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The coastal salt marsh wetland is mainly located in the tidal area where sea and land are intertwined, which has the functions of promoting silt and consolidating beach, wave reduction and disaster reduction, and is an ecological barrier against erosion in the coastal zone, which has important ecological value. Nevertheless, owing to the intricate nature of wetland species formation mechanisms and community distribution patterns, the impact of coastal squeeze on Suaeda salsa wetlands loss may not exhibit a linear relationship, necessitating further elucidation of the specific processes involved. Precisely understanding the extent to which coastal squeeze affects the threshold of loss in the Suaeda salsa wetland holds immense importance in safeguarding the distinctive red beach landscape. Furthermore, it represents a pivotal scientific challenge that necessitates resolution in the management of coastal wetlands for their protection and restoration. Hence, drawing upon the theoretical framework concerning the impact of coastal squeeze on the degradation of coastal Suaeda salsa wetland, this study employs the representative silty coastal region of China's northern Liaodong Bay as a case study to conduct empirical investigation. The research integrates Landsat imagery and digital elevation data, and incorporates spatial autocorrelation, elastic coefficient analysis, and barycenter model analysis to examine the threshold of degradation and spatial variations of Suaeda salsa wetland in response to coastal squeeze. The results show that: (1) The risk intensity of coastal squeeze in the study area exhibited a pattern of initial decline followed by an increase from 1995 to 2020, with the highest risk areas predominantly located in the development zone on the eastern bank of the Liao River Estuary. (2) There was a positive correlation between the growth of the coastal squeeze index and the loss of the Suaeda salsa wetland. When the proportion of area in which the coastal squeeze deteriorates reached 43.9%, the Suaeda salsa wetland lose resilience against the impact of coastal squeeze, leading to an intensified rate of loss. (3) Compared with the west side of the Liao River, the critical area of coastal squeeze and the loss barycenter of the Suaeda salsa wetland on the east side of the Liao River have a greater range of changes. The planning and management of coastal ecological restoration necessitates considering the occurrence conditions of the coastal squeeze impact threshold on the loss threshold of wetland and the migration characteristics of the wetland loss area. This approach enables the timely control of coastal squeeze risk intensity in the area and the preservation of wetlands' resistance to external disturbances. Consequently, it holds immense importance for the sustainable development of coastal wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

It focused on heavy metal pollution of green vegetation in Tuokexun County, Xinjiang Northwest China's suburban industrial area, using inductively coupled plasma emission spectrometer to analyze the samples for Mn, Ni, Zn, Cd, Hg, Pb, As, Cu, and Cr contents. The soil's heavy metal content in the study area indicated a minor level of pollution overall (P = 1.77), with the most severe contamination being Hg, which is more likely to be caused by human activities. Heavy metal elements in trees have the most stable composition in comparison to grass and shrubs, with varying concentrations across different vegetation. The concentrations of Mn, Cd and Hg were highest in the Haloxylon ammodendron, Ni in Morus alba, Pb, As and Cu in Nitraria tangutorums, and Cr in Phragmites australis. Heavy metal restoration is most effectively performed by shrubs, and there are disparities in heavy metal enrichment among various vegetation. No significant difference was found in heavy metal enrichment between the aboveground and underground parts of vegetation. Based on the average of the membership function, Tamarix exhibits the strongest ability to enrich heavy metals, while Nitraria tangutorum comes in second, and Cynanchum chinense R.Br. is the least effective among all plant species. Morus alba is recommended as the primary planting species in the area. Nitraria tangutorum and Haloxylon ammodendron have good potential for Cd and As restoration and can be used as supporting vegetation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have app eared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Liaohe coastal wetland has experienced severe degradation of Suaeda salsa (L.) Pall (S. salsa) in recent years. However, the impact of exogenous betaine (GB) on S. salsa growth remains unclear. Therefore, we conducted a natural simulated cultivation in soils of coastal wetland to investigate the effects of GB on S. salsa growth. The results showed that GB increased the height and weight of S. salsa, and meanwhile stimulated the synthesis of endogenous betaine and amino acids, increased soluble sugars and elevated the activity of Na + , K + -ATPase (enhancing osmotic stability). In addition, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased, and malondialdehyde (MDA) and H 2 O 2 decreased correspondingly, thereby improving the antioxidant capacity. Overall, GB application significantly alleviated salt stress and effectively promoted S. salsa growth. This study first indicated the important role of GB in influencing S. salsa growth, offering potential strategies for remediation in coastal wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Coastal wetlands are being greatly affected by global climate change, and understanding how tides influence plant connectivity can provide a basis for plant conservation and wetland restoration decisions in degraded and at-risk areas. In our study, we quantified the structural and functional connectivity of Suaeda salsa in the Yellow River Delta and explored the impact of tidal action on connectivity. The results showed that plant structural connectivity increased with distance inland from the sea. Similarly, seed connectivity was enhanced but gene connectivity was diminished when moving inland. An increase in the tidal channel branching rate was associated with a significant reduction in plant structural connectivity, and tidal inundation frequency significantly promoted gene connectivity. Tidal action was found to reduce seed circulation and germination, but this effect was not significant. Overall, it was established that plant structural connectivity is not equivalent to functional connectivity and that the effects of tides on structural and functional connectivity are inconsistent. In terms of achieving effective plant connectivity, tides can promote connectivity. In addition, when studying plant connectivity, temporal and spatial scales should be considered. This study provides a more comprehensive and insightful understanding tidal drivers of plant connectivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Biochar has the potential to improve soil properties and increase plant productivity. However, due to the different types of soil, plants, and environmental factors, the impact of biochar is likely to vary. We explored the impacts of biochar prepared from an invasive plant Spartina alterniflora on plant performance and soil characteristics in a simulated coastal wetland ecosystem. We investigated the impact of three application ratios (control, 1%, and 5%; weight ratio) of biochar on the germination and growth of a native plant Suaeda salsa, the nutrient content and microbial community characteristics of the rhizosphere soil under three flooding treatments (no flooding, episodic flooding, and continuous flooding). Biochar application had no impact on seed germination of S. salsa, but promoted its seedling growth (biomass, height, root length) and nitrogen content. Biochar application also enhanced soil nutrient content and affected soil microbial community characteristics. Seed germination and seedling growth of S. salsa were sensitive to flooding and were the best under episodic flooding. Notably, flooding inhibited the impact of biochar on S. salsa and rhizosphere soil. In conclusion, biochar can positively affect the growth of S. salsa and improve the quality of rhizosphere soil, especially under no flooding. Our findings highlight the possibility of applying biochar for the restoration of S. salsa in coastal wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

• Identify ancient flood events, which may be the reason for decline of the culture. • Pollen and heavy metals can be used to reflect the strength of human activities. • Pollen and heavy metals revealed the process of culture from prosperity to decline. • This paper defined the chronology from prosperity to decline of Shijiahe culture. • Climate change has been revealed by pollen and heavy metals since 4800 cal. yr BP. The Shijiahe Culture (ca. 4800–4100 yr BP), which originated in the middle Yangtze Basin, was a milestone of prehistoric Chinese civilization. To reveal the interactions between climatic changes and human activities during this time interval, the geochronology and multiple proxies (pollen and heavy metals) of samples from a 220-cm-deep outer wall at the Sanfangwan Site (a typical site of the Shijiahe Culture) were analyzed. Radiocarbon dating indicates that the age range of the Sanfangwan Site is ca. 4800 to 4100 cal. yr BP. From ca. 4800 to 4600 cal. yr BP (the early Shijiahe Culture), pollen assemblages were dominated by Gramineae and an anthropogenic plant community (e.g. Ranunculaceae, Chenopodiaceae, Labiatae, and Cruciferae), indicating an expansion in rice agriculture during this interval. High metal concentrations in the same interval indicate a large flux of metals from smelting and farming activities. Between ca. 4600 and 4100 cal. yr BP (the middle and late Shijiahe Culture), decreases in Gramineae and anthropogenic pollen mirrored the recession of farming. Concurrent decreases in heavy metals may be attributable to a decline in the smelting industry. Three episodes of high pollen concentrations and visible increases in hygrophyte pollen, Pinus pollen, and fern spores at 4600–4550, 4450–4350, and 4200–4100 cal. yr BP probably indicate the occurrence of several flooding events during the middle and late Shijiahe Culture, resulting in the migration of local inhabitants. This study highlights the driving effect of flood events on the collapse of the Shijiahe Culture. [ABSTRACT FROM AUTHOR]