Soil bacterial communities play a crucial role in the functioning of estuarine wetlands. Investigating the structure and function of these communities across various wetland types, along with the key factors influencing them, is essential for understanding the relationship between bacteria and wetland ecosystems. The Liaohe Estuary Wetland formed this study’s research area, and soil samples from four distinct wetland types were utilized: suaeda wetlands, reed wetlands, pond returning wetlands, and tidal flat wetlands. The structure and function of the soil bacterial communities were examined using Illumina MiSeq high-throughput sequencing technology in conjunction with the PICRUSt analysis method. The results indicate that different wetland types significantly affect the physical and chemical properties of soil, as well as the structure and function of bacterial communities. The abundance and diversity of soil bacterial communities were highest in the suaeda wetland and lowest in the tidal flat wetland. The dominant bacterial phyla identified were Proteobacteria and Bacteroidota. Furthermore, the dominant bacterial genera identified included RSA9, SZUA_442, and SP4260. The primary functional pathways associated with the bacterial communities involved the biosynthesis of valine, leucine, and isoleucine, as well as lipoic acid metabolism, which are crucial for the carbon and nitrogen cycles. This study enhances our understanding of the mutual feedback between river estuary wetland ecosystems and environmental changes, providing a theoretical foundation for the protection and management of wetlands.

With the acceleration of global urbanization, the ecosystem services (ES) and ecological balance of nature reserves have been significantly impacted. However, quantitative assessments of the multiple contributions of nature reserves to urban ecological sustainability are still lacking. This study selects Panjin, a wetland city in China (3788 km²), as the study area, utilizing the InVEST model to quantify ES (water yield, carbon storage, soil retention, and habitat quality), and employing redundancy analysis to explore the influencing factors. Ecological source areas were identified, and the Sustainable Development Goals (SDGs) score was calculated to systematically evaluate the contribution of nature reserves. The results indicate that from 1990 to 2010, the built-up area of Panjin increased by approximately 159%, leading to a reduction in carbon storage, soil retention, and habitat quality by 20%, 4%, and 14%, respectively. From 2010 to 2020, ecological restoration policies resulted in a 63% increase in ES compared to 2010. Nature reserves played a crucial role in maintaining ecological stability, providing over 40% of the ecological source areas while occupying only 24% of the city’s area and contributing more than 30% to the overall urban ecological sustainability. This study is the first to systematically assess the multiple contributions of nature reserves to urban ecological sustainability, providing ecological management recommendations for policymakers based on innovative environmental indicators and methods to support sustainable urban development.

The Liaohe Estuary, characterized by Asia’s largest reed marshes and diverse wetland types, provides critical habitats for endangered bird species and performs vital ecological functions, making it a representative international wetland. Tidal flats, as essential components of estuarine wetlands, dissipate wave energy and stabilize shorelines. However, due to their peripheral location within estuarine systems, quantitative monitoring and risk assessment of the Liaohe Estuary tidal flat remain constrained. In this study, 187 cloud-filtered Landsat TM/ETM+/OLI scenes acquired between 2001 and 2021 were integrated with a waterline-derived DEM framework to quantify sedimentation dynamics in the Liaohe Estuary wetland. During the study period, the tidal-flat area exhibited a declining trend, while interannual surface elevations generally ranged from +2.18 to −1.61 m. The mean surface elevation increased by 25.33 cm, accompanied by a mean slope increase of 0.11‰; the average sedimentation rate was 1.27 cm yr⁻¹, with a net depositional volume of 0.51 km³, indicating an overall depositional regime. Moreover, mean elevation displayed a statistically significant upward trend (Kendall’s tau = 0.636, p = 0.0057), corroborating the significant rise in tidal-flat elevation from 2001 to 2021. The coexistence of elevation gain and spatial contraction suggests limited geomorphic resilience and a shrinking spatial extent of the tidal flat. The proposed approach provides a robust framework for long-term monitoring and supports the formulation of quantifiable sustainability targets for coastal management in the Liaohe Estuary.

Desertification sensitivity in semi-arid urbanizing regions remains a critical challenge for sustainable land management. This study analyzes the spatiotemporal dynamics (2018–2022) of desertification sensitivity in the Beijing–Tianjin–Hebei core region using the Normalized Difference Vegetation Index (NDVI), soil texture, the Digital Elevation Model (DEM), and nighttime light data. Using a GIS-based model, we found a decline in overall desertification sensitivity, with vegetation degradation (post-2020) emerging as a key factor. Key recommendations include optimizing urban spatial patterns via ecological red lines, prioritizing vegetation restoration in high-sensitivity zones, and establishing dynamic remote sensing-based monitoring systems. These strategies aim to coordinate urban growth with ecological resilience, offering actionable pathways for semi-arid regions facing similar pressures. Future work should integrate socioeconomic drivers to refine adaptive governance frameworks.

Semi-arid wetlands are highly sensitive to changes in hydrological regimes, as strong evaporation often exceeds limited natural recharge. Ecological water replenishment is widely used to restore these systems, but schemes designed only to meet water-volume targets may cause excessive hydrodynamic disturbance, promote sediment resuspension, and increase the release of internal pollutants. In this study, we developed an ecological water-replenishment assessment framework for Chahannaoer Wetland that incorporates ecological water-demand thresholds, suspended-solids disturbance, and an AHP–entropy weight–TOPSIS decision model. Using hydrological and meteorological data from 2014 to 2024, six replenishment scenarios were evaluated in terms of water-balance recovery, disturbance control, and habitat suitability. The results show that Chahannaoer Wetland experienced a persistent evaporation-dominated water deficit. The mean annual natural recharge was 0.225 × 10⁸ m³, with a mean annual ecological water shortage of 1.03 × 10⁸ m³ and an evapotranspiration-to-recharge ratio of 3.42–4.56. Based on the previous comprehensive water-quality assessment using DO, COD, NH₃-N, TN, and TP, the minimum water volume required to maintain Class IV water quality was 0.86 × 10⁸ m³, whereas the suitable ecological water demand ranged from 1.27 × 10⁸ to 1.56 × 10⁸ m³. With the total replenishment volume held constant, centralized replenishment met the required water volume but substantially increased near-bed disturbance and sediment resuspension risk. By contrast, decentralized uniform replenishment performed best, with the highest relative closeness coefficient of 0.9105, a disturbance index of approximately 0.32, and water depths maintained within the suitable habitat range of 30–50 cm. These findings suggest that ecological restoration in semi-arid wetlands should move beyond volume-based water supplementation and pay greater attention to the timing, pathway, and hydrodynamic effects of replenishment. The proposed framework provides a quantitative basis for optimizing ecological water replenishment in evaporation-dominated wetlands and other inland lakes in arid and semi-arid regions.