Search Results (87)

The influence of forest type on soil aggregates distribution, stability, and the contribution of aggregate-associated carbon (C) to bulk soil organic carbon (SOC) remains poorly understood. This may be crucial for the accumulation and persistence of SOC in subtropical ecosystems. In this study, we examined soil aggregate distribution and stability at two depths (0–15 and 15–30 cm) in 10-, 20-, and 30-year-old Cryptomeria japonica (Japanese cedar) and Chimonobambusa quadrangularis (square bamboo) plantations. We further assessed the contribution of carbon (C) associated with distinct aggregate fractions to bulk SOC. Across all stand ages and soil depths, macroaggregates accounted for 19%–56% of total soil aggregates in Japanese cedar plantations, whereas their proportion was 30%–337% higher in square bamboo plantations. In contrast, fine aggregates constituted 3%–67% of total aggregates in Japanese cedar plantations, but were 29%–94% lower in square bamboo plantations than in Japanese cedar plantations. Compared with Japanese cedar plantations, aggregate mean weight diameter (MWD) and geometric mean diameter (GMD) increased by 17%–88% and 35%–152%, respectively, in square bamboo plantations. In Japanese cedar soils, C and nitrogen (N) were primarily concentrated in coarse macroaggregates and fine macroaggregates, whereas in square bamboo plantations, C and N were mainly associated with coarse macroaggregates only. Both aggregate-associated soil C and N varied significantly with aggregate size and forest type, and Japanese cedar soils exhibited higher aggregate C/N ratios, particularly in older stands. Bulk SOC was positively correlated with macroaggregate-associated C in both forest types and with the silt and clay fractions in Japanese cedar plantations. MWD increased with higher macroaggregate C content and declined as the proportion of C in smaller aggregate fractions increased. These findings indicate that forest type plays a critical role in regulating soil aggregation and SOC stabilization pathways, with square bamboo plantations enhancing C sequestration by promoting macroaggregate formation and stability. Full article

Periostin is a matricellular protein induced by type 2 cytokines. It has been shown to play important roles in airway inflammation and tissue remodeling. Although periostin has been studied in asthma and chronic rhinosinusitis, its role in allergic rhinitis (AR) and nasal hyperresponsiveness (NHR) is unclear. This study aimed to determine whether periostin is involved in the development of NHR in AR. A murine AR model was established by sensitization and repeated intranasal challenges with Japanese cedar pollen (JCP). In this animal model of AR, an increase in nasal responsiveness to histamine was observed 24 h after the last JCP challenge, indicating the development of NHR. RT-qPCR analysis revealed that the JCP-induced NHR was accompanied by increased periostin gene expression. Immunohistochemical examinations demonstrated the expression of integrin subunits α_V (Itgav), β₃ (Itgb3) and β₅ (Itgb5), which are known as receptors for periostin, in the nasal mucosa, especially in the mucosal epithelium. Notably, repeated intranasal administration of recombinant periostin to healthy I mice reproduced the NHR phenotype, as observed in AR model mice. These findings suggest that periostin upregulation in the nasal mucosa plays a causal role in the development of NHR, a key feature of AR. Full article

The Japanese cedar (Cryptomeria japonica), also known as sugi, is one of the most important trees in Japanese forests. It covers 44% of artificial forests, spanning approximately 4.5 million ha. It is cultivated in East Asia, the Azores archipelago, and some islands in the Indian Ocean. It is also grown worldwide as an ornamental tree in parks and gardens. The cultivation and use of sugi in Japan dates back centuries, and clonal forestry through cuttings has been practiced since the early 15th century. Its broad adaptability, genetic diversity, rapid growth, easy propagation, and precocious flowering—enabling early generational crosses—combined with their advanced genomic resources and efficient biotechnological tools, make sugi an outstanding conifer model. This review aims to provide an overview of the biotechnology and genetics of sugi for researchers and stakeholders. Full article

This paper explores the dynamic behavior of different wood species in the form of violin boards, based on experimental modal analysis using a single-input, multiple-output configuration. Thus, two groups of species were studied: the first group for the violin top plates, being analyzed Picea abies (spruce), Taiwania cryptomerioides Hayata (Taiwania), and Cryptomeria japonica (Japanese cedar), and the second group, with species for the back plates, such as Acer pseudoplatanus (maple), Populus nigra (poplar), Salix alba (willow), and Firmiana simplex (Chinese parasol). The results highlighted the frequency spectrum and the dominant resonance frequency, as well as the frequency damping, the signal processing analysis being based on Fast Fourier Transform and Wigner–Ville distribution of signals. The results highlighted that the lowest values of acoustic radiation are recorded for maple wood (7.8 m⁴ kg⁻¹ s⁻¹) and Taiwania (10.08 m⁴ kg⁻¹ s⁻¹), and the highest values for spruce (14.7 m⁴ kg⁻¹ s⁻¹) and Chinese parasol (15.58 m⁴ kg⁻¹ s⁻¹). Regarding the resonance frequency, the Taiwania and Japanese cedar plates present the dominant frequency around 600–635 Hz in comparison with Norway spruce having 920 Hz. The ratios between dominant frequencies of the Chinese parasol, poplar, maple, and willow are 1:1.42:2.62:2.98. It can be concluded that spruce and maple wood present the best dynamic properties, but when using other species, Japanese cedar wood for the top plate and Chinese parasol wood for the back plate represent species with potential in the construction of stringed musical instruments. Either a mechano-thermal treatment or an appropriate finish can enhance the acoustic qualities of these wood species, research that can be undertaken in the future. Full article

The growing worldwide demand for essential oils (EOs) brings new opportunities for Azorean Cryptomeria japonica aerial parts waste valorization. Therefore, the phytochemical and bioactivity investigation of EOs from different Azorean C. japonica tissues, such as twigs (Az–CJT), remains imperative to add more value to C. japonica’s EO industry, alongside the contribution to the local sustainable circular bioeconomy. This study provides, for the first time, GC–MS analysis and brine shrimp toxicity of the EO hydrodistilled from Az–CJT and aims to compare these parameters with those determined for a commercial Azorean C. japonica (branches and foliage) EO obtained through steam distillation. The main Az–CJT EO components were α-eudesmol (19.53%), phyllocladene (14.80%), elemol (12.43%), nezukol (11.34%), and γ-eudesmol (5.32%), while α-pinene (28.62%), sabinene (24.30%), phyllocladene (5.10%), β-myrcene (5.09%), and limonene (4.93%) dominated in the commercial EO. Thus, Az–CJT EO exhibited the highest sesquiterpenoids (43.52%), diterpenes (20.85%), and diterpenoids (13.21%) content, while the commercial EO was dominated by monoterpenes (74.61%). The Az–CJT EO displayed significantly higher toxicity than the commercial EO, with mortality rates of 87.7% and 16.9%, respectively, at 100 µg/mL. This result is likely related to the substantially higher terpenoid content of Az–CJT EO (61.20% vs. 9.44%), largely attributed to the sesquiterpenoid fraction. Due to its distinct chemical profile, Az–CJT EO may have differential commercial applications, warranting further investigation into its bioactive value and safe use. In conclusion, this study adds knowledge on the potentialities of C. japonica aerial parts’ EOs from the Azorean region. Full article

Bamboo invasion into adjacent forests highlights the need to clarify its ecological impacts, particularly on soil solution chemistry, which influences forest nutrient availability and downstream water quality. This study examined how bamboo invasion alters base cations and anion concentrations, their vertical distribution, and the distinct ionic compositions maintaining charge balance in soil solution by comparing Moso bamboo (BF) and adjacent Japanese cedar (CF) forests. In surface soil solution (5 cm), most ion concentrations were significantly higher in CF than in BF, likely attributable to a greater interception of atmospheric nitrogen resulting from taller tree height in CF. In vertical distribution, CF showed generally higher ion concentrations in surface soil solution than at 50 cm, whereas in BF, this phenomenon was observed only for NO₃⁻, NH₄⁺, and K⁺, consistent with bamboo’s high demand for macronutrients. Significant correlations between the concentration of NO₃⁻ and those of Ca²⁺ and Mg²⁺ were absent only in BF soil leachate. Conversely, a deficit of strong anions showed a significant correlation with the concentration of Ca²⁺ and Mg²⁺ in BF soil leachate, with HCO₃⁻ identified as a potentially major component. Our findings provide insights into the concomitant-ion relationships between base cations and NO₃⁻ across forest types and soil depths. Full article

As wooden buildings become larger and taller, wood properties such as the dynamic modulus of elasticity ($MO{E}_{dyn}$), a criterion for evaluating structural timber, are becoming increasingly important. However, the $MO{E}_{dyn}$ of logs is rarely considered in forestry management. In this study, standing trees that can produce logs with high $MO{E}_{dyn}$ at the standing tree stage were identified to facilitate log sales decisions based on the $MO{E}_{dyn}$ values. In the generalized linear mixed model-based prediction of log $MO{E}_{dyn}$, bucking position and site index were selected as random effects. Incorporating random effects improved the coefficient of determination to 0.651, and log $MO{E}_{dyn}$ could be predicted using the site index class, which reflects site productivity. The results indicate that detailed site conditions conventionally used to assess forest productivity are also useful for predicting the $MO{E}_{dyn}$ of logs before harvesting. Moreover, the $MO{E}_{dyn}$ of logs estimated at the standing tree stage can inform decisions regarding appropriate sales destinations. Full article

Sugi-pollinosis poses a significant socioeconomic and public health concern in Japanese society. Consequently, the use of male-sterile plants (pollen-free plants or PFPs) is anticipated in reforestation efforts. In this context, we developed an improved, simplified method for efficiently propagating sugi PFPs. In the present study, we compared the efficiency of different embryogenic cell lines (ECLs) in producing somatic embryos and examined how effectively these embryos germinate and convert into plantlets. We also evaluated the germination potential of somatic embryos stored for various durations at temperatures above freezing and room temperature. The production efficiency of somatic embryos ranged from 129.6 to 504.1 per plate, with an average of 349.8 across the ECLs tested. The overall average germination and conversion rates of somatic embryos were found to be 93.9% and 92.4%, respectively. Furthermore, although differences were observed among the evaluated genotypes, our five-year study demonstrated that sugi somatic embryos could be stored at 25 °C, 15 °C, or 5 °C for 6, 12, or 24 months, respectively, without a notable decline in germination capacity. The developed method enhances flexibility in plant production scheduling and facilitates the optimal timing for transferring somatic seedlings to the field. Full article

Fertilization is occasionally applied to promote early growth of outplanted tree seedlings. However, the effectiveness of fertilization can be obscured by topographic variations and competing vegetation. The aim of this study was to reevaluate the effects of fertilization and glutathione disulfide (GSSG) on Cryptomeria japonica D. Don (Japanese cedar) seedling height using a four-year dataset from a previous study showing no significant effects using linear models. The impact of treatment was examined using random forest, generalized additive models (GAMs), and structural equation models (SEMs), while accounting for topography and competing vegetation. Topographic features, including the topographic wetness index, were the primary determinants of height growth, reflecting C. japonica’s preference for moist environments. Although the effects of fertilization and GSSG were limited, the GAMs indicated marginal positive interactions in specific stable topographic contexts. The SEMs revealed that fertilization and GSSG indirectly negatively reduced height by increasing competing vegetation coverage. By applying these advanced statistical approaches, we demonstrate how treatment effects that conventional analyses might overlook can be detected, illustrating the methodological contribution of this study. These findings show that topography plays a dominant role in early C. japonica growth, and fertilization and GSSG provide only modest, context-dependent benefits. Full article

Pine wilt disease (PWD) is a serious forest disease caused by pine wood nematode (PWN). To examine the relationship between coniferous endophytes and PWD resistance, this study investigated endophytic bacterial and fungal communities in five conifer species: two Japanese black pine populations (Pinus thunbergii from Qingdao University, PQ, and Fushan Forest Park, PF), Chinese arborvitae (Platycladus orientalis, PO), cedar (Cedrus deodara, CD), and Masson pine (Pinus massoniana, PM). Results showed a strong correlation between endophytic microbial diversity and PWD resistance. PO with high PWD resistance hosted the most unique bacterial species, while PM with low PWD resistance had the fewest unique bacteria and significantly lower ACE and Shannon indices. At the bacterial genus level, dominant genera in resistant conifers often showed high nematocidal activity, whereas those in susceptible plants boosted nematode reproduction. PQ featured the unique dominant genus Pantoea, and PO’s unique Acinetobacter and the shared genus Bacillus (with CD) both displayed high toxicity to PWNs. In contrast, PF’s Pseudomonas and PM’s Stenotrophomonas significantly promoted nematode reproduction. Fungal community analysis revealed that the unique endophytic fungi in PQ are more abundant than those in PF, and the Shannon index of its endophytic fungi is comparable to that of CD and significantly higher than that of PF. PF’s dominant fungal genus Pestalotiopsis might facilitate nematode invasion, and its fungal Shannon index is significantly lower than PQ’s. Eight bacterial strains were isolated from these five conifer plants, with six highly nematocidal strains originating from PQ, CD, and PO. This study offers evidence that endophytic microbial communities critically influence PWD resistance, offering a microbial basis for developing resistant conifer cultivars through microbiome engineering. Full article

We investigated whether a cold front passed on the day when the most cedar pollen was dispersed in each year. When we looked at the 10-year period from 2015 to 2024, and found seven cases in which a cold front passed through the pollen survey area in the Tohoku region. In these cases, extremely large amounts of pollen were dispersed in the hours before and after the front passed. What they had in common was that the amount of pollen dispersion increased significantly at the time the front passed and before and after it. There were 3 cases when a large amount of Japanese cedar pollen was dispersed, even though a cold front did not pass through our Tohoku region. In these cases, large amounts of pollen were dispersed during the time when the warm front was located several hundred to one thousand kilometers south from Tohoku region. The large amount of dispersion continued as long as the fronts moved northward and got closer by several hundred kilometers to the Tohoku region, and the pollen dispersion decreased by the time the front reached the Tohoku region. Full article

Type I allergies are triggered by immunoglobulin E (IgE)-mediated hypersensitivity reactions upon allergen exposure. Dogs are diagnosed with allergic dermatitis based on history, clinical signs, and allergen-specific IgE detection. Using the multiple allergen simultaneous test (MAST)–immunoblot assay, this study measured IgE concentrations and analyzed the proportion of dogs showing allergen-specific IgE positivity, and IgE concentrations of environmental and food allergens in South Korea. We examined data from canine serum using the MAST assay in 2023; the allergen panel included 130 allergens. Data were analyzed, with results greater than zero regarded as positive for the prevalence measurements and concentrations compared among subgroups. Overall, 2663 samples were evaluated to assess the proportion of dogs showing allergen-specific IgE positivity and mean concentrations of environmental and food allergens. Among the environmental allergens, Alternaria spp. had the highest IgE prevalence, whereas Japanese cedar had the highest mean IgE concentration. Allergen-specific differences were observed among subgroups categorized by age, sex, and breed. To our knowledge, this research is the first large-scale study to analyze canine serum using a MAST assay to assess the IgE prevalence of allergen-specific IgE positivity and concentration and to examine data by age, sex, and breed. These findings provide information for diagnosis and management of canine allergies. Full article

The wood of Cryptomeria japonica (Japanese cedar or sugi) is widely used in building and adornment. This study aims to identify the composition of the volatile oils (VOs) extracted from C. japonica solid wood boards by gas chromatography–mass spectroscopy, and to investigate their antimicrobial, anti-inflammatory, and potential neuroprotective activities. A total of 58 volatile organic compounds (VOCs) were identified in the VOs from C. japonica solid wood boards with tree ages of 40, 50, and 60 years (VO-40, 50, and 60), with sandaracopimarinol (13.74–17.59%), ferruginol (10.23–11.29%), abieta-7,13-diene (8.20–13.66%), (+)-δ-cadinene (7.15–9.27%), cis-cubenol (4.36–6.36%), and sandaracopimarinal (3.23–6.04%) as major compounds. The VOs exhibited antifungal potential, especially VO-50 against Aspergillus fumigatus (MIC = 0.312 mg/mL), and VO-60 against Gloeophyllum trabeum (MIC = 1.25 mg/mL). However, VOs exhibited weak antibacterial activity (MIC > 10 mg/mL). Additionally, VOs (10 μg/mL) exhibited anti-inflammatory and potential neuroprotective activities, with VO-60 demonstrating the strongest inhibition of NO (25.79% reduction), TNF-α (52.24% reduction), and IL-6 (27.10% reduction) production in lipopolysaccharide-induced RAW264.7 cells, while increasing cell viability by 70.36% and reducing lactate dehydrogenase release by 41.10% in corticosterone-induced PC12 cells. Correlation and docking analyses revealed that sandaracopimarinal, sandaracopimarinol, β-eudesmol, and ferruginol were the potential active compounds. The results demonstrated that the volatile components from C. japonica solid wood boards not only enhance the board’s decay resistance, but also exhibit therapeutic potential for inflammatory disorders and neuropathic diseases. Full article

Cry j 7 is a 7 kDa cysteine-rich gibberellin regulatory protein (GRP) with six disulfide bonds. It was isolated from Japanese cedar as the pollen allergen in this study. It exhibits cross-reactivity with food allergens such as Pru p 7 from peach and causes pollen-food allergy syndrome (PFAS). In this work, recombinant Cry j 7 and Pru p 7 were successfully overexpressed using Pichia pastoris in a high-cell-density fermentation culture, and pure proteins were purified by reverse-phase HPLC. The characterization of Cry j 7 and Pru p 7 were performed by MS, CD, and ¹H-NMR experiments to confirm the correct native conformation of Cry j 7 as well as Pru p 7. When compared, the results showed that Cry j 7 exhibits excellent stability in disulfide linkages and preserves its original structure up to 90 °C in various pH buffers in comparison to Pru p 7. Notably, NMR analyses indicated the greater mobility in the α-helix and loop regions of S38-C47 in Pru p 7 compared to those of Cry j 7. Furthermore, our results showed that the sensitivity of Cry j 7 to enzyme digestion differed from that of Pru p 7: Cry j 7 was more susceptible to proteolysis, while Pru p 7 displayed better resistance in the gastrointestinal tract. These variations in structural stability and sensitivity to proteolysis provide valuable insights into the allergenicity within the GRP family. Full article

With growing worldwide interest in constructing larger and taller wooden buildings, wood properties, such as the dynamic modulus of elasticity (${MOE}_{dyn}$), have become increasingly important. However, the ${MOE}_{dyn}$ of trees and logs has rarely been considered in forest management because a method for estimating the ${MOE}_{dyn}$ of logs based on standing tree characteristics has been lacking. Herein, we explored the multiple relationships between the ${MOE}_{dyn}$ of logs and standing tree characteristics of Japanese cedar (Cryptomeria japonica) such as tree height, diameter at breast height (DBH), and tree age, including the stress-wave velocity of the tree, which is known to be correlated with the ${MOE}_{dyn}$ of logs. The relationship between the ${MOE}_{dyn}$ of logs and standing tree characteristics was investigated by considering the bucking position. Different trends between the bottom logs and upper logs were found for all characteristics, showing a multiple trend of tree characteristics with the ${MOE}_{dyn}$ of logs based on the bucking position. The top three generalised linear mixed models for the prediction of the ${MOE}_{dyn}$ of logs showed relatively high accuracies when the bucking position was considered as a random effect. Although the contribution of the stress-wave velocity of the tree was relatively high, adding tree age improved the accuracy of the model, and this model was selected as the top model. The model for the bottom log, utilising the stress-wave velocity and age of the tree as explanatory variables, was highly explanatory (R² = 0.70); however, the best model for upper logs was only moderately explanatory (R² = 0.44). In addition, tree height and DBH were selected as explanatory variables along with tree age in the second and third models, which suggested the importance of growth rate rather than tree size. Therefore, adding correlates associated to characteristics related to height growth, such as site index, and DBH growth, such as stand density, is expected to improve model accuracy. Full article