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121. 题目: Afforestation of Terrace Promotes Soil Organic Carbon Accumulation but Reduces Soil Organic Carbon Stability in Mountainous Regions of Southern China
文章编号: N26060304
期刊: Land Degradation & Development
作者: Le‐Lin Yu, Xiang‐Rong Du, Yu Xiong, Yun Zhang, Le‐Cheng Ai, Rong Mao
更新时间: 2026-06-03
摘要: Afforestation of farmland is considered a potential strategy to mitigate elevated atmospheric CO 2 concentration by sequestering organic carbon (OC) in plant biomass and soil. However, whether the trends of soil OC stock and stability vary with tree species after afforestation of terraces remains unclear in subtropical mountainous regions. To clarify the effects of tree species on soil OC dynamics, we measured the concentrations, chemical compositions, and δ 13 C values of soil OC, particulate organic C (POC), and mineral–associated organic C (MAOC), along with other soil physicochemical properties at depths of 0–10 cm and 10–30 cm in abandoned terraces, Cunninghamia lanceolata plantations, and Liquidambar formosana plantations in the western Wuyi Mountains of southern China. Results showed that afforestation of terraces significantly increased soil OC stock, with a greater increase under C. lanceolata plantations (52.4%) than under L. formosana plantations (26.8%). At 0–10 cm soil depth, both plantations had significantly greater soil POC and MAOC concentrations than abandoned terraces. Afforestation of terraces only significantly increased the δ 13 C values of OC at 10–30 cm soil depth, indicating accelerated OC turnover in subsurface soils. In both POC and MAOC fractions, afforestation of terraces had a lower proportion of aromatic‐C fractions, and thus exhibited a lower OC chemical stability index. Soil OC fractions correlated significantly with soil C:N ratio and minerals at 0–30 cm depths. These findings suggest that, regardless of tree species, afforestation of terrace promotes soil OC accumulation at the cost of reduced OC stability in the mountainous regions of southern China.

122. 题目: Agricultural Impacts on Soil Particulate Organic Carbon: The Role of Edaphic Factors in Global Tillage and Fertilization Responses
文章编号: N26060303
期刊: Land Degradation & Development
作者: Ziyu Guo, Xinhao Zhu, Xiaofeng Xu, Changchun Song, Fenghui Yuan
更新时间: 2026-06-03
摘要: Particulate organic carbon (POC) is a key indicator of soil health and plays a critical role in ecosystem functioning and land productivity. Its dynamics are strongly influenced by environmental disturbances and anthropogenic land‐use practices. However, the mechanisms by which agricultural practices regulate POC remain insufficiently understood. In this study, we synthesized 1179 paired observations from global agricultural landscapes to examine how common agricultural practices, tillage and fertilization, alter POC concentration and to identify the underlying mechanism modulated by edaphic and environmental factors. We found that tillage disrupts soil structure, alters bulk density and pH, and accelerates carbon decomposition, resulting in POC losses. In contrast, fertilization, particularly with organic amendments, enhances POC by promoting carbon inputs and supporting microbial turnover. Random forest model indicates that edaphic characteristics are the primary regulators of POC responses, while structural equation modeling demonstrates that total soil carbon mediates the effects of management practices on POC concentration. Overall, soil‐specific properties constrain plant inputs, physical protection, and microbial turnover, fundamentally determining POC responses to agricultural practices. These findings highlight the importance of targeted land management strategies to mitigate degradation and promote ecological restoration.

123. 题目: The impact of microplastics on soil micro-food webs is regulated by biochar and earthworms.
文章编号: N26060302
期刊: Ecotoxicology and Environmental Safety
作者: Cancan Zhao, Xufeng Yan, Yaojun Zhang, Nicholas T Girkin, Guoyong Li, Yuan Miao, Yinzhan Liu, Weixin Zhang, Yuanhu Shao, Yulong Wang, Shenglei Fu
更新时间: 2026-06-03
摘要: Microplastic contamination in agricultural soils is becoming increasingly severe worldwide. Microplastic may impact soil organisms and their functions through both toxic and non-toxic effects, thereby threaten soil and human health. However, to date, numerous studies have focused solely on the effects of microplastics on individual taxa, neglecting the composition and function of the soil micro-food web. Biochar and earthworms as mitigation agents are constantly employed to improve microplastic-contaminated farmland soil. It remains unclear whether the presence of biochar and earthworms influences the effects of microplastics on the soil micro-food web. Hence, we conducted an extensive microcosm experiment to investigate the effects of microplastics, biochar, earthworms, as well as their interactions on soil microbial and nematode communities, carbon cycle associated with the energy flux, and co-occurrence network of the micro-food web. Our results showed that microplastics increased microbial biomass and nematode abundance by 2 and 8 times, respectively, and changed nematode community composition. Microplastics elevated the relative abundance of bacterivores while decreasing that of fungivores, shifting the energy pathway towards a bacteria-dominated channel, subsequently accelerating bacterial and total energy flux in the soil food web. Moreover, microplastics reduced nematode diversity but increased the number of edges and average degree of the co-occurrence network, thereby enhancing food web complexity. Biochar application reduced network complexity and interacted with microplastics, antagonistically diminishing the role of microplastics in rapid energy flux. Earthworm addition improved network complexity and synergistically amplified the preference of microplastics for bacterial and fast energy channels. Our study provides new perspectives on the effects of microplastics, biochar and earthworms on the function of the soil micro-food web, offering a basis for soil management in global agricultural ecosystems.

124. 题目: Enhanced Remediation of PAHs and Heavy Metals Contaminated Soils Using MOF-Functionalized Biochar Produced via Co-Pyrolysis of Sewage Sludge and Wheat Straw.
文章编号: N26060301
期刊: Environmental Research
作者: Tatiana Bauer, Ekaterina Kravchenko, Vladimir Polyakov, Mikhail Kirichkov, Tamara Dudnikova, Natalia Chernikova, Leônidas Carrijo Azevedo Melo, Zengwei Yuan, Tatiana Minkina
更新时间: 2026-06-03
摘要: The rapid accumulation of sewage sludge worldwide demands safe and sustainable disposal technologies, as improper management poses serious risks to soil, water, and human health. Pyrolysis is a promising method for converting sewage sludge into biochar, reducing waste volume and stabilizing contaminants. However, sludge-derived biochar often retains elevated pollutant levels, making it unsuitable for agricultural use and limiting its environmental applicability. Co-pyrolysis with agricultural residues can dilute and stabilize contaminants, while subsequent functionalization with metal-organic frameworks (MOFs) further enhances sorption and immobilization capacity. In this study, co-pyrolized biochar produced from sewage sludge and wheat straw (BSSWS) and its MIL-100(Fe) nanocomposite (BSSWS@MIL-100(Fe)) were synthesized, characterized, and applied (2%w/w) in a pot experiment with a PAH- and heavy metals (HMs) contaminated soil. Alfalfa (Medicago sativa) and Sarepta mustard (Brassica juncea) were grown for 30 days to assess changes in PAHs and HMs concentrations in soil and plant tissues. The results revealed that co-pyrolysis increased the biochar surface area from 14 to 25 m2/g, while the deposition of MIL-100(Fe) further enhanced it to 196-243 m2/g, transforming the materials into microporous biosorbents. In contaminated soil, total PAH concentrations (3578 ng/g) were reduced by 1.1-3.5-fold after sorbent addition, with BSSWS@MIL-100(Fe) achieving a 54% decrease in chrysene and a substantial reduction in the content of low-ring PAHs. Plant uptake mirrored these trends: total PAHs in roots and shoots declined by 3.4-3.7 and 1.6-1.7 times, respectively, and benzo(g,h,i)perylene decreased by up to 37% in roots and stems. MIL-100(Fe) nanocomposite significantly reduced the exchangeable fraction of HMs in soil and lowered Mn, Ni, Cu, Zn, and Pb concentrations in plant roots and shoots. Overall, MOF-functionalized co-pyrolyzed biochar effectively mitigated combined PAHs-HMs contamination in soil and reduced pollutant transfer to forage crops, highlighting its potential for the sustainable remediation of contaminated sites.

125. 题目: Improvement Effects of Calcium Silicate Hydrate and Humic Acid-Encapsulated Alcaligenes faecalis on Acidic Farmland Soil and Alterations in Microbial Community Structure
文章编号: N26060205
期刊: Water, Air, & Soil Pollution
作者: Luhua Jiang, Manjun Miao, Ziwen Guo, Jiejie Yang, Yulong Peng, Junzhao Wu, Bo Miao, Yili Liang, Huidan Jiang, Xueduan Liu
更新时间: 2026-06-02
摘要: Soil acidification poses a critical threat to sustainable agricultural production by compromising soil fertility. Conventional remediation strategies for acidic soils face persistent challenges including short-lived efficacy, structural deterioration, and secondary pollution risks. This study presents an innovative bioremediation approach utilizing Alcaligenes faecalis (A. faecalis), a potent alkaline-metabolizing microorganism, coated with calcium silicate hydrate (CSH) and humic acid (HA) as a biocarrier for acidic farmland soil restoration. Through microcosm experiments and high-throughput sequencing analysis, we demonstrat that the remediation approach achieved a substantial soil pH increase from 4.66 to 6.41 within 21 d. Soil available nitrogen (AN) and silicon (ASi) contents increased to 252.83–595.70 mg/kg and 89.24–133.57 mg/kg at 21 d, respectively; and available phosphorus (AP) content increased from 15.59–39.88 mg/kg to 20.44–55.98 mg/kg at 7 d. Positive correlations were observed between pH and all nutrient indicators for soil samples. Moreover, the restoration could also change the microbial diversity and structure. This led to an increase in the relative abundance of functional genera including Bacillus (from 0.44–0.65% to 4.92–21.89%), Arthrobacter (from 0.13–0.30% to 0.17–16.31%), and Paenochrobactrum (from 0.02–0.04% to 0.75–17.43%) at 5 d. These microorganisms were related to soil nitrogen, phosphorus, and silicon cycling, which were positively correlated with an increase in AN, ASi and AP content in soils. These findings highlight the application potential of A. faecalis as a biomaterial for soil improvement in acidic farmland, providing a novel option for the improvement of acidic soil.

126. 题目: Synergistic effects of iron tailings and maize straw on soil compression: roles of sand content and organic carbon
文章编号: N26060204
期刊: Journal of Soils and Sediments
作者: Aobo Sun, Changdong Han, Yanyu Han, Jiaqi Li, Jing An, Guangyan Liu, Na Yu, Hongtao Zou, Hongdou Liu
更新时间: 2026-06-02
摘要: Purpose Soil compaction poses a significant threat to agricultural productivity. The application of industrial and agricultural wastes as soil amendments offers a promising strategy for its mitigation. This study investigated the individual and combined effects of iron tailings (an industrial byproduct) and maize straw (an agricultural residue) on soil compression characteristics. Materials and methods A laboratory incubation experiment employing a completely randomized factorial design was conducted, with iron tailings applied at 0%, 5%, 10%, and 15%, and maize straw at 0%, 0.5%, 1%, and 1.5% of the air-dried soil mass. Soil compression parameters—pre-compression stress (σp), compressibility coefficient (Cc), and recovery coefficient (Rc)—were determined using uniaxial confined compression tests. Results and discussion Iron tailings application significantly increased sand content (Sand) but decreased soil organic carbon (SOC), leading to reduced σp and a non-linear effect on Rc. In contrast, maize straw incorporation significantly increased SOC, resulting in enhanced Rc and an initial increase followed by a decrease in σp. The Cc was primarily reduced by iron tailings addition, with no significant effect from straw. Variation partitioning analysis and structural equation modeling revealed that Sand was the dominant driver of σp and Cc, while SOC governed Rc. Conclusions The combined application of 5% iron tailings and 1% maize straw was identified as the optimal treatment, effectively balancing the amendments’ effects to yield higher σp and Rc alongside a lower Cc. These findings demonstrate the synergy between iron tailings and maize straw in improving soil compression characteristics, offering a sustainable strategy to mitigate soil compaction through waste co-utilization.

127. 题目: Prediction of total organic matter in marsh sediments: integrating reflectance clustering, spectral subranges, and color coefficients
文章编号: N26060203
期刊: Journal of Soils and Sediments
作者: Z A Dastgheib, M Goharrokhi, S Clark, D Lobb, N Badreldin, G McCullough
更新时间: 2026-06-02
摘要: Purpose Total organic matter (TOM) in lake and marsh sediments is an important indicator of ecosystem function, carbon storage, and environmental changes. This study evaluated whether reflectance spectroscopy and color coefficients can provide accurate, rapid, and cost-effective alternatives to conventional TOM quantification in sediment cores. Materials and methods A total of 350 samples from 10 sediment cores were collected in Netley Marsh, a freshwater coastal wetland at the southern end of Lake Winnipeg, Manitoba, Canada. Reflectance spectra were obtained across the visible (VIS; 350–700 nm), near-infrared (NIR; 700–1000 nm), short-wave infrared (SWIR; 1000–2500 nm), and full-spectrum (350–2500 nm) ranges. Fifteen color coefficients were derived from the visible range. Partitioning Around Medoids (PAM) clustering was used to explore spectral shape variation, while Partial Least Squares Regression (PLSR), Random Forest (RF), and Cubist models were trained using 10-fold cross-validation and validated on an independent test set. Results All models achieved strong predictive performance (R² > 0.80, RPD > 2.2). Cubist consistently outperformed the other models, with the visible range yielding the most accurate results (R² = 0.95, RMSE = 1.7%, RPD = 4.32). Models based on color coefficients performed comparably to full-spectrum inputs. Conclusion Visible-range reflectance and derived color metrics provide robust, rapid, and cost-efficient prediction of TOM in sediment cores. This approach offers a practical tool for reconstructing carbon dynamics and supporting sediment and wetland management in aquatic ecosystems.

128. 题目: Universal Apparent Quantum Yield Model Manifests a Dual Role of Dissolved Organic Matter as Sensitizer and Inhibitor of Methylmercury Photodegradation in Lakes.
文章编号: N26060202
期刊: Environmental Science & Technology
作者: Andrea G Bravo, Torfi Geir Hilmarsson, Birgit Koehler, Erik Björn, Anders V Lindfors, Tomas Landelius, Sergi Díez, Stefan Bertilsson, Ulf Skyllberg
更新时间: 2026-06-02
摘要: Photodegradation in lakes is a major sink for the toxin methylmercury (MeHg) in forest-wetland-lake ecosystems. Previous attempts to estimate annual rates of MeHg photodegradation in lakes have followed a black-box approach, where the process has been related to incident sunlight rather than photon absorption. Here we use experimental data from three contrasting dark and clear boreal lakes to develop the first apparent quantum yield (AQY) model for spectral MeHg photodegradation rates in lakes. The model was proven universal by its ability to predict experimental data from 22 lakes representing five global regions, covering wide ranges in dissolved organic carbon (DOC), specific UV absorbance at 254 nm, and pH (1.8-39.5 mg C L-1, 1.7-5.7 L mg-1 C m-1 and 4.8-8.5, respectively). The AQY model manifests a dual role played by dissolved organic matter (DOM) as a sensitizer, by producing reactive transient species (RTS) upon photon absorbance, and as an inhibitor, by scavenging of RTS by antioxidants associated with aromatic structures in DOM. Using site-specific data on direct and diffuse solar irradiance, MeHg concentrations, and spectral light absorption properties in 1033 lakes, we estimate an annual MeHg photodegradation rate of 12.1 kg y-1 in the total volume of Swedish lakes. This value corresponds to 24% of the estimated 51 kg of MeHg that annually is transported with runoff from soil into the same lakes. By the AQY model, we calculate the first regional estimates of MeHg photodegradation in lakes of boreal and temperate Europe, temperate North America, subtropical North America, and tropical South America, providing a basis for the establishment of regional MeHg cycling models.

129. 题目: Synergistic enhancement of selenium accumulation in rice: elucidating the role of biochar and selenobacteria in reshaping root microbiome assembly
文章编号: N26060201
期刊: Plant and Soil
作者: Yan-Shan Wang, Zhi-Jiang Wang, Yan Wang, Zhan-Tong Ma, Chen-Wei He, Wei-Kang Wang, Jin-Yu Sun, Su-Tao Shi, Cheng-Xi Lu, An-Yong Hu, Hong Mei, Xi-En Long
更新时间: 2026-06-02
摘要: Aims Selenium (Se) bioavailability often limits the production of Se-rich crops in naturally Se-enriched soils. While biochar and selenobacteria individually show promise in enhancing Se mobility, their synergistic effects and underlying mechanisms remain poorly understood. Methods This work investigated the synergistic impact of rice straw-derived biochar and selenobacterium Bacillus megaterium on Se accumulation in rice and elucidated the associated shifts in root microbiome. Results The findings demonstrated a synergistic interaction between the treatments, inducing an increase in shoot Se content surpassing that observed with any single treatment. This effect was accompanied by an obvious decrease in total soil Se, particularly evident with co-application, highlighting their synergistic ability of mobilizing the native soil Se reservoir effectively. Biochar was the dominant driver of soil fertility improvement, causing increased availability of phosphorus, potassium and organic carbon. It also played key roles in reshaping root-associated bacterial communities, reducing rhizosphere bacterial diversity while simultaneously enriching specific beneficial taxa like Paenibacillaceae and Bdellovibrionaceae under co-application treatment. Co-occurrence network analysis further identified compartmentalized associations between specific microbial taxa and shoot Se content. Specifically, key taxa such as Planctomycetes and Mortierellaceae in the rhizosphere, Thermoleophilia, Solirubrobacterales, and Sordariomycetes in the rhizoplane, alongside Rubrivivax and Sphingomonadaceae in the endosphere, were revealed as being significantly correlated. Peroxidase activity showed strong correlative associations with Se accumulation across compartments. Conclusions The combined use of biochar and Bacillus megaterium enhances Se bioavailability and translocation by beneficially restructuring the root microbiome, offering a sustainable strategy for the biofortification of rice in naturally Se-enriched soils.

130. 题目: Agro-waste biochars as soil amendments for peat-reduced substrates: balancing nutrient supply, salinity stress, and buffering capacity for plant growth.
文章编号: N26060103
期刊: Environmental Science and Pollution Research
作者: Chomsri Choochuay, Kitiyot Tungsudjawong, Woranuch Deelaman
更新时间: 2026-06-01
摘要: A replacement of the non-renewable type of peat with circular ones entails the resolution of the so-called nutrient-salinity conflict of pyrolyzed agro-wastes. This study aims to assess physicochemical profiles, toxicity mechanisms, and critical safety levels of biochars obtained from shrimp shells (SS), pineapple peels (PP), and eggshells (ES). Biochars were produced through slow pyrolysis at 500 °C and characterized for macronutrients, electrical conductivity (EC), pH, and elemental composition. Agronomic validation was conducted using three indicator crops (Capsicum annuum, Solanum lycopersicum, and Cucumis sativus) to determine safe substitution levels in peat-reduced substrates. Slow pyrolysis concentrated essential macronutrients (SS: 15.5% P₂O₅; PP: 15.2% K₂O) but also produced very high EC (39.5 and 31.9 dS m⁻1) and highly alkaline matrices (pH 10.0-12.0). Elemental profiling described a marine salinity complex in SS biochar with extreme salinity coupled with cadmium (4.35 mg kg⁻1) exceeding international safety limits. Salinity-induced osmotic stress was the main physiological limitation on plant survival. A maximum substitution rate of 10% (v/v) was identified for high-salinity biochars (SS, PP). Although biomass remained lower than the peat control due to nitrogen dilution and residual osmotic stress, this level prevented plant mortality and moderated alkalinity through natural buffering capacity. Low-salinity ES biochar functioned as a calcitic buffer at 30% (v/v). These results provide practical safety thresholds for using agro-waste biochars in peat-reduced substrates, balancing nutrient supply, salinity stress, and buffering capacity for sustainable plant growth.

131. 题目: Straw return reshapes soil organic carbon stability: A global meta-analysis.
文章编号: N26060102
期刊: Journal of Environmental Management
作者: Jianyu Tao, Xiaoyuan Liu, Zhongbin Zhang, Xinhua Peng
更新时间: 2026-06-01
摘要: Straw return is widely adopted in croplands to promote soil organic carbon (SOC) sequestration and mitigate climate change. However, its replenishing effects on particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) are still not well-understood. Here, we conducted a meta-analysis to evaluate the responses of POC and MAOC to straw return, whilst the variations of other SOC pools were also examined to provide a comprehensive assessment of SOC dynamics [i.e., dissolved organic carbon (DOC), easily oxidizable organic carbon (EOC), microbial biomass carbon (MBC), and microbial necromass carbon (MNC)]. Results indicated that straw return significantly enhanced SOC pools compared to straw removal, with the most pronounced increases in POC (35.73%), EOC (41.17%), and MNC (35.59%). Straw return significantly decreased the MAOC/SOC ratio and increased EOC content, suggesting a decline in SOC stability. Linear regression analyses indicated that POC and MAOC accumulation decreased with increasing initial soil total nitrogen (TN) and mean annual precipitation (MAP). Shapley additive explanation (SHAP) analyses further revealed that initial soil TN, sand, and silt contents were key factors regulating POC responses to straw return. Specifically, straw return tended to suppress POC accumulation under conditions of high initial soil TN or sand contents, with corresponding thresholds of 1.57 g kg-1 and 24%, respectively. Meanwhile, initial soil pH, straw return duration, and potential evapotranspiration (PET) were the primary drivers of MAOC accumulation. Straw return preferentially promoted MAOC accumulation when soil pH exceeded 8.01 or straw return duration was longer than six years. Further structural equation modeling revealed that MAOC played a dominant role in SOC sequestration compared to POC under straw return conditions, whereas straw-induced POC increases were strongly dependent on environmental conditions. Collectively, this study highlights that straw return preferentially increases the POC pool, which may undermine its contribution to SOC sequestration. Therefore, integrating additional agricultural practices may represent a promising approach to enhance the efficacy of straw return for SOC sequestration, warranting further investigation in the future.

132. 题目: Unraveling Soil Organic Matter Dynamics in Tropical Wetlands Through Advanced Thermal and Pyrolytic Approaches
文章编号: N26060101
期刊: European Journal of Soil Science
作者: Karen Luko‐Sulato, Everton Tiago Sulato, Nicasio T Jiménez‐Morillo, José Maria de la Rosa, José A González‐Pérez, Vania Rosolen
更新时间: 2026-06-01
摘要: The dynamics of soil organic matter (SOM) and humic acids (HA) in a permanent and seasonal wetland located in southeastern Brazil (hydromorphic soils and gramineous vegetation) were assessed through thermogravimetry, evolved gas analysis, and analytical pyrolysis. The n ‐alkane series in all samples spanned from C 13 to C 35 , regardless of season, wetland type, or matrix, being C 13 the most abundant in HA and C 15 , in soils. The n ‐alkane homologous series exhibited a unimodal distribution in soils, whereas it showed a bimodal pattern in HA, especially in the seasonal wetland. Average chain length values ranged from 17.89 to 24.14 in soil and 17.85 to 27.26 in HA. The short/long n ‐alkane ratio was greater in seasonal wetland soils (5.3 ± 1.8) than in the permanent wetland (2.1 ± 0.7, p < 0.01) and in permanent wetland HA (3.8 ± 1.4) than in the seasonal wetland (1.3 ± 0.8, p < 0.01). Carbon preference index values were slightly above 1 in all cases with a subtle odd‐over‐even predominance. Based on thermogravimetric analysis, labile fractions were similar between the two hydrological regimes, whereas the seasonal wetland was characterized by a higher proportion of recalcitrant organic matter, particularly during the rainy season. In contrast, the permanent wetland exhibited more pronounced seasonal shifts, with a decrease in labile fractions during the dry season and an increase in thermally stable compounds. Thus, the permanent wetland exhibited a greater sensitivity to environmental variability than the seasonal wetland, which suggests that permanently flooded systems may respond more rapidly to climatic and hydrological perturbations. These results emphasize the influence of hydrological conditions on carbon turnover in tropical wetlands.

133. 题目: Agricultural allochthonous dissolved organic matter is associated with microbial functional differentiation in methane- and nitrogen-related gene profiles in rural rivers.
文章编号: N26053106
期刊: Environmental Research
作者: Yi Zhu, Hong Liu, Yongjiao Yi, Zhengyang Li, Jianfeng Ye
更新时间: 2026-05-31
摘要: Agricultural non-point source (ANPS) pollution introduces chemically complex dissolved organic matter (DOM) into rural rivers, yet how different agricultural practices structure DOM-microbial differentiation at the molecular scale remains unclear. Here, we compared rivers polluted by three dominant ANPS subtypes-aquaculture (AQ), livestock and poultry farming (LP), and crop farming (CF)-across winter and summer in Shanghai, China, by integrating Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) with 16S rRNA gene sequencing and metagenomics. Distinct DOM-microbial differentiation patterns were identified among ANPS subtypes. AQ was characterized by higher proportions of heteroatom-rich compounds (30.6%) and higher-molecular-weight compounds, LP by more aromatic and lignin-/tannin-associated molecular features (AI_mod = 0.261), and CF by CHOS-enriched (26.8%) but overall lower DOM chemodiversity. These molecular fingerprints co-occurred with differences in microbial diversity, community assembly (βNTI), and co-occurrence network topology, indicating relatively stable DOM-microbial templates shaped by long-term agricultural inputs. Seasonal variability further modified DOM composition and microbial differentiation, but responses differed among ANPS subtypes. Event-driven systems (AQ and LP) exhibited pronounced winter-summer shifts, whereas the background-dominated system (CF) showed weaker temporal variability but more persistent DOM-microbial coupling patterns. Low- to medium-molecular-weight (m/z 100-550) DOM fractions showed the strongest co-variation with nitrogen- and methane-related functional gene potentials, suggesting molecular-weight-dependent associations between DOM composition and microbial functional gene profiles. Overall, these findings suggest that ANPS pollution comprises source- and season-specific DOM-microbial templates that can be distinguished using molecular and functional indicators, providing a basis for source-oriented monitoring and targeted management of agriculturally impacted rural river systems.

134. 题目: From wastewater treatment to energy devices: A comprehensive review on biochar utilization and reuse pathways.
文章编号: N26053105
期刊: Science of the Total Environment
作者: Prateek Gururani, Pooja Bhatnagar, Pramod Rawat, Sanjeev Kimothi, Naveen Chandra Joshi, Manu Pant, Raja Joshi
更新时间: 2026-05-31
摘要: In current years, the elimination of heavy metals from wastewater systems has become a global concern due to persistent adverse effects on ecosystems and human health. Adsorption technique has gained much attention for the removal of heavy metals from aquatic environments because of advantages like great efficiency, cost-effectiveness and simple operation. Biochar, a carbonaceous material, has been extensively applied for removing heavy metals from aqueous systems due to its low cost and eco-friendly nature. However, numerous existing studies are focusing on elimination of heavy metals from wastewater by using biochar as an adsorbent, but very few emphasize on re-utilization of spent biochar, which is a crucial concern. This is because if spent biochar is discharged or landfilled untreated into the environment can increase the risk of secondary pollution thus harming the ecosystem and mankind. Therefore, the present paper critically reviews the recent applications of biochar in removing heavy metals from wastewater along with potential electrochemical applications of metals loaded biochar in developing super-capacitors or other energy storage devices. The review also comprehensively discussed the characteristics of different biomass feedstock, methods used for biochar production and various physical, chemical and biological biochar engineering techniques. The key mechanisms involved in adsorption of heavy metals from aquatic systems through biochar have been reviewed. The paper also highlighted technical barriers, benefits-cost analysis, market status, future directions and scope of biochar as an adsorbent. Hence, the review will assist the successful development of highly efficient biochar-based adsorption techniques for eliminating heavy metals from aqueous environments.

135. 题目: A tidal marsh creek system acts as a main carbon source to adjacent coastal waters
文章编号: N26053104
期刊: Limnology and Oceanography
作者: Yawen Bai, Zhongjie Liu, Guangxuan Han, Haiqing Ma, Buli Cui, Weimin Song, Xiaojie Wang, Xiaojing Chu, Xiaoshuai Zhang, Tian Ma, Mingliang Zhao
更新时间: 2026-05-31
摘要: The lateral carbon exchange between tidal flat wetlands and adjacent coastal water is an essential process determining whether a salt marsh is a carbon source or sink, yet current research predominantly focuses on vertical carbon exchange. A tidal creek in the Yellow River estuary salt marsh was monthly sampled from April 2024 to March 2025 to explore the spatiotemporal patterns, origins, and influencing factors of dissolved organic carbon, dissolved inorganic carbon, and particulate organic carbon across complete tidal cycles and seasonal variations. Both dissolved organic carbon and dissolved inorganic carbon exhibited pronounced seasonal variations, with lower concentrations in winter, whereas particulate organic carbon exhibited no pronounced seasonal variations. Different carbon concentrations exhibited a seaward‐to‐landward increasing gradient across the creek system and an inverse trend with water depth, except winter particulate organic carbon, with terrestrial humic‐like components making up about 66%. This indicates that salt marshes act as lateral carbon sources, primarily in the form of dissolved inorganic carbon (accounting for about 80% of the total carbon), exporting terrestrial carbon to adjacent coastal waters via tidal creeks. Carbon dynamics were seasonally controlled by shifting biotic and abiotic drivers. Temperature and phytoplankton regulated dissolved organic carbon in spring and summer, while tidal forcing dominated in winter; terrestrial inputs dominated year‐round. Tidal activity and biological processes primarily governed dissolved inorganic carbon, with enhanced nutrient‐driven effects in summer and winter. Particulate organic carbon was driven by biotic factors, especially phytoplankton and microphytobenthos, across seasons. This study provides foundational data for quantifying lateral carbon exchange in salt marshes, essential for assessing blue carbon contribution to climate change mitigation.

136. 题目: Mercury reduction in water by engineered silver nanoparticles (AgNPs): Effects of light irradiation and humic acid coating of AgNPs.
文章编号: N26053103
期刊: Science of the Total Environment
作者: Peter Olusakin Oladoye, Guangliang Liu, Yong Cai
更新时间: 2026-05-31
摘要: Silver nanoparticles (AgNPs), due to their electrochemical capability of reducing mercury (Hg), amalgamation potential with elemental Hg (Hg(0)), and surface plasmon properties under light, may play important roles in Hg redox transformation and cycling when coexisting in the environment. However, the potential effects of AgNPs on the aqueous reduction of Hg(II) are still largely unknown. Herein, we investigated the reduction of 5 mg/L and 250 μg/L Hg(II) by bare AgNPs and humic acid coated-AgNPs (HA-AgNPs) under dark condition and light irradiation for 30 min using acetate buffer as matrix. In addition, we examined the potential role of AgNPs in Hg(II) reduction in wastewater using incubation experiments. We found that coating impacted on the total Hg(0) generated from redox reaction of the nanoparticles with Hg(II), with higher amount in bare AgNPs compared to HA-AgNPs under dark condition. Under light irradiation, coating significantly reduced Hg(0) obtained, suggested to be as a result of photo-production of Hg(0)-oxidants by the humic acid coating. Hg(0) generated was found to amalgamate readily with the solid phase (AgNPs/HA-AgNPs), with little released as purgeable Hg(0). Overall, the concentrations of purgeable Hg(0) obtained from AgNPs and HA-AgNPs suspensions under light irradiation were significantly higher than under dark condition. Results from incubation experiment demonstrated the potential of AgNPs to play key role in Hg(II) reduction in wastewaters under light irradiation than dark condition. This study highlighted the potential roles of AgNPs and HA-AgNPs to act as a sink for Hg(0) (via amalgamation) or a facilitator of reduction (via redox reactions) of Hg(II) in different environmental compartments, thereby playing important roles in the biogeochemical cycling of Hg.

137. 题目: Extracellular polymeric substances regulate depth-and-season-dependent soil organic carbon stabilization under prescribed fire in karst soils.
文章编号: N26053102
期刊: Journal of Environmental Management
作者: Qilin Yang, Ansa Rebi, Tao Yang, Chenghao Zheng, Yang Rongkang, Yang Yuanli, Xinglei Cui, Jinxing Zhou
更新时间: 2026-05-31
摘要: This study explores the dynamics of soil organic carbon (SOC) in karst ecosystems under prescribed fire and seasonal variations, emphasizing the role of deeper soil horizons often overlooked in previous research. We investigated the influence of fire and seasonality on extracellular polymeric substances (EPS) production at two soil depths (0-10 cm and 20-30 cm) in burned and unburned soils. EPS-protein content ranged from 3.09 to 7.52 mg kg-1 in burned soils and 3.09 to 5.34 mg kg-1 in unburned soils, with higher concentrations at 20-30 cm in burned soils during the dry season. EPS-polysaccharide content was highest in unburned soils (9.92 mg kg-1) at 0-10 cm during the wet season. Amino sugar levels varied significantly, with Glucosamine concentrations reaching 99.96 mg kg-1 in burned soils at 20-30 cm in the dry season. Microbial biomass carbon (MBC) and nitrogen (MBN) displayed significant seasonal and depth-dependent variations, with higher MBC:SOC ratios in burned soils during the dry season at 0-10 cm. Enzyme activities, including acid phosphatase, β-glucosidase, and N-acetylglucosaminidase, were higher in unburned soils, indicating more active nutrient cycling. Structural equation modeling and Random Forest analysis identified soil nutrients, EPS-protein, and microbial biomass as key drivers of the EPS-C:SOC ratio. These findings highlight the importance of deeper soils in SOC stabilization and provide new insights into the impacts of fire and seasonality on microbial processes, enhancing our understanding of carbon sequestration in karst ecosystems.

138. 题目: Large stocks of permafrost soil organic carbon and nitrogen in Arctic river deltas.
文章编号: N26053101
期刊: Nature Communications
作者: Matthias Fuchs, Torsten Sachs, Loeka L Jongejans, Jens Strauss, Gustaf Hugelius, Gerald V Frost, Benjamin M Jones, Steven V Kokelj, Lars Kutzbach, Ingmar Nitze, Pier Paul Overduin, Juri Palmtag, Chien-Lu Ping, Oleg S Pokrovsky, Elizaveta Rivkina, Alexandra Runge, Lutz Schirrmeister, Georg Schwamborn, Matthias B Siewert, Claire Treat, Alexandra Veremeeva, Sebastian Zubrzycki, Guido Grosse
更新时间: 2026-05-31
摘要: Arctic deltas are highly dynamic environments at the land-ocean interface that have acted as long-term sinks of sediment, carbon (C), and nitrogen (N). Climate impacts Arctic deltas and their upstream catchments through sea-level rise, altered river discharge, increased sediment fluxes, intensified biogeochemical cycling, and permafrost thaw. As a result, soil C and N in Arctic delta deposits are becoming more bioavailable. Here, we present a C and N inventory for Arctic delta compiled from over 1600 soil samples spanning 17 river deltas. We estimate that Arctic delta deposits store 57.5 ( + 9.2/-8.2) Pg C and 3.8 ( + 0.8/-0.7) Pg N across a combined area of nearly 100,000 km², representing large and potentially vulnerable biogeochemical pools. Our findings underscore the potentially pivotal role of Arctic deltas in the pan-Arctic carbon cycle and highlight their importance as dynamic zones of both C and N storage and release in a rapidly changing Arctic.

139. 题目: Lithology-mediated shifts in microbial life strategies and CAZyme genes shape soil organic carbon pools in subtropical coniferous forest
文章编号: N26052921
期刊: Catena
作者: Tao Yang, Shiran Cao, Changchang Sheng, Haoran Zhang, Yuguo Liu, Jinxing Zhou, Saman Herath, Xiawei Peng
更新时间: 2026-05-29
摘要: Soil inherits key properties from its parent lithological material, profoundly shaping microbial carbon (C) metabolism. Although the role of lithology in influencing soil organic C (SOC) dynamics is increasingly recognized, the mechanisms through which lithology affects microbial metabolic pathways and their subsequent impact on SOC dynamics have not been systematically investigated. Therefore, this study systematically investigated microbial life-history strategies, and the expression of carbohydrate-active enzyme (CAZyme) genes involved in the decomposition of plant- and microbial-derived organic matter in relation to SOC and its fractions—particulate organic C (POC) and mineral-associated organic C (MAOC)—in karst and non-karst forest soils. Our findings revealed that karst soils harbored a higher abundance of copiotrophic microbe than non-karst soils, with soil nutrient exerting stronger positive effects on copiotrophs in the karst environment. CAZyme genes associated with the degradation of both plant- and microbial-derived substrates were more abundant in non-karst soils. Furthermore, a significant correlation between bacterial and fungal life strategies and CAZyme gene profiles was observed in karst soils, whereas in non-karst soils, fungal life strategies alone were linked to CAZyme gene expression. These findings indicate a lithology-dependent coupling between microbial strategies and enzymatic functions. As expected, karst soils had higher SOC content than non-karst soils, a difference mainly attributed to the higher MAOC content. In karst soils, microbial life strategies and CAZyme genes significantly influenced the variations in SOC and POC, but had limited effects on MAOC. In contrast, in non-karst soils, MAOC content was strongly associated with CAZyme gene abundance, while being only marginally associated with microbial life strategies. Overall, this study identifies lithology as a key driver of microbial-mediated SOC dynamics, revealing how geological substrates shape microbial strategies and enzyme activity, with important implications for predicting SOC stability across bedrock types.

140. 题目: Microbial carbon controls particulate and mineral-associated soil organic matter depending on cropping system in subtropical regions
文章编号: N26052920
期刊: Applied Soil Ecology
作者: Pujia Yu, Yakov Kuzyakov, Caixian Tang, Mo Chen, Xizao Sun, Weiyu Shi
更新时间: 2026-05-29
摘要: Particulate (POM) and mineral-associated organic matter (MAOM) are two pools of soil organic carbon (C) with distinct sources, persistence and functions. Little is known about plant and microbial C in POM and MAOM response to cropping systems in subtropical soils. Soils (Luvisols, 0–15 cm depth) from four cropping systems: abandoned land (ABAN), and single (SINGLE), double (DOUBLE) and triple (TRIPLE) cropping frequencies were analyzed for contents and compositions of amino sugars and lignin phenols as biomarkers for the plant and microbial C in POM and MAOM, respectively. The microbial C accounted for a significantly larger portion of total C in POM (44%) and MAOM (72%), respectively, while the plant C contributed only 24% and 14% of total C in POM and MAOM, respectively. Consequently, the microbially-derived organic compounds were the main C source in POM and MAOM. Additionally, ratios of microbial C to plant C in POM (1.7–1.9) were significantly lower than those in MAOM (4.9–5.4), suggesting the much stronger dominance of microbial C in MAOM as compared with POM. The contributions of plant C or microbial C to total POM and MAOM were independent on crop frequencies during three years, reflecting simultaneous changes in plant and microbial C, which were confirmed by the coincident increases in plant (47%) and microbial C (43%) in POM under TRIPLE compared with SINGLE and DOUBLE. Contribution of plant C in POM under abandoned land significantly increased by 27% compared with croplands because of the large plant biomass inputs and low soil disturbance. In conclusion, our finding of microbial dominance in POM challenges the conventional views, highlighting the important role of microbial C in POM and MAOM accumulation. Three years of crop frequencies did not alter the contributions of plant and microbial C in POM and MAOM, while cropland abandonment increased the accumulation of plant C in POM.