Journal of Environmental Management最新文献

Soil degradation poses a critical threat to ecosystem services and climate mitigation, particularly in semi-arid regions. Grassland restoration is effective measurement of soil restoration, however, the mechanisms by which rhizosphere processes enhance soil organic carbon (SOC) accumulation and soil quality remain poorly understood. This study investigated how rhizosphere effects influence soil organic carbon (SOC) accumulation and soil quality enhancement during grassland restoration using a 60-year chronosequence (3-60 years since agricultural abandonment) on the Ansai county, Loess Plateau, China. The results revealed consistently higher SOC and total nitrogen (TN) concentrations in rhizosphere compared to bulk soil across all restoration stages, with the most pronounced difference at the 60-year site (114 % higher rhizosphere SOC). Rhizosphere effect indices for SOC and TN (REI_SOC and REI_TN) showed strong positive correlations with restoration age, increasing by 141.8 % and 164.0 %, respectively, over the chronosequence. Mean weight diameter of soil aggregates increased by 67.0 % across the chronosequence, indicating enhanced structural stability with restoration progression. Model selection showed that SOC_rhizosphere and REI_SOC were the strongest predictors of SOC_bulk, while bulk-soil variables, rhizosphere pH, and REIs jointly determined soil quality (SQI). Structural equation modeling showed that TN in bulk soil (TN_bulk) had positive direct effect on SOC in bulk soil (SOC_bulk, standardized total path coefficient = 0.97) and soil quality index (0.85). Interestingly, REI_SOC showed a negative direct effect on SOC_bulk (-0.48) while REI_TN exhibited a positive effect (0.50), suggesting a dynamic equilibrium where rhizosphere organic carbon enrichment initially limits bulk soil carbon transfer but eventually enhances it through improved nitrogen cycling. This research provides new insights into the critical role of rhizosphere processes in soil organic carbon accumulation and quality restoration in semi-arid regions.

Amid shrinking ecological space and deteriorating basin ecosystems, understanding drivers and pathways of ecosystem service trade-offs remains a key challenge for ecological civilization. This research examines the Luo River Basin. Based on trade-offs of water yield, carbon sequestration, soil conservation, and habitat quality from 2000 to 2023 at multiple scales (1 km grid, township, county), the Optimal Multivariate Geographical Detector (OMGD) was used to identify the local optimal scale. A Bayesian network model was applied to analyze driving factors and dominant influence paths. Findings show (1) Trade-off intensity among ecosystem services diminishes with increasing scale, with spatial heterogeneity stabilizing. At the county scale, the area with intensified trade-offs between carbon sequestration and soil conservation accounts for 95.80 %. (2) OMGD recognizes the county scale as locally optimal (average q-value 0.69), with explanatory power 46.8 % and 102.9 % higher than township and grid scales. (3) Precipitation, NDVI (Normalized Difference Vegetation Index), and nighttime light act as dominant shared drivers, displaying marked spatial heterogeneity across different service trade-offs, mountain areas are mainly driven by precipitation and NDVI, while urban areas are influenced by nighttime light. (4) Among 12 key pathways, the slope - NDVI link is central (mutual information 0.730). Combined with sensitivity analysis, it provides a governance entry point integrating natural and human systems. The study proposes a targeted ecological management framework for the Luo River Basin and analogous areas, emphasizing county-based planning, vegetation recovery, and integrated natural-human system strategies, supporting enhanced ecosystem service synergy and sustainable governance.

Globally, feedlots rely on weather data to provide foundational information describing and predicting cattle exposure to heat load throughout the summer months. Anecdotally, in Australia feedlots are installing weather stations in close proximity to office buildings, for ease of maintenance. However, there is limited information available describing the variability of microclimatic conditions within feedlots, nor do recommendations exist regarding the ideal placement of weather stations to provide an accurate representation of the thermal environment experienced by feedlot cattle. The aim of this study was to evaluate the variability between in pen microclimate obtained from within pen data loggers, and weather stations situated at feedlot pens and in close proximity to the feedlot office. A total of six (n = 6) Australian feedlots covering a broad geographical range were enrolled into this study. Each feedlot had an automated weather station located in close proximity to i) office buildings (50-75 m from office) and second station located at ii) feedlot pens (2-10 m from pens). In addition (n = 16) ambient temperature (T_A, °C) and relative humidity (RH, %) data loggers were placed within a number of pens at each feedlot. From these data comparisons between within pen, at pen and office climatic conditions were evaluated. The relationships between the climatic variables on the two weather stations located at each feedlot were determined using regression analysis, where linear and quadratic relationships were evaluated. Results from this study provides evidence highlighting the variability of within feedlot microclimate conditions, emphasising the importance of onsite weather monitoring. Weather station placement at feedlots is important to ensure that the data collected provides an accurate representation of the feedlot climate conditions. This study highlights the importance of identifying the ideal location for correct weather stations placement for feedlots. Failing to position onsite weather stations in an appropriate location may result in an under- or over-estimation of heat load that cattle are experiencing, which likely reduces the effectiveness of heat load mitigation strategies utilised.

Urban heat islands (UHIs) pose a growing environmental challenge associated with rapid urbanization, leading to increased heat exposure risks for urban populations. The associations between land use configurations and UHIs have been established in many earlier works, however, limited studies have quantitatively assessed the differential impacts of multiple land use types across scales of space. To bridge this gap, we introduce an integrated approach that leverages the PLUS model with the SHAP method to predict future UHI patterns under multi-scale land use influences. The framework is implemented in Wuhan, China, which identifies the optimal spatial scale of influence for each land use type and projects future UHI distributions under three different land use scenarios. The results show that land use patterns at raster scales of 390 m and below have the greatest impact on UHI intensity, while fine-scale single-point effects are limited. Water bodies demonstrate strong cooling effects with rapid decline over distance, whereas the cooling contribution of vegetation is constrained by its fragmented spatial distribution. However, SHAP-based temporal analysis from 2005 to 2022 reveals that the mitigation effect of water has declined, with its relative importance decreasing by 7.6 %, while the intensifying influence of urban areas has grown by 10.6 %. Together, these spatial and temporal patterns suggest that enhancing vegetation connectivity and preserving the proximity between urban and water could effectively mitigate UHI effects. In addition, scenario simulations further indicate that optimizing land use patterns and improving how land use is organized has the potential to lower heat exposure risks for more than 1,000,000 people, which emphasize the potential for policy interventions to improve thermal environments in cities.

Wildfires are becoming more frequent and severe globally, particularly in the Mediterranean Basin due to rapid climate and land-use changes. These trends threaten soil biodiversity and ecosystem functioning. In fire-prone forests, prescribed burning is increasingly used to reduce fuel loads, yet the long-term effects of repeated prescribed fires on post-wildfire soil functioning remain unclear, particularly regarding soil fauna, which has rarely been examined in this context. We assessed the effects of a wildfire that took place in 2021 affecting an area treated five times with low-intensity prescribed burns (conducted between 1984 and 2017) on soil mesofauna communities, the QBS-ar index (Soil Biological Quality-arthropods; an index based on the ecological adaptation of soil fauna), soil functions, and soil multifunctionality (SMF) in a maritime pine (Pinus pinaster Ait.) reforestation in northwestern Spain. Three fire history treatments were compared: unburned (U), wildfire only (C + W; plots used as unburned controls during the prescribed fires that were burned in 2021), and prescribed burning followed by wildfire (PF + W). Soils were sampled at three post-wildfire time points to assess mesofauna and physical, chemical, and microbiological properties used to calculate four soil functions (water regulation, fertility, climate regulation, and organic matter decomposition) and SMF. PF + W plots hosted more resilient mesofauna communities than W plots and shared several indicator taxa with unburned soils. Similarly, a principal component analyses (PCA) revealed that overall soil conditions in PF + W plots were intermediate between U and C + W. Wildfire alone had the strongest negative impact on climate regulation and decomposition, whereas water regulation and soil fertility functions were similar among treatments. Soil multifunctionality was lowest in W plots and highest in both U and PF + W plots, with fire treatment and mesofauna jointly explaining 44 % of SMF variation, and soil properties accounting for 25 %. These findings indicate that repeated low-intensity prescribed burns can precondition soils, thereby maintaining biodiversity and soil multifunctionality after a wildfire, and highlight the importance of ecological memory and soil biota in post-fire recovery.

Carbon dots (CDs) have potential to become adsorbents due to low toxicity, good biocompatibility, abundant surface functional groups and easy modification. However, the nanoscale size makes recycling become a challenge. Therefore, in this work, L-serine and L-cystine were selected as precursors for carbon dots (LL-CDs), which were modified on the surface of sodium alginate (SA) hydrogel. LL-CDs was used to increase adsorption capacity and enhance the rigid structure between SA chains, which was beneficial for the internal diffusion of REEs. An adsorption capacity of 217.9 mg/g for Er (III) represented a significant enhancement compared to the unmodified SA hydrogel. The adsorption mechanism of REEs was determined to involve electrostatic, ligand exchange, and chelation interactions. According to the theory of hard and soft acid-base, compared to S atom, O and N atoms had the stronger affinity with REEs, which were confirmed by Materials studio calculations. When 1 M HNO₃ was used as the desorption solution, the adsorption capacity for Er (III) was still better compared to some other adsorbents. It revealed that the LL-CD modified SA hydrogel had strong potential for the recovery of REEs.

Sulfadiazine (SDZ), a widely used antibiotic, poses a significant threat to aquatic ecosystems due to its environmental persistence. Advanced oxidation processes (AOPs), particularly those combining photocatalysis with peroxymonosulfate (PMS) activation, offer a promising solution for its removal. This study aimed to construct a novel 2D/2D Z-scheme heterojunction photocatalyst, CuFe-LDH/BiOBr (4-CFB), and evaluate its synergistic performance with PMS for the efficient degradation of SDZ under visible light. The 4-CFB composite was synthesized via electrostatic self-assembly and comprehensively characterized using SEM, HRTEM, XRD, XPS, ESR, and DRS. The optimal composite (4-CFB) exhibited exceptional catalytic activity, achieved a rate constant (0.21 min^-1) 3 and 10.5 times higher than that of CuFe-LDH (0.07 min^-1) and BiOBr (0.02 min^-1), respectively. It demonstrated excellent stability during multiple reuse cycles, minimal metal leaching (Cu²⁺ < 1.1 mg/L), and broad-spectrum efficacy against various antibiotics. Mechanistic studies revealed that the direct Z-scheme heterojunction drove efficient charge separation, while the Fe(II)/Fe(III) redox cycle alongside oxygen vacancies proved critical for activating PMS, where singlet oxygen (¹O₂) and holes (h⁺) emerged as the primary drivers of SDZ degradation. The Vis/PMS/4-CFB system presents a highly efficient, stable, and environmentally compatible strategy for antibiotic wastewater remediation.

Global climate change intensifies rainstorms and reshapes environmental sensitivity, posing growing challenges for managing environmental risks from tailing ponds (TPs). However, existing research fails to integrate multi-scenario climate change with the evolving hazards and environmental sensitivity of TPs, leaving a gap in nationwide assessments of future environmental risks. This study integrated climate change and human activities under four Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5), to project rainstorm intensity, source hazards, environmental sensitivity, and environmental risks for 7232 TPs for 2023-2100. The study further evaluated environmental risk management capability gaps and proposed targeted management strategies. The results indicate significant regional disparities in future hazards, with the highest hazard scores observed in Northwest region, followed by the Southwest. Rainstorm intensity increased across all SSP scenarios. Environmental sensitivity increased only under the SSP3 scenario, but decreased under the others. The spatial pattern of future environmental risks for TPs in China remains "higher in the south, lower in the north". Due to increased rainstorm intensity offsetting the effect of reduced hazards and sensitivity, environmental risk values increased by 2.26 %-3.33 % compared with current conditions across scenarios. Nationally, 69.56 %-80.07 % of TPs exhibited increasing risks. Areas where high environmental risks from TPs overlapped with insufficient management were primarily concentrated in the Mid-South region. Strengthened management could reduce TP environmental risks by 1.18-4.55 %, with wastewater compliance emerging as the most cost-effective priority under constrained resources. This study provides a methodology for global environmental risk assessments of TPs under climate change and offers scientific support for risk prevention and policy-making under SSPs.

Wind-wave-induced sediment resuspension is a common phenomenon in large, shallow lakes and is supposed to sustain elevated total phosphorus (TP) concentrations during the dry season in Lake Longgan (LGL), a large shallow muddy lake adjacent to the middle-lower Yangtze River, China. However, the dynamics of sediment resuspension and its quantitative impact on TP in relation to suspended sediment concentration (SSC) in this lake remains unknown. Here, this study presents in situ observations of wind, waves, turbidity, suspended sediments, phosphorus, and bottom sediment collected during the dry season. Results indicated that resuspension occurred when bottom wave shear stress exceeded 0.028 N/m², corresponding to northeasterly winds> 4.4 m/s. TP was strongly correlated with SSC, with a regression slope (0.8 ‰) closely matched phosphorus content in the bed sediment (0.8 mg/kg) and an intercept (0.0357 mg/L) reflected the background dissolved total phosphorus concentration (DTP) levels. These findings identify critical threshold for sediment initiation in LGL. Furthermore, we demonstrate that wind-wave-induced sediment resuspension is a key driver of SSC variability, which controls particulate phosphorus (PP) concentration and thus regulates TP in large shallow muddy lakes. We suggest that restoring aquatic vegetation, combined with water level management, could be a potential strategy to mitigate sediment resuspension and reduce TP. In summary, this study reveals the dynamic process linking TP dynamics to wind-wave-induced sediment resuspension, providing valuable insights for environment management of large, shallow lakes.