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, Available online doi: 10.11833/j.issn.2095-0756.20260149
Abstract:
Objective This study examined the retrogressive succession of alpine grasslands in Gannan Tibetan Autonomous Prefecture under Ligularia virgaurea expansion, and the associated shifts in community structure and functional characteristics of poisonous-weed-dominated degraded grasslands. Method Taking the typical Ligularia virgaurea-degraded alpine grasslands in Xiahe, Luqu, and Maqu counties as the study area, 4 degradation gradients (non-degraded, lightly degraded, moderately degraded, and severely degraded) were established. Through field vegetation quadrat surveys combined with quantitative ecological analysis, the variations in community structure, species diversity, and biomass were systematically investigated across different successional stages of degradation. Result With increasing degradation intensity, the dominance of desirable forage species from Poaceae and Cyperaceae decreased significantly (P＜0.05), and the community dominance was progressively replaced by Ligularia virgaurea. Species diversity showed marked spatial heterogeneity across sites. In Xiahe and Maqu sites, the Shannon-Wiener index and Pielou evenness index were generally highest at the lightly or moderately degraded stages, while in Luqu site, these indices were lowest at the lightly degraded stage. Species richness was significantly (P＜ 0.05) higher at the lightly or moderately degraded stages than at the other degradation gradients. Aboveground total biomass was significantly (P＜0.05) highest at the severely degraded stage in all 3 counties. However, when Ligularia virgaurea biomass was excluded, the highest biomass was observed at the non-degraded stage in Xiahe and Maqu, and at the lightly degraded stage in Luqu. Biomass of desirable forage species consistently peaked at the non-degraded stage across all sites. Belowground biomass showed pronounced regional heterogeneity across sites. In Xiahe and Luqu sites, belowground biomass reached its minimum at the severely degraded stage, whereas in Maqu site, it peaked at the severely degraded stage. Conclusion Overall, the findings demonstrate that Ligularia virgaurea expansion is a key driver of retrogressive succession and the formation of poisonous-weed-dominated degradation in the alpine grasslands of Gannan. These results provide a scientific basis for ecological restoration and near-natural community reconstruction of poisonous-weed-degraded grasslands in this region. [Ch, 3 fig. 4 tab. 42 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260170
Abstract:
Objective Anoectochilus roxburghii is the sole medicinal source for industrial production of kinsenoside and also serves as a material for ornamental bonsai. Currently, commercially available A. roxburghii is primarily derived from artificial cultivation. However, the effects of three main cultivation modes (tissue culture, understory planting, and greenhouse planting) on phenotype, kinsenoside accumulation, and leaf coloration remain unclear. This study aims to elucidate the effects of these three cultivation modes on the phenotype and quality of A. roxburghii. Method The effects of cultivation modes on phenotype were analyzed using macroscopic and microscopic observations. Leaf coloration was investigated by color observation, digitization, and metabolomics. Kinsenoside accumulation was determined by HPLC-ELSD and metabolomics. Result Significant or non-significant differences in biomass per plant, stem length, stem diameter, leaf area, and root length were observed among the three modes. These indicators were the highest in understory-grown plants, followed by greenhouse-grown plants, and the lowest in tissue-cultured plants. Microstructural analysis showed that differences in cell morphology, size, and arrangement contributed to the variations in stem length and leaf area. Leaf coloration was mode-specific and showed a “dark adaxial and light abaxial” pattern. Understory-grown plants exhibited the deepest color, followed by greenhouse-grown plants, and tissue-cultured plants were the lightest. The accumulation patterns of rhodionin, quercetin-O-glucoside, kaempferol-3-O-galactoside, kaempferol, quercetin-3β-pyranoglucosyl-6′-acetate, rutin, quercetin, quercetin-3β-D-glucoside, and rhamnetin were consistent with leaf color phenotypes and showed negative correlations (significant or not) with color parameters. These metabolites are the main pigments for leaf coloration. No kinsenoside isomer was detected in plants of all three modes. Kinsenoside was mainly accumulated in aerial parts, with content ranked as: understory-grown＞ tissue-cultured＞ greenhouse-grown. Conclusion Understory cultivation can simultaneously improve biomass, ornamental leaf color, and kinsenoside content in A. roxburghii, representing the optimal mode for efficient cultivation of high-quality and high-color varieties. The results provide a scientific basis for quality evaluation and support precision breeding and standardized cultivation. [Ch, 5 fig, 5 tab. 31 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260332
Abstract:
Objective This study aims to clarify the layer-specific effects of stand density on the composition and diversity pattern of the understory shrub and herb communities in Pinus tabuliformis plantations on the Loess Plateau. Method Five P. tabuliformis plantations with different stand densities were selected: low density (800 plants·hm−2), medium-low density (1 200 plants·hm−2), medium density (1 600 plants·hm−2), medium-high density (2 000 plants·hm−2), and high density (2 400 plants·hm−2). Species composition of the shrub and herb layers was investigated, and importance values, α diversity indices, and β diversity were calculated. Principal coordinate analysis (PCoA) and permutational multivariate analysis of variance (PERMANOVA) were used to examine differences in the composition of the understory shrub and herb communities under different densities. Result With increasing stand density, the dominant species of shrub and herb layers both changed markedly. In the shrub layer, the dominant species gradually changed from Hippophae rhamnoides and Xanthoceras sorbifolium under low density to Caragana korshinskii, Caryopteris mongholica, and Prinsepia uniflora under medium-high and high densities. In the herb layer, the dominant species changed from Potentilla sischanensis and Saussurea japonica to Stipa bungeana, Artemisia sacrorum, and Astragalus melilotoides. The overall α diversity of the shrub layer was generally higher under medium-low density, with Margalef richness, Shannon-Wiener, Simpson, and Pielou evenness indices being 1.34, 1.63, 0.80, and 0.98, respectively, and then decreased with increasing stand density. The α diversity of the herb layer increased first and then decreased with increasing stand density, and reached the highest level under medium density. The Margalef richness index, Shannon-Wiener index, Simpson index and Pielou evenness index were 2.44, 2.51, 0.91, and 0.97, respectively. The community composition of both layers under different densities showed significant differentiation. The β diversity was mainly due to the species turnover component. The species turnover intensity of the shrub layer generally increased with stand density, with the most significant difference observed between medium-high and high density stands, while the species turnover of the herb layer was mainly concentrated in low-density and medium to low density forests. The contribution rate of species to β diversity (SCBD) showed that the compositional differentiation of the shrub layer was mainly associated with changes in the importance values of species such as C. mongholica, C. korshinskii, X. sorbifolium, P. uniflora, and Lespedeza bicolor, while the composition differentiation of the herb layer was mainly related to the changes in the importance values of species such as P. sischanensis, S. bungeana, Picris hieracioides, Glycyrrhiza uralensis, Potentilla chinensis, Dracocephalum moldavica, Poa sphondylodes, and A. melilotoides. Conclusion Medium-low density and medium density stands are more conducive to maintaining the diversity of the understory shrub and herb communities in P. tabuliformis plantations. Among them, medium-low density stands were more favorable for shrub-layer diversity, while medium density stands are more favorable for the diversity of the herb layer. [Ch, 3 fig. 4 tab. 32 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260186
Abstract:
Objective Integrating ecosystem service supply and demand into ecological security patterns has opened up a new approach for revealing the dynamic connections between ecological processes and societal activities. Method Taking Hangzhou metropolitan circle as a case study, this study used multi-source data (land use, ecological remote sensing, basic geographic data) and models (InVEST, ArcGIS, Linkage Mapper) to quantify five ecosystem services (carbon sequestration, water conservation, food production, habitat quality, landscape recreation) from 2004 to 2024. then extracted ecological corridors, ecological pinch points, and ecological barrier points from an ecological resistance surface, and supply-demand corridors from a movement resistance surface to construct a social-ecological security pattern, which was optimized by setting supply-demand nodes and extracting optimized corridors. Result (1) The matching of supply and demand of comprehensive ecosystem services formed a spatial pattern of “surplus in the west and deficit in the east.” Economic growth (absolute mean value of coefficient: 0.91) was the core driving force for the aggravation of supply and demand imbalance. (2) From 2004 to 2024, the ecological sources were greatly reduced by 2026.11 km2, and the demand sources were slightly reduced by 177.80 km2. (3) The ecological corridors in the western region were “long and concentrated” cobweb-like distribution, and the supply-demand corridors formed a “short and sparse” decentralized pattern. The number of pinch points increased by 20, and the number of barrier points increased by 13. (4) In 2024, 8 supply-demand nodes and 14 optimized corridors were identified. Based on the supply-demand relationship of ecosystem services and spatiotemporal characteristics of social-ecological security pattern in Hangzhou metropolitan circle in 2024, an optimized layout scheme of “three belts, three clusters and four zones” was formed. Conclusion This study reveals the spatial mismatch pattern of the social-ecological security pattern of the imbalance between supply and demand of ecosystem services in Hangzhou metropolitan circle. Future efforts should protect the western ecological source areas, restore the broken corridors in the central region, and regulate the demand hotspots in the eastern region, driving the social-ecological system from spatial alignment toward functional synergy. [Ch, 5 fig. 3 tab. 35 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260196
Abstract:
Objective Aiming at the problems of long identification and screening cycles and high research and development costs of traditional bioactive peptides, as well as the limitation that existing machine learning-based peptide activity prediction models adopting a single data embedding method struggle to distinguish the sequence features of peptides with different action targets under the same biological function, this study develops a multi-task bioactive peptide prediction model integrating a customized gating unit, contrastive learning and cross-attention mechanism. Method This study combined pre-trained models for protein sequence and structure and peptide physicochemical property prediction models with a Transformer encoder, adopted an expert gating system to optimize the model architecture, and integrated comprehensive information including target structure, peptide sequence and physicochemical properties to optimize and predict bioactive peptide-target classification. Result A novel multi-task bioactive peptide prediction model named Biopepformer was developed in this study. In the peptide target classification task, the model achieved an overall accuracy of 0.899 and a weighted F1 score of 0.902 on the hypolipidemic bioactive peptide dataset. In the binary binding prediction task, it obtained an F1-score of 0.958, an average accuracy of 0.959 and an average area under curve (AUC) of 0.952, with its performance significantly outperforming that of traditional machine learning models. Further ablation experiments confirmed that the multi-task learning framework and the gated mixture-of-experts unit were the key contributors to the model’s performance improvement. After transfering fine-tuning of the pre-trained model to the hypoglycemic bioactive peptide dataset, the model achieved an F1 score of 0.969, an overall accuracy of 0.969 and an AUC of 0.976 in the target binding prediction task, as well as an average accuracy of 0.863 and a weighted F1-score of 0.884 in the target classification task, demonstrating its potential for cross-target generalization. Conclusion Biopepformer can serve as an efficient virtual screening tool for the mining and design of bioactive peptides targeting different targets, and also provides a novel approach for the bioactivity exploration of functional bioactive peptides. [Ch, 6 fig. 1 tab. 25 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260207
Abstract:
Objective The purpose is to clarify the differences in the coupling and coordination relationships between healthy and dead Picea crassifolia vegetation and soil across different gullies in Helan Mountain of Inner Mongolia, and to accurately assess the current status and degradation stages of forest decline. Method P. crassifolia trees were selected from 5 typical gullies: Zhenmuguan, Maoleqike, Xialingnangou, Ganshuwan, and Zhongliangzi. Based on the investigation and analysis of the target tree species and soil conditions, an evaluation system comprising 6 vegetation indicators and 11 soil indicators was constructed. The Analytic Hierarchy Process (AHP) and the entropy weight method were utilized to determine the weights of each indicator. A coupling coordination degree model was then employed to evaluate the coordination status between P. crassifolia vegetation and soil system under different growth conditions across Helan Mountain. Result (1) Moisture content and bulk density in soil were the main limiting factors affecting the growth status of P. crassifolia. (2) In both healthy and dead sample plots, the contents of total nitrogen and soil organic carbon were significantly positively correlated with growth indicators such as tree height and diameter at breast height (P＜0.05). In the dead sample plots, soil conductivity was positively correlated with plant mortality rate. (3) The overall coupling coordination degree between vegetation and soil for both healthy and dead P. crassifolia across different gullies was relatively low. Even in healthy sample plots, the vegetation-soil system showed a trend of degradation. (4) In healthy sample plots, Zhenmuguan and Ganshuwan were respectively at the levels of soil-lagging and vegetation-lagging development, while Maoleqike, Xialingnangou, and Zhongliangzi were in varying degrees of vegetation-soil synchronous development. The mortality process further exacerbated the system imbalance in the dead sample plots, which led to the transformation of Zhenmuguan and Ganshuwan into areas with low-level vegetation and soil synchronous development, Zhongliangzi into an area with delayed vegetation development, while the coupling patterns of Maoleqike and Xialingnangou remained unchanged. Conclusion There are significant differences in the coupling coordination relationship between vegetation and soil systems of healthy and dead P. crassifolia stands in different gullies of Helan Mountain, exhibiting an overall low-level coordination state. The vegetation-soil system in healthy plots show a trend of degradation while that in dead plots remained in an imbalanced state. [Ch, 3 fig. 5 tab. 51 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260163
Abstract:
Objective This study aims to overcome the limitations of traditional average crown width modeling methods in depicting the spatial extreme expansion capabilities of trees, accurately describing the maximum crown width growth potential of trees under density constraints, and providing a theoretical basis for reasonable stand density management. Method Based on field survey data from 91 permanent sample plots of Larix olgensis plantations located on the western slope of Zhangguangcai Mountains, relative stand density (RD) was calculated using Reineke’s stand density relationship. Quantile regression and nonlinear mixed-effects quantile regression were employed to construct maximum crown width–diameter at breast height (DBH) models, and model performance was evaluated using the root mean square error (RMSE) and adjusted coefficient of determination (Radj 2). Result Compared to the base maximum crown width model, the generalized maximum crown width model with the inclusion of RD shows slight improvements in fitting performance, with Radj 2 increasing by approximately 10.6% and RMSE decreasing by about 2.8%. The overall fitting accuracy of the quantile maximum crown width model is lower than that of the base maximum crown width model, with Radj 2 decreasing by about 19.8% and RMSE increasing by about 19.3%. In contrast, the nonlinear mixed-effects quantile maximum crown width model at τ=0.90 shows significant advantages (P＜0.05). Compared to the base model, its Radj 2 increases by approximately 52.6% and RMSE decreases by about 13.8%. The τ=0.90 quantile curves at different density levels show significant differences. Under the same diameter conditions, the maximum crown width corresponding to RD=0.2 is generally the highest, while that for RD=0.8 is the lowest, indicating that low-density conditions are more conducive to the potential crown expansion of trees, while crown growth is significantly suppressed under high-density conditions. The quantile curves for different density levels crossed at medium and large diameter stages (DBH≥22 cm), reflecting the variation of density effects with diameter class. The test results showed that the model performance in prediction was ranked as follows: nonlinear mixed-effects quantile maximum crown width model ＞ generalized maximum crown width model＞base maximum crown width model＞quantile maximum crown width model. Conclusion Indicate that nonlinear mixed-effects quantile regression is effective in capturing variations in maximum crown width of L. olgensis plantations across different RD levels. Particularly at the τ=0.90 quantile, the model not only reveals an overall decreasing trend in maximum crown width with increasing stand density, but also identifies diameter-dependent thresholds at which density effects shift, demonstrating that the regulatory influence of stand density on potential crown expansion is not constant across growth stages. By accounting for plot-level heterogeneity while improving model stability and prediction accuracy, this approach provides a robust quantitative basis for density regulation and precision management of L. olgensis plantations at different developmental stages. [Ch, 1 fig. 5 tab. 38 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260166
Abstract:
Objective The trehalose-6-phosphate phosphatase encoding gene CnRAMOSA3 (CnRA3) was cloned from Chrysanthemum nankingense, and its bioinformatics characteristics and expression patterns were analyzed to characterize its structural features and explore its potential roles in abiotic stress responses. Method Using C. nankingense as the experimental material, the full-length coding sequence of the CnRA3 gene was cloned based on transcriptome database information. Bioinformatics analysis were conducted to investigate its phylogenetic relationships, protein structural characteristics, and cis-acting elements in the promoter region. In addition, real-time quantitative PCR (RT-qPCR) was employed to analyze the expression patterns of CnRA3 under exogenous abscisic acid (ABA), PEG-simulated drought, and salt stress treatments, as well as in different tissues. Result The open reading frame (ORF) of CnRA3 was 1095 bp in length, encoding 364 amino acids. The encoded protein contained a typical trehalose-6-phosphate phosphatase (TPP) domain, without transmembrane structure, and exhibited overall hydrophilic characteristics. Phylogenetic analysis showed that CnRA3 was conserved in the Asteraceae family, with its promoter enriched in ABA- and stress-responsive cis-acting elements. RT-qPCR analysis revealed that CnRA3 was expressed in multiple tissues with distinct tissue specificity and developmental stage differences. During the vegetative growth stage, CnRA3 was primarily expressed in stems and shoot tips, while during the reproductive growth stage, it was mainly expressed in roots and stems. Under ABA, PEG, and salt stress treatments, the expression level of CnRA3 changed significantly, exhibiting a time-dependent decrease followed by an increase. Conclusion CnRA3 may exhibit an inhibitory response under drought and salt stress conditions and participate in ABA-mediated abiotic stress responses. [Ch, 5 fig. 2 tab. 26 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260182
Abstract:
Objective The aim of this study is to explore the effects of different green manure and organic fertilizer combination treatments on the structure of soil arbuscular mycorrhizal (AM) fungal communities and Citrus reticulata fruit quality through field experiments, so as to provide a scientific basis for sustainable green C. reticulata production. Method In a field experiment in the C. reticulata orchard of Quzhou, Zhejiang Province, four green manure treatments were set up: clean tillage (ck), Vulpia myuros, Trifolium repens, and Astragalus sinicus, each paired with compound fertilizer (CF), commercial organic fertilizer (COF), and bio-organic fertilizer (BOF). After two years, fruit quality, soil chemical properties, enzyme activities, and AM fungal spore density were measured. AM fungal community structure was analyzed via Illumina MiSeq sequencing, and the community stability was assessed by co-occurrence network analysis. Result Compared with the application of ck combined with CF, the treatment of V. myuros combined with BOF significantly increased fruit soluble solids-to-titratable acidity ratio and vitamin C content by 73.6% and 16.6% (P＜0.05), respectively. At the same time, soil total nitrogen, easily extractable glomalin and AM fungal spore density significantly increased (P＜0.05). After the combined application of green manure and organic fertilizer, the dominant genera shifted to Glomus, Claroideoglomus and Paraglomus. The combination of green manure and organic fertilizer enhanced AM fungal network modularity, with a modularity index of 0.844 for the treatment of V. myuros with BOF. Conclusion The combined application of green manure (especially V. myuros) and bio-organic fertilizer can improve soil nutrient and glomalin contents, optimize AM fungal community structure and increase network modularity, and promote C. reticulata fruit quality. [Ch, 7 fig. 4 tab. 58 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20250599
Abstract:
Objective Crocus sativus is an important medicinal plant whose dried stigmas possess high economic value. However, due to its complex triploid genome, FT homologs have not been systematically characterized. This study aims to identify key FT homologs involved in floral primordium differentiation, thereby providing candidate genes for elucidating flowering mechanisms and molecular breeding in saffron. Method Based on the recently published haplotype-resolved genome, FT genes associated with floral primordium differentiation were identified and functionally analyzed. Members of the PEBP gene family were identified through bioinformatics analysis, and a phylogenetic tree was constructed for subfamily classification. Transcriptome data from key stages of floral primordium differentiation were integrated to identify 5 FT-like genes potentially involved in this process. Result CsatFT2-1 and CsatFT2-2 were continuously upregulated from the early stages of floral primordium differentiation in flowering apical buds under normal temperature conditions and exhibited significantly higher expression levels than those in non-flowering buds under low-temperature conditions. Their expression levels were extremely low or undetectable in non-flowering samples but gradually increased during floral development. In contrast, CsatFT3-1, CsatFT3-2, and CsatFT6-1 showed increasing expression trends, but no obvious differences were observed between flowering and non-flowering samples, and CsatFT6-1 exhibited overall low expression levels. These results suggested that CsatFT2 genes may participate in floral initiation. Among them, CsatFT2-2 showed specifically high expression in flowering apical buds, indicating an important role in floral primordium differentiation and flowering induction. CsatFT2-2 belongs to the flowering-promotive clade and contains a conserved PEBP domain. RT-qPCR analysis showed that the expression level of CsatFT2-2 increased by approximately 20-fold during flowering induction under normal temperature conditions but was significantly downregulated under low temperature, drought, and hypoxic stresses. Subcellular localization analysis reveals that the CsatFT2-2 protein was localized in the nucleus and plasma membrane. Heterologous overexpression of CsatFT2-2 in Arabidopsis thaliana resulted in bolting approximately 9 days earlier and reduced rosette leaf number by approximately 54%, further confirming its flowering-promoting function. Conclusion This study systematically reveals the roles of FT homologs in flowering regulation in C. sativus and identified CsatFT2-2 as a key positive regulatory gene involved in floral primordium differentiation, providing an important molecular target for elucidating flowering mechanisms and molecular breeding in saffron. [Ch, 8 fig. 2 tab. 30 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260233
Abstract:
Objective To address the harsh conditions and poor selectivity control in conventional monophasic hydrodeoxygenation (HDO) of anisole, a decalin/water biphasic catalytic system was developed and evaluated. Method Amphiphilic Ru/xNb2O5-yMC(x+y=100) catalysts were synthesized and characterized by SEM, TEM, XRD, BET, and contact angle measurements. The HDO performance of anisole was investigated in a decalin/water biphasic system under various catalyst compositions, solvent ratios, temperatures, and hydrogen pressures. Result The Ru/40Nb2O5-60MC catalyst exhibited the largest specific surface area (366.7 m2·g−1) and optimal amphiphilicity. Under 200 ℃ and 0.6 MPa initial H2 pressure for 6.0 h, anisole conversion reached 62.7% with 91.9% benzene selectivity. The catalyst showed no significant deactivation after five cycles. The apparent activation energy was 49.57 kJ·mol−1, much lower than the typical C–O bond dissociation energy (＞240 kJ·mol−1). Conclusion The synergy between Ru nanoparticles and the Nb2O5-MC composite support, along with tunable wettability, enables highly selective HDO of anisole to benzene under mild conditions. This biphasic strategy offers a promising route for upgrading lignin-derived phenolic compounds from agricultural and forestry waste. [Ch, 6 fig. 2 tab. 41 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260181
Abstract:
Objective The objective is to explore a scientific and reasonable grassland management model to maintain the stability of grassland ecosystem structure and function. Method A comparative experiment involving long-term enclosure and moderate grazing was conducted to investigate the effects of the two management practices on grassland plant community structure, species diversity, and productivity in an alpine grassland on the eastern margin of the Qinghai-Tibet Plateau. Result (1) Compared with grazing, long-term enclosure significantly reduced overall plant diversity of grassland communities (P＜ 0.05), with the most significant declines observed in the species richness of legumes, sedges, and forbs. (2) Enclosure did not significantly alter total aboveground biomass, but it significantly shifted biomass allocation among functional groups, significantly promoting biomass accumulation in legumes and forbs (P＜0.05). Additionally, enclosure led to substantial litter accumulation (about 5.5 times that of grazed grasslands). (3) Long-term enclosure significantly reduced species evenness compared with moderate grazing (P＜0.001), resulting in a significant differentiation in plant community structure and function. Conclusion Long-term enclosure drives grassland plant communities toward high productivity characterized by increased biomass and litter accumulation, while grazing is beneficial for the maintenance of a high level of species diversity. For non-degraded alpine grasslands, moderate grazing is more conducive to maintaining species diversity and stabilizing ecosystem functions. [Ch, 6 fig. 1 tab. 54 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20260146
Abstract:
Objective The objective is to investigate the passivation effects of Fe-Mg bimetallic modified coconut shell biochar (FCBC) on arsenic (As) and cadmium (Cd) in tropical paddy soil under different moisture conditions, as well as its impact on microbial community structure. Method A 30-day indoor soil incubation experiment was performed from August to September 2025, with two moisture treatments: flooded and moist. The effects of FCBC on the mobility of As and Cd, soil physicochemical properties, and microbial community structure were systematically analyzed. Result Compared with the control and unmodified biochar, FCBC significantly (P＜0.05) reduced the contents of available As (by 8.74%–12.5%) and available Cd (by 92.88%–93.50%) in soil under moist conditions. Under flooded conditions, it decreased the available Cd content (by 76.92%–86.2%), but significantly (P＜ 0.05) promoted the migration and transformation of As (by 24.95%–33.45%), thereby increasing its potential ecological risk. Mantel analysis revealed that the passivation effect of FCBC on As was mainly regulated by Fe and S cycling driven by moisture changes, while its effect on Cd was primarily achieved by altering soil pH and other physicochemical properties. The application of FCBC overall reduced soil microbial α-diversity and significantly altered the bacterial community structure under different moisture conditions. Compared with other treatments, FCBC significantly decreased the relative abundance of taxa such as Thermodesulfobacteriota, and Clostridium, and increased that of Pseudomonadota, Microvirga and Neobacillus, thereby affecting the migration and transformation of As and Cd. Moisture conditions further affected bacterial community composition. Co-occurrence network analysis showed that FCBC reduced the complexity and stability of the soil bacterial network, while the anaerobic environment enhanced the synergistic relationships among bacterial species. The functional prediction results of PICRUSt2 revealed that the application of FCBC under aerobic conditions enhanced protein functions related to As and Cd resistance, and promoted key metabolic processes such as amino acid metabolism and organic matter synthesis. Conclusion The synergistic effect of moisture management and Fe-Mg modified coconut shell biochar affects the migration and transformation of As and Cd in paddy soil by regulating the structure and function of microbial communities.[Ch, 8 fig. 3 tab. 38 ref.]
