Invasive plants, like Spartina alterniflora (SA), have a competitive advantage over native flora due to their rapid utilization of vital soil nutrients. This results in the depletion of resources for native plant species, significantly impacting ecosystem diversity and stability. This comprehensive review addresses several key aspects related to SA’s spread and spatial distribution in China’s wetlands. The rapid expansion of Spartina alterniflora is attributed to its high reproductive ability, adaptability to environmental factors like elevated salinity, and ability to disperse its seeds via tides. Spartina alterniflora mainly were found in Zhejiang, Jiangsu, Fujian, and Shanghai provinces, accounting for more than 90% of China’s total Spartina alterniflora area. Spartina alterniflora rapid growth results in displacement of native species and loss of vital microbial, plant, and animal diversity. Some studies reported that Spartina alterniflora increases carbon storage, while others argue that it weakens this function. The impact of Spartina alterniflora on organic and inorganic carbon requires further research for better understanding dynamics of carbon in coastal wetlands. The controlled growth of Spartina alterniflora can be beneficial in many aspects of the coastal wetlands’ ecosystem. In China, various methods have been employed to control the invasion of SA. Physical control, such as removing the plants and converting them into fertilizer or bioenergy, has been commonly used but has limitations like air pollution and the potential for re-invasion. Chemical herbicides like Imazapyr and Haloxyfop-R-methyl have effectively controlled and prevented re-invasion in specific areas, but their potential adverse impacts are still uncertain. Wetland Park construction, aquaculture development, and substituting native or exotic species with mangroves or reed communities have also been successful. It becomes evident that a long-standing and Contextual approach is necessary to effectively manage the advantages and curtail the drawbacks associated with S. alterniflora across China.

Glyoxal (CHOCHO) and formaldehyde (HCHO) trace gases were successfully retrieved from a multi-axis differential optical absorption spectroscopy (MAX-DOAS) system in Beijing (39.95°N, 116.32°E) and Baoding (39.15°N, 115.40°E), China. The measurements of these trace gases span the period from May 2017 to April 2018. Higher levels of trace gases were observed in Beijing most likely due to increased transport and industrial activities compared to Baoding. Different time scales were analyzed from seasonal to daily levels. Seasonal variation categorized by wintertime maximum and summertime minimum was observed for CHOCHO, while for HCHO maximum values were recorded during summer at both observation points. Variations in the diurnal cycle of trace gases were examined. The results are consistent with strong links to photo-oxidations of VOCs for HCHO production, whereas the CHOCHO diurnal variation can be related to anthropogenic effects in the evening. Weekends didn’t have any significant effect on both HCHO and CHOCHO. We investigated the temperature dependency of HCHO and CHOCHO. HCHO shows positive correlation with air temperature, which strengthened the argument that HCHO production is linked to photo-oxidation of VOCs. CHOCHO is anti-correlated with air temperature. This suggests that photolysis is a major sink for CHOCHO in Beijing and Baoding. We also investigated the relationship between CHOCHO and HCHO VCDs with enhanced vegetation index (EVI) data obtained from MODIS, which represents a direct relation with biogenic emissions. The positive correlations were observed among monthly mean HCHO VCDs and monthly mean EVI at both monitoring stations. The strong correlation of HCHO with EVI found, suggests that oxidation of isoprene and HCHO production is strongly related, while negative correlation was observed among CHOCHO VCDs and EVI.

The chemical transformation of selenium (Se) in the topsoil, especially when regarded as low to sufficient Se (with high bioavailability) in dry arid environments, has great importance in the alkaline soils to yield Se-enriched food regionally. The Se content in the highly alkaline soil of the northwest region of China has inordinate agriculture economic potential, and such soil distribution is likely to produce Se-enriched crops with distinct features. One such large area of Zhongwei was investigated for the distribution of soil Se and its bioavailability, and the influencing chemical factors of soil total Se (T-Se) and bioavailable Se (B-Se) in the agroecosystem. The results suggested that the T-Se in Zhongwei soils (mg/kg) ranged from 0.01 to 0.55 with a mean of 0.2 ± 0.08, which was lower than the average Se distribution of both China (0.29 mg/kg) and the world (0.40 mg/kg). However, the overall B-Se proportion (16%) in T-Se was adequately higher than in other Se-rich soils. Spatial distribution depicted that the T-Se was specified as deficient in 42.6% and sufficient in 55.5% of the studied area, while Zhongning county was prominent with a higher B-Se proportion (22%) in the T-Se of Zhongwei. The influencing factors, such as pH and organic matter (OM), showed significant association with B-Se, as suggested by Pearson’s correlation and multiple linear regression (MLR). Furthermore, the vertical distribution of T-Se and B-Se was higher in agricultural soil (AS) than in natural soil (NS) and can be justified in the context of their association with OM. Based on these results, the Se-fortified crops can be yielded by practices to improve corresponding influencing chemical factors of soil, especially in dry areas.