Soil salinity is a serious problem for agriculture in coastal regions. Nevertheless, the effects of soil salinity on microbial community composition and their metabolic activities are far from clear. To improve such understanding, we studied microbial diversity, community composition, and potential metabolic activity of agricultural soils covering non–, mild–, and severe–salinity. The results showed that salinity had no significant effect on bacterial richness; however, it was the major driver of a shift in bacterial community composition and it significantly reduced microbial activity. Abundant and diverse of microbial communities were detected in the severe–salinity soils with an enriched population of salt–tolerant species. Co–occurrence network analysis revealed stronger dependencies between species associated with severe salinity soils. Results of microcalorimetric technology indicated that, after glucose amendment, there was no significant difference in microbial potential activity among soils with the three salinity levels. Although the salt prolonged the lag time of microbial communities, the activated microorganisms had a higher growth rate. In conclusion, salinity shapes soil microbial community composition and reduces microbial activity. An addition of labile organic amendments can greatly alleviate salt restrictions on microbial activity, which provides new insight for enhancing microbial ecological functions in salt–affected soils.

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Microbial Community Composition and Activity in Saline Soils of Coastal Agro–Ecosystems

Passivation of lead and cerium in soil facilitated by biochar-supported phosphate-doped ferrihydrite: Mechanisms and microbial community evolution.

Relationships between soil biodiversity and multifunctionality in croplands depend on salinity and organic matter

Urban ventilation planning and its associated benefits based on numerical experiments: A case study in beijing, China

Extreme precipitation events severely affect ecosystems and human society. While most existing studies investigated either their temporal changes or spatial extent, the joint behaviors in both time and space are neglected. Here, we examine different evolution patterns of spatiotemporally contiguous precipitation events (SCEPEs) across China during 1997–2021 from a three-dimensional (3D, latitude × longitude × time) perspective. The SCEPEs exhibit distinct behaviors in different subregions. The SCEPEs in northwestern areas have relatively longer moving distances and weaker magnitude, mostly originating from the west and traveling to the east. Southeastern events display stronger magnitudes and travel at shorter distances, characterized by a more localized phenomenon. Since 1997, the frequency of SCEPEs in China has nearly doubled, their magnitude and affected areas have increased, but the moving distance and speed have decreased. Our findings provide important references for predicting extreme weather events and mitigating their detrimental impacts. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2022GL098840

Spatiotemporal Evolution Patterns of Contiguous Extreme Precipitation Events Across China From a 3D Perspective

Interactive effects of salinity and SOM on the ecoenzymatic activities across coastal soils subjected to a saline gradient

Abstract. Heatwaves (HWs) paired with higher ozone (O3) concentration at the surface level pose a serious threat to human health. Their combined modulation of synoptic patterns and urbanization remains unclear. Using 5 years of summertime temperature and O3 concentration observation in Beijing, this study explored potential drivers of compound HWs and O3 pollution events and their public health effects. Three favorable synoptic weather patterns were identified to dominate the compound HWs and O3 pollution events. These weather patterns contributing to enhance those conditions are characterized by sinking air motion, low boundary layer height, and high temperatures. Under the synergy of HWs and O3 pollution, the mortality risk from all non-accidental causes increased by approximately 12.31 % (95 % confidence interval: 4.66 %, 20.81 %). Urbanization caused a higher risk of HWs and O3 in urban areas than at rural stations. Particularly, due to O3 depletion caused by NO titration at traffic and urban stations, the health risks related to O3 pollution in different regions are characterized as follows: suburban stations &gt; urban stations &gt; rural stations &gt; traffic stations. In general, favorable synoptic patterns and urbanization enhanced the health risk of these compound events in Beijing by 33.09 % and 18.95 %, respectively. Our findings provide robust evidence and implications for forecasting compound HWs and O3 pollution events and their health risks in Beijing or in other urban areas all over the world that have high concentrations of O3 and high-density populations. 

Joint occurrence of heatwaves and ozone pollution and increased health risks in Beijing, China: role of synoptic weather pattern and urbanization

The influence of the deposition of three different particles (NaCl, C and SiO2) on the initial atmospheric corrosion of 7B04 aluminum alloy was investigated via laboratory exposure testing, environmental scanning electron microscope (E-SEM), energy dispersive X-ray spectroscopy (EDS), and scanning Kelvin probe (SKP). The results showed that the deposition of NaCl had a significant acceleration effect on the initial corrosion of 7B04 aluminum alloy and resulted in the occurrence of localized corrosion on sample surface. Because of its capillary condensation effect, SiO2 could absorb the vapor in humid environment to form a local water-rich area around the particles which could promote the corrosion of 7B04 aluminum alloy. C had basically no effect on the corrosion of 7B04 aluminum alloy. 

Influence of solid particles deposition on the initial atmospheric corrosion of 7B04 aluminum alloy

Abstract. The summertime air pollution events endangering public health in the Guangdong–Hong Kong–Macao Greater Bay Area are connected with typhoons. The wind of the typhoon periphery results in poor diffusion conditions and favorable conditions for transboundary air pollution. Random Forest models are established to predict typhoon-associated air quality in the area. The correlation coefficients and the root-mean-square errors of the air quality index (AQI) and PM2.5, PM10, SO2, NO2 and O3 concentrations are 0.84 (14.88), 0.86 (10.31 µg/m3), 0.84 (17.03 µg/m3), 0.51 (8.13 µg/m3), 0.80 (13.64 µg/m3) and 0.89 (22.43 µg/m3), respectively. Additionally, the prediction models for non-typhoon days are established. According to the feature importance output of the models, the differences in the meteorological drivers of typhoon days and non-typhoon days are revealed. On typhoon days, the air quality is dominated by local source emission and accumulation as the sink of pollutants reduces significantly under stagnant weather, while by the transportation and scavenging effect of sea breeze on non-typhoon days. Therefore, our findings suggest that different air pollution control strategies for typhoon days and non-typhoon days should be proposed. 

/pdf/typhoon-associated-air-quality-over-the-guangdong-hong-kong-2u4lyong.pdf

J A J Murphy

Papers

Interactive effects of salinity and SOM on the ecoenzymatic activities across coastal soils subjected to a saline gradient

Interactive effects of salinity and SOM on the ecoenzymatic activities across coastal soils subjected to a saline gradient

Joint occurrence of heatwaves and ozone pollution and increased health risks in Beijing, China: role of synoptic weather pattern and urbanization

Influence of solid particles deposition on the initial atmospheric corrosion of 7B04 aluminum alloy

Typhoon-associated air quality over the Guangdong–Hong Kong–Macao Greater Bay Area, China: machine learning-based prediction and assessment