Search Results (311)

Research on young trees’ adaptation to shade has predominantly focused on leaf-level responses, overlooking critical structural and functional adaptations in branch systems. In this study, we address this gap by investigating hierarchical branch morphology–physiology integration in 20-year-old Pinus koraiensis specimens across four distinct light conditions classified by photosynthetic photon flux density (PPFD): three in the understory (low light, LL: 0–25 μmol/m²/s; moderate light, ML: 25–50 μmol/m²/s; and high levels of light, HL: 50–100 μmol/m²/s) and one under full light as a control (FL: 1300–1700 μmol/m²/s). We measured branch base diameter, length, and angle as well as chlorophyll and NSCs content in branches and needles. Branch base diameter and length were more than 1.5-fold higher in the FL Korean pine trees compared to the understory-grown ones, while the branching angle and ratio in the LL Korean pine trees were more than two times greater than those in the FL trees. As light levels increased, Chlorophyll a and b and total chlorophyll (Chla, Chlb, and Chl) concentrations in the needles all significantly decreased. Starch, glucose, and NSC (Starch + Soluble Sugars) concentrations in both needles and branches were the highest in the trees under FL and lowest under ML (except for soluble sugars in branches). Understory young P. koraiensis trees morphologically and physiologically adapt to limited light conditions, growing to be more horizontal, synthesizing more chlorophyll in needles, and attempting to increase their light-foraging ability. We recommend gradually expanding growing spaces to increase light availability for 20-year-old Korean pine trees grown under canopy level. Full article

Historically, wood has been among the main materials used in heritage buildings. However, the species and mechanical properties of these elements are often unknown. This uncertainty complicates safety assessment calculations, aggravated by the natural variability of the wood properties. The aim of this work is to assess the density of wooden elements in service using semi-destructive techniques that retain the integrity of structural elements. This research had two phases. First, penetration resistance tests were carried out on laboratory scale on Pinus sylvestris L. wood samples taken from 18th, 19th, and 20th century heritage buildings in Lisbon, Portugal. Later, a field study was carried out on wooden elements from the same buildings, involving needle penetration, core drilling, and moisture content determination tests. The laboratory test results showed a strong correlation between the needle penetration depth and wood density, with an R² value of 0.76. The results of the field study indicated that the density estimated by the needle penetration test correlated effectively with the measured density of extracted cores after moisture correction, with an R² of 0.99. In conclusion, the experimental results confirm that penetration resistance and moisture tests are reliable and practical for estimating wood density under in-service conditions. Full article

Pine needles are an industrial feedstock for extracts used in a variety of applications, but conventional extraction methods often result in a degradation of the terpenoid compounds that naturally occur in loblolly pine (Pinus taeda). Separation of these compounds from pine biomass is an energy-intensive operation, typically requiring a significant input of thermal energy. An alternative separation approach with potential energy savings is extraction with a condensable gas, namely, dimethyl ether. Biomass materials are exposed to liquid dimethyl ether under pressure, which mobilizes the organics. The extract is then separated from the insoluble pine matter, and dimethyl ether is volatilized away from the separated organic species. A variety of terpene derivatives were extracted from pine needle biomass using this approach, including monoterpenes, sesquiterpenes, and related oxygenates, which were identified using two-dimensional gas chromatography/mass spectrometry. Additionally, the dimethyl ether-treated needles resemble needles subjected to low-temperature drying, whereas needles treated with a high-temperature drying method appear to have shrunken structures. The results suggest that dimethyl ether extraction has significant potential for separating valuable organics from complex matrices without the application of thermal energy during treatment. Full article

The purpose of this study was to investigate the effects of fermented pine needles on the carcass traits, meat quality, and antioxidant capacity of finishing pigs. In total, 80 Duroc × (Landrace × Large white) crossbred pigs of approximately 4 months of age, with an initial body weight of 60.5 ± 2.5 kg, were randomly assigned to four experimental treatments, which were then denoted as the control treatment (basal diet), the fermented pine needle (FR) 1 treatment, the FR2 treatment, and the FR3 treatment (the pigs were fed the basal diet supplemented with 1.0, 2.0, and 3.0% fermented pine needles, respectively) for 55 d. The obtained results showed that, compared with the CON group, the fermented pine needle treatments increased the lean meat percentage, total antioxidative capacity, and superoxide dismutase activity in the serum and longissimus dorsi muscle. In addition, the treatments increased the mRNA expression levels of SOD1, catalase, and Nrf2 in the muscle and decreased the malondialdehyde activity in the serum and longissimus dorsi muscle and the Keap1 mRNA expression level. Compared with the CON and FR1 treatment, the FR2 and FR3 treatments increased springiness, serum GSH-Px activity, and longissimus dorsi muscle CAT activity, and decreased hardness, chewiness, gumminess, and cohesiveness. Moreover, compared with the CON treatment and other fermented pine needle treatments, the FR2 treatment not only significantly elevated the carcass weight, dressing percentage, pH_24h, a* value (redness), and marbling scores of the finishing pigs, but also remarkably reduced the L* value (lightness), b* value (yellowness), and shear force in the meat quality. In conclusion, the experiment indicated that the addition of fermented pine needles to the diet has no negative impact on the carcass characteristics of finishing pigs and could improve the tenderness and freshness of the meat, as evidenced by the modified antioxidant enzyme activity and mRNA expression levels of antioxidant genes in the muscles of finishing pigs. Full article

Dothistroma needle blight (DNB) is one of the most significant diseases of conifers, causing premature defoliation, growth reduction, and, in extreme cases, mortality. Histological analysis was undertaken on inoculated seedlings of three different seed sources of Pinus sylvestris L. to investigate the process of infection and degradation of needle tissue on this host species. Seedlings were inoculated using a single spore isolate of Dothistroma septosporum (Doroguine) M. Morelet (D636) from northern Scotland. Mesophyll degradation in the needles occurred by four weeks after inoculation; collapse of mesophyll, bundle sheath tissues, and tracheids by five weeks; and eruption of fruiting bodies in near proximity to stomatal openings by six weeks. Significantly greater collapse of mesophyll during the early stages of infection occurred in the Austrian provenance compared with the United Kingdom provenance, although in the later stages of infection, this difference disappeared. Furthermore, disease severity, assessed as the proportion of needles with D. septosporum conidiomata on each tree, was not significantly different between seed sources. Full article

The nitrogen (N) and phosphorus (P) additions were commonly used to improve plantation quality. However, the balance between nutrient uptake in the underground part and nutrient utilization in the aboveground part of Pinus elliottii (Slash pine) plantation in subtropical regions after N and P addition is still unclear. We conducted the experiment using a randomized complete block design with four treatments: N (50 kg N ha⁻² yr⁻¹, P (100 kg P ha⁻² yr⁻¹), NP (N + P), and a control (CK). Nutrient transport dynamics of underground (rhizosphere soil and roots) and aboveground (twigs and needles) parts of a 10-year-old Pinus elliottii plantations were evaluated. The trial was maintained for three consecutive growing seasons. The results showed that N and P additions significantly increased the N, P, and potassium (K) contents of soils and plant tissues in subtropical slash pine plantation forests, and showed a significant and gradual increase in interannual variations over the observation period (except for TN in soils, which increased first and then decreased). In terms of nutrient transport and reabsorption efficiency, N addition promoted the transport of elemental P from the translocating root system to the twigs, whereas P addition inhibited this process. P addition significantly increased the nitrogen reabsorption efficiency (NRE) of the needles, but decreased the phosphorus reabsorption efficiency (PRE), showing an element-specific response to the nutrient reabsorption process. Structural equation modeling further revealed that N or P addition had direct positive effects on soil N, P, and K content (path coefficients r: 0.54, 0.71, 0.41). N addition indirectly negatively affected N resorption efficiency (NRE) and K resorption efficiency (KRE) (r: −0.62, −0.51) but positively affected PRE (r: 0.44). Conversely, P addition had an indirect negative effect on PRE (r: −0.59). These results reveal that in subtropical regions, slash pine plantations adapt to N or/and P addition by adjusting nutrient absorption, transport, and resorption efficiency. This provided new insights into nutrient transport and distribution strategies in underground and aboveground parts of plants under N or/and P additions. Full article

Essential oils have been utilized in the health, learning/memory, and agricultural fields, but not much is known about the biological activity of their individual components. Terpinyl acetate is a p-menthane monoterpenoid commonly found in cardamom, pine, cajeput, pine needle, and other essential oils. Using a cell culture model system, we found that terpinyl acetate is a potent and specific inhibitor of mitochondrial ATP production, suggesting it might function as a plant toxin. Remarkably, however, terpinyl acetate was not cytotoxic because cells switched to glycolysis to maintain ATP levels. Based on these findings, we hypothesized that terpinyl acetate might be employed to benefit plant survival by modulating metabolism/behavior of plant pollinators such as the honey bee. This hypothesis was tested by investigating terpinyl acetate’s effect on honey bee foraging. Free-flying honey bee flower color choice was recorded when visiting a blue-white dimorphic artificial flower patch of 36 flowers. The nectar–reward difference between flower colors was varied in a manner in which both learning and reversal learning could be measured. Terpinyl acetate ingestion disrupted reversal learning but not initial learning: this change caused bees to remain faithful to a flower color longer than was energetically optimal. Full article

Potentially toxic elements (PTEs) have steadily become a serious environmental problem, especially regarding brownfields chosen for reuse, e.g., as a residential area. “Norra Hamnstaden” in Lidköping (Sweden) has a long history of industrial activity, including porcelain production with the resultant industrial waste deposited close by resulting in elevated levels of metals used for porcelain glazes, especially lead. To estimate the bioavailability of twelve PTEs (As, Ba, Pb, Cd, Co, Cu, Cr, Mn, Mo, Ni, V, Zn), their uptake by birches (Betula pendula) as well as Scots pines (Pinus sylvestris) was investigated through analyzing their leaves. Sampling was carried out on five trees once per month in the period from May to August. Different uptake patterns were observed for birches and pines, for the latter even varying with age. The birch samples showed higher contents of nickel, cobalt, molybdenum, and lead compared to the reference trees. Also, the pine needles had elevated lead levels, although by a lower factor. Birch leaves revealed surprising patterns of elevated element bioaccumulation factors, with barium reaching up to eight, offering the possibility to limit analyses to plant material for risk assessments instead of soil analysis. Full article

Bursaphelenchus xylophilus is a pine wood nematode capable of destroying pine forests. Exploring the genes providing resistance to this pathogen and understanding their resistance mechanisms is thus necessary and constitutes an effective way to tackle this problem. We used Pinus tabuliformis Carriere to dissect its response to B. xylophilus strain BxFC. The 30 d inoculation results showed that the P. tabuliformis germplasms exhibited a wide resistance spectrum. Some lines were sensitive with the needles fully wilted and the MDA content and the relative conductivity of needles greatly increased, while some lines demonstrated strong resistance with good needle vigor and better physiological conditions. Moreover, the transcriptome analysis revealed 7928 differentially expressed genes (DEGs) between the resistant and sensitive germplasm pools, including 3754 upregulated and 4174 downregulated genes in the resistant lines. These DEGs were specially enriched in the pathways of plant–pathogen interaction (318 genes), phenylpropanoid biosynthesis (108 genes), ubiquitin-mediated proteolysis (47 genes), carotenoid biosynthesis (18 genes), and monoterpenoid biosynthesis (9 genes). Accordingly, P. tabuliformis utilized multiple ways to control the proliferation and activity of B. xylophilus, such as immune response, ubiquitination, thickening plant cell walls, and increasing its terpenoid and antioxidant contents. Our results could thus help in better understanding the resistance process of P. tabuliformis against B. xylophilus and offer some new strategies and gene resources for a molecular breeding program of resistant P. tabuliformis. Full article

Pine needle blight of Pinus massoniana caused by pathogens of the Pestalotiopsis genus is a destructive disease worldwide, especially in young forests. Chemical fungicides accelerate the formation of resistant strains among plant pathogenic fungi, which makes microbial biocontrol particularly important. In this study, we identified Neopestalotiopsis camelliae-oleiferae as a new pathogen of pine needle blight in P. massoniana via pathogen isolation, inoculation, pathogenicity assays, morphology observations, and multilocus phylogenetic analyses of the ITS, TEF1, and TUB2 regions. PSM-6, an endophytic bacterium, was subsequently isolated from pine needles and was shown to have excellent antagonistic activity against N. camelliae-oleiferae in vitro. Based on the morphology, physiology, and molecular analysis, we identified this strain as P. silvicola. The extracellular secondary metabolites of PSM-6 were further proven to cause the shrinkage and collapse of pathogen hyphae. The decreased disease index and mortality indicated that pretreatment with PSM-6 may effectively protect pine seedlings from pathogen infection. In addition, PSM-6 exhibited broad-spectrum antifungal activity in several phytopathogenic fungi, including Fusarium graminearum, Botrytis cinerea, and Verticillium dahliae. These findings establish PSM-6 as a promising biocontrol agent, offering an environmentally friendly alternative to chemical fungicides for managing pine needle blight and other fungal diseases. Full article

Essential oils are mixtures of volatile compounds often found in the leaves, wood, and fruits of coniferous trees and shrubs. The composition and abundance of individual oil components vary across different plant parts. Terpenes (monoterpenes, sesquiterpenes, diterpenes, triterpenes) dominate in the essential oils of many plants. They are the most abundant class of secondary metabolites, with plants containing over a hundred of them at varying concentrations. The terpene profile of certain species consists of a few dominant (abundant) components and numerous less abundant ones. It is believed that the biological activity of essential oil mostly depends on the dominant terpene components. In most of the analyzed Pinus species, the most abundant terpene compounds are α-pinene, β-pinene, δ-3-carene, β-caryophyllene, limonene/β-phellandrene, and germacrene D. In certain taxa, additional dominant compounds include α-cedrol, bornyl acetate, caryophyllene oxide, α-phellandrene, trimethylbicyclo [3.1.1]hept-2-ene, 2H-benzocyclohepten-2-one, phenylethyl butyrate, 4-epi-isocembrol, β-thujene, and thunbergol. Moreover, compounds with abundances exceeding 15% include methyl chavicol (=estragole), geranylene, myrcene, γ-muurolene, sabinene, and abieta-7,13-diene. It can be concluded that the terpene profiles of the needles of the analyzed pine taxa depend on the type of chromatographic columns, the method of obtaining essential oils, the origin of the trees (in natural habitat or artificial plantation), the age of the needles, the variety, and the season in which the needles were collected. Full article

One of the key modeling procedures is model verification, which ensures its reliability and confidence. In many respects, the length of the crown is an interesting biophysical property. Precise determination of crown length can be one of the components used in estimating the mass of needles or leaf area index (LAI), and consequently the amount of transpiration or the amount of carbon dioxide bound, which is crucial in the context of climate change. The objective of this study was to calculate the length of the crown Pinus sylvestris using an allometric model and to compare these results with the actual ones to establish the degree of discrepancy. The model that was tested was based on three predictor variables, i.e., diameter at breast height, tree height, and stand density index. The verification was carried out using empirical data collected for 300 sample trees on 20 experimental plots located in south-western Poland. All the stands were pine monocultures located in the habitats of fresh or mixed fresh forest aged from 28 to 40 years. The studied stands differed in terms of diameter at breast height, height, and density (0.68–1.81). The comparison between empirical (${CL}_{emp}$) and calculated (${CL}_{cal}$) mean crown lengths in the stand using the model was expressed by the correlation coefficient’, which was R = 0.955, with a divergence (±) of 4.57%. The tested model is dedicated to calculating the length of tree crowns at the population level. The model uses a density index, which is a constant value for all trees within the area. Further work is needed to improve the model and allow for precise calculation of the crown length of a single tree, taking into account the space it has at its disposal. Full article

This study hypothesized that different base fertilizer application has different effects on improving the efficiency of maize water utilization and promoting maize growth. Utilizing field positioning sloping farmland micro-zone experiments, six distinct types of base fertilizers were designed: a control group without fertilization (CK), chemical fertilizer alone (T1), a mixture of local farmyard manure (40% pine needles and 60% livestock manure, T2), a 50% reduction in chemical fertilizer combined with farmyard manure (T3), the incorporation of crushed straw through deep plowing (T4), and the fermentation of crushed straw mixed with urea before field application (T5). The results indicate that, compared to the CK treatment, the T3 and T5 treatments significantly enhanced soil moisture content, with increases ranging from 4.06% to 18.67% during the normal year (2023) and the drought year (2024), respectively. Additionally, the water utilization efficiency of maize was improved significantly, with values of 35.38% and 41.54%, and the yield increased by 12.30% to 25.92%. The maize yields under T3 and T5 treatments reached 12.19 and 13.31t/ha, respectively. Therefore, we propose that crushing straw and incorporating urea and water for fermentation as a base fertilizer in maize fields can ensure efficient water use in this region, leading to higher yields. Full article

The Chinese red pine, Pinus tabulaeformis, is one of the most important evergreen conifer trees in China. It is widely planted in southern Gansu Province and is commonly used for garden trees, hedges, windbreaks, and soil and water conservation. However, Matsucoccus sinensis, a scale insect, has become a major pest of the P. tabulaeformis forests, and its life history and biological characteristics remain unknown. In this study, we investigated the biological characteristics, male cocoon emergence, adult mating period, and egg developmental period of M. sinensis, providing valuable insights for its prevention and control. We conducted continuous observation of the different developmental stages of M. sinensis, both in the laboratory and in P. tabulaeformis fields. The least squares method was used to calculate the egg developmental period of M. sinensis. Our results showed that the scale insect is a monophagous species with one generation occurring per year. The second-instar nymphs overwinter on the needles in the medium shell and reproduce sexually, without parthenogenesis. Male M. sinensis adults reach their peak appearance at the end of April in the study region. The peak emergence of male cocoons occurred between 2:00 AM and 4:00 AM, and the adult mating period lasted from 11:00 AM to 13:00 PM. The larvae of M. sinensis attack the needles of P. tabulaeformis. The nymphs crawled and moved to the inner base of the needles, with first- to third-instar nymphs fixing themselves to the needles to feed. The effective accumulated temperature and starting temperatures for the development of M. sinensis eggs were found to be 86.1 °C and 3.5 °C, respectively. Overall, understanding the biology and life history of M. sinensis is essential for identifying key developmental stages and determining the optimal timing for pest control, ultimately aiding in the development of targeted management strategies to protect P. tabulaeformis forests from this emerging pest. Full article

The diversity of foliar fungal endophyte communities was examined in three economically and ecologically important pine species in Scotland: Scots pine, Corsican pine and lodgepole pine. Two plantation sites comprising all three species were selected in climatically contrasting parts of Scotland and were sampled in late spring by collecting healthy needles from two age classes. Surface sterilisation was carried out before obtaining cultures of fungal isolates, and representatives of common sterile morphotypes were sequenced to determine taxonomic placement. Overall relative proportions of the dominant taxa across sites, tree species and needle age classes were as follows: Anthostomella spp. (52%), Lophodermium seditiosum (17%) and Desmazierella acicola (7%). Many other less frequent taxa were recovered. The results agreed with previous endophyte studies in that the combined effects of site and tree species produced unique endophytic fungal assemblages. Phylogenetic analyses revealed potential sub-species variation associated with site in Anthostomella pinea. Our findings point to the potential naturalisation of European fungal endophytic species (e.g., Anthostomella spp.) in Scottish pine plantations, particularly in association with Corsican pine. Full article