Effects of restoration years on soil stoichiometric ratios in subtropical secondary forests.

Soil stoichiometric ratios serve as valuable indicators for the composition and quality of soil organic matter. While available studies predominantly examine the soil stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P), limited attention has been paid on the influence of forest restoration on soil stoichiometric ratios of potassium (K), calcium (Ca), and magnesium (Mg). We analyzed soil K, Ca, and Mg content, as well as elemental stoichiometric ratios, in secondary forests with varying restoration periods (5, 8, 21, 27 and 40 years) and a natural forest, in order to examine the impact of forest restoration on soil stoichiometry. The results showed that soil C and N contents decreased significantly with increasing soil layers. Soil stoichiometric ratios decreased significantly with increasing soil layers except for K:P, Mg:P, and P:Ca. With the increases of forest restoration years, soil C and N contents significantly increased in 0-10 cm soil layer, Ca content in 10-20 cm soil layer significantly increased, and total P content in 20-40 cm layer significantly decreased. However, soil K and Mg contents in each soil layer did not differ among five restoration ages. With the increases of restoration years, C:Ca, N:Ca and P:Ca in 0-10 cm soil layer significantly increased, and C:P, N:P, and K:P in 20-40 cm soil layer significantly increased, while P:Ca in 20-40 cm soil layer significantly decreased. In all soil layers, K:P and Mg:P were significantly and negatively correlated with soil total P content, and C:Ca and N:Ca were significantly and positively correlated with soil mineral N, available P, and available K content. With the increases of the restoration ages of secondary forests, soils are gradually P-limited and progressively restricted by Ca element in the later years, leading to the limitation of multiple nutrients.

[Relationships between functional traits and litterfall nutrient return characteristics across 21 tree species in subtropical plantations]. / 亚热带21ä¸ªæ ‘ç§äººå·¥æž—åŠŸèƒ½æ€§çŠ¶ä¸Žå‡‹è½ç‰©å »åˆ†å½’è¿˜ç‰¹å¾çš„å ³ç³».

The contribution of litterfall nutrient return to the maintenance of soil carbon pool and nutrient cycling is a crucial aspect of forest ecosystem functioning. Taking 21 tree species in subtropical young plantations as subjects, we investigated the correlation between litterfall nutrient return characteristics and functional traits of leaf and root and. The results showed notable variations in litterfall production, standing crop, and nutrient return across all the examined tree species. Mytilaria laosensis exhibited the highest litterfall production (689.2 g·m-2·a-1) and standing crop (605.1 g·m-2), while Cryptomeria fortunei demonstrated the lowest litterfall production (36.0 g·m-2·a-1) and standing crop (10.0 g·m-2). The nitrogen and phosphorus return amounts of 21 species ranged from 3.0 to 48.3 kg·hm-2 and from 0.1 to 2.0 kg·hm-2, respectively. Castanopsis fissa demonstrated the highest nitrogen return, while Liquidambar formosana exhibited the highest phosphorus return. C. fortunei had the lowest nitrogen and phosphorus return. Results of the stepwise regression analysis indicated that litterfall production exhibited a significant negative correlation with leaf nitrogen content and leaf dry matter content, and a significant positive correlation with fine root tissue density. Additionally, leaf nitrogen content, leaf dry matter content, and specific root length had a significant negative impact on standing crop. The structural equation modelling results indicated that leaf dry matter content had a direct or indirect negative effect on nitrogen return amount through the reduction of litterfall production. Conversely, fine root tissue density had a significant positive impact on nitrogen return amount by increasing litter leaf nitrogen content. Both leaf nitrogen content and leaf dry matter content had direct or indirect negative effects on phosphorus return amount through the reduction of litterfall production. In conclusion, the tree species with low leaf nitrogen content and dry matter content, as well as high fine root tissue density, was recommended for the establishment of plantations in the subtropical zone in order to enhance nutrient cycling through litter decomposition and improve soil fertility and forest productivity.

Fungal composition associated with host tree identity mediates nutrient addition effects on wood microbial respiration.

Fungi are key decomposers of deadwood, but the impact of anthropogenic changes in nutrients and temperature on fungal community and its consequences for wood microbial respiration are not well understood. Here, we examined how nitrogen and phosphorus additions (field experiment) and warming (laboratory experiment) together influence fungal composition and microbial respiration from decomposing wood of angiosperms and gymnosperms in a subtropical forest. Nutrient additions significantly increased wood microbial respiration via fungal composition, but effects varied with nutrient types and taxonomic groups. Specifically, phosphorus addition significantly increased wood microbial respiration (65%) through decreased acid phosphatase activity and increased abundance of fast-decaying fungi (e.g., white rot), while nitrogen addition marginally increased it (30%). Phosphorus addition caused a greater increase in microbial respiration in gymnosperms than in angiosperms (83.3% vs. 46.9%), which was associated with an increase in Basidiomycota:Ascomycota operational taxonomic unit abundance in gymnosperms but a decrease in angiosperms. The temperature dependencies of microbial respiration were remarkably constant across nutrient levels, consistent with metabolic scaling theory hypotheses. This is because there was no significant interaction between temperature and wood phosphorus availability or fungal composition, or the interaction among the three factors. Our results highlight the key role of tree identity in regulating nutrient response of wood microbial respiration through controlling fungal composition. Given that the range of angiosperm species may expand under climate warming and forest management, our data suggest that expansion will decrease nutrient effects on forest carbon cycling in forests previously dominated by gymnosperm species.

Logistic regression analysis of risk factors for pediatric burns: a case-control study in underdeveloped minority areas in China.

Background: Pediatric burns are common, especially in underdeveloped countries, and these can physically affect the children involved and have an impact on their mental health. The aim of the present study was to assess the effect of pediatric burns in underdeveloped minority areas of China. Methods: Case information from 192 children was collected from outpatient and inpatient clinics using a survey questionnaire. These included 90 pediatric burn cases and 102 controls who were children without burns. A stepwise logistic regression analysis was used to determine the risk factors for pediatric burns in order to establish a model. The goodness-of-fit for the model was assessed using the Hosmer and Lemeshow test as well as receiver operating characteristic and internal calibration curves. A nomogram was then used to analyze the contribution of each influencing factor to the pediatric burns model. Results: Seven variables, including gender, age, ethnic minority, the household register, mother's employment status, mother's education and number of children, were analyzed for both groups of children. Of these, age, ethnic minority, mother's employment status and number of children in a household were found to be related to the occurrence of pediatric burns using univariate logistic regression analysis (p < 0.05). After a collinearity diagnosis, a multivariate logistic regression analysis of variables with tolerances of >0.2 and variance inflation factor <5 showed that age was a protective factor for pediatric burns [odds ratio (OR) = 0.725; 95% confidence interval (CI): 0.665-0.801]. Compared with single-child parents, those with two children were at greater risk of pediatric burns (OR = 0.389; 95% CI: 0.158-0.959). The ethnic minority of the child and the mother's employment status were also risk factors (OR = 6.793; 95% CI: 2.203-20.946 and OR = 2.266; 95% CI: 1.025-5.012, respectively). Evaluation of the model used was found to be stable. A nomogram showed that the contribution in the children burns model was age > mother's employment status > number of children > ethnic minority. Conclusions: This study showed that there are several risk factors strongly correlated to pediatric burns, including age, ethnic minority, the number of children in a household and mother's employment status. Government officials should direct their preventive approach to tackling the problem of pediatric burns by promoting awareness of these findings.

Trophic interactions in soil micro-food webs drive ecosystem multifunctionality along tree species richness.

Rapid biodiversity losses under global climate change threaten forest ecosystem functions. However, our understanding of the patterns and drivers of multiple ecosystem functions across biodiversity gradients remains equivocal. To address this important knowledge gap, we measured simultaneous responses of multiple ecosystem functions (nutrient cycling, soil carbon stocks, organic matter decomposition, plant productivity) to a tree species richness gradient of 1, 4, 8, 16, and 32 species in a young subtropical forest. We found that tree species richness had negligible effects on nutrient cycling, organic matter decomposition, and plant productivity, but soil carbon stocks and ecosystem multifunctionality significantly increased with tree species richness. Linear mixed-effect models showed that soil organisms, particularly arbuscular mycorrhizal fungi (AMF) and soil nematodes, elicited the greatest relative effects on ecosystem multifunctionality. Structural equation models revealed indirect effects of tree species richness on ecosystem multifunctionality mediated by trophic interactions in soil micro-food webs. Specifically, we found a significant negative effect of gram-positive bacteria on soil nematode abundance (a top-down effect), and a significant positive effect of AMF biomass on soil nematode abundance (a bottom-up effect). Overall, our study emphasizes the significance of a multitrophic perspective in elucidating biodiversity-multifunctionality relationships and highlights the conservation of functioning soil micro-food webs to maintain multiple ecosystem functions.

Effects of stand ages on soil enzyme activities in Chinese fir plantations and natural secondary forests.

Forest type and stand age are important biological factors affecting soil enzyme activities. However, the changes in soil enzyme activities across stand ages and underlying mechanisms under the two forest restoration strate-gies of plantations and natural secondary forests remain elusive. In this study, we investigated the variations of four soil enzyme activities including cello-biohydrolase (CBH), ß-1,4-glucosidase (ßG), acid phosphatase (AP) and ß-1,4-N-acetylglucosaminidase (NAG), which were closely associated with soil carbon, nitrogen, and phosphorus cycling, across Cunninghamia lanceolata plantations and natural secondary forests (5, 8, 21, 27 and 40 years old). The results showed that soil enzyme activities showed different patterns across different forest types. The acti-vities of AP, ßG and CBH in the C. lanceolata plantations were significantly higher than those in the natural secon-dary forests, and there was no significant difference in the NAG activity. In the plantations, AP activity showed a decreasing tendency with the increasing stand ages, with the AP activity in the 5-year-old plantations significantly higher than other stand ages by more than 62.3%. The activities of NAG and CBH decreased first and then increased, and ßG enzyme activity fluctuated with the increasing stand age. In the natural secondary forests, NAG enzyme activity fluctuated with the increasing stand age, with that in the 8-year-old and 27-year-old stand ages being significantly higher than the other stand ages by more than 14.9%. ßG and CBH enzyme activities increased first and then decreased, and no significant difference was observed in the AP activity. Results of the stepwise regression analyses showed that soil predictors explained more than 34% of the variation in the best-fitting models predicting soil enzyme activities in the C. lanceolata plantations and natural secondary forests. In conclusion, there would be a risk of soil fertility degradation C. lanceolata plantations with the increasing stand age, while natural secondary forests were more conducive to maintaining soil fertility.

Updated epithelial barrier dysfunction in chronic rhinosinusitis: Targeting pathophysiology and treatment response of tight junctions.

Tight junction (TJ) proteins establish a physical barrier between epithelial cells, playing a crucial role in maintaining tissue homeostasis by safeguarding host tissues against pathogens, allergens, antigens, irritants, etc. Recently, an increasing number of studies have demonstrated that abnormal expression of TJs plays an essential role in the development and progression of inflammatory airway diseases, including chronic obstructive pulmonary disease, asthma, allergic rhinitis, and chronic rhinosinusitis (CRS) with or without nasal polyps. Among them, CRS with nasal polyps is a prevalent chronic inflammatory disease that affects the nasal cavity and paranasal sinuses, leading to a poor prognosis and significantly impacting patients' quality of life. Its pathogenesis primarily involves dysfunction of the nasal epithelial barrier, impaired mucociliary clearance, disordered immune response, and excessive tissue remodeling. Numerous studies have elucidated the pivotal role of TJs in both the pathogenesis and response to traditional therapies in CRS. We therefore to review and discuss potential factors contributing to impair and repair of TJs in the nasal epithelium based on their structure, function, and formation process.

Epithelial Tight Junction Anomalies in Nasal Inverted Papilloma.

OBJECTIVES: As a critical component of the epithelial barrier, tight junctions (TJs) are essential in nasal mucosa against pathogen invasion. However, the function of TJs has rarely been reported in nasal inverted papilloma (NIP). This study aims to investigate the potential factors of TJs' abnormality in NIP. METHODS: We assessed the expression of ZO-1, occludin, claudin-1, claudin-3, and claudin-7 in healthy controls and NIP by real-time quantitative polymerase chain reaction and immunofluorescent staining. The correlation between TJs expression and neutrophil count, TH 1/TH 2/TH 17 and regulatory T cell biomarkers, and the proportion of nasal epithelial cells was investigated. RESULTS: Upregulation of ZO-1, occludin, claudin-1, and claudin-7, along with downregulation of claudin-3, was found in NIP compared to control (all p < 0.05). An abnormal proportion with a lower number of ciliated cells (control vs. NIP: 37.60 vs. 8.67) and goblet cells (12.52 vs. 0.33) together with a higher number of basal cells (45.58 vs. 124.00) in NIP. Meanwhile, claudin-3 was positively correlated with ciliated and goblet cells (all p < 0.01). Additionally, neutrophils were excessively infiltrated in NIP, negatively correlated with ZO-1, but positively with claudin-3 (all p < 0.05). Furthermore, FOXP3, IL-10, TGF-ß1, IL-5, IL-13, and IL-22 levels were induced in NIP (all p < 0.01). Occludin level was negatively correlated with IL-10, IL-5, IL-13, and IL-22, whereas ZO-1 was positively with TGF-ß1 (all p < 0.05). CONCLUSION: Nasal epithelial barrier dysfunction with TJs anomalies is commonly associated with abnormal proliferation and differentiation of epithelial cells and imbalance of immune and inflammatory patterns in NIP. LEVEL OF EVIDENCE: NA Laryngoscope, 134:552-561, 2024.

Litter decomposition and nutrient release are faster under secondary forests than under Chinese fir plantations with forest development.

In terrestrial ecosystems, leaf litter is the main source of nutrients returning to the soil. Understanding how litter decomposition responds to stand age is critical for improving predictions of the effects of forest age structure on nutrient availability and cycling in ecosystems. However, the changes in this critical process with stand age remain poorly understood due to the complexity and diversity of litter decomposition patterns and drivers among different stand ages. In this study, we examined the effects of stand age on litter decomposition with two well-replicated age sequences of naturally occurring secondary forests and Chinese fir (Cunninghamia lanceolata) plantations in southern China. Our results showed that the litter decomposition rates in the secondary forests were significantly higher than those in the Chinese fir plantations of the same age, except for 40-year-old forests. The litter decomposition rate of the Chinese fir initially increased and then decreased with stand age, while that of secondary forests gradually decreased. The results of a structural equation model indicated that stand age, litter quality and microbial community were the primary factors driving nutrient litter loss. Overall, these findings are helpful for understanding the effects of stand age on the litter decomposition process and nutrient cycling in plantation and secondary forest ecosystems.

Functional identity drives tree species richness-induced increases in litterfall production and forest floor mass in young tree communities.

Forest floor accumulation is a key process that influences ecosystem carbon cycling. Despite evidence suggesting that tree diversity and soil carbon are positively correlated, most soil carbon studies typically omit the response of the forest floor carbon to tree diversity loss. Here, we evaluated how tree species richness affects forest floor mass and how this effect is mediated by litterfall production and forest floor decay rate in a tree diversity experiment in a subtropical forest. We observed that greater tree species richness leads to higher forest floor accumulation at the soil surface through increasing litterfall production - positively linked to functional trait identity (i.e. community-weighted mean functional trait) rather than functional diversity - and unchanged forest floor decay. Interestingly, structural equation modelling revealed that this lack of overall significant tree species richness effect on forest floor decay rate was due to two indirect and opposite effects cancelling each other out. Indeed, tree species richness increased forest floor decay rate through increasing litterfall production while decreasing forest floor decay rate by increasing litter species richness. Our reports of greater organic matter accumulation in the forest floor in species-rich forests suggest that tree diversity may have long-term and important effect on ecosystem carbon cycling and services.

Automatic three-dimensional nasal and pharyngeal airway subregions identification via Vision Transformer.

OBJECTIVES: Upper airway assessment requires a fully-automated segmentation system for complete or sub-regional identification. This study aimed to develop a novel Deep Learning (DL) model for accurate segmentation of the upper airway and achieve entire and subregional identification. METHODS: Fifty cone-beam computed tomography (CBCT) scans, including 24,502 slices, were labelled as the ground truth by one orthodontist and two otorhinolaryngologists. A novel model, a lightweight multitask network based on the Swin Transformer and U-Net, was built for automatic segmentation of the entire upper airway and subregions. Segmentation performance was evaluated using Precision, Recall, Dice similarity coefficient (DSC) and Intersection over union (IoU). The clinical implications of the precision errors were quantitatively analysed, and comparisons between the AI model and Dolphin software were conducted. RESULTS: Our model achieved good performance with a precision of 85.88-94.25%, recall of 93.74-98.44%, DSC of 90.95-96.29%, IoU of 83.68-92.85% in the overall and subregions of three-dimensional (3D) upper airway, and a precision of 91.22-97.51%, recall of 90.70-97.62%, DSC of 90.92-97.55%, and IoU of 83.41-95.29% in the subregions of two-dimensional (2D) crosssections. Discrepancies in volume and area caused by precision errors did not affect clinical outcomes. Both our AI model and the Dolphin software provided clinically acceptable consistency for pharyngeal airway assessments. CONCLUSION: The novel DL model not only achieved segmentation of the entire upper airway, including the nasal cavity and subregion identification, but also performed exceptionally well, making it well suited for 3D upper airway assessment from the nasal cavity to the hypopharynx, especially for intricate structures. CLINICAL SIGNIFICANCE: This system provides insights into the aetiology, risk, severity, treatment effect, and prognosis of dentoskeletal deformities and obstructive sleep apnea. It achieves rapid assessment of the entire upper airway and its subregions, making airway management-an integral part of orthodontic treatment, orthognathic surgery, and ENT surgery-easier.

Contribution of tree species to the co-occurrence network of the leaf phyllosphere and soil bacterial community in the subtropical forests.

The underlying mechanisms of the interactions between bacterial communities and tree species are still unknown, primarily attributed to a focus on the soil system while ignoring the leaf phyllosphere, which is a complex and diverse ecosystem that supports microbial diversity in the forest ecosystem. To gain insights into the mechanisms, the effects of seven common subtropical tree species, involving Pinus massoniana Lamb., Mytilaria laosensis Lecomte., Ilex chinensis Sims., Michelia macclurei Dandy., Liquidambar formosana Hance., Quercus acutissima Carruth., and Betula luminifera H.Winkler on the bacterial communities were investigated in the leaf phyllosphere and soil systems. We found that the bacterial community was dominated by Proteobacteria in the leaf phyllosphere (63.2-84.7%), and was dominated by Proteobacteria (34.3-45.0%) and Acidobacteria (32.5-40.6%) in soil. Mycorrhizal types and leaf phenology had no apparent effects on the bacterial abundance in the bacterial diversity in the leaf phyllosphere and soil. The bacterial community composition was greatly influenced by tree species in the leaf phyllosphere rather than in soil, with soil parameters (soil pH and C/N) and litter N identified as the most important factors. Ectomycorrhizal trees exerted positive effects on the complexity of the bacterial community at the expense of decreasing the robustness of the soil bacterial community, potentially threatening ecosystem stability. Evergreen trees decreased the network robustness of bacterial community by 21.9% higher than this of deciduous trees in the leaf phyllosphere. Similarly, evergreen trees decreased soil bacterial abundance by 50.8% and network robustness by 8.0% compared to deciduous trees, indicating the adverse impacts of leaf phenology on the bacterial stability in both leaf and soil. Overall, our results highlight the need for studies of leaf-associated bacteria to comprehensively understand the potential effects of tree species on microbial diversity and stability in subtropical forests.

Predictive Significance of Claudin-3 for Epithelial Barrier Dysfunction in Chronic Rhinosinusitis With Nasal Polyps.

PURPOSE: The abnormal expression of tight junction (TJ) plays a vital role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, there is no appropriate tool to distinguish and diagnose epithelial barrier defects in clinical practice. This study aimed to evaluate the predictive value of claudin-3 for epithelial barrier dysfunction in CRSwNP. METHODS: In this study, TJ protein levels were evaluated by real-time quantitative polymerase chain reaction, immunofluorescent, and immunohistochemistry staining in control subjects and CRSwNP patients. The receiver operating characteristic (ROC) curve was created to assess the predictive value of TJ breakdown in clinical outcomes. In vitro, human nasal epithelial cells were cultured at the air-liquid interface to analyze the transepithelial electrical resistance (TER) level. RESULTS: The expression levels of occludin, tricellulin, claudin-3, and claudin-10 were decreased (all P < 0.05), and those of claudin-1 was increased (P < 0.05) in CRSwNP patients as compared to healthy subjects. Additionally, claudin-3 and occludin levels were negatively correlated with the computed tomography score in CRSwNP (all P < 0.05), and the ROC curve indicated that the claudin-3 level had the most predictive accuracy in evaluating epithelial barrier disruption (area under the curve = 0.791, P < 0.001). Finally, the time-series analysis showed the highest correlation coefficient between TER and claudin-3 (cross-correlation function = 0.75). CONCLUSION: In this study, we suggest that claudin-3 could be a valuable biomarker for predicting nasal epithelial barrier defects and disease severity in CRSwNP.

Healing mechanism of diabetic foot ulcers using single-cell RNA-sequencing.

Background: Diabetic foot ulcer (DFU) is one of the common and severe complications in diabetic patients, mainly caused by the interaction of various factors such as peripheral neuropathy, peripheral vascular disease, and infection. Moreover, vascular damage, disorder of tissue cells, decreased expression level of neurotrophic factor, and decreased growth factor caused by long-term exposure to a high glucose environment can also lead to prolonged or incomplete wound healing. This imposes a tremendous financial burden on the patients' family and society. Although various innovative techniques and drugs have been developed to treat DFU, the therapeutic effect is still unsatisfactory. Methods: We filtered and downloaded the single-cell dataset of diabetic patients from the Gene Expression Omnibus (GEO) website and used the Seurat package in R for creation of single-cell objects, integration, control of quality, clustering, cell type identification, differential gene analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and intercellular communication analysis. Results: Diabetic healing-related differentially expressed gene (DEG) analysis showed that there were 1,948 differential genes between tissue stem cells in healing and non-healing wounds, of which 1,198 genes were up-regulated and 685 genes were down-regulated. The results of GO functional enrichment analysis in tissue stem cells showed that they were closely related to wound healing. The CCL2-ACKR1 signaling pathway activity in tissue stem cells influenced the biological activity of endothelial cell subpopulation, which ultimately promoted the healing of DFU wounds. Conclusions: The CCL2-ACKR1 axis is closely associated with DFU healing.

Soil nitrification and denitrification in Cunninghamia lanceolata plantations with different stand ages.

The variations in soil nitrification and denitrification processes, together with the abundances of functional microbes were investigated in Cunninghamia lanceolata plantations with different stand ages of 5, 8, 21, 27, and 40 years old. The results showed that the net nitrification rate fluctuated with increasing forest ages, with that of 8-year- and 27-year-old C. lanceolata plantations being significantly lower than other stand ages. The abundance of ammonia-oxidizing archaea (AOA) amoA in the 27-year-old plantation was significantly lower than that of the 40-year-old plantation, while there was no significant difference among the other stand ages. There was no significant difference in the abundance of AOB amoA gene, denitrifying functional genes or soil denitrification potential among different stand ages. The results of stepwise regression analysis showed that the abundance of AOA amoA gene was not significantly affected by soil physical and chemical properties. In addition, the abundance of AOB was positively associated with soil total carbon content and soil pH. The abundance of denitrifying functional genes including narG, nirK and nosZ increased with increasing soil pH. The abundance of nirK and nirS was influenced by soil total carbon. Stand age influenced soil net nitrification rate through the AOA amoA abundance. Moreover, soil denitrification potential was directly affected by stand age, or indirectly affected by stand age through soil microbial biomass carbon, soil pH and denitrifying gene abundance of narG and nirK. Compared with the denitrification process, soil nitrification and associated AOA amoA gene abundance were more sensitive to the development of C. lanceolata plantations. The rotation period sould be appropriately extended to reduce the risk of nitrogen losses resulting from soil nitrification.

Drivers of foliar 15 N trends in southern China over the last century.

Foliar stable nitrogen (N) isotopes (δ15 N) generally reflect N availability to plants and have been used to infer about changes thereof. However, previous studies of temporal trends in foliar δ15 N have ignored the influence of confounding factors, leading to uncertainties on its indication to N availability. In this study, we measured foliar δ15 N of 1811 herbarium specimens from 12 plant species collected in southern China forests from 1920 to 2010. We explored how changes in atmospheric CO2 , N deposition and global warming have affected foliar δ15 N and N concentrations ([N]) and identified whether N availability decreased in southern China. Across all species, foliar δ15 N significantly decreased by 0.82‰ over the study period. However, foliar [N] did not decrease significantly, implying N homeostasis in forest trees in the region. The spatiotemporal patterns of foliar δ15 N were explained by mean annual temperature (MAT), atmospheric CO2 ( P CO 2 ), atmospheric N deposition, and foliar [N]. The spatiotemporal trends of foliar [N] were explained by MAT, temperature seasonality, P CO 2 , and N deposition. N deposition within the rates from 5.3 to 12.6 kg N ha-1  year-1 substantially contributed to the temporal decline in foliar δ15 N. The decline in foliar δ15 N was not accompanied by changes in foliar [N] and therefore does not necessarily reflect a decline in N availability. This is important to understand changes in N availability, which is essential to validate and parameterize biogeochemical cycles of N.

Differential response of soil microbial and animal communities along the chronosequence of Cunninghamia lanceolata at different soil depth levels in subtropical forest ecosystem.

Introduction: Soil biota plays a crucial role in the terrestrial ecosystem. There is growing momentum to understand the community structure and diversity of total belowground soil biota across large ecological scales. Soil biota follow divergent trends with respect to soil physiochemical properties in different ecosystems; however, little is known about their response to stand development across multiple soil depths in Chinese fir plantations, which is the most important tree species across all over China, popular for its timber production. Objectives: Here, we investigated the community assembly of soil bacteria, fungi, archaea, protists and animals across three different vertical soil profiles (0-10, 10-20, 20-40 cm) using a chronosequence of Chinese fir representing five different stand ages (5, 8, 21, 27, 40 years) in South China. Methods: High throughput illumine Hiseq2500 sequencing. Results: Our results showed that soil biotic communities exhibited a decreasing trend in alpha diversity of bacteria, fungi, protists and animals with increasing soil depth; however, archaea showed an opposite trend. Most abundant soil bacterial, fungal, archaeal, protist and animal classes were Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, respectively. Correlation of vertical distribution of biotic communities and variations in soil physiochemical properties explained that total nitrogen (TN), available phosphorus (AP) and pH were the most influencing factors for changes in soil biotic communities. Although the stand age was a contributing factor for fungal and animal beta diversity, however, as compared to soil depth, it was not dominatingly influencing the structure of other biotic communities. Conclusions: Collectively, these results reveal a new perspective on the vertical variation and distinct response patterns of soil biotic communities at a fine scale across different stand ages of Chinese fir plantations.

[Relationships between tree functional traits and leaf nitrogen and phosphorus resorption efficiencies in subtropical young plantations]. / äºšçƒ­å¸¦å¹¼æž—æ ‘æœ¨åŠŸèƒ½æ€§çŠ¶ä¸Žå¶ç‰‡æ°®ç£·é‡å¸æ”¶çŽ‡çš„å ³ç³».

We examined the relationship between tree functional traits and leaf nitrogen and phosphorus resorption efficiencies across 29 species in 3-year-old pure plantations in subtropical China. The results showed that the average nitrogen (NRE) and phosphorus (PRE) resorption efficiencies in 29 young plantations were 50.5% and 57.3%, respectively. The average NRE of 22 arbuscular mycorrhizal (AM) tree species was 52.7%, significantly higher than that of the seven ectomycorrhizal (EM) tree species (45.1%). NRE was positively correlated with fine root tissue density across the 29 tree species. PRE was positively correlated with root diameter in the seven EM tree species. Functional traits of 22 AM tree species were not associated with NRE and PRE. Among all of the 29 tree species, mycorrhizal type, specific leaf area, fine root tissue density, leaf thickness, and the interaction effects of mycorrhizal type with leaf thickness explained 27% variation in NRE. Specific root length, fine root carbon content, fine root carbon to nitrogen ratio, mycorrhizal type, leaf carbon content, and the interaction effects of mycorrhizal type with leaf carbon content explained 35% variation in PRE. Root functional trait of subtropical species could predict nitrogen and phosphorus resorption efficiencies. The model with multiple functional traits could better reveal the relative importance of different biological factors on nutrient resorption efficiency.

Pyroptosis-Related Gene Signature Is a Novel Prognostic Biomarker for Sarcoma Patients.

Sarcoma is a rare and an extremely aggressive form of cancer that originates from mesenchymal cells. Pyroptosis exerts a dual effect on tumours by inhibiting tumour cell proliferation while creating a microenvironment suitable for tumour cell development and proliferation. However, the significance of pyroptosis-related gene (PRG) expression in sarcoma has not yet been evaluated. Here, we conduct a retrospective analysis to examine PRG expression in 256 sarcoma samples from The Cancer Genome Atlas database. We identified the PRGs that had a significant correlation with overall patient survival in sarcoma by performing a univariate Cox regression analysis. Subsequently, we conducted a LASSO regression analysis and created a risk model for a six-PRG signature. As indicated from the Kaplan-Meier analysis, this signature revealed a significant difference between high- and low-risk sarcoma patients. A receiver operating characteristic curve analysis confirmed that this signature could predict overall patient survival in sarcoma patients with high sensitivity and specificity. Gene ontology annotation and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analyses revealed that five independent PRGs were closely associated with increased immune activity. Moreover, we also deciphered that increased number of immune cells infiltrated the tumour microenvironment in sarcoma. In brief, the PRG signature can effectively act as novel prognostic biomarker for sarcoma patients and is associated with the tumour immune microenvironment.