Search

A new species of the genus Sychnotylenchus Rühm, 1956, S. kulinchi sp. n., inhabiting the bark beetle galleries of Pityogenes chalcographus in Pinus koraiensis was found in the Primorsky Krai of Russia. The new species differs morphologically from the closely related species S. yasinskii and S. mayor in having a shorter body length (626-1030 vs 1250-1280 and 1935-1455 μm, respectively) and from S. sparnugus in having a greater value of the ratio between spicule length and tail length (0.9-11 vs less than 0.7). Phylogenetic analysis of the partial 18S rRNA, D2-D3 expansion segments of the 28S rRNA, the ITS rRNA and COI gene sequences showed that the Russian S. kulinichi sp. n. population grouped with populations from Israel and an unspecified locality that were identified incorrectly as Ditylenchus forepolitor, which are considered conspecific with S. kulinichi sp. n. in this study. Phylogenetic analyses aiming to clarify the controversial taxonomic status of Neoditylenchus and Sychnotylenchus species indicated that, although the genus Sychnotylenchus was paraphyletic in some phylogenetic trees, testing of alternative topologies for the 18S rRNA, D2-D3 of 28S rRNA and ITS rRNA gene trees and datasets using the maximum likelihood method did not exclude the monophyly of this genus and did not justify the validity of the genus Neoditylenchus, which should be considered a junior synonym of Sychnotylenchus as proposed by Fortuner & Maggenti (1987). Molecular phylogeny showed close relationships of Sychnotylenchus with plant-parasitic nematodes from the genera Ficotylus, Orrina and Pterotylenchus, and also with the insect-associated genus Neomisticius. A polytomous key listing 24 morphological diagnostic characters for the identification of 33 species of Sychnotylenchus is provided, along with a table listing associated bark beetle species. [ABSTRACT FROM AUTHOR]

Water is a crucial component for plant growth and survival. Accurately estimating and simulating plant water content can help us promptlymonitor the physiological status and stress response of vegetation. In this study, we constructed water loss curves for three types of conifers with morphologically different needles, then evaluated the applicability of 12 commonly used water indices, and finally explored leaf water content estimation from hyperspectral data for needles with various morphology. The results showed that the rate of water loss of Olgan larch is approximately 8 times higher than that of Chinese fir pine and 21 times that of Korean pine. The reflectance changes were most significant in the near infrared region (NIR, 780-1300 nm) and the short-wave infrared region (SWIR, 1300-2500 nm). Thewater sensitive bands for conifer needlesweremainly concentrated in the SWIR region. The water indices were suitable for estimating the water content of a single type of conifer needles. The partial least squares regression (PLSR) model is effective for the water content estimation of all three morphologies of conifer needles, demonstrating that the hyperspectral PLSR model is a promising tool for estimating needles water content. [ABSTRACT FROM AUTHOR]

(1) Background: In recent years, forest fires have become increasingly frequent both domestically and internationally. The pollutants emitted from the burning of fuel have exerted considerable environmental stress. To investigate the influence of forest fires on the atmospheric environment, it is crucial to analyze the variations in PM2.5 emissions from various forest fuels under differing fire conditions. This assessment is essential for evaluating the effects on both the atmospheric environment and human health. (2) Methods: Indoor simulated combustion experiments were conducted on the branches, leaves, and bark of typical tree species in the Liangshui National Natural Reserve, including Pinus koraiensis (PK), Larix gmelinii (LG), Picea koraiensis (PAK), Betula platyphylla (BP), Fraxinus mandshurica (FM), and Populus davidiana (PD). The PM2.5 concentrations emitted by six tree species under various combustion states were measured and analyzed, reflecting the impact of moisture content on the emission of pollutants from fuel combustion, as indicated by the emission factors for pollutants. (3) Results: Under different fuel loading and moisture content conditions, the mass concentration values of PM2.5 emitted from the combustion of different organs of various tree species exhibit variability. (4) Conclusions: Among the various tree species, broad-leaved varieties release a greater quantity of PM2.5 compared to coniferous ones. A positive correlation exists between the moisture content of the fuel and the concentration of PM2.5; changes in moisture content notably influence PM2.5 levels. The emission of PM2.5 from fuel with varying loads increases exponentially. Utilizing the Response Surface Methodology (RSM) model for simulation, it was determined that both moisture content and fuel load exert a significant combined effect on the release of PM2.5 during combustion. [ABSTRACT FROM AUTHOR]

In order to preliminarily evaluate the early growth of Pinus koraiensis and select excellent families, taking 117 full-sib family seedlings obtained by controlled pollination in the Affinity Seed Garden of Wangqing Forestry Branch of Changbaishan Forest Industry Group as materials, we observed their growth for three consecutive years and conducted a comprehensive evaluation after establishing a progeny measurement forest in the Affinity Seed Garden in the 91st forest class, class 4. The differences in seedling height and ground diameter of the offspring of P. koraiensis full-sib family lines from 6 to 8 years old were highly significant among family lines, and the interaction between family lines and district groups was highly significant (P<0. 01); the average seedling height at 6 years old was 39. 79 cm, the average annual growth rate at 8 years old was 25%, the average ground diameter at 6 years old was 11.11 mm, the average annual growth rate at 8 years old was 34%, and the phenotypic coefficient of variation of each trait ranged from 15. 84% to 25. 43%. The heritability of each trait was high, which was conducive to the further selection and evaluation of the family line. Using the Breggin multiple trait analysis method to select superior family lines, 24 superior family lines were from 117 familes with a benchmark of 20%. The excellent family lines selected by growth traits can provide the basis and materials for renewing the seed orchard generation and promoting the superiority and expansion of P. koraiensis. [ABSTRACT FROM AUTHOR]

In order to explore the effect of chemical treatment on adventitious bud formation of P. koraiensis top pruned seedlings, 5-year-old P. koraiensis bare root seedlings were used as experimental materials. After top pruning at the beginning of the growing season, different chemicals were sprayed every 15 days (GA3 (200, 500, 1 000 mg/L), 6-BA (100, 300, 500 mg/L), KMnO4 (0. 1%, 0. 2%, 0. 3%)). Using spray water treatment as a control, the formation of adventitious buds of P. koraiensis seedlings treated with different chemicals was investigated. The results showed that the chemical treatment (except 1 000 mg/L GA3 and 0. 1% KMnO4) increased the incidence of adventitious buds of P. Koraiensis top pruned seedlings. Compared with the control, the sprouting rate increased by 5. 72% to 48. 58%, and the number of sprouting strip increased by 15. 37% to 175. 94%. The suitable concentration of GA3 to promote P. koraiensis top pruned seedlings was 200 mg/L, which can increase the sprouting rate by 34. 28%, and the number of sprouting strip by 33. 63%. The suitable concentration of 6-BA to promote P. koraiensis truncated seedlings was 500 mg/L, which can increase the sprouting rate by 48. 58%, and the number of sprouting strip by 175. 94%. The suitable concentration of KMnO4 to promote P. koraiensis top pruned seedlings was 0. 2%, which can increase the sprouting rate by 42. 85%, and the number of sprouting strip by 95. 18%. The better effect of promoting adventitious bud formation can be obtained by using 500mg/L 6-BA to treat P. koraiensis top pruned seedlings. [ABSTRACT FROM AUTHOR]

Forest defoliating pests are significant global forest disturbance agents, posing substantial threats to forest ecosystems. However, previous studies have lacked systematic analyses of the continuous spatiotemporal distribution characteristics over a complete 3–5 year disaster cycle based on remote sensing data. This study focuses on the Dendrolimus superans outbreak in the Changbai Mountain region of northeastern China. Utilizing leaf area index (LAI) data derived from Sentinel-2A satellite images, we analyze the extent and dynamic changes of forest defoliation. We comprehensively examine the spatiotemporal patterns of forest defoliating pest disasters and their development trends across different forest types. Using the geographical detector method, we quantify the main influencing factors and their interactions, revealing the differential impacts of various factors during different growth stages of the pests. The results show that in the early stage of the Dendrolimus superans outbreak, the affected area is extensive but with mild severity, with newly affected areas being 23 times larger than during non-outbreak periods. In the pre-hibernation stage, the affected areas are smaller but more severe, with a cumulative area reaching up to 8213 hectares. The spatial diffusion characteristics of the outbreak follow a sequential pattern across forest types: Larix olgensis, Pinus sylvestris var. mongolica, Picea koraiensis, and Pinus koraiensis. The most significant influencing factor during the pest development phase was the relative humidity of the year preceding the outbreak, with a q-value of 0.27. During the mitigation phase, summer precipitation was the most influential factor, with a q-value of 0.12. The combined effect of humidity and the low temperatures of 2020 had the most significant impact on both the development and mitigation stages of the outbreak. This study's methodology achieves a high-precision quantitative inversion of long-term disaster spatial characteristics, providing new perspectives and tools for real-time monitoring and differentiated control of forest pest infestations. [ABSTRACT FROM AUTHOR]

Dioryctria sylvestrella (Lepidoptera: Pyralidae) is a destructive borer pest on Korean pine (Pinus koraiensis) indigenous to northeastern China. The antennal sensilla of D. sylvestrella were examined by scanning electron microscopy to understand the behavioral ecology of this insect pest. Both the male and female antennae are filiform, and each consists of a scape, a pedicel, and a flagellum. D. sylvestrella is characterized by sexual dimorphism. Only the male antennae present two deeply grooved thumblike protuberances on the crest surfaces of their fourth and fifth flagellomeres, respectively. These structures have never been reported for any other Pyralidae. Eight different types of sensilla with unique bioecological functions were detected on the antennae of both sexes. There may be structure–location–function relationships for these sensilla, and most of them are involved in communication between the insect and the host plant, mate detection, and oviposition site selection. [ABSTRACT FROM AUTHOR]

Coarse roots and the root plate play an important role in tree resistance to uprooting. In this study, a qualitative mechanistic model was developed to analyze coniferous tree resistance to uprooting in relation to tree morphological characteristics. The sizes of the crown, stem, and root plate of twenty sample spruces and twenty sample Korean pines were individually measured for this purpose. Using Ground Penetrating Radar (GPR), the coarse root distribution and root plate size were detected. In the qualitative mechanistic model, a larger crown area increased the overturning moment, while higher DBH and root plate mass increased the resistance moment. The resistance coefficient (Rm) was calculated by comparing resistive and overturning moments, classifying samples into three uprooting hazard levels. Trees with smaller crown areas, larger stems, and root plates tend to have higher resistance to uprooting, as indicated by higher Rm values. This qualitative mechanistic model provides a useful tool for assessing coniferous standing tree uprooting resistance. [ABSTRACT FROM AUTHOR]

Pinus koraiensis (PK) leaf extract, derived from Korean pine byproducts, holds promise for alleviating postprandial hyperlipidemia. In this study, we investigated the potential of PK leaf extract for modulating postprandial hyperlipidemia in adults with normal or borderline fasting triglyceride levels. In a randomized, double-blind, parallel design, 70 subjects were randomly assigned to either the placebo or PK group for 4 weeks. After 4 weeks of consuming PK leaf extract, the results indicated a trend toward decreased serum apolipoprotein B-100 (ApoB100) levels 2 h after a high-fat challenge. Furthermore, significant improvements were observed in the incremental area under the curve (iAUC) at 0–4 h and 2–4 h compared to baseline, particularly among individuals with a higher body weight (>61.35 kg) and daily caloric intake (>1276.5 kcal). Based on these findings, PK leaf extract may have beneficial effects on postprandial lipoprotein metabolism, especially among individuals with a relatively high body weight and caloric intake. [ABSTRACT FROM AUTHOR]

Due to its advantages such as speed and noninvasive nature, near-infrared spectroscopy (NIRS) technology has been widely used in detecting the nutritional content of nut food. This study aims to address the problem of offline quantitative analysis models producing unsatisfactory results for different batches of samples due to complex and unquantifiable factors such as storage conditions and origin differences of Korean pine nuts. Based on the offline model, an online learning model was proposed using recursive partial least squares (RPLS) regression with online multiplicative scatter correction (OMSC) preprocessing. This approach enables online updates of the original detection model using a small amount of sample data, thereby improving its generalization ability. The OMSC algorithm reduces the prediction error caused by the inability to perform effective scatter correction on the updated dataset. The uninformative variable elimination (UVE) algorithm appropriately increases the number of selected feature bands during the model updating process to expand the range of potentially relevant features. The final model is iteratively obtained by combining new sample feature data with RPLS. The results show that, after OMSC preprocessing, with the number of features increased to 100, the new online model's R 2 value for the prediction set is 0.8945. The root mean square error of prediction (RMSEP) is 3.5964, significantly outperforming the offline model, which yields values of 0.4525 and 24.6543, respectively. This indicates that the online model has dynamic and sustainable characteristics that closely approximate practical detection, and it provides technical references and methodologies for the design and development of detection systems. It also offers an environmentally friendly tool for rapid on-site analysis for nut food regulatory agencies and production enterprises. [ABSTRACT FROM AUTHOR]

Juglans mandshurica is an important component of Korean pine mixed and secondary forests in Northeast China and is also a precious timber and economic species. In this study, plant regeneration of J. mandshurica has been established using stems with bud and mature zygotic embryos as explants. The results showed that placing the stems with buds in low-temperature conditions (0 to 4°C) and in darkness for 5 d inhibited the browning of the explants and promoted bud sprouting; Na2S2O3 also inhibited the browning of mature zygotic embryos significantly. The suitable basal media and hormones for bud sprouting and zygotic embryo germination were (1) WPM medium (woody plant medium) containing 2.0 mg·L−1 6-benzylaminopurine (6-BA) and 0.01 mg·L−1 3-indolebutyric acid (IBA) and (2) DKW medium (Driver and Kuniyuki medium) containing 2.5 mg·L−1 6-BA and 0.1 mg·L−1 IBA. The suitable basal medium and hormone for rooting of shoots from buds was 1/2 Murashige and Skoog (MS) medium (the macro-elements were half-strength of MS medium) supplemented with 1.0 mg·L−1 IBA, and the suitable basal medium and hormone for rooting of seedlings derived from zygotic embryo was 1/2 MS medium containing 1.0 mg·L−1 IBA, and DKW medium with 2.5 mg·L−1 6-BA, 0.1 mg·L−1 IBA, 0.2 mg·L−1 gibberellin A3 (GA3), and 0.2 g·L−1 activated carbon (AC). About 95% of the rooted plantlets survived after acclimation and transplantation. These results provided a foundation for the scale propagation to meet the demands of forestry production of the species. [ABSTRACT FROM AUTHOR]

This document is a diagnostic protocol for Dendrolimus sibiricus, a species of moth. It provides information on the taxonomy, distribution, and identification of D. sibiricus, as well as its life stages and detection methods. The document emphasizes the need for species identification based on male genitalia or molecular methods, as morphology alone is not reliable. It also includes descriptions and images of the eggs, larvae, pupae, and adults of D. sibiricus for reference. Reference materials and further information sources are provided for those seeking more information on this species. [Extracted from the article]

Conspecific adults impose strong negative density‐dependent effects on seed survival nearby parent trees, however, the underlying mechanisms are diversified and remain unclear. In this study, we presented consistent evidence that parent‐scented forest floor masked seed odor, reduced cache recovery rate by scatter‐hoarding animals, and then increased seed dispersal far away from mother trees. Our results showed that seed odors of Korean pine Pinus koraiensis match well with the volatile profile of their forest floor. Moreover, scatter‐hoarding animals selectively transported P. koraiensis seeds toward the areas where seed odor was more contrasting against the background substrate, possibly due to the fact that accumulation of conspecific volatile compounds in caches hindered seed detection by scatter‐hoarding animals. Our study provides insight into the role of leaf litter in directing seed dispersal process, representing a novel mechanism by which P. koraiensis increases selection for seed dispersal far away from the parent tree. [ABSTRACT FROM AUTHOR]

In order to study the effects of top pruning time and retained stem height on the quality of Pinus koraiensis seedlings, a top pruning test was carried out with 4-year bare root seedlings of Pinus koraiensis as materials, and 3 retained stem heights （20, 25, 30 cm） and 5 top pruning times （April, May, June, July, August） were set. The root collar diameter, biomass, shoot to root ratio, root length, root surface area and root volume of seedlings under different top pruning treatments were measured. The results showed that top pruning treatment in the middle of the growing season （June） could significantly increase the root collar diameter growth of Pinus koraiensis seedlings by 23. 68% compared with the control, but the effect of top pruning treatment at other times was not obvi‐ ous. The top pruning treatment had no effect on the increase of biomass, the decrease of shoot to root ratio and the growth of thick roots, but had a significant effect on the growth of fine roots of Pinus koraiensis seedlings. The length of fine roots, surface area of fine roots and volume of fine roots were increased by 18. 27%-84. 95%, 9. 38%-75. 01% and 1. 28%-64. 68%, respectively, compared with the control. The top pruning in the middle of the growing season （June） increased the root collar diameter growth of Pinus koraien⁃ sis seedlings, promoted the growth of fine roots and promoted the quality of Pinus koraiensis seedlings to a certain extent. [ABSTRACT FROM AUTHOR]

In order to analyze the growth pattern of tree height of planted Pinus koraiensis and screen the provenances with fastest growth, we grouped the provenances using the differences in tree height, diameter at breast height (DBH) and volume of timber of 234 individuals of planted P. koraiensis from 26 provenances in Maoershan Experimental Forest Farm. We constructed the growth equation for tree height by combining the base models of Gompertz, Korf, Richards, Logistic, and Schumacher, and then selected the optimal one. We introduced the provenance grouping as a dummy variable into the base model, and evaluated the optimal tree height growth equation by a comprehensive evaluation of the model according to the coefficient of determination (R²), the root-mean-square error (RMSE), the Akaikei Information Criterion (AIC), and the model's predictive precision (FP). The results showed that the growth traits of the 26 provenances had significant difference among the groups, and that tree height and DBH showed significant differences among the provenances. According to the comprehensive consideration of different growth traits, the four groups of provenance growth were divided into group A (Wuying, Hebei, Linjiang, Dongfanghong, Huanan, Lushuihe, Fangzheng) >group B (Aihuisanzhan, Liangshui, Tieli, Qinghe) > group C (Wuyiling, Zhanhe, Liangzihe, Baihe, Chaihe, Caohekou, Bajiazi) >group D (Tongzigou, Dashitou, Wangqing, Helong, Yanshou, Dahailin, Xiaobeihu, Muling). The optimal base tree height growth model of the four groups was the Gompertz model, and the fitting accuracy of the model after the introduction of dummy variables (R² = 0.9353) was higher than that of the base model (R² = 0.9303), and the model prediction accuracy was also improved. The tree height growth curves of each provenance group conformed to the "S"-shaped rule of change. There were obvious differences among the groups, with the best performance of the provenances in group A. The growth of P. koraiensis from different provenances was different, and the tree height growth model with dummy variables of provenance groups could effectively improve the prediction accuracy of the model, reflect the differences in height growth of P. koraiensis of different provenances, which could provide the scientific basis for the selection and cultivation of P. koraiensis plantations. [ABSTRACT FROM AUTHOR]

Introduction: Abscisic acid (ABA) can negatively regulate seed germination, but the mechanisms of ABA-mediated metabolism modulation are not well understood. Moreover, it remains unclear whether metabolic pathways vary with the different tissue parts of the embryo, such as the radicle, hypocotyl and cotyledon. Methods: In this report, we performed the first comprehensive metabolome analysis of the radicle and hypocotyl + cotyledon in Pinus koraiensis seeds in response to ABA treatment during germination. Results and discussion: Metabolome profiling showed that following ABA treatment, 67 significantly differentially accumulated metabolites in the embryo were closely associated with pyrimidine metabolism, phenylalanine metabolism, cysteine and methionine metabolism, galactose metabolism, terpenoid backbone biosynthesis, and glutathione metabolism. Meanwhile, 62 metabolites in the hypocotyl + cotyledon were primarily involved in glycerophospholipid metabolism and glycolysis/gluconeogenesis. We can conclude that ABA may inhibit Korean pine seed germination primarily by disrupting the biosynthesis of certain plant hormones mediated by cysteine and methionine metabolism and terpenoid backbone biosynthesis, as well as reducing the reactive oxygen species scavenging ability regulated by glutathione metabolism and shikimate pathway in radicle. ABA may strongly disrupt the structure and function of cellular membranes due to alterations in glycerophospholipid metabolism, and weaken glycolysis/gluconeogenesis in the hypocotyl + cotyledon, both of which are major contributors to ABAmediated inhibition of seed germination. These results highlight that the spatial modulation of metabolic pathways in Pinus koraiensis seeds underlies the germination response to ABA. [ABSTRACT FROM AUTHOR]

Introduction: Pinus koraiensis is a dominant tree species in northeastern China. Estimating its biomass is required for forest carbon stock monitoring and accounting. Methods: This study investigates biomass estimation methods for P. koraiensis components. A Bayesian approach was used to synthesize the parameter distributions of 298 biomass models as prior information to estimate the trunk, branch, leaf, and root biomass of P. koraiensis. The results were compared with non-informative prior and the minimum least squares (MLS). Results: The results indicated that the Bayesian approach outperformed the other methods regarding model fit and prediction error. In addition, the responses of different components to tree height varied. The models of trunk and root biomass exhibited a smaller response to tree height, whereas those of branches and leaves showed a larger response to tree height. The model parameters yield precise estimations. Discussion: In sum, this study highlights the potential of the Bayesian methods in estimating P. koraiensis biomass and proposes further enhancements to improve estimation accuracy. [ABSTRACT FROM AUTHOR]

Flammable litter such as Pinus koraiensis needle accumulation increases the risk of wildfire. In the event of a high-intensity fire, forest resources can be severely damaged. To reduce the occurrence of forest fires, it is important to reduce loads and modify structures. This study conducted 270 indoor degradation experiments to determine physicochemical properties of Pinus koraiensis during the combustion degradation process. Combustion degradation treatment variables were constructed with different durations, Trichoderma fungi, and doses. The results show that the physicochemical properties of flammable litter changed significantly after degradation, with a maximum degradation rate of 11. The degradation rate was affected by time and microbial agents, but there was no significant difference between different doses. Principal component analysis was used to determine overall combustibility, and it was found that a dose of 4 mL of Trichoderma harzianum had the best effect on degradation for 42 days, reducing combustibility by 203%. It was found that the 6ml composite mould had the best inhibitory effect on fire spread rate, reaching the lowest value. After 42 days, the flame intensity of 4 mL Trichoderma harzianum reached its lowest value of 57.17 kw/m, which represents a decrease of 54% compared to the initial value. Similarly, the flame's length reached its lowest value of 4.91 cm, which represents a decrease of 31% compared to the same period last year. The aim of this study is to establish the relationship between time, microbial agents, dosage, flammable physical and chemical properties, overall flammability, and potential fire behaviour. The values of the goodness-of-fit index and the comparative fit index are both >0.98, and the values of the standardised root mean square residual and the approximate root mean square error are both <0.05. This study has a positive effect on accelerating the decomposition of combustibles, reducing the content of flammable components, reducing flammability and potential fire behaviour, and reducing the risk of forest fires. It is of great significance for strengthening natural resource management and forest ecological conservation. [ABSTRACT FROM AUTHOR]

Pinus koraiensis is one of the important tree species in Northeast China. Due to its high pine-needle-oil content and the density of human activities in its habitat, the forest-fire prevention situation is severe in the context of climate change. The rate of surface-fire spread is one of the key indicators for scientifically advancing early fire prevention and is crucial for guiding forest firefighting operations. In this study, we investigated how moisture content, load, and slope impact the surface-fire spread rate using indoor-simulated fire-spread experiments. Furthermore, we analyzed the limitations in the Rothermel model for predicting the surface-fire spread rate in P. koraiensis plantations and proposed modifications to the model by the modification method of priority to no-wind or slope conditions and slope conditions. Additionally, we evaluated the prediction accuracy of the original Rothermel model and two other modified models on the surface-fire spread rate. A high moisture content and low slope demonstrated an absolute inhibitory effect on the rate of surface-fire spread, whereas the promotional effect of a low moisture content and high slope was easily disturbed by the other factors. Under high-slope conditions, an overestimation situation was observed in the Rothermel model. Both of the modification methods involving priority to no-wind or slope conditions and slope conditions could improve this situation. Furthermore, the modification method demonstrated a better improvement effect on the prediction accuracy. Our findings provide valuable insights for refining the Rothermel model and offer guidance for improving the accuracy of predicting fire spread rates and behavior for Pinus koraiensis. This bears immense significance for advancing the understanding and calculation of the ROS of forest fires in the region. [ABSTRACT FROM AUTHOR]

The regulation of stand density has been studied in specific aspects of plantations with different age categories. A clearer understanding is still required of the extent to which stand density impacts multiple plantation attributes such as tree growth, understory vegetation diversity, and soil properties in Korean pine (Pinus koraeinsis Sieb. et Zucc) plantations. This study utilized a 43-year-old middle-aged Korean pine plantation in Qingping Forest Farm in northeast China to answer the research question posed. Three stand density levels, low stand density (LSD, 716 trees/ha), medium stand density (MSD, 850 trees/ha), and high stand density (HSD, 916 trees/ha) were studied for their effects on plantation attributes enumerated above. The results revealed a significant (p < 0.05) effect of stand density on mean stand volume (m3). Medium stand density had the highest mean stand volume of 26.16 (±0.27) m3 while the lowest stand volume was recorded for the low stand density at 14.90 (±1.72) m3. Also, significant differences in total nitrogen, total potassium, available nitrogen, available potassium, and percentage soil moisture content were observed among stand density levels. Additionally, stand density was found to have significant effects on species richness, Shannon–Wiener, and Simpson's diversity indexes for the shrub and herb layers of the plantation. This study shows that a medium stand density is the most optimal for promoting tree growth and understory biodiversity, as well as enhancing the status of certain soil nutrients. Thus, medium density achieves a balance between growth, nutrient availability, and biodiversity in middle-aged Korean pine plantations after a short period of thinning. These findings provide valuable knowledge for forest management, emphasizing the significance of continuous, long-term, and site-specific research. [ABSTRACT FROM AUTHOR]

As a new vector insect of pine wood nematodes in China, the Monochamus saltuarius (Coleoptera: Cerambycidae) vectors pine wilt nematodes into healthy pine trees through feeding and oviposition, resulting in huge economic losses to forestry. A promising control strategy is to develop safe and efficient attractants. This study aims to screen for the key active volatiles of Pinus koraiensis (Pinales: Pinaceae), Pinus tabuliformis (Pinales: Pinaceae), and Picea asperata (Pinales: Pinaceae) that can attract M. saltuarius, and to study the synergistic attraction of the main attractant plant volatiles with ethanol and insect aggregation pheromones. The preference of M. saltuarius for three hosts is P. koraiensis > P. tabuliformis > Picea asperata. We detected 18 organic volatiles from three host plants. Through EAG assays and indoor Y-tube behavioral experiments, 3-carene, (-)-camphor, β-pinene, α-phellandrene, terpinolene, α-pinene, D-limonene, and myrcene were screened to have attractive effects on M. saltuarius. We found that 3-carene, β-pinene, and α-pinene are the most attractive kairomones in field experiments, which may play a crucial role in the host localization of M. saltuarius. Ethanol has a synergistic effect on the attractant activity of 3-carene and β-pinene, and the synergistic effect on β-pinene is the best. The mixture of ethanol, 2-undecyloxy-1-ethanol, and ipsdienol can significantly enhance the attraction effect of β-pinene on M. saltuarius. These new findings provide a theoretical basis for the development of attractants for adult M. saltuarius and contribute to the green control of M. saltuarius. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Pinus koraiensis cone essential oil (PEO) contains functional compounds such as monoterpene hydrocarbons, and the administration of PEO reduced methane (CH4) emissions during growing phase of goats. However, the mode of action of PEO driven CH4 reduction is not known, especially how the administration of PEO can affect rumen microbiota and host metabolism in goats during the fattening phase. This study aimed to elucidate the potential microbial and host responses PEO supplementation in goats using metataxonomics (prokaryotes and protozoa) and metabolomics (rumen fluid and serum). Results: Ten fattening Korean native goats were divided into two dietary groups: control (CON; basal diet without additives) and PEO (basal diet + 1.5 g/d of PEO) with a 2 × 2 crossover design and the treatment lasted for 11 weeks. Administration of PEO reduced CH4 concentrations in the exhaled gas from eructation by 12.0–13.6% (P < 0.05). Although the microbial composition of prokaryotes (bacteria and archaea) and protozoa in the rumen was not altered after PEO administration. MaAsLin2 analysis revealed that the abundance of Selenomonas, Christensenellaceae R-7 group, and Anaerovibrio were enriched in the rumen of PEO supplemented goats (Q < 0.1). Co-occurrence network analysis revealed that Lachnospiraceae AC2044 group and Anaerovibrio were the keystone taxa in the CON and PEO groups, respectively. Methane metabolism (P < 0.05) was enriched in the CON group, whereas metabolism of sulfur (P < 0.001) and propionate (P < 0.1) were enriched in the PEO group based on microbial predicted functions. After PEO administration, the abundance of 11 rumen and 4 serum metabolites increased, whereas that of 25 rumen and 14 serum metabolites decreased (P < 0.1). Random forest analysis identified eight ruminal metabolites that were altered after PEO administration, among which four were associated with propionate production, with predictive accuracy ranging from 0.75 to 0.88. Additionally, we found that serum sarcosine (serum metabolite) was positively correlated with CH4 emission parameters and abundance of Methanobrevibacter in the rumen (|r|≥ 0.5, P < 0.05). Conclusions: This study revealed that PEO administration reduced CH4 emission from of fattening goats with altered microbial interactions and metabolites in the rumen and host. Importantly, PEO administration affected utilizes various mechanisms such as formate, sulfur, methylated amines metabolism, and propionate production, collectively leading to CH4 reduction. The knowledge is important for future management strategies to maintain animal production and health while mitigate CH4 emission. [ABSTRACT FROM AUTHOR]

Korean pine is one of the most important tree species in northeastern China, where Korean pine plantations produce timber and edible seeds. Often, seeds create more income than timber. Predicting the timber and cone yields of alternative management schedules of the plantations involves uncertainty because the future climatic conditions for tree growth and cone production are unknown. This study developed a simulation model that generates stochastic variation around the predictions of tree growth and cone yield models, allowing the forest manager to seek cutting schedules that maximize the expected amounts of timber or cones, or the expected economic profit, under uncertain future states of nature. Stochastic analysis also facilitates management optimizations for different risk attitudes. The differential evolution algorithm and the developed stochastic simulation model were used to optimize the management of planted Korean pine. Timber and cone yields of a management schedule were calculated under 100 different scenarios for tree growth and cone production. When the growth and cone yield scenarios were stationary (no temporal trends), the optimal management schedules were similar to those of deterministic optimization. The benefits of stochastic optimization increased when it was assumed that the tree growth scenarios may contain climate-change-induced trends. Non-stationary growth variation led to shorter optimal rotation lengths than stationary growth variation. Increasing risk tolerance shortened optimal rotations. [ABSTRACT FROM AUTHOR]

Introduction: As an important coniferous tree in northeast China, Pinus koraiensis not only maintains the stability of the forest ecosystem at high latitudes but also plays a crucial role in regional socioeconomic development. With the intensification of climate change in recent years, the stability of P. koraiensis habitats is constantly disturbed by external uncertain environmental factors, which greatly affects the geographical distribution of P. koraiensis. However, its geographical distribution is still unclear, which greatly hinders further understanding of the ecological process of P. koraiensis. Consequently, it is particularly important to explore the potential distribution and migration of P. koraiensis during several critical periods. Methods: Random forest (RF) was used to establish the redistribution of P. koraiensis. Results: The results showed that temperature seasonality and precipitation in the coldest quarter were the key factors limiting the current distribution of P. koraiensis. Currently, P. koraiensis is mainly distributed in the Lesser Khingan Mountains and Changbai Mountains, with a total suitable area of ~4.59 x 105 km². In the past, the historical distribution of P. koraiensis during the LIG period was basically consistent with the current distribution range, but its distribution range was more complete. In the LGM period, the suitable distribution of P. koraiensis became fragmented, especially at the connection between the Lesser Khingan Mountains and the Changbai Mountains. Under future climate scenarios, the suitable distribution of P. koraiensis is projected to increase, while the highly suitable distribution will be reduced. The dramatically worrying change is that the suitable habitats of P. koraiensis are gradually breaking and separating in the junction zone between the Lesser Khingan Mountains and Changbai Mountains, which will cause the ecological corridor to break. The shifts in the distribution centroid indicated that the P. koraiensis population will migrate northward. Discussion: However, it remains to be verified whether long-distance migration can be achieved without human assistance. Our results can provide some solutions for protection and management strategies for P. koraiensis populations and the impact of climate change, shedding light on the effectiveness of management responses. [ABSTRACT FROM AUTHOR]

Summary: The genus Ektaphelenchoides is a diverse group of nematodes; they are either inhabitants of trees or present in the rhizosphere of economical plants. Members of the genus have ecological relevance in terms of being associated with insects and predators of other nematodes. In the present study, a new Ektaphelenchoides species, E. factum n. sp., is described and illustrated. The new species was isolated from a log sample of Pinus taeda imported from the USA. It is characterised by the lateral field with three incisures, stylet distinctly tripartite. Females having a vulval flap, the anus and rectum indistinct, and the tail (posterior part of body) filiform. Males having arcuate and 21.5 (19.4-22.9) μ m long spicules, the lamina of the spicule is smoothly curved to distal end, condylus well developed with a broadly rounded tip, rostrum triangular with finely rounded tip and cucullus absent, tail arcuate and conical with terminus bearing a sharply pointed mucron. The new species is different from other Ektaphelenchoides species in having a vulval flap. Molecular characterisation and phylogenetic studies also supported its unique status. In addition, a Chinese native population of E. pini , detected in Pinus koraiensis branches from Liaoning province, P.R. China, is described. [ABSTRACT FROM AUTHOR]

Forest ecosystems are essential to the global carbon cycle because they are the biggest terrestrial carbon reserves. In the management of forests, thinning is a commonly employed strategy, impacting the respiration and biomass loss of trees, thereby modifying forest carbon dynamics. However, there is a lack of scientific research to confirm the impacts of thinning intensities on carbon storage in trees, soil layers, shrubs, and ground vegetation layers as well as its impact on wood production and growth rate. The goal of this study was to find the optimal thinning levels for increasing carbon sequestration during the growth stage of the Korean pine (Pinus koraiensis) middle-aged plantations in Northeast China. In this study, thinning intensity (0, 10, 11, 16, 18, and 22%) affected the carbon storage of trees, tree growth, volume, and, we suspected, soil layer, shrubs, and vegetation (herbs, litter, and grass) also. Specifically, after four years of thinning, the 18% treatment significantly increased total carbon storage, individual organ storage, growth, and tree volume (p < 0.05). These results give us abundant information about how thinning affects the dynamics of carbon storage, wood production, and the interactions between soil and plants in P. koraiensis plantations, contributing to multi-objective management strategies for optimizing carbon sequestration, wood production, and ecosystem health. [ABSTRACT FROM AUTHOR]

Abstract Background Early selection in tree breeding could be achieved by addressing the longevity of tree improvement activities. Genetic parameter changes and age–age correlations are essential for determining the optimal timing of early selection. Practical tracking of genetic parameters of Pinus koraiensis, a major timber species with economic and ecological value, has become feasible as its progeny testing has entered the mid-term age in Korea. However, research on the age−age correlation of P. koraiensis as progeny trials approach rotation age is limited. This study aimed to investigate genetic parameter trends and age−age correlations in P. koraiensis progeny. P. koraiensis progeny were assessed at two sites using a linear mixed-effects model with two-dimensional spatial autoregressive structure. Height, diameter, and volume growth were measured in 11 assessments over 40 years. Results Genetic parameters, such as height and diameter, showed different patterns of change. The heritability ranged for the three growth traits in 0.083–0.710, 0.288–0.781, and 0.299–0.755 across the sites and age. Height heritability and its coefficient of variance decreased, whereas the diameter and volume estimates remained relatively constant. Correlations with Age 40 for phenotypic, genetic, and rank of breeding values ranged between 0.16 and 0.92, 0.594 and 0.988, and 0.412 and 0.965, respectively. These correlations generally increased as the age approached Age 40, with particularly high levels observed at Age 26 and Age 30. Conclusion The observed genetic trends in P. koraiensis progeny testing offer valuable insights for early and precise selection. Notably, selecting superior genotypes at Ages 26–30 is supported by discernible genetic gains and robust correlations. Future research should integrate unbalanced data for selecting mother trees or families and conduct a comprehensive economic analysis of early selection to validate its practical benefits.

Data on the status of two natural populations of the rare, endemic medicinal species Alangium platanifolium known from the Russian Federation is provided in this article. Information about one of them is reported for the first time. Geobotanical descriptions of the phytocenoses are presented. In southern Primorskii krai, A. platanifolium has been noted to grow in the shrub layer of coniferous/broad-leaved forest with Pinus koraiensis and Abies holophylla. It has also been found that the area of the population discovered 20 years ago has expanded tenfold and now amounts to 10 ha. The new locality of A. platanifolium covers an area of 0.25 ha. The total number of A. platanifolium is more than 700 of various-age plants. The data obtained extends the current knowledge of the distribution and life state of A. platanifolium and indicates the fact of the growth of subtropical elements in phytocenoses of the Russian Federation. [ABSTRACT FROM AUTHOR]

The regeneration of Korean pine (Pinus koraiensis Sieb. et Zucc.) is a core issue for restoration from secondary to primary forests in northeastern China. However, Korean pine exhibits limited recruitment within its own canopy in primary forests, but demonstrates excellent regeneration in secondary forests. Until now, the mechanisms underlying this phenomenon have not been satisfactorily explained. Hence, we conducted studies in both primary and secondary forests to investigate whether light availability during the non-growing season determines the fate of regeneration. In spring and autumn, understory light availability in the secondary forest was significantly better than that in the primary forest. The biomass and non-structural carbohydrate (NSC) concentrations of natural pine seedlings were considerably greater in the secondary forests compared to primary forests. The carbohydrate concentrations increased during spring and autumn and decreased in summer. In the manipulation experiment, the biomass of seedlings was positively correlated with the organ NSCs in spring, while the survival rates were correlated with NSCs in autumn. The light availability during the spring and autumn seasons may have a crucial role in the regeneration of Korean pine seedlings. This finding may support our practical management approach for the transformation of secondary forests into Korean pine forests. [ABSTRACT FROM AUTHOR]

The difference in the leaf unfolding date of Mongolian oak obtained through MODIS image analysis between the urban center and the outskirts of Seoul was found to be seven days. The difference in the flowering date of cherry obtained through field observations was also found to be seven days between the urban center and the outskirts. The frequency of the abnormal shoot of Korean red pine differed by 71% between the urban center and the outskirts, and the length growth differed by 8.6 cm. There was a statistically significant correlation between the leaf unfolding date of Mongolian oak, the flowering date of the cherry, and the spatial difference in the frequency and length of the abnormal shoot of the Korean red pine. The temperature difference between the urban center and the outskirts of Seoul based on the mean temperature over the past 30 years was about 5 °C. The spatial difference in plant phenology showed a statistically significant negative relationship with the spatial difference in temperature. On the other hand, the spatial difference in temperature showed a statistically significant positive relationship with the spatial difference in the urbanization rate. These results are interpreted as the result of excessive land use during urbanization causing the heat island phenomenon, and the resulting temperature difference is reflected in the phenology of plants. These results are evidence that urbanization, which uses excessive land and energy, has a very significant impact on climate change. In addition, it is also evidence that sustainable land use could be an important means to achieve climate change adaptation and further solve climate change problems. [ABSTRACT FROM AUTHOR]

Two kinds of grafted Pinus koraiensis were cultivated in the northeasteran area of China as a viable effort to foster Korean pine nut production. The physical characteristic, color (L*, a*, b* value) and texture (instrumental hardness), along with the chemical and sensory properties were significantly influenced by species graft and roasting conditions. Both raw grafted pine nuts showed significant differences in all proximate analyses, except for ash content. Fatty acid profiles were similar, while linoleic acid was accounted to be the largest proportion. During roasting, malondialdehyde content reached the highest at 180 °C for 30 min (sixfold). Bioactive compounds (total phenolic, total flavonoid, and proanthocyanidin) and antioxidant properties were gradually increased during roasting, while some major individual phenolic acid and flavonoid was quantified by HPLC. Multivariate analysis and sensory evaluation showed that a favourable healthy nut composition and desired sensory quality for both pine nuts could be achieved at 150 °C for 20 min. [ABSTRACT FROM AUTHOR]

To investigate the disparities in product quality and storage stability between wax-based Korean pine seed oil gel and butter when used for frying steak, a comparative analysis was conducted on cooking loss, color, texture characteristics, sensory evaluation, and volatile flavor substances using headspace solid phase microextraction combined with GM-MS. Furthermore, the storage stability was assessed. The findings revealed that the cooking loss rate of steaks significantly increased with doneness, with butter steak exhibiting a significantly higher loss rate compared to the three oil gel steaks. Hardness, chewiness, and adhesiveness greatly increased as doneness progressed; however, cohesiveness, elasticity, and resilience showed minimal variation. The L* value and b* value of steaks initially increased before stabilizing with increasing doneness levels while the a* value first rose before gradually declining. Medium rare steak received the highest sensory score among all categories tested and 69 volatile flavor compounds were detected. Multivariate data analysis indicated similarities in volatile compounds between butter steak and BW (wax-based Korean pine seed oil gel) steak groups. Additionally, during storage at 4 °C temperature conditions pH level retention water content TVB-N (total volatile basic nitrogen), TBARS (thiobarbituric acid reactive substances) were evaluated to determine advantages or disadvantages within each group: Beeswax (BW) > Carnauba wax (CW) > Rice bran wax (RBW) > butter based on these parameters' values. It can be concluded that utilizing wax-based Korean pine seed oil gel for frying steaks not only effectively retains significant amounts of unsaturated fatty acids but also preserves steak quality while extending shelf life—a healthier cooking method resulting in reduced oil absorption. [ABSTRACT FROM AUTHOR]

Background: The prediction accuracy for the rate of surface fire spread varies in different regions; thus, increasing the prediction accuracy for local fuel types to reduce the destructive consequences of fire is critically needed. Aims: The objective of this study is to improve the Rothermel model's accuracy in predicting the ROS for surface fuel burning in planted forests of Pinus koraiensis in the eastern mountains of north-east China. Methods: Fuel beds with various fuel loads and moisture content was constructed on a laboratory burning bed, 276 combustion experiments were performed under multiple slope conditions, and the ROS data from the combustion experiments were used to modify the related parameters in the Rothermel model. Results: The surface fire spread rate in Pinus koraiensis plantations was directly predicted using the Rothermel model but had significant errors. The Rothermel model after modification predicted the following: MRE = 25.09%, MAE = 0.46 m min−1, and R 2 = 0.80. Conclusion: The prediction accuracy of the Rothermel model was greatly enhanced through parameter tuning based on in-lab combustion experiments Implications: This study provides a method for the local application of the Rothermel model in China and helps with forest fire fighting and management in China. The ROS of surface fire in Pinus koraiensis plantation was measured in the laboratory for different fuel loads, fuel moisture contents, and slope conditions. Fuel particle and environmental parameters in the Rothermel model were modified. The modified I R and ϕ S parameters significantly improved the Rothemel model prediction accuracy. [ABSTRACT FROM AUTHOR]

In this study, we utilized the remarkable capabilities of Bacillus subtilis ls-45 during the fermentation process to generate pine nut peptide. Through gene sequencing, we confirmed the proficiency of Bacillus subtilis ls-45 in producing protease, thereby serving as a valuable enzymatic source for protein hydrolysis. Our investigation focused on examining the variations in amino acid types and quantities between enzymatic pine nut protein peptide (EPP) and fermented pine nut protein polypeptide (FPP). Furthermore, we conducted a comprehensive assessment of the in vitro antioxidant activities of EPP and FPP, encompassing measurements of their Hydroxyl radical scavenging rate, Total reducing capacity, Superoxide anion scavenging rate, and ABTS+ radical scavenging rate. Notably, FPP exhibited superior antioxidant capacity compared to EPP. By employing semi-inhibitory mass concentration (IC50) analysis, we determined that FPP displayed enhanced efficacy in neutralizing hazardous free radicals when compared to EPP. [ABSTRACT FROM AUTHOR]

Gremmenia abietis (Dearn.) Crous (syn: Phacidium abietis) was originally described in North America to accommodate the species associated with snow blight of Abies and Pseudotsuga spp. In Japan, this species was first observed on the dead needles on Abies sachalinensis and Picea jezoensis var. jezoensis in 1969. However, the identity of Japanese species was unclear due to the lack of molecular data and the absence of anamorph description. In this study, we collected fresh specimens from various conifer species (A. sachalinensis, A. veitchii, Pic. jezoensis var. jezoensis, Pic. jezoensis var. hondoensis, Pinus koraiensis, and Pin. pumila) in Japan and revised the taxonomy based on morphological and phylogenetic analyses. Phylogenetic analyses based on nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and RNA polymerase II second largest subunit (RPB2) regions indicated that the species belongs to Phacidiaceae. Conidiomata formed in vitro produced pyriform, hyaline conidia without mucoid appendage, which distinguished the species from phylogenetically related genera. Consequently, we established Chionobium takahashii to accommodate the snow blight fungus in Japan. Further phylogenetic analyses also indicated that C. takahashii includes several distinct clades corresponding to the host genera (Abies, Picea, Pinus). Morphological differences among those clades were unclear, suggesting that C. takahashii may contain host-specific cryptic species. [ABSTRACT FROM AUTHOR]

To study the ultrasonic -assisted extraction (UAE) process of oil and proanthocyanidins from Pinus koraiensis seed scales, a single-factor analysis experiment was conducted with oil and proanthocyanidins yield as response values. The Box-Behnken response surface optimization method was applied to determine the optimal process conditions, which were as follows: 67% ethanol aqueous solution, liquid material ratio of 10 ∶ 1 mL/ g, tea saponin mass concentration of 0. 3%, power of 100 W, time of 20 min, water bath temperature of 50 ℃, expected yield of 21. 24% and 3. 03 mg / g respectively, actual yield of 20. 86% and 2. 98 mg / g, relative error of 1. 79% and 2. 97%. Comparison analysis revealed that UAE reached equilibrium in a relatively short time. UAE treatment increased the specific surface area of the seed powder in the solution. The order of DPPH and ABTS + free radical scavenging activities for oil and proanthocyanidins was proanthocyanidins, Ve and oil, indicating that Pinus koraiensis seed scales oil and proanthocyanidins possess good antioxidant capabilities. The use of tea saponin as an inducer for UAE extraction of oil and proanthocyanidins from Pinus koraiensis seed scales demonstrated advantages. These research findings provide a theoretical basis for the in-depth development of Pinus koraiensis seed scales. [ABSTRACT FROM AUTHOR]

In this paper, data obtained by scanning 10 artificial Korean pine forests based on Terrestrial Laser Scanning (TLS), were combined with field survey data to construct tree height curve model, height to crown base prediction model and crown contact height prediction model, and a simultaneous equation system was established. First, from the five kinds of tree height curve models selected, two models with better fitting effects were selected as the candidate models of the simultaneous equations. Then one model with good fitting effect and high applicability from the five height to crown base models was selected as base model, and the stand factors (mean DBH of stand, stand basal area, ratio of height to diameter, mean DBH of dominant trees and mean height of dominant trees) were introduced into the basic model by means of re-parameterization and optimal subset regression, the model with better fitting effect was selected as the alternative model of height to crown base model. The same method was used to select alternative crown contact height model with good fitting effect. Finally, the tree height curve model, alternative height to crown base model and alternative crown contact height model were combined in pairs to establish simultaneous equations. Through seemingly unrelated regression estimation, the best equations were selected by the goodness of fit and the test results, and the simultaneous equations were evaluated. When the optimal simultaneous equation was used to estimate the tree height, the decision coefficient R² = 0. 896, and the root mean square error RMSE= 0. 612 m; when the equations was used to estimate the height to crown, R² = 0. 575, RMSE = 0. 850 m; when the equations was used to estimate the crown contact height, R² = 0. 719, RMSE= 0. 791 m, and all kinds of inspection indexes were good. On the whole, the equation system had better fitting accuracy and test effect for tree height, height to crown and crown contact height, and can solve the internal correlation problem of tree height, height to crown and crown contact height, which provided the basis for further study of crown structure and dynamic changes of Korean pine. [ABSTRACT FROM AUTHOR]

Plant resources are used as raw materials in various industries related to humans, such as edible, medicinal, taste, and flavor industries, depending on processes such as drying, processing, and collection period. In this study, we investigated the terpene compound composition and antioxidant activity of essential oils extracted from the needles of Pinus densiflora, Pinus koraiensis, Abies holophylla, and Juniperus chinensis collected in the harvest period (February, April, July, and October) planted on the campus of Chungbuk National University. The essential oil was separated by hydrodistillation. According to the analysis results of gas chromatography–mass spectrometry, the terpene compounds changed depending on the season and tree species. The proportions of monoterpene and sesquiterpene classes in the needles of P. densiflora, P. koraiensis, A. holophylla, and J. chinensis changed depending on the harvest period. The antioxidant activity by DPPH and ABTS assays varied depending on the species and seasons, and needles harvested from P. koraiensis showed the highest activity in all harvest periods. High antioxidant activity has been confirmed even at low concentrations in pine trees, so it is expected to play a role as a natural antioxidant. Additionally, since the composition of terpene compounds varies depending on the harvesting time and species, it is expected to have various uses in the pharmaceutical, cosmetics, and food industries. [ABSTRACT FROM AUTHOR]

To improve the ecological and economic benefits of Korean pine (Pinus koraiensis), we analysed and evaluated its germplasm resources. This promotes in-depth research and utilisation of germplasm resources, providing excellent genetic resources for Korean pine breeding. We performed genetic analysis based on morphological and physiological traits and nuclear SSR molecular marker data was performed by collecting 314 clones (5 ramets of each clone) of Korean pine from eight (8) locations within the Korean pine range. The core collection underwent testing and evaluation for representativeness using variable rate (VR), coincidence rate (CR), variance difference percentage (VD), mean difference percentage (MD), Shannon index (I), and other indicators. The results indicated significant differences in morphological and physiological traits among the populations. All traits had a coefficient of variation (CV) greater than 10%, except for the water content of the needles (WC), which had an average CV of 17.636%. The populations showed high overall genetic diversity, with the HL (Helong) population exhibiting the highest genetic diversity, with an Ne (number of effective alleles), I, and He (expected heterozygosity) of 3.171, 1.103, and 0.528, respectively. Genetic variation mainly originated from individuals within populations, while the variation between populations was relatively small, at only 3%. The population did not exhibit any distinct subpopulation structures and was mainly derived from two admixed gene pools. Six core sets were obtained using different sampling strategies, and subset 6 was identified as the core collection, consisting of 114 individuals, representing a selection rate of 36.31%. In conclusion, the most appropriate method for constructing the core collection of Korean pines is the M-strategy (maximizing the number of alleles), based on both phenotypic and molecular data. The resulting core collection effectively represents the genetic diversity of the entire population effectively. [ABSTRACT FROM AUTHOR]

In trees, injuries resulting from subfreezing temperatures can cause damage to the cellular biofilm system, metabolic functions, and fibrous reticulum, and even cell death. Investigating the occurrence of freezing damage and its contributing factors could help understand the mechanisms underlying freezing injury and prevent the subsequent damage in trees. To achieve this, a laboratory experiment was conducted using cut wood samples from Korean pine (Pinus koraiensis Siebold & Zucc) and Simon poplar (Populus simonii Carr.), and the effects of environmental freezing factors, including freezing temperatures, freezing duration, and cooling rate, on the temperature at which freezing injuries occur were examined using the electrical impedance spectroscopy (EIS) method. The semi-lethal temperature (LT50), as an indicator of freezing injury in wood tissue, was theoretically deduced based on the measured extracellular resistance (re) using EIS. The contributory factors to changes in LT50 were determined and their relationship was established. The results revealed that all freezing factors exhibited significant effects on electrical impedance characteristics (re, ri, and t), significantly influencing the LT50 of the wood. Random forest (RF) and support vector machine (SVM) models were used to assess the contribution of the freezing factors and moisture content (MC). Among the factors examined, freezing duration had the greatest impact on LT50, followed by the MC, whereas the contribution of the cooling rate was minimal. The model accuracies were 0.89 and 0.86 for Korean pine and Simon poplar, respectively. The findings of our study illustrate that the occurrence of freezing injury in trees is primarily influenced by the duration of freezing at specific subzero temperatures. Slow cooling combined with prolonged freezing at low subzero temperatures leads to earlier and more severe freezing damage. [ABSTRACT FROM AUTHOR]

Background: Early selection in tree breeding could be achieved by addressing the longevity of tree improvement activities. Genetic parameter changes and age–age correlations are essential for determining the optimal timing of early selection. Practical tracking of genetic parameters of Pinus koraiensis, a major timber species with economic and ecological value, has become feasible as its progeny testing has entered the mid-term age in Korea. However, research on the age−age correlation of P. koraiensis as progeny trials approach rotation age is limited. This study aimed to investigate genetic parameter trends and age−age correlations in P. koraiensis progeny. P. koraiensis progeny were assessed at two sites using a linear mixed-effects model with two-dimensional spatial autoregressive structure. Height, diameter, and volume growth were measured in 11 assessments over 40 years. Results: Genetic parameters, such as height and diameter, showed different patterns of change. The heritability ranged for the three growth traits in 0.083–0.710, 0.288–0.781, and 0.299–0.755 across the sites and age. Height heritability and its coefficient of variance decreased, whereas the diameter and volume estimates remained relatively constant. Correlations with Age 40 for phenotypic, genetic, and rank of breeding values ranged between 0.16 and 0.92, 0.594 and 0.988, and 0.412 and 0.965, respectively. These correlations generally increased as the age approached Age 40, with particularly high levels observed at Age 26 and Age 30. Conclusion: The observed genetic trends in P. koraiensis progeny testing offer valuable insights for early and precise selection. Notably, selecting superior genotypes at Ages 26–30 is supported by discernible genetic gains and robust correlations. Future research should integrate unbalanced data for selecting mother trees or families and conduct a comprehensive economic analysis of early selection to validate its practical benefits. [ABSTRACT FROM AUTHOR]

In this paper, we consider the long-term sustainability of the northeast Korean pine. We propose a class of natural Korean pine population system with time delay and diffusion term. First, by analyzing the roots distribution of the characteristic equation, we study the stability of the model system with diffusion terms and prove the occurrence of Hopf bifurcation. Second, we introduce lactation time delay into a population model with a diffusion term, based on stability theory of ordinary differential equation, norm form methods and center manifold theorem, the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are given. Finally, some numerical simulations are given. [ABSTRACT FROM AUTHOR]

Pinus koraiensis, an economically and ecologically vital five-needle pine species, was surveyed for female and male strobilus production variation among 52 clones over five years in a seed orchard in Gangwon province of South Korea. We estimated heritability, effective population size and gene diversity, calculated maleness index, and drew parental balance curves for the strobilus production annually. Results demonstrated marked variation in female and male strobilus production among clones and years, particularly in male strobilus production. The maleness indices indicated a considerable deviation from sexual balance. Parental balance curves revealed that the top 20% of the most fertile clones contributed significantly to the total strobilus production. High heritability values underscored the substantial genetic influence on strobilus production. The gene diversity of orchard parents (GDp) was set as one (GDp = 1) considering panmictic situations, and then loss of gene diversity in the female gametes (GDf) was relatively estimated to be ranged from 0.096 (loss = 1 − GDf = 1 − 0.904, 9.6% in 2017) to 0.017 (= 1 − 0.983, 1.7% in 2020). We emphasize the importance of the effective number of parents as a crucial parameter for informing seed orchard management decisions. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis of Korean pine (Pinus koraiensis Sieb. Et Zucc.), an ecologically and econimically very important conifer species, was hindered by the graduallyweakens and fast runaway of the embryogenicity and embryo competence of the embryogenic callus. Brassinolide (BL) has shown the enhancing capability of somatic embryo regeneration. For checking the function of BL in this issue, we applied different concentrations of BL to Korean pine callus materials exhibiting different embryogenic capacities and subsequently monitored the physiological alterations and hormone dynamics of the embryogenic callus. Our study revealed that calli with different embryogenic strengths responded differently to different concentrations of BL, but the effect after the addition of BL was very uniform. The addition of BL during the proliferation phase of embryogenic callus may help to stimulate the biological activity of callus during the proliferation process and improve the level of cell metabolism, which is accompanied by a reduction in storage substances. BL could reduce the level of endogenous auxin IAA in embryogenic callus and increase the level of abscisic acid to regulate cell division and differentiation. In addition, the MDA content in the callus was significantly decreased and the activity of antioxidant enzymes was significantly increased after the addition of BL. During the proliferation of embryogenic callus, BL was added to participate in the metabolism of phenylpropane in the cells and to increase the activity of phenylalanine ammonia-lyase and the content of lignin in the cells. We deduced that the proper doses of BL for Korean pine embryogenic callus culture were as follow: calli with low, high and decreasing embryogenicitywere subcultured after the addition of 0.75 mg/L, 0.35 mg/L, 2.00 mg/L BL, respectively, during proliferation culture stage. [ABSTRACT FROM AUTHOR]

Traditionally, selective breeding has been used to improve tree growth. However, traditional selection methods are time-consuming and limit annual genetic gain. Genomic selection (GS) offers an alternative to progeny testing by estimating the genotype-based breeding values of individuals based on genomic information using molecular markers. In the present study, we introduced GS to an open-pollinated breeding population of Korean red pine (Pinus densiflora), which is in high demand in South Korea, to shorten the breeding cycle. We compared the prediction accuracies of GS for growth characteristics (diameter at breast height [DBH], height, straightness, and volume) in Korean red pines under various conditions (marker set, model, and training set) and evaluated the selection efficiency of GS compared to traditional selection methods. Training the GS model to include individuals from various environments using genomic best linear unbiased prediction (GBLUP) and markers with a minor allele frequency larger than 0.05 was effective. The optimized model had an accuracy of 0.164-0.498 and a predictive ability of 0.018-0.441. The predictive ability of GBLUP against that of additive best linear unbiased prediction (ABLUP) was 0.86-5.10, and against the square root of heritability was 0.19-0.76, indicating that GS for Korean red pine was as efficient as in previous studies on forest trees. Moreover, the response to GS was higher than that to traditional selection regarding the annual genetic gain. Therefore, we conclude that the trained GS model is more effective than the traditional breeding methods for Korean red pines. We anticipate that the next generation of trees selected by GS will lay the foundation for the accelerated breeding of Korean red pine. [ABSTRACT FROM AUTHOR]

A growing societal interest exists in the application of lidar technology to monitor forest resource information and forestry management activities. This study examined the possibility of estimating the diameter at breast height (DBH) of two tree species, Pinus koraiensis (PK) and Larix kaempferi (LK), by varying the number of terrestrial laser scanning (TLS) scans (1, 3, 5, 7, and 9) and DBH estimation methods (circle fitting [CF], ellipse fitting [EF], circle fitting with RANSAC [RCF], and ellipse fitting with RANSAC [REF]). This study evaluates the combination that yields the highest estimation accuracy. The results showed that for PK, the lowest RMSE of 0.97 was achieved when REF was applied to the data from nine scans after noise removal. For LK, the lowest RMSE of 1.03 was observed when applying CF to the data from seven scans after noise removal. Furthermore, ANOVA revealed no significant difference in the estimated DBH from nine scans when more than three scans were used for CF and RCF and more than five for EF and REF. These results are expected to be useful in establishing efficient and accurate DBH estimation plans using TLS for forest resource monitoring. [ABSTRACT FROM AUTHOR]

Age controls a tree's responses to environmental cues and shading influences tree growth and physiology. These are basic principles of "Afforestation under canopy", an approach that is widely used in the regeneration of Korean pine forests. Studying the underlying mechanism helps us to understand tree adaptation and utilize it in forest management. In this study, we investigated the transcriptomic changes in the uppermost main stems of the Korean pine tree (Pinus koraiensis, Sieb. et Zucc.) at different ages (5, 7, 10, 14, and 17 years) and in different growth conditions (open-grown and shade-grown trees) using RNA-Seq. In total, 434,005,837 reads were produced and assembled into 111,786 unigenes. After pairwise comparisons, 568 differentially expressed unigenes (DEUs) were identified. The greatest number of DEUs was identified in the comparison between 5-year-old open-grown trees and 17-year-old shade-grown trees, while no DEUs were identified in 15 pairwise comparisons. Among these 568 DEUs, 45 were assigned to gene ontology (GO) terms associated with response to environmental changes, including "response to stress" (26) and "response to light and temperature" (19); 12 were assigned to GO terms associated with sexual reproduction, such as "sexual reproduction", "specification of floral organ identity", "pollen tube guidance", and "fruit ripening"; 15 were heat shock protein genes and showed decreased expression patterns with age; and one, annotated as Pinus tabuliformis DEFICIENS-AGAMOUS-LIKE 1, showed an increased expression pattern with age, independent of the reproductive state or growth conditions of Korean pine trees. Altogether, these findings not only demonstrate the molecular aspects of the developmental and physiological effects of age and shading on Korean pine trees, but also improve our understanding of the basic principles of "Afforestation under canopy". [ABSTRACT FROM AUTHOR]

Certain fluctuations were found when using the opening degree index to evaluate the effects of the adjacent broadleaved trees on the under-canopy target Korean pine (Pinus koraiensis Sieb. et Zucc.) trees in a mixed forest of planted Korean trees and natural broadleaved trees. The fluctuations were probably caused by the different positions and sizes of the adjacent broadleaved trees over the target Korean pine trees. For the purpose of clarifying this issue, the effect of the position and size (marked by height and diameter) of the neighborhood broadleaved trees on the height and diameter growth of Korean pine trees under the canopy in a secondary forest at different opening degree levels was studied. Generally, the mean DBH (diameter at breast height) and mean height of P. koraiensis trees under the canopy were higher when the adjacent broadleaved trees were located on the north or east sides of the target P. koraiensis trees than when they were located on the south or west sides. This was the case at all opening degree levels except the 0.5 opening degree level, where no significant difference was observed among the growth indexes of Korean pine trees based on the different positions of neighborhood trees. The mean DBH and height of P. koraiensis trees under the canopy decreased with the increase in the DBH and height of the adjacent broadleaved trees at all orientations and at all opening degree levels, but only those of the Korean pine trees with adjacent broadleaved trees on the south side in the 12.6–13.5 m height range and those with adjacent broadleaved trees on most sides in the 18.6–21.0 cm and 13.6–14.5 m height ranges at opening degree levels of K = 2.0, 1.5, and 1.0 reached a significant level of difference; whereas those of most Korean pine trees with adjacent broadleaved trees on the south and west sides in the height range of 11.6–12.5 m and DBH ranges of 13.6–16 cm and 16.1–18.5 cm, as well as the ones with adjacent broadleaved trees on most sides in the DBH range of 18.6–21.0 cm and the height range of 13.6–14.5 m at the opening degree level of K = 0.5, reached a significant level of difference, with a few exceptions. In conclusion, the broadleaved trees with a large diameter, great height, and a south or west orientation of the target P. koraiensis trees had a negative impact on their growth, but influence intensities changed at different opening degree levels. [ABSTRACT FROM AUTHOR]

Carbon (C), nitrogen (N), and phosphorus (P) are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales. However, our knowledge of how these nutrients vary with tree size, organ age, or root order at the individual level remains limited. We determined C, N, and P contents and their stoichiometric ratios (i.e., nutrient traits) in needles, branches, and fine roots at different organ ages (0–3-year-old needles and branches) and root orders (1st–4th order roots) from 64 Pinus koraiensis of varying size (Diameter at breast height ranged from 0.3 to 100 cm) in northeast China. Soil factors were also measured. The results show that nutrient traits were regulated by tree size, organ age, or root order rather than soil factors. At a whole-plant level, nutrient traits decreased in needles and fine roots but increased in branches with tree size. At the organ level, age or root order had a negative effect on C, N, and P and a positive effect on stoichiometric ratios. Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level. It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival. Conversely, nutrient storage strategy in older trees and organ fractions are mainly for steady growth. Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations. [ABSTRACT FROM AUTHOR]