To explore the patterns of forest carbon storage evolution influenced by the implementation of dual-carbon policies, This study selects Jiangmen City, a key ecological barrier in the Guangdong-Hong Kong-Macao Greater Bay Area, as a case study. Using land cover and carbon density data from five periods between 2000 and 2020, the study employs the InVEST model to quantitatively assess the area's carbon storage, in conjunction with the Policy Modeling Consistency (PMC) index model and the Least Absolute Shrinkage and Selection Operator (Lasso) regression model to analyze the quality of forestry policies and their impact on carbon storage. The results indicate that forest and agricultural lands were the principal contributors to carbon storage changes in Jiangmen City. From 2000 to 2015, these lands was significantly converted to built-up areas, causing carbon storage to decrease from 34.22×10⁶t to 33.59×10⁶t, accounting for 72.8% of the decrease in the Greater Bay Area's carbon storage during the same period, which represented a 14.35% reduction. After 2015, the implementation of subsidy policies related to forest city development resulted in an increase in the area of carbon storage exceeding areas of loss from 2015 to 2020, with a net increase of 0.5% in carbon storage. The “incentive safeguard” variable was identified as a principal factor in this increase. Spatially, the areas of increased and decreased carbon storage in Jiangmen City exhibited clustered distributions, reflecting the “forest surrounding cities and trees entering cities”policy. Based on the joint spatial distribution characteristics of carbon storage density and building density, the study proposes carbon sequestration enhancement strategies for different functional zones, including forest protection in ecological conservation areas, carbon planning in wilderness areas, spatial transformation in central old urban areas, and garden construction in newly developed urban areas. These recommendations provide theoretical support and practical examples for formulating sustainable urban development policies.

This study used the urban sprawl index and InVEST model to analyze the spatiotemporal changes of urban sprawl and its impact on ecosystem services in 19 provincial capital cities along the main and tributary streams of the Yangtze River Basin from 2000 to 2020. It also explored the factors influencing ecosystem services in the urban sprawl areas. This study found that: (1) 47.37%and 73.63% of cities experienced urban sprawl during 2000~2010 and 2010~2020, respectively. (2) From 2000 to 2020, the average habitat quality, total food and meat production services, and total carbon storage of provincial capital cities in the Yangtze River Basin (central urban area) decreased by 4.25%, 7.03%, and 4.53%, respectively, while the total water production increased by 12.10%. (3) The loss of ecosystem services due to urban sprawl was the most significant in terms of habitat quality, with a loss of 71.56% from 2010 to 2020 compared to 2000. (4) A correlation analysis was conducted on the impact of land-use conversion, socio-economic factors, and climate on ecosystem services, and it was determined that land-use and use conversion and socio-economic factors were the most influencing factors.

We used the PLUS model to predict the land use pattern under different development scenarios in 2030 in the Loess Plateau, an important ecological barrier in China, and applied the InVEST-Geodector model to analyze the spatiotemporal changes and driving factors in ecosystem carbon storage from 2020 to 2030. The findings were as follows: (1) The area of cropland will decrease under the natural development and ecological protection scenarios; the area of grassland decreases significantly under the cropland protection scenario, and forests and waters are effectively protected under all three scenarios. (2) The ecosystem carbon storage under the natural development, ecological protection, and cropland protection scenarios is 4.922, 5.021, and 4.922Pg, respectively. Compared with those in 2020, carbon storage will increase by 8.07, 37.22, and 8.07Tg, respectively. Carbon storage has obvious spatial heterogeneity, with high carbon density in the northern Qinling Mountains, Taihang Mountains, and Lvliang Mountains and low carbon density in Erdos City and its surrounding areas. Changes in carbon storage are closely related to the changes in the number of land classes and conversion of land use types. In conclusion, the ecological protection scenario is more in line with the future development needs of the study area. (3) The core determinants of ecosystem carbon storage are slope and precipitation, and the dominating combinations of factors driving regional differences and changes in carbon storage are the interactions of slope, soil type, or average annual temperature content with other variables.

The spatiotemporal evolution of water quality in the Yangtze River Basin since the impoundment of the Three Gorges Reservoir is critical for formulating comprehensive basin management strategies. Using stepwise multiple linear regression analysis, key water quality indicators influencing the basin from 2003 to 2024 were identified as total phosphorus (TP), permanganate index(COD_Mn), ammonia nitrogen (NH₃-N), lead (Pb), and dissolved oxygen (DO). Evaluations via the single-factor method and the WQI_min index demonstrated that the average water quality across the entire Yangtze River Basin has reached an excellent level. However, secondary basins—including the Wu River Basin, Min-Tuo River Basin, and Taihu Lake water system—exhibited relatively severe pollution, with TP and NH₃-N being the most prominent contaminants. Significant spatial heterogeneity in water quality was observed. Linear regression and seasonal Kendall tests indicated a statistically significant upward trend in the overall water quality of the Yangtze River Basin. All secondary basins, except the Han River Basin, demonstrated significant improvements. Following the Three Gorges Reservoir impoundment, TP concentrations in the upper reaches of the Yangtze River (specifically the Jialing River Basin, Wu River Basin, and the mainstream section from Yibin to Yichang) initially increased and subsequently declined. Similarly, NH₃-N concentrations in the middle reaches (e.g., Dongting Lake and Poyang Lake water systems) and the Wu River Basin located in the upper Yangtze River exhibited comparable trends of initial rise followed by reduction. Conducting research on the spatiotemporal evolution characteristics of water quality across the entire Yangtze River Basin, incorporating secondary tributaries through multi-scale, long-term time series, and multi-indicator analyses, provides critical scientific support for precise pollution mitigation strategies in the region. Such an integrated approach enables a comprehensive understanding of water quality dynamics, identifies pollution hotspots, and informs spatially differentiated management actions, thereby enhancing the efficacy of basin-wide environmental governance.

As a typical arid oasis in northwest China, economic development in the Turpan Basin is heavily dependent on groundwater. In this study, hydrogeochemical mechanisms controlling groundwater boron (B) enrichment and associated health risks through an integrated approach combining hydrochemical analysis, isotopic tracing, and UNMIX receptor modeling were systematically investigated based on 6 river water and 49 groundwater collected in the study area. The results indicated that: (1)surface water in the study area was neutral to slightly alkaline, while groundwater ranged from slightly acidic to slightly alkaline;groundwater B existed in a mixed form of H₃BO₃ and B(OH)₄^-, with H₃BO₃ being the dominant species. (2) Groundwater B concentrations ranged from ND to 4.26mg/L, with 24.5% exceeding China's drinking water standard (1.0mg/L, GB5749-2022). High-B groundwater (mainly Cl·SO₄-Na·Ca type) exhibited significant spatial heterogeneity, clustering in the Gaochang District downstream of B-bearing river. (3) Groundwater B enrichment originated from mountain rock weathering (dominant source), supplemented by anthropogenic inputs (wastewater/fertilizers), with surface water infiltration being the principal transport pathway. Key controlling processes included pH-dependent speciation, cation exchange, competitive adsorption, dissolution of evaporite, and the mixing, with significant variations between aquifers. (4) The UNMIX model identified four factors: surface water infiltration recharge (36.6%), carbonate-silicate dissolution (21.8%), evaporite dissolution (21.6%), and industrial/agricultural activities (20.0%), with boron primarily originating from surface water infiltration recharge (56.0%). (5) The order of vulnerable segments of the population in terms of risk posed by B in groundwater was: infants > adult men > adult women > children. in the arid region of Northwest China.

Accurately assessing the degradation status of seagrass bed ecosystems was essential for formulating effective protection and restoration decisions However, existing assessments of seagrass bed ecological degradation were primarily conducted from the health perspective, neglecting the endpoint of degradation and its critical levels during the degradation process. This study took ecosystem collapse as the endpoint of degradation and, from an ecological risk perspective, the assessment framework of the Red List of Ecosystems was drawn upon. Three main criteria—habitat range degradation, abiotic environmental degradation, and biological process degradation—were integrated to establish an assessment framework for seagrass bed ecosystem degradation. Fourteen seagrass bed distribution areas along the South China coast were selected for empirical study. The assessment results showed that the seagrass bed in Tangjiawan had reached an extremely degraded level. Eight seagrass beds, such as Zhelin Bay, were severely degraded (57%); the seagrass bed in Li'an Port was moderately degraded; and four seagrass beds, such as Liusha Bay, were slightly degraded (29%). Among the three major assessment criteria, biological processes were identified as the main manifestation of seagrass bed degradation along the South China coast. From the perspective of ecosystem collapse risk, a framework for assessing seagrass bed ecosystem degradation was constructed, providing a new perspective for evaluating the degradation status of seagrass beds and other ecosystems, and offering important decision-making support for ecosystem conservation and restoration.

This paper reviewed the occurrence characteristics and abundance of microplastics (MPs) in disinfection processes of water treatment plants both inside and outside China, and analyzed the MPs removal effectiveness of chlorine, ozone and ultraviolet disinfection, followed by an in-depth discussion of the effects of MPs presence on disinfection and its secondary pollution. The results showed significant differences in the abundance of MPs across different water treatment plants, primarily existing in the forms of fibers and fragments, predominantly composed of polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP), with most sizes less than 1.0mm and colors mostly black, white, or transparent. The removal rate of the chlorine disinfection unit ranged from 0% to 71.38%; but part of the water treatment plants had seen a rise in MPs abundance after the ozone and ultraviolet disinfection. The removal mechanisms of MPs by disinfection processes remained required further research. Additionally, the trihalomethane formation potential (THMFP) of microplastic-derived dissolved organic matter (MP-DOM) in the chlorine disinfection process could reach as high as 453.3µg/mg, higher than the formation potential of typical aquatic natural organic matter and algae organic matter, pointing to greater health risks.

Microplastics (MPs) pollution has become a hot research topic in the environmental field, while few studies have reported the MPs pollution in the gastrointestinal tract of river fish in Hainan Island. In the present study, 222 freshwater fish specimens belonging to 35 species with different feeding habits were collected from 11 sampling sites located in the upper, middle, and lower reaches of the Nandu River. The pollution characteristics of MPs in the gastrointestinal tract of fish samples were analyzed. The results showed that MPs were detected in 94.5% of the fish gastrointestinal tracts, with an average abundance of (4.85±3.51)MPs per fish. The MPs in fish gastrointestinal tract were dominated by <1.0mm (73.3%) transparent (38.9%) fibers (60.6%), and were mainly composed of polypropylene (53.3%) and polyethylene (34.2%). The highest abundance of MPs was recorded in the gastrointestinal tract of filter-feeding planktivorous fish (7.00 per fish) and the lowest abundance was recorded in the gastrointestinal tract of insectivorous fish (2.57 per fish). From the upper to the lower reaches, the percentage of blue fragment MPs with size <1.0mm in the fish gastrointestinal tract was increasing, while the percentage of yellow/red fiber/film MPs with size >1.0mm was decreasing. This could be attributed to the increase of aquacultural activities, the usage of agricultural films, and a large amount of sewage and industrial wastewater in the lower reaches.

The study investigates the spatio-temporal dynamics of anthropogenic emissions in China under a carbon-neutral scenario, with a focus on synergistic reductions in carbon dioxide (CO₂), volatile organic compounds (VOCs), and nitrogen oxides (NO_x). Using the Dynamic Projection model for Emissions in China (DPEC), emissions trends were analyzed and compared with two Shared Socio-economic Pathway (SSP) scenarios (SSP1-1.9 and SSP1-2.6). The findings reveal that under the DPEC carbon-neutral scenario, CO₂ emissions will peak by 2030 and decrease by 91% by 2060 relative to 2020 levels. Emissions of VOCs and NO_x show continuous reductions since 2020, with declines of 65% and 88%, respectively, by 2060. Compared to the two SSP scenarios, the DPEC scenario shows a weaker reduction in VOCs but a stronger reduction in NO_x. Sectoral analysis highlights that CO₂ reductions primarily stem from the energy and industrial sectors, whereas the transportation sector drives notable decreases in VOCs and NO_x. By 2060, the industrial sector will remain the dominant source of emissions for CO₂, VOCs, and NO_x. The results suggest that the DPEC carbon-neutral scenario aligns closely with China's future emission reduction trends, demonstrating significant potential for synergistic emission reductions. Achieving these targets on schedule will require robust policy implementation and sectoral commitment, offering substantial improvements in air quality and environmental outcomes.

This study collected the surface soil samples (0~10cm) from the freshwater (salinity: 0) and mesohaline (salinity:10~15) P. australis marshes in the six main estuaries in China, which are the Liao River Estuary, Yellow River Estuary, Yangtze River Estuary, Oujiang River Estuary, Minjiang River Estuary, and Pearl River Estuary. The production rates of soil CH₄ and CO₂ were measured using laboratory anaerobic slurry incubation method, and the extracellular enzyme activity and abundance of methanogen functional genes (mcrA) were also measured. Mean CH₄ production rate in the freshwater and saltwater P. australis marshes was (2.69±1.63) and (2.97±1.71) ng CH₄/(g·d), respectively. Mean CO₂ production rate was (7.64±4.94)and (10.28±6.84)µg CO₂/(g·d), respectively. CO₂ production rate in the freshwater P. australis marshes was significantly lower than that in mesohaline P. australis marshes, but no significant difference in CH₄ production rate was observed between freshwater and mesohaline marshes. Soil pH and soil organic carbon (SOC) content were identified as the main factors influencing extracellular enzyme activity and methanogen abundance. A decrease in pH led to a significant reduction in the production rates of CH₄ and CO₂. Total carbon, total nitrogen, SOC, activity of five extracellular enzymes, and abundance of mcrA were identified as the key factors influencing CH₄ and CO₂ production. Our research results suggest that across the Chinese coastal estuarine freshwater and mesohaline P. australis marshes, salinity is not a main factor controlling CH₄ production, however, the increase in salinity perhaps raise soil anaerobic mineralization rates, which indicates that sea level rise and saltwater intrusion will cause carbon emission increase from estuarine P. australis marshes.