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China is currently focusing on the cooperative control of air pollution and CO2 emissions, as well as the mitigation of economic policy uncertainty (EPU). By using panel data from 282 cities spanning from 2003 to 2017 and a newly constructed city-level EPU index, a spatial Durbin, two-way fixed-effects model is employed, with the aim of estimating the impact of EPU on the synergistic emissions intensity (SEI) of air pollutants and CO2. Additionally, this paper investigates the potential channels through which EPU influences SEI. It also explores how pressures related to environmental protection and economic development affect the impact of EPU on SEI. The results indicate that a unit increase in EPU will result in a rise in the SEI of local cities, adjacent cities, and total cities by 930.9%, 69,162.7%, and 70,093.6%, respectively. Moreover, the channel analysis suggests that EPU exacerbates SEI by undermining the upgrading of the industrial structure, augmenting industrial structure distortion, and escalating labor market distortion. Furthermore, the effect of EPU on SEI may be lessened by an increase in environmental protection pressure, while an increase in economic development pressure may exert a positive influence. Finally, this paper concludes by recommending that policymakers should prioritize the maintenance and stability of economic policies, facilitate the advancement of the industrial structure, enhance the efficiency of labor resource allocation, and underscore the significance of managing urban air pollution and CO2 emissions. [ABSTRACT FROM AUTHOR]

Land use/land cover (LULC) changes driven by diverse policies in arid ecologically fragile areas have sizeable impacts on agricultural production and water-related ecosystem services (ESs) and their trade-offs. However, the relative and cumulative impacts of diverse policies on ESs and their trade-offs in different periods are still unclear and need further differentiation. The western Jilin Province, China was taken as a case study, and actual LULC conversions associated with policy implementation rules were selected to disentangle the relative and cumulative impacts of diverse policies on food- and water-related ESs and their trade-offs in the historical (2000–2010) and recent (2010–2020) periods. Policies that have the greatest impact on ESs trade-offs at county scale in different periods were further identified. The results showed that food production improved the most (203.50%), but habitat quality (−7.79%) and water purification (−7.61%) decreased the most in the food security plan (FSP) during 2000–2020. Habitat quality improved the most (3.73%) in the river-lake connection program (RLCP), and water purification improved the most (3.85%) in the Grain for Green (forest) program (GFGP). The impact of diverse policies on ESs in the historical period was generally greater than that in the recent period. The cumulative impact of the ecological protection and restoration improved all ESs. While the saline-alkali land amelioration program (SLAP) mitigated most ES trade-offs in the historical period, all ecological protection and restoration policies enhanced most ES trade-offs in the recent period. Policies that have the greatest impact on ESs and their trade-offs varied over time. The SLAP and RLCP have immense potential to improve ESs and their trade-offs. This study can serve as a reference for future agricultural development and ecological protection and restoration strategies in arid areas. [Display omitted] • Land use/cover pattern under each policy was mapped based on implementation rules. • Relative impacts of diverse policies on ecosystem services were disentangled. • Impact of policies on ecosystem services and their trade-offs was time-sensitive. • River-lake connection programs had great potential to improve ecosystem services. • Policies have the greatest impact on ecosystem service trade-offs varied over time. [ABSTRACT FROM AUTHOR]

Swamp wetlands play a pivotal role in conserving water sources, regulating river runoff, and maintaining water safety and balance. The study pioneers a new research framework in the field of pollution ecology of swamp wetlands, with a focus on the complex "source-transfer-sink" processes affecting water quality in micro swamp wetlands, an area previously under-researched. Taking the Momoge Wetland in the Songnen Plain as an example, we innovatively combined the "source-transfer-sink" theory with landscape patterns, topographic factors, and their impacts on wetland water quality. Using Partial Least Squares Structural Equation Modeling (PLS-SEM), our research quantifies and models the relationships among various environmental factors. This approach reveals how landscape patterns influence pollutant migration and water quality at a micro-scale. Our findings suggest that a 700-m buffer zone is most effective in capturing the fluctuations in water quality in arid wetlands, which is crucial for wetland management practices. We identified the main pollution sources in the Momoge Wetland, including sediment (21.60%), vegetation (24.94%), livestock and crop-related non-point sources (41.21%), and hydrodynamic factors such as water diversion (12.25%). In pollutant migration, land use emerged as the most significant factor affecting water quality (56.64%), followed by landscape patterns (25.54%). Notably, our study finds that grasslands are essential for water purification, and a uniform distribution of landscape patches significantly improves water quality. This research marks a significant stride in understanding and optimizing landscape patterns to enhance water quality in micro swamp wetlands. The insights gained are invaluable for the protection of these ecosystems and promoting their ecological value functions, providing a reference point for future wetland conservation and management strategies. [Display omitted] • "Source-Transfer-Sink" theory explains the decline in water quality in small micro wetlands. • Revealing water quality fluctuations by combining source apportionment and landscape patterns during migration. • 700m buffer zone is optimal for controlling water quality in small micro wetlands. • Increased grassland area improves water quality in small micro wetlands. • Uniform distribution among different patches enhances water quality. [ABSTRACT FROM AUTHOR]