Suitability assessment of tidal flat saltmarsh vegetation restoration after Spartina alterniflora suppression in Jinghai Bay, Weihai

Conducting suitability assessments for mudflat ecological restoration is crucial for enhancing the targeting, effectiveness, and sustainability of restoration efforts. Based on field survey data of the current suitable habitat for Suaeda salsa, an index system was developed incorporating five key factors: hydrological conditions (inundation duration), sedimentary conditions (total water-soluble salt content, organic carbon, grain size), native vegetation, biological invasion threat, and spatial utilization. The suitable range for each factor was determined, and a three-tiered classification method (suitable, fairly suitable, and unsuitable) was established. Combining with survey data of critical mudflat elements, the suitability for salt marsh vegetation restoration in Jinghai Bay after the suppression of Spartina alterniflora was evaluated. Results indicate that after S. alterniflora suppression, sediment types in Jinghai Bay were predominantly silty sand or sandy silt, and the average inundation duration was 4.03 h/d and the mean total water-soluble salt content was 8.05 g/kg, which are conducive to Suaeda salsa growth, the overall suitability was categorized as “fairly suitable” due to potential S. alterniflora regrowth, and we shall be cautious when implementing salt marsh vegetation restoration projects. Therefore, close monitoring to S. alterniflora regrowth during restoration and timely management are essential to ensure the restoration effectiveness and consolidate the ecological gains achieved after S. alterniflora suppression.