Urbanization-induced air quality deterioration has triggered a series of problems. Fortunately, urban forests are an effective solution to these problems. However, the differential capacity of various forest types to purify air pollutants and modulate human comfort remains inadequately quantified along the urban-rural transect. Thus, this study quantified the spatiotemporal heterogeneity in forest-mediated mitigation of air pollutants and modulation of human comfort along the urban-rural transect by field measurement. The results revealed that the capability of urban forests to mitigate pollution and enhance human comfort depended collectively on their position on the transect, season, and forest type. Along the urban-rural transect in Nanchang, the atmosphere purification capacity decreased sequentially from suburban to exurban to urban core regions. Seasonally, purification capacity was lowest during summer. Regarding forest types, coniferous forests were the primary source of negative air ions in urban areas, effectively improving air quality in both suburban and exurban regions. In contrast, evergreen broadleaf forests were particularly effective at enhancing urban air quality and thermal comfort. These context-dependent results suggest: (1) Increasing broad-leaved forest coverage in densely populated urban cores to prioritize urban heat island (UHI) mitigation; (2) Prioritizing coniferous forests in industrially active suburban areas for targeted air pollution; and (3) Focusing on expanding mixed-species forests in exurban regions to maintain the ecological advantage of high negative air ion concentrations. These findings provide empirical evidence for optimizing urban forest configurations through strategic spatiotemporal zoning and conifer-broadleaf ratio adjustments to maximize air quality regulation services. It should be noted that extrapolation of the above results should be done with special caution, especially outside the subtropical monsoon zone.

Urbanization can alter soil organic carbon (SOC) storage, while glomalin-related soil protein (GRSP) is crucial for SOC sequestration. However, whether and how GRSP mediates the response of SOC to urbanization remains unclear. We investigated 184 soil samples by analyzing GRSP and its C-functional structures along an urban expansion gradient using redundancy analysis and structural equation modeling (SEM) in Nanchang, China. Four C-functional groups of GRSP were characterized using infrared spectroscopy, including aromatic hydrocarbons, aliphatic hydrocarbons, proteins, and polysaccharides/nucleic acids. Average GRSP and SOC contents were 2.38 and 16.76 g·kg⁻¹, respectively, and both decreased significantly during urbanization (p < 0.05). Crucially, the relative abundance of the fourC-functional groups of GRSP exhibited a more pronounced decline with urbanization than that of bulk soil C-functional groups, providing a mechanistic basis for its sensitivity. SEM indicated that GRSP was significantly associated with the pathway linking urbanization and SOC, suggesting that urbanization may be indirectly associated with SOC variation through changes in soil properties (e.g., enzyme activities) and GRSP. This study suggests that GRSP content and its C-functional structure may serve as potential biochemical indicators of urbanization-associated changes in SOC dynamics. It provides a biochemical tool for assessing soil carbon vulnerability in urban ecosystems.

[Objective]This study explored the soil arbuscular mycorrhizal(AM)fungal communities in park green spaces under the context of urbanization,aimed to provide foundational data support for the soil microbial diversity and ecological conservation of parks in Nanchang City.[Method]In this study,three urbanization gradient levels(high,medium,and low)were divided according to the proportion of impervious surface area in the built-up area of Nanchang City,and 63 sample plots of park green space soil were sampled and investigated.High-throughput sequencing technology was used to detect the community characteristics of arbuscular mycorrhizal(AM)fungi in the soil,analyze the differences in the structural composition,Alpha diversity and Beta diversity of AM fungal communities,and reveal the correlation between AM fungal communities and soil physicochemical properties through RDA analysis.[Result]The AM fungal communities in the park green spaces of Nanchang City were predominantly composed of dominant genera such as Glomus and Paraglomus.The Shannon and Simpson indices exhibited a significant logarithmic increase with rising urbanization intensity by 3.89％and 1.90％,whereas the Dominance index showed a significant logarithmic decrease by 44.36％.Soil pH value,electrical conductivity,soil organic carbon content and total nitrogen content were positively correlated with the abundance of genera such as Glomus,Claroideoglomus,Scutellospora and Gigaspora;total potassium content,moisture content and soil bulk density were positively correlated with the abundance of genera such as Archaeospora and Diversispora,and soil total phosphorus content was positively correlated with the abundance of genera such as Paraglomus.[Conclusion]With the increase in urbanization intensity,species diversity and community evenness of AM fungi communities increased,while the dominance of the dominant genera weakened.Soil physicochemical factors such as soil organic carbon,pH value,total phosphorus content,and total potassium content play a key role in influencing the composition of AM fungal communities.

Urban expansion and land-use change are transforming human living environments, and PTEs (potentially toxic elements) pollution is exacerbating. However, the spatial distributions, risks, and drivers of soil PTEs enrichment in urban forest remain unclear. To elucidate this, 184 forest plots were examined in built-up area of Nanchang, China (road forests, landscape forests, institution-affiliated forests, and ecological public-welfare forests), and classified based on different urbanization intensities. Nine soil PTEs (V, Cr, Co, Ni, Cu, Zn, As, Cd, and Pb) levels and pollution evaluation indices were calculated. Results showed a contamination factor of 2.02, a Nemerow pollution index of 2.40, and a potential ecological risk index of 169.66, indicating a moderate level of soil pollution in Nanchang. Cr was 38%-52% higher in landscape forests than that in the other forest types (p < 0.05). Cr, Cd, and Pb deposition increased significantly with advancing urbanization intensity (p < 0.05). Moreover, Cr, As, Cd, and Pb levels were 1.21-7.83-fold higher than their background values in Nanchang. Soil total phosphorus, available phosphorus, NO3-, bulk density, and total potassium were key factors affecting PTEs. This study provides a theoretical basis for mitigating PTEs pollution in urban forest management within subtropical red soil regions.

Butenolide [5-octylfuran-2(5H)-one] is a highly effective and environmentally friendly antifouling compound derived from marine natural products, but little was known about its toxic mechanisms toward marine microalgae. In this study, the diatom Phaeodactylum tricornutum was used as a model organism and DCOIT as the positive control to investigate the effects of butenolide on the growth, photosynthetic efficiency, and oxidative stress of microalgae. The results showed that although DCOIT and butenolide both significantly inhibited the growth of P. tricornutum, butenolide demonstrated much lower toxicity than the commercial antifouling agent DCOIT (96-h EC50 values of 2.49 mg L-1 and 0.099 mg L-1, respectively). At high concentrations (0.12 mg L-1), DCOIT caused significantly higher stress on algal cell photosynthetic efficiency than butenolide, with a much lower recovery potential for the algae cells. In contrast, the effect of butenolide was relatively reversible enabling better recovery of algal cells. Measurements of Reactive Oxygen Species (ROS) levels indicated both antifoulants induced excessive intracellular ROS accumulation, which lead to lipid peroxidation and photosynthetic impairment. However, butenolide caused a significant increase of antioxidant enzymes (superoxide dismutase, SOD; glutathione peroxidase, GPx), which indicated the algae cells can still activate cellular defense mechanisms against butenolide-induced oxidative stress, whereas DCOIT likely inhibited the algae cells' antioxidant systems directly and caused more severe oxidative damage. Therefore, butenolide demonstrated better environmental friendliness, while DCOIT may pose higher ecological risks and induce irreversible impacts in marine microalgae. This study provides insights into the toxic effects and potential ecological risks of butenolide and DCOIT on P. tricornutum.

To address the risks of cross-border transmission of pathogenic microorganisms posed by the failure or non-compliance of shipboard ballast water treatment systems, ports urgently require efficient and flexible emergency response solutions. This study presents a novel, containerized, integrated ship-to-shore emergency response system specifically designed for the rapid inactivation of pathogenic microorganisms in ballast water. The core innovation lies in the integration of a three-degree-of-freedom (3-DOF) hydraulic robotic arm, a vision and positioning system, and a dynamic inflatable sealing structure designed for rapid, automated docking with a ship’s ballast water discharge outlet (DN250), thereby enhancing operational safety and efficiency. The system employs a purely physical treatment process of “ultrasound (US) pre-treatment + dual-stage ultraviolet (UV) disinfection,” allowing for reception and treatment without secondary chemical pollution. The integrated treatment train, consisting of US (30 kHz, 7.6–12 kW, minimum acoustic energy density ≥ 0.45 J/cm2) followed by dual-stage UV disinfection (minimum UV dose: 147 mJ/cm2), maintained effective microbial inactivation at turbidity levels of 15, 125, 250, and 500 NTU. US alone showed little direct bactericidal effect, whereas the first UV stage achieved log reduction values (LRVs) of 3.31–4.13, and the complete US + UV + UV process achieved total LRVs of 5.07–7.34 for Escherichia coli. The results showed that dual-stage UV disinfection was key to achieving high inactivation efficacy (p < 0.001), while ultrasound, despite its limited direct bactericidal effect, may have facilitated downstream UV disinfection within the sequential treatment train. This system not only fills a critical gap in port biosecurity emergency infrastructure but also provides an experimentally validated, efficient, environmentally friendly, and flexibly deployable shore-based solution.

Afforestation has been considered to be the cost-effective way to sequestrate carbon (C) dioxide from the atmosphere in the soils, while concurrent responses of soil inorganic C (SIC) and soil organic C (SOC), and their turnover are still not well-defined. During the C cycle, inorganic C is enriched in heavy isotopes (13C), while organic C, due to photosynthetic fractionation, is enriched in light isotopes (12C). This leads to distinct C isotope fractionation in terrestrial ecosystems. In this study, 72 paired soils (0–20 cm) from poplar shelterbelts and adjacent farmland sites were collected in six regions (Zhaozhou, Fuyu, Dumeng, Zhaodong, Lanling, and Mingshui) of northeastern China. Five soil fractions of dissolved organic C (DOC), particulate organic matter (POM), sand and stable aggregates (S + A), silt and clay (S + C), and resistant SOC (rSOC) and bulk soils were used in C content assay and the natural δ13C determination. The results showed that, compared with SOC, poplar shelterbelts resulted in SIC accrual in the soils across all six sites; however, only half of the six sites showed SOC accrual, indicating an ambiguous effect of afforestation on SOC. The natural δ13C method could identify the SOC turnover owing to the C isotopic discrimination. The δ13C–SOC-derived turnover ratio was 23%. When SIC was included in the δ13C measurement, bulk soils and four soil fractions (S + C, S + A, rSOC, DOC) showed a 2%–10% lower turnover percentage than the δ13C–SOC-derived turnover ratios. The SIC inclusion resulted in the dependency of δ13C–TC (TC = SIC + SOC) values on SOC (negative, R2: 0.21–0.44) and SIC content (positive, R2: 0.39–0.63). By contrast, when SIC was excluded, the δ13C–SOC values were independent of them (R2 < 0.18). Redundancy ordination analysis manifested that more SOC in the soils, together with more POM and farming uses would be accompanied with the lower δ13C values. Moreover, forest characteristics (e.g., age and density) and farmland backgrounds (e.g., crop history and distance between forest and farmland) could explain differences in δ13C-related features. Our results highlighted that SIC in natural δ13C determination underestimated the C turnover ratio in general. However, SIC storage should be included in the soil C sequestration evaluation owing to a general SIC accrual pattern across regions when compared with those of SOC.

Glomalin-related soil protein (GRSP) exhibits strong adsorption and sequestration capacities for heavy metals. However, the contribution rate of GRSP to the sequestration of soil heavy metals under rapid urbanization remains unclear. Therefore, 184 soil samples from the green spaces in a built-up area of Nanchang, China were selected as the research site according to the urbanization intensity levels and the impervious surface area rates. The GRSP, soil heavy metal (V, Ni, Cr, Cu, Pb, Co, As, Cd, and Zn), and GRSP-bound heavy metal contents were determined to analyze the adsorption potential and differences of GRSP for heavy metals. With increasing urbanization intensity, the Pb, Cd, and Cr contents decreased by 28-66%, and GRSP contents declined by 19-24% (P < 0.05). The contribution rates of GRSP-Cd, GRSP-Pb, and GRSP-Cr to Cd, Pb, and Cr sequestration were 1.98-3.35-fold higher in low urbanization areas than that in heavy urbanization areas (P < 0.05). The adsorption potential of GRSP-Cu was the highest (14.71-23.77%). The findings showed that GRSP could enhance the capability of heavy metals adsorbed by urban soil, while urbanization decreased the content and sequestration potential of GRSP-bound heavy metals, thereby contributing to the improvement of the urban soil environment.

For accurate and reliable monitoring, compliance monitoring devices (CMDs) in Port State Control must meet strict and uniform quality standards. This study evaluates how effectively CMDs, using variable fluorescence (VF) and fluorescein diacetate (FDA) technologies, detect live organisms in the 10–50 μm size range. Employing a detailed analytical framework, we analyzed key performance indicators, including accuracy, precision, sensitivity, specificity, trueness, detection limits, and reliability by comparing CMD outputs to those of traditional microscopic methods. Reliability assessments revealed that VF-type CMD and FDA-type CMD performed robustly, with a stability rate of 99% for both, surpassing the 90% verification threshold. Precision analysis indicated an average CV exceeding 0.25; however, some samples, especially those below the D-2 standard, achieved a CV of less than 0.25. Concordance evaluations revealed that VF-CMDs and FDA-CMDs achieved rates of 63% and 55%, respectively, falling short of the 80% verification standard and underscoring the need for further calibration or optimization. Structural equation modeling shows that organism density significantly influences CMD performance. These findings underscore the challenges of accurately detecting low organism concentrations, further complicated by biological diversity and environmental variability. Despite their limitations in assessing ballast water compliance, CMDs are effective initial screening tools.

Examining the changing patterns and underlying mechanisms of soil biomass carbon stocks constitutes a fundamental aspect of soil biology. Despite the potential influence of the sulfur cycle and the life strategies of organisms on community biomass, these factors have rarely been studied in tandem. Biocrusts are model systems for studying soil ecosystems. In this study, metagenomic analysis of biocrusts related to different life strategies from five batches over four consecutive years demonstrated that, in free-living communities, microbial biomass carbon (MBC) synthesis, via assimilatory sulfate reduction (ASR), is primarily coupled with the 3-hydroxypropionate/4-hydroxybutyrate and Calvin–Benson–Bassham cycles. These pathways are affected by the oxidation-reduction potential (Eh), pH, electrical conductivity, and nutrient levels. The decomposition of organic carbon (OC) via dissimilatory sulfate reduction (DSR) was accompanied by the production of dimethyl sulfide (DMS), which was influenced by the C/S ratio and moisture, whereas the synthesis of MBC by symbiotic communities was found to be affected by Eh and pH, and decomposition was affected by the C/S ratio. The MBC stock was influenced by all strategies, with resource strategies having the greatest impacts during the growing season, and the contribution of chemotrophic energy was most significant in free-living communities. In conclusion, the MBC in biocrusts is associated with both ASR and DSR and is facilitated by the A-, S-, and P-strategies under the regulation of the stoichiometric C/S ratio. The exploration of microbial life strategies and sulfur cycling in biocrusts within arid ecosystems in this study offers a new perspective on the patterns of change in soil biomass carbon stocks.

Urban forests are essential components of green infrastructure, however, rapid urbanization-induced changes in landscape patterns may affect their ecosystem services through complex ecological processes. A total of 184 sample plots in the built-up areas of Nanchang, China, were used as research sites. Urbanization intensities were categorized by the rate of impervious surface area, and forest types were classified into landscape and relaxation forest, attached forest (AF), road forest (RF), and ecological public welfare forest. This study aimed to explore the spatial variations in vegetation characteristics and landscape pattern indices of different forest types under rapid urbanization. The results indicated that the largest patch index (LPI), aggregation index (AI), and percentage of landscape (PLAND) in RF and AF were lower than those in the other forest types (p < 0.05). With increasing urbanization intensity, the mean perimeter-area ratio increased by 130.84

Soil health plays an important role in environmental and ecosystem sustainability. Urban forest soil health has been gradually deteriorating, resulting in several challenges. Here, a soil health index was employed to explore the soil health conditions and spatial differences in urban forests. We assessed soil health in urban forests in Nanchang, China, by establishing a minimum data set model using 20 soil indicators. The results suggested that the minimum data set included soil organic carbon, clay, pH, soil moisture content, nitrate nitrogen, and mean weight diameter, which could be key indicators for assessing soil health conditions. The average of the soil health index-total data set was 0.45 and that of the soil health index-minimum data set was 0.49, both representing grade III moderate health. Soil health index-minimum data set was positively correlated with soil health index-total data set (p < 0.001), with an R-2 of 0.77, which suggests that the minimum data set can closely reflect the total data set. In different urban forest types, the average soil health index value represented a grade III moderate health level, among which the soil health index value in landscape forest was remarkably higher (0.51) than that in the other forest types (p < 0.05). With increasing urbanization intensity, the soil health index decreased significantly (p < 0.05), indicating that soil health differed across the components of urban expansion. Our findings, along with further analysis and assessment of urban forest soil health index, can help establish a theoretical basis for soil management in the mid-reaches of the Yangtze River and provide references for managing the adverse effects of urbanization on soil health.

Exploring the mechanisms of the impacts of urbanization on soil aggregate stability and soil organic carbon （SOC） content will contribute to improving soil quality in urban greenspaces. Using the built-up area of Nanchang City, Jiangxi Province as a case study, the urbanization intensity was differentiated by impervious rate, and the vegetation characteristics and soil properties of 184 greenspace plots were investigated and determined. Variations in the stability parameters （geometric mean diameter, mean weight diameter, fractal dimension, and unstable aggregate index） and SOC contents across soil aggregate-size fractions （&gt;2, 1-2, 0.25-1, 0.053-0.25, and &lt;0.053 mm） and their interaction mechanisms with soil physicochemical properties and vegetation characteristics were analyzed in different urbanization intensities. The results showed that： ① The mass fractions of 0.053-0.25 mm aggregates in low urbanization areas were significantly lower than that in medium and high urbanization areas （P&lt;0.05）, whereas there was no significant difference in soil aggregate stability among different urbanization intensities （P&gt;0.05）. ② The SOC contents of &gt;2, 1-2, 0.25-1, and 0.053-0.25 mm aggregates were significantly higher than that in high urbanization areas by 26%-39% （P&lt;0.05）, while the SOC contents of &lt;0.053 mm aggregates were not affected by urbanization （P&gt;0.05）. ③ Both redundancy analysis and structural equation modeling demonstrated that urbanization influenced the changes in soil physicochemical properties （decreasing total nitrogen and phosphorus and increasing bulk density）, which indirectly reduced SOC accumulation of aggregates, whereas the larger tree height, diameter at breast height, crown diameter, diversity index, and herb coverage could directly or indirectly improve SOC content and the stability of aggregates. In conclusion, although urbanization indirectly decreased the SOC contents of aggregates, the aggregate stability was not affected by it. The manipulation of soil physicochemical properties and vegetation characteristics could alleviate the negative effects of urbanization on the SOC accumulation of aggregates, which provides a theoretical foundation for improving soil quality in urban greenspaces.

Toona ciliata var. pubescens, known as “Chinese mahogany”, has high commercial value and is classified as a level II priority protected wild plant in China. However, due to overexploitation and its poor natural regeneration capacity, natural T. ciliata var. pubescens forests show varying degrees of decline in habitat adaptability. Arbuscular mycorrhizal fungi (AMF) symbiosis presents a potential strategy to enhance its regeneration. In this study, T. ciliata var. pubescens seedlings were inoculated with Septoglomus viscosum, followed by RNA-Seq analysis to compare gene expression differences between AMF-inoculated (AMI) and non-mycorrhizal (NM) treatments three months post-inoculation. A total of 16,163 differentially expressed genes (DEGs) were upregulated by AMF colonization, constituting 96.46% of the total DEGs. Specifically, 14,420 DEGs were exclusively expressed in the AMI treatment, while 35 DEGs were completely silenced. Most of the upregulated DEGs were located on the cell membrane, nucleus, and cytoskeleton and functioned in protein binding, S-adenosylmethionine-dependent methyltransferase activity, and lipid binding during cellular/macromolecule/protein localization, intracellular/protein transport, the cell cycle, and signal transduction. Additionally, lots of key genes related to oxidative stress responses, nutrient transport, and small GTPase-mediated signal transduction were found to be upregulated. These results suggest that AMF inoculation may enhance root cell growth by activating genes involved in nutrient uptake, stress responses, signal transduction, and substance transportation. This study elucidates the molecular mechanisms underlying the growth promotion of T. ciliata var. pubescens through AMF symbiosis, laying a foundation for the future application of AMF in its natural forest regeneration.

This study aimed to explore the impact of the expansion and subsequent felling of Moso bamboo (Phyllostachys pubescens), a dominant species in China's bamboo cultivation history, on both above-ground and underground soil fauna communities and the soil food web within Japanese cedar (Cryptomeria japonica) forests in Lushan Mountain, subtropical China. We identified three distinct areas where Moso bamboo had expanded into pure Japanese cedar forests. In each area, two experimental scenarios were created: a deforestation site (DF) where Moso bamboo had intruded and was later felled, and a control site (UF) with ongoing bamboo growth. Soil fauna communities were collected using pitfall traps (above-ground soil fauna) and the Tullgren dry funnel method (underground soil fauna), while stable isotope analyses were used to determine the trophic levels of these communities. Deforestation significantly reduced the abundance of Acari, the most populous taxon, as well as Collembola, Diptera, and Diptera larvae. Above-ground Hymenoptera populations declined in deforested plots, while underground numbers rose. Undeforested forests supported higher densities of Coleoptera, Hymenoptera, and Arachnida. Despite similar annual biomass trends across plots, deforested areas had a greater biomass, driven by larger soil fauna. Soil total nitrogen, total phosphorus, and organic matter content increased in deforested areas and showed a strong correlation with most soil fauna, especially Diptera larvae. Following deforestation, habitat alterations have affected soil fauna's food sources, resulting in a lower trophic level for groups like Diptera, Collembola, and Hymenoptera. Our study underscores the significant impact of Moso bamboo expansion and subsequent felling on the soil fauna communities and food web in Cryptomeria japonica forests. These findings highlight the need for further research into the long-term effects and recovery patterns of these ecosystems.

The dinoflagellate cysts present in the ballast water sediment of foreign ships in Shanghai Port have not been previously studied. Therefore, sediment samples were collected from the ballast water of 16 foreign ships in Shanghai Port, and the types of dinoflagellate cysts were identified and their abundance was calculated, with a specific focus on the analysis of toxic and harmful dinoflagellates. Moreover, simulations of temperature and salinity conditions throughout the year in the Shanghai port waters were conducted to carry out dinoflagellate cyst germination experiments, with analyze and compare the germinated dinoflagellate cysts under different conditions. Dinoflagellate cysts were found in 100 % of the ship sediment samples, including a total of 9 species of toxic and harmful dinoflagellate cysts. In the germination experiment, 15 °C was found to be the optimal temperature for the germination of dinoflagellate cysts in ballast water sediment, and high salinity is more favorable for cyst germination.

Soil microorganisms and enzymes play crucial roles in soil organic carbon (SOC) sequestration by promoting soil aggregate formation and stability and by participating in SOC cycling and accumulation. However, the effects by which soil microorganisms and enzymes act as mediators driving dynamic changes in SOC during rapid urbanization remain unclear. Therefore, this study selected the built-up area of Nanchang City, China (505 km2), as the study area. Sampling surveys were conducted using 184 sample plots stratified based on the proportion of impermeable surface area to distinguish different urbanization levels. The driving factors of dynamic changes in SOC of different aggregates during the process of urbanization were analyzed using the soil microbial community and enzyme activities. The results demonstrated that with an increase in urbanization intensity, both SOC content and stock exhibited a significant decline (p < 0.05). The highest SOC stock and contribution rate were observed in the 0.25–1 mm aggregates, and they were significantly influenced by urbanization (p < 0.05). In addition, the biomass of gram-positive bacteria (G+) and actinomycetota, and the activities of N-acetylglucosaminidase and acid phosphatase (AP) were significantly higher in low-urbanization areas than in high-urbanization areas (p < 0.05). SOC of each aggregate was positively correlated with fungi, arbuscular mycorrhizal fungi, G+, gram-negative bacteria, actinomycetota, protozoa, β-1,4-glucosidase, N-acetylglucosaminidase, AP, urease, and catalase. Compared to soil enzymes, soil microorganisms exhibited a greater role in SOC sequestration (22.7%). Additionally, a structural equation model indicated that urbanization can directly or indirectly lead to a decrease in SOC of aggregates by altering soil physicochemical properties and affecting microbial and enzyme dynamics. However, the larger vegetation characteristics index mitigate the negative impacts of urbanization on SOC. Overall, urbanization had a negative impact on soil carbon storage. In the future, it is important to consider strategies that focus on improving soil nutrients, maintaining soil structure, protecting existing urban trees, and enhancing plant diversity during the urbanization process. These measures can help increase soil microbial biomass and enzyme activity, thereby improving soil and aggregate-related SOC content. The study could contribute to enhancing carbon sequestration in urban greenspaces.

Rosa rugosa, which originated in China, is an important industrial plant, which have been used for landscaping, while its components have been included in foods, pharmaceuticals, and beauty and skin care products. As a potential available oil rose variety, the limited comprehensive understanding of R. rugosa 'Han Xiang' has hindered their development and utilization. In this study, UPLC-MS/MS and GC-MS techniques were applied to analyze metabolite dynamics during the development and processing of R. rugosa flowers. In total, 1816 nonvolatile metabolites and 1029 volatile metabolites were identified in the development and processing of R. rugosa flowers. Significant differences in the non-volatile and volatile metabolites were detected in the petals and hydrosol. The differentially regulated non-volatile metabolite contents were highest in the bud stage petals, the differentially regulated volatile metabolite contents were highest in the full-bloom stage petals. Some key metabolites affect the presentation of rose color, flavor, and taste, as well as the efficacy of the product. The aim of this article is to provide a comprehensive understanding of R. rugosa 'Han Xiang' and to serve as a basis for further research and development. This study provides useful data for assessing rose flower quality as well as new insights into R. rugosa development and utility.

Rapid urbanization has exerted immense pressure on urban environments, severely constraining the growth of ancient trees. The growth of ancient trees is closely linked to the microbial communities in their rhizospheres, and studying their community characteristics may provide new insights into promoting the growth and rejuvenation of ancient trees. In this study, the rhizosphere soil and root systems of ancient Ginkgo biloba trees (approximately 200 years old) and adult G. biloba trees (approximately 50 years old) in Shanghai were selected as research subjects. Phospholipid fatty acid (PLFA) analysis and high-throughput sequencing were employed to investigate the diversity of microbial communities in the G. biloba rhizosphere. The results indicated that the 19 PLFA species selected to characterize the soil microbial community structure and biomass were present in the rhizosphere soil of both ancient and adult G. biloba trees. However, the total microbial biomass and the microbial biomass in the rhizosphere soil of ancient G. biloba were lower than the microbial biomass in the rhizosphere soil of adult G. biloba. The biomasses of Gram-negative bacteria (G−), arbuscular mycorrhizal fungi (AMF), and protozoans (P) were significantly different. Total phosphorus, organic matter, and pH may be the key factors influencing the soil microbial community in the rhizosphere zone of ancient G. biloba. An in-depth study of AMF showed that the roots and rhizosphere soil of G. biloba contained abundant AMF resources, which were assigned to 224 virtual taxa using the MaarjAM reference database, belonging to four orders, ten families, and nineteen genera. The first and second most dominant genera were Glomus and Paraglomus, respectively. Archaeospora and Ambispora were more dominant in the rhizosphere than the roots. Furthermore, the abundance of live AMF was significantly higher in ancient G. biloba than in adult G. biloba. Therefore, future research should focus on the improvement of soil environmental characteristics and the identification and cultivation of indigenous dominant AMF in the rhizosphere of ancient G. biloba, aiming for their effective application in the rejuvenation of ancient trees.