Biochar is increasingly promoted as a climate-smart amendment, yet its long-term effects on nutrient retention and greenhouse gas emissions in flooded rice systems remain poorly resolved. Here, we combine a 13 year field trial with graded straw biochar applications (0-22.5 t ha-1 season-1) and a 60 day anaerobic incubation of year-13 soils to investigate how mineral and microbial processes regulate soil organic carbon (SOC), phosphorus (P), and methane (CH4) dynamics. Long-term biochar progressively depleted Fe oxides and enriched Ca phases, promoting the formation of Ca-bridged OC-mineral-P complexes that costabilize OC and P. Under prolonged anoxia, soils amended with high rates of biochar exhibited 2.5-3.2-fold slower Fe(III) reduction and delayed sulfate reduction, resulting in 53-80% lower CH4 emissions and 60-71% P release relative to the no-biochar control. Nanoscale imaging and microbial profiling corroborated this mineral transition, showing a shift toward redox-resilient organo-mineral complexes and microbial communities associated with suppressed methanogenesis and enhanced nutrient retention. These findings provide long-term field-based evidence that biochar can simultaneously sustain crop productivity, enhance C and P retention, and mitigate CH4 emissions in flooded rice agroecosystems. Our findings highlight biochar's potential as a scalable nature-based strategy for integrating nutrient management with climate mitigation in global rice production.

Ditches function as vital biogeochemical buffers that mediate phosphorus (P) transport from agricultural landscapes to downstream water bodies. However, their capacity to retain or release P is highly sensitive to hydrodynamic forces, particularly flow velocity. In this study, we employed a controlled ditch mesocosm to investigate the effects of contrasting flow velocities (V3: 3 cm s- 1; V10: 10 cm s- 1) on P dynamics. Total P (TP) concentrations in the water column declined under both treatments, with the maximum TP removal rate reaching 209 mu mol P m- 2 h-1 at 12 h under V3, compared to 184 mu mol P m- 2 h-1 under V10. Particulate P (PP) behavior exhibited flow-dependence: sedimentation dominated under V3, while V10 induced sediment resuspension and elevated PP concentrations. High flow conditions also stimulated alkaline phosphatase (ALP) activity and microbial diversity in suspended particulate matter (SPM), accelerating organic P (OP) mineralization. Diffusive P flux across the sediment-water interface was significantly greater under V10 (0.58 pg s- 1 cm- 2) than V3 (0.38 pg s-1 cm- 2), driven by shear stress and redox fluctuations. Sediment-derived P resuspension increased nearly ninefold under V10 (7.54 mg m- 2 h-1) relative to V3 (0.88 mg m- 2 h-1). These findings demonstrate that flow velocity governs the balance between P retention and release through interacting physical and microbial processes, offering new insight into the design and management of ecologically engineered ditch systems.

Benthic macroinvertebrates are widely used as bioindicators for assessing freshwater eco-system health. This study investigated the diversity patterns and community structure of benthic macroinvertebrates across 21 sampling sites along the middle and lower reaches of the Yangtze River. A total of 74 species belonging to 3 phyla, 7 classes, 17 orders, 37 families, and 58 genera were identified, with aquatic insects dominating the assemblages. Alpha diversity indices showed no significant differences among river sections, whereas multivariate analyses (NMDS and PERMANOVA) revealed significant spatial variation in community composition, indicating that beta diversity plays a key role in structuring as-semblages at the basin scale. Canonical correspondence analysis (CCA) identified nutrient variables (TN and NH₄⁺-N), as well as pH and conductivity, as the main environmental drivers influencing community distribution. The results suggest that benthic macroinver-tebrate diversity patterns in large river systems are jointly shaped by regional environ-mental gradients and local habitat conditions. These findings provide insights into biodi-versity conservation and ecological management of large river ecosystems.

Biochar application and straw return are widely promoted as sustainable fertilization practices to enhance crop production, yet their impacts on growth processes, structural traits and physiological functioning remain insufficiently quantified, particularly from a canopy-scale perspective. During the 2025 rice-growing season, we conducted a field experiment in Yixing, located in the lower Yangtze River region, to investigate rice functional responses to biochar and straw return and to evaluate the capability of sun-induced chlorophyll fluorescence (SIF) to detect these responses.The experiment included conventional fertilization as a control, three biochar application rates (0.10%, 0.50%, and 1.00%), and partial straw return. Biochar and straw return substantially enhanced root biomass (by 25–37%) and leaf area index (by 10–31%) across key growth stages, indicating improved resource acquisition capacity and canopy development. These belowground-driven changes translated into increased aboveground biomass accumulation, particularly before heading, and higher panicle density, contributing to yield formation. At the same time, biochar application increased canopy temperature and reduced leaf chlorophyll content, suggesting altered nitrogen distribution and canopy energy balance under intensified growth conditions. High biochar application reduced grain filling percentage, indicating that productivity gains are constrained by physiological regulation during reproductive stages.To characterize canopy-scale functional dynamics, unmanned aerial vehicle (UAV) campaigns were conducted at jointing, heading, and grain-filling stages to acquire SIF observations. SIF showed strong sensitivity to management-induced differences in canopy structure, biomass accumulation, and phenological progression, consistently reflecting treatment effects across growth stages. Importantly, SIF captured both enhanced canopy function under moderate biochar and straw return and constrained physiological performance under excessive application, demonstrating its ability to integrate multiple plant functional responses.Our results show that biochar and straw return regulate rice productivity through coordinated changes in root development, canopy structure, and physiological functioning. UAV-based SIF provides an effective, non-destructive approach to monitor these management-driven functional responses, offering new opportunities to link field experiments with larger-scale assessments of sustainable agricultural practices.

Organic phosphorus (Po) mineralization is a major internal source of soluble reactive phosphorus (SRP) in lakes, yet the molecular and microbial mechanisms governing this transformation remain poorly understood. Here, we aim to elucidate these mechanisms by integrating excitation-emission fluorescence spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and metagenomics across two contrasting ecological niches in Taihu Lake, namely the Cyanophyta-dominated and macrophyte-dominated regions. We also supplement our results with the findings from a global meta-analysis. We found that fulvic-associated Po (Fu-Po) dominated sedimentary Po inventories, whereas Po extracted with NaHCO3 (NaHCO3-Po) and microbial biomass Po (biomass-Po) exhibited higher decomposition potential. Fluorescence indices indicated increasing lability with depth, and humic-like materials exhibited a higher tendency to be decomposed under anoxia, accompanied by the accumulation of fulvic-like fractions. FT-ICR-MS revealed proteins and lignins as key constituents of humic-associated Po and Fu-Po, supporting their bioavailability, while NaHCO3-Po was enriched in compounds with lipid-like CHOSP formulas, suggesting greater lability. Metagenomics identified phoD as the most abundant phosphatase-encoding gene, with rare but highly connected phoD-harboring taxa emerging as potential keystone regulators alongside abundant functional groups. Across global lake sediments, alkaline phosphatase activity, Po content, and phoD abundance were found to covary positively, and structural equation modeling highlighted Fu-Po as a disproportionate indirect driver of SRP replenishment via phoD-mediated phosphatase activity. These findings reveal a mechanistic cascade linking molecular composition to phoD-mediated enzymatic potential in Po mineralization, identifying Po bioavailability, rather than inorganic phosphorus pools alone, as a critical driver for reducing internal loading. Targeting this pathway could modulate Po mineralization mechanisms in sediments worldwide, offering valuable insights into the management of lake eutrophication under accelerating nutrient pressures.

Forward osmosis (FO) is an energy-saving and high-efficient membrane process. However, the operation of FO process for municipal wastewater treatment is hindered by the dilution of the draw solution (DS). To address this challenge and recover drawing solution working concentration, the photothermal evaporation technology is coupled with forward osmosis process, where the black polyurethane sponge blocks were used as the photothermal materials and modified with tannic acid and ferric chloride to enhance their photothermal conversion capacity. In this research, the Polyvinyl alcohol and tannic acid modified sponge photothermal materials (PU@TA@PVA) were fabricated by a coordination-based modification strategy, and their performance in FO process was systematically evaluated. To optimize the integration of FO and photothermal evaporation process, the effect of operation conditions (varying temperatures and flow rates on water flux, reverse salt permeation, contaminant retention) and membrane fouling were investigated. Additionally, the influence of external environmental conditions on solar evaporation (SE) efficiency was examined. The optimal operating parameters for the FO process were identified as an operating temperature of 25 degrees C, a cleaning temperature of 45 degrees C, an operating flow rate of 140 mL/min, and a cleaning flow rate of 280 mL/min, respectively. The impact of environmental factors on system performance was also assessed. Operational tests of the FO-SE coupled system demonstrated a 10% increase in net water recovery, a 75.02% reduction in conductivity, and 20% flux decline after 3 consecutive cycles compared to standalone FO. This work demonstrates the integration of solar evaporation and forward osmosis through system-level coupling and water flux balance optimization, providing a new solution for the in-situ regeneration of DS.

Seagrass meadows are crucial in marine blue carbon storage. However, in subtropical estuaries dominated by small-sized species, their carbon storage capacity tends to be underestimated, and the key drivers of organic carbon (Corg) variability remain poorly understood. To address these issues, we investigated the spatial patterns of blue carbon storage and sediment Corg sources in a subtropical estuarine meadow dominated by the small seagrass Halophila beccarii in the Yifengxi Estuary, China, and identified the primary environmental factors governing its spatial heterogeneity. Our results showed that although the living biomass carbon stock was relatively low (0.028 ± 0.017 Mg C ha-1), consistent with the pioneer traits of Halophila beccarii, the sediment carbon stock in the upper 1 m was substantial (82.41 ± 29.99 Mg C ha-1), with considerable spatial variability (33.57-125.29 Mg C ha-1). Sediment Corg served as a robust indicator of carbon storage, showing positive correlations with multiple carbon metrics. The observed positive correlation with higher salinity and moisture suggests that sediment Corg preferentially accumulates in low-energy, waterlogged environments. Stable carbon isotope analysis and Bayesian mixing model results showed that terrestrial sources constituted the largest proportion of sediment Corg (49.84 ± 23.57 %), followed by seagrass (26.83 ± 21.43 %) and phytoplankton-derived carbon (23.33 ± 19.98 %), with clear spatial and vertical variations. These patterns reflect the combined influence of terrestrial inputs and intrinsic ecological dynamics on the carbon sink function of the meadow. Our findings provide critical biogeochemical insights into the carbon sequestration role of this ecosystem and underscore the need for management strategies that mitigate terrestrial pressures, enhance autochthonous carbon, implement zonal management, and sustain long-term monitoring.

In this study, a humic acid-modified coal gangue (H-C) adsorbent was prepared by loading humic acid onto calcined coal gangue. The material was utilized as filter media in a bioretention system to evaluate its efficacy in retaining heavy metals from runoff, along with its effects on the system's plants and microorganisms. The results revealed that, under influent concentrations of Zn 1.5-3.0 mg/L, Cu 0.3-1.0 mg/L and Pb 0.2-0.8 mg/L (rainfall recurrence periods of 1 a, drying periods of 2 d), the system amended with 15 % H-C achieved retention efficiencies of 99.4-99.6 %, 99.6-99.7 % and 99.6-99.8 %, respectively. After the completion of the influent test, the growth parameters of Buxus sinica (such as plant height, leaf number, and biomass) in the system amended with H-C were significantly improved. Furthermore, H-C promoted the uptake of heavy metals by Buxus sinica, and the catalase (CAT) and superoxide dismutase (SOD) indices indicated that H-C could help Buxus sinica recover and mitigate the negative effects of oxidative stress on high heavy metal accumulation. H-C substrate alleviated the inhibition of heavy metal accumulation on microbial diversity, and the dominant bacteria (Proteobacteria and Bacteroidetes) increased, showing good adaptability to heavy metals in high concentration runoff. Overall, this study demonstrated that the H-C amended bioretention system exhibits excellent removal performance and biological effects on heavy metals and provides a method for waste resource utilization.

The conversion of long-term rice-wheat rotation fields to greenhouse vegetable cultivation (GVC) covered by plastic film has been widely adopted in China for its economic benefits, however, its short-term environmental impacts remain poorly understood. This study examined correlations between GVC, potential plastic-derived phthalate ester (PAE) contaminations and soil microbial communities during an initial six-month transition period. We investigated these shifts in soils transitioning from long-term rice-wheat rotation to GVC under inorganic fertilization and organic manure. Results showed that fertilization enhanced the availability of soil nutrients. However, the application of inorganic and organic fertilizers resulted in reductions of soil pH by 6.35% and 5.49% respectively. GVC substantially elevated PAE concentrations in the soil from 0.26 mg kg(-1) to 1.03 and 1.21 mg kg(-1) under inorganic and organic fertilization, respectively, and triggered systemic accumulation in capsicum (root > stem > fruit > leaf). The application of organic fertilizer led to more pronounced declines in soil microbial richness, with reductions of 9.76% in the Chao1 index and 12.2% in phylogenetic diversity, compared to the lesser reductions of 2.73% and 6.14% observed under inorganic fertilization. Redundancy analysis identified soil pH, dissolved organic carbon, total potassium, C/N ratio, clay content, and PAEs as key drivers of microbial community restructuring. The richness (Chao1 index) and diversity (Shannon index) of soil bacteria declined significantly with increasing PAE concentrations (p < 0.05). These findings highlight trade-offs between soil fertility enhancement and ecological risks in intensive GVC systems and underscore the need for optimized fertilization strategies to mitigate PAE contamination and preserve microbial integrity during land-use transitions.

Coastal lagoons act as critical biogeochemical reactors within the land-ocean aquatic continuum (LOAC), processing anthropogenic nitrogen and releasing nitrous oxide (N2O). However, the multi-scale mechanisms driving N2O emissions from local hotspots to regional patterns remain poorly constrained. Here, we employ a “local-regional” scale investigation framework to elucidate the spatiotemporal dynamics and drivers of N2O emissions in subtropical coastal lagoons of South China. At local scale (Pinqing Lagoon), both the concentrations and fluxes of N2O exhibit a consistent land-to-sea decreasing gradient. The N2O emissions peak during the early wet season (19.00 μmol m−2 d−1). Statistical modeling identifies ammonium (NH4+-N), rather than nitrate, as the primary driver, suggesting that N2O production in this coastal lagoon is consistent with NH4+-associated pathways. At regional scale (20 coastal lagoons), profound spatial heterogeneity in N2O fluxes (0.16 to 63.23 μmol m−2 d−1) is observed across these lagoons. Hierarchical partitioning reveal that watershed land use and nitrogen nutrients, rather than in-situ physicochemical properties, fundamentally determine these regional emission configurations. Furthermore, a continuous land-to-sea decreasing spatial pattern of N2O (Reservoirs > Rivers > Coastal Lagoons > Estuaries > Bays > Continental Shelves) is revealed in the South China region by embedding our dataset into the broader LOAC. These findings empirically substantiate that the anthropogenic nitrogen cascade fundamentally shapes coastal N2O emission patterns. We highlight the critical necessity of explicitly differentiating hydrologically restricted coastal lagoons from open estuaries in global greenhouse gas inventories, and emphasize that effective climate mitigation requires source-oriented interventions targeting watershed land use.

Phosphorus (P)-driven eutrophication remains a major ecological threat to aquatic ecosystems, particularly in intensively farmed regions. However, the relative contributions of agricultural legacy P and internal sediment-derived P remain poorly constrained due to complex transformation pathways and the lack of integrated source-tracing approaches. In this study, we combined chemical fractionation, phosphate oxygen isotope (δ18OP) tracing, and high-resolution molecular characterization to identify dominant P sources and their bioavailability in Nanyihu Lake, China. Results from lake and estuarine sediments, as well as adjacent agricultural soils, indicate that labile (LP) and moderately labile phosphorus (MLP) are the main bioavailable fractions. Bayesian mixing models indicate that agricultural sources attributed 46 % of total P inputs, including agricultural soils (25 %) and feces (21 %), exceeding contributions from internal sediment release (38 %) and wastewater treatment plants (16 %). In situ profiling using diffusive gradients in thin films (DGT) and Peeper methods reveals that iron (oxy)hydroxide reduction facilitates sedimentary P release, with soluble reactive phosphorus (SRP) fluxes reaching 6.32 ± 0.11 mg m-2d-1, underscoring its substantial role in annual internal P loading. Furthermore, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) indicates that lipid- and protein-like organic P compounds in sediments can be readily mineralized, continuously replenishing bioavailable P pools. These findings demonstrate that agricultural activities not only drive external P loading but also promote accumulation of reactivatable P in sediment, sustaining internal P cycling and long-term eutrophication. Effective watershed management requires integrating control of external inputs and sediment legacy P across the landscape.

Environmental DNA (eDNA) metabarcoding offers a promising tool for ecological monitoring. This study employed eDNA metabarcoding to examine microbial communities along the continuous river-estuary-sea gradient in the Yellow River Delta (YRD). We aimed to elucidate how habitats shape microbial biogeography across these complex environmental transitions. Results revealed clear spatial heterogeneity in microbial diversity and community structure among habitats. The Beta Nearest Taxon Index analyses showed that the assembly of microbial communities in the river and estuary were influenced by stochastic processes, while deterministic processes in the estuary and sea, which showed an increase from stochastic processes to deterministic processes in winter. Furthermore, spatial factors were identified as more influential drivers than environmental variables. IBI was applied to quantitatively assess the ecological status of YRD, and the assessment outcomes exhibited satisfactory health status. This study demonstrates the potential of eDNA metabarcoding for assessing ecological impacts across river-estuary-sea continua, providing a new perspective for the management of the Yellow River Estuary.

Phosphorus (P) fertilizer runoff provides a direct, rapid pathway to aquatic systems. Conventional assessments attribute about 25% of China’s water P pollution to this source, but often overlook retention in hierarchical water systems. Using an integrated framework combining a P runoff database, Structural Equation Modeling, and a Water Network-based Nutrient Prediction Framework, we reassessed this rapid-response component nationally. Annual fertilizer P loss via runoff totaled 21.66 Gg, with substantial in-stream removal (19.5% by lakes/reservoirs, 27.9% by rivers) before reaching coastal waters. After accounting for cascade retention, current-year fertilizer runoff contributed 7.3% to P concentrations in lakes/reservoirs and 10.1% in rivers—well below previous estimates. While our study excludes legacy P from historical applications, it suggests that the immediate water quality impact of current fertilizer use has been overestimated. Effective management should broaden its focus beyond fertilizer controls to encompass other sources, including accumulated soil P, while maintaining long-term fertilizer stewardship.

Rising atmospheric CO2 reduces soil phosphorus (P) availability in paddy soils by promoting soil organic P accumulation and crop harvest removal. Atmospheric CO2 and temperatures are increasing simultaneously, yet their interaction with the soil P cycle remains unresolved. Here we report a decade-long free-air CO2 enrichment experiment integrated with in situ warming (+2 degrees C) in a typical paddy-upland rotation system. We find that both elevated CO2 and warming exacerbate P constraints, and that warming alone and in combination with elevated CO2 has a greater impact than elevated CO2 alone. All climate change treatments significantly depleted soil available P (32-54%) and increased the soil C:P ratios (4-30%). Moreover, warming initially accelerated P mineralization but reduced P availability by enhancing Fe-organic carbon complexes and microbial immobilization. These processes, together with increased crop P demand driven by accelerated growth under elevated CO2, exacerbate P depletion. We identify Fe-organic carbon interactions as a previously overlooked mechanism that significantly reduces P bioavailability. Our findings offer a mechanistic framework linking aboveground-belowground C-P coupling with microbially driven Fe-organic matter dynamics, highlighting the urgent need for adaptive nutrient management strategies to sustain rice production under future climate change.

The spread of antibiotic resistance genes (ARGs) within terrestrial inputs and marine dispersal in estuarine deltas has posed significant environmental challenges, exacerbated by diverse microbial habitats, estuarine eutrophication, and other anthropogenic impacts. However, the precise mechanisms governing persistence and associated risks of ARGs in this region remain poorly understood. In this study, the distribution, mobility, removal and hosts of ARGs in wetlands and rivers of the Yellow River Delta (YRD) region were systematically investigated through metagenomic approaches. A total of 23 antibiotics were detected in water (0.07-4.67 ng/L) and 14 antibiotics in sediment (0.0042-0.4768 ng/g). Following wetland treatment, despite a 67.5% reduction in antibiotic concentrations, the relative abundance of antibiotic resistance genes decreased by only 7.60%, indicating substantial persistence of genetic resistance. Moreover, Proteobacteria were identified as primary hosts for ARGs. ARGs carried by resistant pathogens, especially ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), also showed a significant reduction in the abundance and diversity throughout the wetland. Notably, total nitrogen in water (Water-TN) greatest shaped the composition of the resistome and microbiome, while the presence of antibiotics exerted stronger selective pressure on ARGs in wetland than in river. Collectively, this study highlights the associated risks of ARGs in YRD, offering insights for controlling antimicrobial resistance in deltas.

Farm ponds are traditional water conservancy facilities in subtropical China, where precipitation varies considerably across seasons. The farm ponds, though small in area, are significant yet often overlooked sources of nitrous oxide (N2O) due to their high numbers. This study combined seasonal in situ monitoring, isotopic tracing, and molecular analysis to quantify N2O dynamics and identify production pathways in farm ponds in a subtropical region of China. The type of farm ponds significantly affected the N2O emission, with aquaculture ponds (AP) exhibiting higher observed fluxes at 676.7 nmol m(-2)h(-1) in July during the mid-growing season compared to 193.2 nmol m(-2)h(-1) in domestic ponds (DP). N2O emissions were influenced by both natural seasonal patterns and agricultural practices. Sediment nutrient properties such as TN, TP, and NH4+-N had a greater impact on N2O emissions than biotic factors including denitrification rates and denitrifier gene abundances. Surface layers were identified as hotspots for N2O production based on sediment source-sink indices. During the highest measured emission period in July, isotopic analysis revealed that N2O production in AP was dominated by NH4+-derived pathways (similar to 76.5%), while the NO3--derived pathway prevailed in DP (similar to 92.3%). We estimated that farm ponds in this watershed could emit between 3.7 and 5.0 kg of N2O each year. Farm ponds therefore represent significant but often overlooked sources of N2O, and it is imperative to incorporate them into greenhouse gas inventories.

Phosphorus (P) is critical for forest ecosystems but is increasingly affected by soil alternate wetting and drying (AWD) under climate change. Yet, how AWD frequency reshapes soil P fractions through microbial community shifts and metabolic strategies remains elusive. We examined P fraction allocation, bacterial/fungal communities, and C/N/P functional potentials under continuous moisture (W), low-frequency (3DW), and high-frequency (6DW) AWD in rubber plantation soil. Both AWD treatments reduced P activity and soil total P, available P, and microbial P, while increasing r-strategist abundance and recalcitrant polymer degradation genes (e.g., tpx, xylH, xylF). Notably, 3DW induced a stronger r-strategist proliferation than 6DW and additionally enriched P uptake and transport genes (e.g., phnC, ugpE). Consequently, AWD promoted P redistribution from labile to stable pools, decreasing Resin-P and NaHCO3-Po but increasing NaHCO3-Pi, NaOH-Po, and HCl-P. The two AWD frequencies differed in efficacy, 6DW exerted stronger effects on Resin-P, NaOH-Po, and Sonic-Po, whereas 3DW more strongly influenced NaHCO3-Po. Labile P fractions correlated with P mineralization, solubilization, nitrogen fixation, and denitrification, driven by Firmicutes, Basidiomycota, and Chytridiomycota. Recalcitrant P pools linked to P uptake/transport, nitrification, and complex carbon decomposition, associated with Proteobacteria and Myxococcota. Structural equation modeling revealed that microbial community structure and metabolic functions primarily governed P fraction allocation and availability under AWD, with direct contributions from pH, TN, and NO3--N. These findings advance mechanistic understanding of P dynamics under changing precipitation regimes and inform sustainable P management in tropical plantation soils.

The organic phosphorus (P) pool is one of the key sources of available P in Chernozem, and its efficient utilization is important for optimizing P application strategies. However, the effects of microbial communities on the transformation of organic P (Po) under different fertilization conditions in Chernozem remain unclear. Therefore, we investigated how four long-term P fertilization treatments (Non-P: no P fertilizer, P90: 90 kg P2O5 ha− 1 yr− 1, P180: 180 kg P2O5 ha− 1 yr− 1, and P360: 360 kg P2O5 ha− 1 yr− 1) and two types of manure (PM: pig manure, IM: insect manure) affected Po mineralization by altering microbial communities, through field and incubation experiments. In the 9th -year field experiment, a significant correlation was observed between moderately labile organic P (MLPo) and bacterial and fungal communities under varying P application rates. Additionally, in the Non-P treatment, the network structure of the phoD-harboring bacterial community was more stable (indicative of P-deficient soil), and ALP activity was significantly higher (p < 0.05) than in other treatments. The incubation results showed that Olsen-P increased by 13.8 and 2.62 mg kg− 1 in PM and IM treatments, respectively, compared to the no-fertilization (CK) treatment. The partial least squares structural equation modeling (PLS-SEM) revealed that manures promoted P effectiveness by regulating Po mineralization through modulation of microbial diversity and extracellular enzyme activity. In summary, these findings provide insights into the mechanisms by which Po pools are utilized to enhance P use efficiency and reduce its application in Chernozem.

As the world's largest ocean current in terms of volume transport, the Antarctic Circumpolar Current (ACC) significantly affects the movement of heat and water in the Southern Ocean. However, the impact of the ACC on the biogeographic distribution of marine bacteria is unknown. Here, by sampling and investigating the bacterial communities from surface seawater samples surrounding Antarctica and across the ACC region, we show that the ACC acts as a barrier limiting the dispersal of bacteria through it. This dispersal limitation, which reduces the communication between bacteria near Antarctica and foreign bacteria, will possibly be impacted by future climate change.

Seagrass meadows are crucial in marine blue carbon storage. However, blue carbon storage of seagrass meadows in subtropical regions dominated by small-sized species may be overestimated, and the primary factors regulating organic carbon (Corg) variability remain uncertain. Here we investigated spatial patterns in blue carbon storage and sediment Corg sources in China's subtropical estuarine meadows of the small seagrass, Halophila beccarii, and identified key environmental drivers influencing its spatial heterogeneity. The results revealed that these species may store less blue carbon than estimated, with low carbon stocks revealed in China’s estuarine meadows. Sediment carbon varied spatially, influenced by moisture, salinity, CaCO₃, and bulk density. Terrigenous sources contributed most sediment carbon, followed by seagrass, and phytoplankton, exhibiting distinct spatial variation along the transect. These findings highlight the need for refined blue carbon assessments in subtropical regions and suggest managing environmental factors to enhance seagrass carbon storage as a climate solution.