in rhizosphere soils but not in non-rhizosphere soils, suggesting that higher synergistic rhizosphere soil N and P limitation. The mean N:P values of rhizosphere and non-rhizosphere soils were 4.98 and 8.40, respectively, indicating that the growth of P. sylvestris var. mongolica was restricted by soil N and the rhizosphere soils were more N-restricted. The C:N:P stoichiometry of rhizosphere and non-rhizosphere soils were significantly influenced by soil properties, with available phosphorus being the most important driver. The growth of P. sylvestris var. mongolica was limited by N in the Hulunbuir desert, and root system played an obvious role in enriching and maintaining soil nutrients. It was recommended that soil nitrogen should be supplemented appropriately during the growth stage of P. sylvestris var. mongolica plantation, and phosphorus should be supplemented appropriately according to the synergistic nature of nitrogen and phosphorus limitation.

Modeling potential distribution and above-ground biomass of Scots pine (Pinus sylvestris L.) forests in the Inner Anatolian Region, Türkiye.

Scots pine (Pinus sylvestris L.) holds a substantial position as a tree species designated for biomass energy within European forests, covering a significant part of Türkiye's forests. We used the machine learning technique, namely, maximum entropy (MaxEnt), to estimate the suitable areas for Scots pine and to investigate its potential future distribution under various climate change scenarios in Inner Anatolian Region, Türkiye. The distribution data of Scots pine was utilized, and a set of 20 variables was chosen from spectral, topographic, and bioclimatic datasets to train the MaxEnt model. A map depicting the potential distribution of Scots pine in the area was generated, and alterations in its spatial distribution under SSP2-4.5 and SSP5-8.5 climate change scenarios were predicted. The results showed that the most effective factors for the distribution of Scots pine in the region were normalized difference vegetation index (NDVI), Red band of the imagery, and Bio19 variables, and the contribution percentages were 45.6%, 18.5%, and 18.1%, respectively. Current conditions have indicated that 81.11% of the region is not suitable for Scots pine. Highly suitable areas for Scots pine constituted 0.88% of the total area in the east and southeast parts of the region. Considering the SSP2-4.5 and SSP5-8.5 scenarios, it has been determined that there may be a partial increase in highly suitable areas. The above-ground biomass (AGB) data generated based on potential distribution areas were predicted between 0.04 and 168.76 t ha-1, and the areas with dense biomass over 120 t ha-1 were identified in the west, north, and northeast parts of the region. While actual AGB of Scots pine was 6.92 MT, its potential AGB was estimated 125.93 MT in total area. The difference may well be attributed to the wide potential distribution of Scots pine stands in the area apart from the current forest lands. Nevertheless, this research contributes to the holistic management of forests and provides substantial values for formulating well-suited silvicultural interventions, developing sustainable forest management strategies, and furthering research aimed at estimating biomass reserves.

Plant Growth-Promoting Rhizobacteria Promote Growth of Seedlings, Regulate Soil Microbial Community, and Alleviate Damping-Off Disease Caused by Rhizoctonia solani on Pinus sylvestris var. mongolica.

As the excessive use of chemical fertilizers harms organisms and adversely affects the soil environment, the replacement of chemical fertilizers with biological fertilizers has attracted widespread attention as an environmental protection strategy. In this study, the effects of rhizosphere bacteria inoculation on growth of Pinus sylvestris var. mongolica seedlings, soil parameters, soil microbial community structure, and the biocontrol of damping-off were studied by pot experiments. The results showed that all three rhizosphere bacteria (Pseudomonas chlororaphis, Pseudomonas extremaustralis, and Acinetobacter lwoffii A07) tested exhibited growth-promoting properties, such as the production of indole-3-acetic acid, hydrolase, siderophores, and hydrogen cyanide; nitrogen fixation; and phosphorus solubilization. The application of the three bacteria increased plant biomass, root structure, and nutrient content and also increased soil nutrient content and enzyme activity. Bacterial inoculation promoted the growth of beneficial bacteria and antagonistic bacteria by adjusting the physicochemical properties of the soil, thereby improving the bacterial community structure. Among the soil features, available nitrogen, total nitrogen, available potassium, and urease activity were the main influencing factors. In addition, it was also found that bacterial inoculation significantly increased the activities of plant superoxide dismutase, catalase, peroxidase, and other defense enzymes; enhanced plant disease resistance; effectively inhibited damping-off; and promoted plant growth. In summary, the application of three rhizosphere bacteria systematically affected the interaction between plants, soil parameters, and soil microbial communities. These results provide a basis for understanding how rhizosphere bacteria promote the growth of P. sylvestris var. mongolica, thereby offering a promising sustainable alternative to chemical fertilizers.

The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds.

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.

Measuring recent effective gene flow among large populations in Pinus sylvestris: Local pollen shedding does not preclude substantial long-distance pollen immigration.

The estimation of recent gene flow rates among vast and often weakly genetically differentiated tree populations remains a great challenge. Yet, empirical information would help understanding the interaction between gene flow and local adaptation in present-day non-equilibrium forests. We investigate here recent gene flow rates between two large native Scots pine (Pinus sylvestris L.) populations in central Iberian Peninsula (Spain), which grow on contrasting edaphic conditions six kilometers apart from each other and show substantial quantitative trait divergence in common garden experiments. Using a sample of 1,200 adult and offspring chloroplast-microsatellite haplotypes and a Bayesian inference model, we estimated substantial male gametic gene flow rates (8 and 21%) between the two natural populations, and even greater estimated immigration rates (42 and 64%) from nearby plantations into the two natural populations. Our results suggest that local pollen shedding within large tree populations does not preclude long-distance pollen immigration from large external sources, supporting the role of gene flow as a homogenizing evolutionary force contributing to low molecular genetic differentiation among populations of widely distributed wind-pollinated species. Our results also indicate the high potential for reproductive connectivity in large fragmented populations of wind-pollinated trees, and draw attention to a potential scenario of adaptive genetic divergence in quantitative traits under high gene flow.

Extracts of pine bark (Pinus sylvestris) inhibit Cryptosporidium parvum growth in cell culture.

The widespread apicomplexan parasite Cryptosporidium parvum is responsible for severe gastrointestinal disease in humans and animals. The treatment options are limited, and the efficacy of available drugs is low. Bark contains condensed tannins (CT), which are bioactive compounds previously shown to inhibit parasite development. Here, we examined the anti-cryptosporidial properties of bark extract of Scots pine (Pinus sylvestris) against C. parvum by means of an in vitro growth inhibition test. We hypothesised that bark extracts would have dose-dependent inhibitory effects on the development of C. parvum in cell culture.Bark extracts from Scots pine extracted with acetone, methanol, and water as solvents were investigated using human colorectal adenocarcinoma cells infected with C. parvum. Oocysts were inoculated onto the cell monolayer and bark extract was added at seven different concentrations. Parasite growth inhibition was quantified by qPCR.The acetone and methanol extracts demonstrated a sigmoid dose-dependent inhibition of C. parvum. The IC50 values were 244.6 and 279.1 µg dry matter extract/mL, and 25.4 and 24.1 µg CT/mL, for acetone and methanol extracts, respectively. The IC50 for both extracts were similar, both with regard to the dry matter concentration of each extract and to CT concentrations.Given the limited treatment options available for Cryptosporidium spp., the evidence generated in our study encourages further investigation into the in vitro and in vivo effects of pine bark extracts against C. parvum.

Pinosylvin Shifts Macrophage Polarization to Support Resolution of Inflammation.

Pinosylvin is a natural stilbenoid found particularly in Scots pine. Stilbenoids are a group of phenolic compounds identified as protective agents against pathogens for many plants. Stilbenoids also possess health-promoting properties in humans; for instance, they are anti-inflammatory through their suppressing action on proinflammatory M1-type macrophage activation. Macrophages respond to environmental changes by polarizing towards proinflammatory M1 phenotype in infection and inflammatory diseases, or towards anti-inflammatory M2 phenotype, mediating resolution of inflammation and repair. In the present study, we investigated the effects of pinosylvin on M2-type macrophage activation, aiming to test the hypothesis that pinosylvin could polarize macrophages from M1 to M2 phenotype to support resolution of inflammation. We used lipopolysaccharide (LPS) to induce M1 phenotype and interleukin-4 (IL-4) to induce M2 phenotype in J774 murine and U937 human macrophages, and we measured expression of M1 and M2-markers. Interestingly, along with inhibiting the expression of M1-type markers, pinosylvin had an enhancing effect on the M2-type activation, shown as an increased expression of arginase-1 (Arg-1) and mannose receptor C type 1 (MRC1) in murine macrophages, and C-C motif chemokine ligands 17 and 26 (CCL17 and CCL26) in human macrophages. In IL-4-treated macrophages, pinosylvin enhanced PPAR-γ expression but had no effect on STAT6 phosphorylation. The results show, for the first time, that pinosylvin shifts macrophage polarization from the pro-inflammatory M1 phenotype towards M2 phenotype, supporting resolution of inflammation and repair.

Toxicological and bioactivity evaluation of blackcurrant press cake, sea buckthorn leaves and bark from Scots pine and Norway spruce extracts under a green integrated approach.

Aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), Scots pine bark (SP), and sea buckthorn leaves (SB) were obtained using maceration and pressurized hot water and tested for their bioactivities. Maceration provided the extraction of higher dry matter contents, including total phenolics (TPC), anthocyanins, and condensed tannins, which also impacted higher antioxidant activity. NS and SB extracts presented the highest mean values of TPC and antioxidant activity. Individually, NS extract presented high contents of proanthocyanidins, resveratrol, and some phenolic acids. In contrast, SB contained a high concentration of ellagitannins, ellagic acid, and quercetin, explaining the antioxidant activity and antibacterial effects. SP and BC extracts had the lowest TPC and antioxidant activity. However, BC had strong antiviral efficacy, whereas SP can be considered a potential ingredient to inhibit α-amylase. Except for BC, the other extracts decreased reactive oxygen species (ROS) generation in HCT8 and A549 cells. Extracts did not inhibit the production of TNF-alpha in lipopolysaccharide-stimulated THP-1 macrophages but inhibited the ROS generation during the THP-1 cell respiratory burst. The recovery of antioxidant compounds from these by-products is incentivized for high value-added applications.

Dynamic changes of soil microbial community in Pinus sylvestris var. mongolica plantations in the Mu Us Sandy Land.

Soil microbial communities maintain multiple ecosystem functions in terrestrial ecosystems. The response of soil microbial communities to vegetation restoration in desertification environments is still poorly understood. Therefore, the purpose of our study was to evaluate the dynamic changes of the soil microbial community during the growth of Pinus sylvestris var. mongolic (P. sylvestris) plantations. We collected soil samples from five P. sylvestris plantations with different stand age. High-throughput sequencing was performed to determine the microbial community structure. The dynamic relationship between soil microbial community and edaphic factors was analyzed using the co-occurrence network, mantel test and partial least squares path modeling. The results showed that the soil microbial alpha diversity and community structure were significantly various among the plantations (P < 0.001). The number of nodes and edges in microbial co-occurrence network gradually decreased and the interrelationships between species became weak with stand age. The Available phosphorus was the most significant factor affecting the structure of bacterial community (R2 = 0.952), while the total phosphorus was the most significant factor affecting the structure of fungal community (R2 = 0.745). However, soil moisture had no significant effect on the microbial community. pH (0.73) and available nitrogen (0.91) had the largest positive total effects on bacterial and fungal community, respectively. Stand age (-0.65) was an indirect factor with the largest negative total effects on the bacterial community. Therefore, we concluded that the soil microbial community was not limited by soil moisture during the natural restoration process of P. sylvestris plantations in the desertification environment and the phosphorus utilization efficiency played a leading role in shaping the soil microbial community.

Verification of Chromatographic Profile of Primary Essential Oil of Pinus sylvestris L. Combined with Chemometric Analysis.

Chromatographic profiles of primary essential oils (EO) deliver valuable authentic information about composition and compound pattern. Primary EOs obtained from Pinus sylvestris L. (PS) from different global origins were analyzed using gas chromatography coupled to a flame ionization detector (GC-FID) and identified by GC hyphenated to mass spectrometer (GC-MS). A primary EO of PS was characterized by a distinct sesquiterpene pattern followed by a diterpene profile containing diterpenoids of the labdane, pimarane or abietane type. Based on their sesquiterpene compound patterns, primary EOs of PS were separated into their geographical origin using component analysis. Furthermore, differentiation of closely related pine EOs by partial least square discriminant analysis proved the existence of a primary EO of PS. The developed and validated PLS-DA model is suitable as a screening tool to assess the correct chemotaxonomic identification of a primary pine EOs as it classified all pine EOs correctly.

Bioactive Properties of the Aqueous Extracts of Endophytic Fungi Associated with Scots Pine (Pinus sylvestris) Roots.

Despite the continuing interest in various plant and natural products, only a small portion of the biologically active compounds from nature has been discovered and exploited. In this study, antioxidant and antibacterial properties of aqueous fractions of three endophytic fungi isolated from the roots of 8-year-old Scots pines (Pinus sylvestris) growing on a drained peatland were investigated. The endophytic fungi species were Acephala applanata, Phialocephala fortinii, and Humicolopsis cephalosporioides/Coniochaeta mutabilis. The bioactivities were examined using hydrogen peroxide scavenging and oxygen radical absorbance capacity tests as well as sensitive Escherichia coli-based biosensors, which produce a luminescent signal in the presence of substances with oxidative or genotoxic properties. In addition, cell models for Parkinson's disease, age-related macular degeneration, and osteoarthritis were used to evaluate the potential for pharmaceutical applications. The aqueous extracts of fungi and 19 out of 42 fractions were found to be active in one or more of the tests used. However, no activity was found in the age-related macular degeneration and osteoarthritis cell model tests. Additionally, bioactivity data was connected with metabolites putatively annotated, and out of 330 metabolites, 177 were interesting in view of the bioactivities investigated. A majority of these were peptides and all three fungal species shared a highly similar metabolome. We propose that Scots pine endophytic fungi are a rich source of interesting metabolites, and synergistic effects may cause the bioactivities, as they were found to vary after the fractionation process.

Pine (Pinus sylvestris L.) bark proanthocyanidins affords prevention of peroxynitrite-induced l-tyrosine nitration, DNA damage and hydroxyl radical formation.

Peroxynitrite is known as a strong deleterious species that may readily trigger several geriatric diseases via injuring cellular constituents. Proanthocyanidins, a biological flavonoids constituent of Pinus sylvestris L. bark, has been attributed a large variety of pharmacological functions to its antioxidant potential. The results revealed that peroxynitrite could cause the generation of hydroxyl radical, the breakage of φX-174 plasmid DNA brand as well as the nitration of L-tyrosine. However, pine (Pinus sylvestris L.) bark proanthocyanidins extracts at low concentration range markedly inhibited the peroxynitrite -induced the formation of open circular DNA form (IC50 = 5.03±0.39 mg/mL). The 3-Nitro-L-tyrosine generated by the reaction of peroxynitrite with L-tyrosine was reduced by PBP (IC50 = 1.01±0.01 mg/mL). Besides, electron spin resonance spectroscopy data indicates that the intensive signal of dimethyl pyridine N-oxide hydroxyl radical adduct from peroxynitrite was reversed by pine bark proanthocyanidins extracts (IC50 =1.02±0.04 mg/mL). Moreover, the obtained data shows that PBP provides more efficient protection against peroxynitrite than that of ascorbic acid. Together, the present study suggests that pine bark proanthocyanidins could exert potent preventive activity against peroxynitrite -elicited cytotoxicity on the biomacromolecules, a study-worthy finding with pharmacological importance.

Long-term nutrient imbalances linked to drought-triggered forest dieback.

Drought-induced forest dieback is causing reductions in productivity, increasing tree mortality and impairing terrestrial carbon uptake worldwide. However, the role played by long-term nutrient imbalances during drought-induced dieback is still unknown. To improve our knowledge on the relationships between dieback and nutrient imbalances, we analysed wood anatomical traits (tree-ring width and wood density), soil properties and long-term chemical information in tree-ring wood (1900-2010) by non-destructive Micro X-ray fluorescence (µXRF) and destructive (ICP-OES) techniques. We studied two major European conifers with ongoing drought-induced dieback in mesic (Abies alba, silver fir) and xeric (Pinus sylvestris, Scots pine) sites. In each site we compared coexisting declining (D) and non-declining (ND) trees. We used dendrochronology and generalized additive and linear mixed models to analyse trends in tree-ring nutrients and their relationships with wood traits. The D trees presented lower growth and higher minimum wood density than ND trees, corresponding to a smaller lumen area of earlywood tracheids and thus a lower theoretical hydraulic conductivity. These differences in growth and wood-anatomy were more marked in silver fir than in Scots pine. Moreover, most of the chemical elements showed higher concentrations in D than in ND trees during the last two-five decades (e.g., Mn, K and Mg), while Ca and Na increased in the sapwood of ND trees. The Mn concentrations, and related ratios (Ca:Mn, Mn:Al and P:Mn) showed the highest differences between D and ND trees for both tree species. These findings suggest that a reduced hydraulic conductivity, consistent with hydraulic impairment, is affecting the use of P in D trees, making them more prone to drought-induced damage. The retrospective quantifications of Mn ratios may be used as early-warning signals of impending dieback.

[Soil carbon, nitrogen and phosphorus stoichiometry characteristics of Pinus sylvestris var. mongolica belt-mixed forests.] / 沙地樟子松带状混交林土壤碳氮磷化学计量特征.

To provide theoretical basis for management of Pinus sylvestris var. mongolica mixed plantation, the variation of soil carbon, nitrogen and phosphorus stoichiometry in different P. sylvestris var. mongolica belt-mixed plantations were explored. Taking the monoculture plantation as control, soil samples were collected at the distance of 0, 1, 2, 3, and 4 m from the center point in P. sylvestris var. mongolica and Ulmus pumila mixed plantation and P. sylvestris var. mongolica and Maackia amurensis mixed plantation along the two directions of P. sylvestris var. mongolica and its associated species in different soil layers. Contents and stoichiometric ratios of soil organic C, total N, total P, available N, available P were analyzed. The results showed that soil organic C, total N, and available N in P. sylvestris var. mongolica mixed plantations were higher than those in pure plantation. The soil organic C, total N contents, C/N and C/P in deep soil layers were increased under P. sylvestris var. mongolica and U. pumila mixed plantation. The soil N content increased but P content decreased in P. sylvestris var. mongolica and M. amurensis mixed plantation. With the increases of distance from the center of mixed plantation, soil C/N firstly increased and then decreased, while soil total P and available P contents decreased and N/P increased in P. sylvestris var. mongolica belt. Soil C/N decreased and available P contents firstly increased and then decreased with the increases of distance from the center in U. pumila belt of P. sylvestris var. mongolica and U. pumila mixed plantation. Soil total N content firstly decreased and then increased in P. sylvestris var. mongolica belt, but it firstly increased and then decreased in M. amurensis belt of P. sylvestris var. mongolica and M. amurensis mixed plantation. P. sylvestris var. mongolica mixed plantation could improve soil C and N stocks compared with pure plantation. The best mixed mode was P. sylvestris var. mongolica and U. pumila mixed by one row, as well as P. sylvestris var. mongolica and M. amurensis mixed in two rows.

Stoichiometric characteristics of nitrogen and phosphorus in leaf-litter-soil system of Pinus sylvestris var. mongolica plantations.

To reveal the allocation pattern and stoichiometric characteristics of N and P in Pinus sylvestris var. mongolica plantation, we selected three P. sylvestris plantation with different stand ages (middle-aged, near-mature, mature) in the Hulunbuir, Horqin, and Mu Us sandy land as objects, and analyzed the contents of nitrogen, phosphorus and the N:P stoichiometry ratios in the leaf, litter, and soil. The results showed that the contents of N, P and N/P ratios in leaf, litter and soil varied in the range of 0.17-49.02, 0.11-3.01 g·kg-1 and 0.51-19.74, respectively, with the order of leaf>litter>soil. The content of N and N:P ratio were significantly different between leaf, litter and soil; the P content in leaf was significantly higher than that in litter and soil. The different areas and stand ages affected N, P content and N/P stoichiometry ratio, but the interaction of area and stand age had no significant effect on N/P stoichiometry ratio. The N, P contents in leaf, litter and soil increased with stand age, and were highest in the mature forest. The contents of N, P and N/P ratios were significantly positively correlated among the leaf, litter and soil. In the Hulunbuir and Horqin sandy land, the N/P ratros of leaf were between 14.53 to 15.57, which indicated that the P. sylvestris var. mongolica plantations was restricted by both N and P availability. In Mu Us sand land, the N:P ratios of leaf were between 18.56 to 19.71, which indicated P limitation. The stand age had no significant influence on soil N and P limitation. To improve the productivity of P. sylvestris var. mongolica plantations, we could appropriately add N or P fertilization in the plantation tending management based on local conditions. Our findings could contribute to a further understanding of the mechanism of interactions and constraints between N and P in the leaf-litter-soil system of P. sylvestris var. mongolica plantations, and provide a scientific guidance for the management.

Atmospheric depositions affect the growth patterns of Scots pines (Pinus sylvestris L.)-a long-term cause-effect monitoring study using biomarkers.

Recording the causes, effects, and effect mechanisms of vegetation health is crucial to understand process-pattern interactions in ecosystem processes. NOX and SOX in the form of air pollution are both triggers and sources of vegetation health that can have an effect on the local or the global level and whose impacts need to be monitored. In this study, the growth patterns in Scots pines (Pinus sylvestris L.) were studied in the context of changing atmospheric depositions in the lowlands of north-eastern Germany. Under the influence of atmospheric sulfur (S) and nitrogen (N) depositions, pine stands showed temporal variations in their normal growth behavior. In such cases, the patterns of normal growth can be suppressed or accelerated. Pine stands which were influenced by high S deposition up until 1990 changed from suppressed growth to accelerated growth by decreasing S, but increasing N depositions between 1990 and 2003. The cause of these changes in pine growth patterns was imbalances in S and N nutrition, in particular, enrichments of sulfate, non-protein nitrogen or arginine, and finally, also imbalances and deficiencies in phosphorus, glucose, and adenosine triphosphate in the needles. Our long-term monitoring study shows that biochemical markers (traits) are crucial bioindicators for the qualitative and quantitative assessment of tree vitality and growth patterns in Scots pines. Furthermore, we were able to show that NOX and SOX depositions need to be monitored locally to be able to assess the local effects of biomolecular markers on the growth patterns in Scots pine stands.

We Are What We Eat: A Stoichiometric and Ecometabolomic Study of Caterpillars Feeding on Two Pine Subspecies of Pinus sylvestris.

Many studies have addressed several plant-insect interaction topics at nutritional, molecular, physiological, and evolutionary levels. However, it is still unknown how flexible the metabolism and the nutritional content of specialist insect herbivores feeding on different closely related plants can be. We performed elemental, stoichiometric, and metabolomics analyses on leaves of two coexisting Pinus sylvestris subspecies and on their main insect herbivore; the caterpillar of the processionary moth (Thaumetopoea pityocampa). Caterpillars feeding on different pine subspecies had distinct overall metabolome structure, accounting for over 10% of the total variability. Although plants and insects have very divergent metabolomes, caterpillars showed certain resemblance to their plant-host metabolome. In addition, few plant-related secondary metabolites were found accumulated in caterpillar tissues which could potentially be used for self-defense. Caterpillars feeding on N and P richer needles had lower N and P tissue concentration and higher C:N and C:P ratios, suggesting that nutrient transfer is not necessarily linear through trophic levels and other plant-metabolic factors could be interfering. This exploratory study showed that little chemical differences between plant food sources can impact the overall metabolome of specialist insect herbivores. Significant nutritional shifts in herbivore tissues could lead to larger changes of the trophic web structure.

Attenuating Effects of Nortrachelogenin on IL-4 and IL-13 Induced Alternative Macrophage Activation and on Bleomycin-Induced Dermal Fibrosis.

Excessive alternative macrophage activation contributes to fibrosis. We studied the effects of nortrachelogenin, the major lignan component of Pinus sylvestris knot extract, on alternative (M2) macrophage activation. J774 murine and THP-1 human macrophages were cultured with IL-4+IL-13 to induce alternative activation, together with the extract and its components. Effects of nortrachelogenin were also studied in bleomycin-induced murine dermal fibrosis model. Knot extract significantly decreased the expression of alternative activation markers-arginase 1 in murine macrophages (97.4 ± 1.3% inhibition at 30 µg/mL) and CCL13 and PDGF in human macrophages-as did nortrachelogenin (94.9 ± 2.4% inhibition of arginase 1 at 10 µM). Nortrachelogenin also decreased PPARγ expression but had no effect on STAT6 phosphorylation. In vivo, nortrachelogenin reduced bleomycin-induced increase in skin thickness as well as the expression of collagens COL1A1, COL1A2, and COL3A1 (all by >50%). In conclusion, nortrachelogenin suppressed IL-4+IL-13-induced alternative macrophage activation and ameliorated bleomycin-induced fibrosis, indicating therapeutic potential in fibrosing conditions.

Distribution of low-molecular lipophilic extractives beneath the surface of air- and kiln-dried Scots pine sapwood boards.

During industrial wood drying, extractives migrate towards the wood surfaces and make the material more susceptible to photo/biodegradation. The present work provides information about the distribution, quantity and nature of lipophilic substances beneath the surface in air- and kiln-dried Scots pine (Pinus sylvestris L.) sapwood boards. Samples were taken from knot-free sapwood surfaces and the composition of lipophilic extractives, phenols and low-molecular fatty/resin acids layers at different nominal depths below the surface was studied gravimetrically, by UV-spectrometry and by gas chromatography-mass spectrometry (GC-MS). The concentration of total extractives was significantly higher in kiln-dried than in air-dried samples and was higher close to the surface than in the layers beneath. The scatter in the values for the lipophilic extractives was high in both drying types, being highest for linoleic acid and slightly lower for palmitic, oleic and stearic acids. The amount of fatty acids was low in kiln-dried boards, probably due to a stronger degradation due to the high temperature employed. The most abundant resin acid was dehydroabietic acid followed by pimaric, isopimaric, and abietic acids in both drying types. It is concluded that during kiln-drying a migration front is created at a depth of 0.25 mm with a thickness of about 0.5 mm.

Canopy tree species determine herb layer biomass and species composition on a reclaimed mine spoil heap.

According facilitative models of succession, trees are great forest ecosystem engineers. The strength of tree stand influences on habitat were tested in rather homogenous conditions where heterogeneity of site condition was not an important influence. We hypothesized that canopy composition affects total aboveground vascular herb layer biomass (THB) and species composition of herb layer plant biomass (SCHB) more significantly than primary soil fertility or slope exposure. The study was conducted in 227 randomly selected research plots in seven types of forest stands: pure with Alnus glutinosa, Betula pendula, Pinus sylvestris, Quercus petraea and Robinia pseudoacacia, and mixed with dominance of Acer pseudoplatanus or Betula pendula located on hilltop and northern, eastern, western, and southern slopes on a reclaimed, afforested post-mining spoil heap of the Belchatów Brown Coal Mine (Poland). Generalized linear models (GLZ) showed that tree stand species were the best predictors of THB. Non-parametric variance tests showed significantly higher (nearly four times) THB under canopies of A. glutinosa, R. pseudoacacia, B. pendula and Q. petraea, compared to the lowest THB found under canopies of P. sylvestris and mixed with A. pseudoplatanus. Redundancy Analysis (RDA) showed that SCHB was significantly differentiated along gradients of light-nutrient herb layer species requirements. RDA and non-parametric variance tests showed that SCHB under canopies of A. glutinosa, R. pseudoacacia and mixed with A. pseudoplatanus had large shares of nitrophilous ruderal species (32%, 31% and 11%, respectively), whereas SCHB under B. pendula, Q. petraea, mixed with B. pendula and P. sylvestris were dominated by light-demanding meadow (49%, 51%, 51% and 36%, respectively) and Poaceae species. The results indicated the dominant role of tree stand composition in habitat-forming processes, and although primary site properties had minor importance, they were also modified by tree stand species.