Ecological Indicators (Jul 2022)
Distribution and disturbance dynamics of habitats suitable for Suaeda salsa
Abstract
Suaeda salsa, as the last biological barrier of coastal wetlands from land to sea, is one of the best nature-based restoration solution for shoreline stabilization and soil improvement in coastal wetlands. The quality of habitat determines the potential scope of wetland ecological restoration. To enlarge the Suaeda salsa area and to prevent the erosion and degradation of coastal wetland shorelines, we assessed the suitability of habitats for Suaeda salsa growth and identified the causes of encroachment into areas suitable for Suaeda salsa growth. Assessing the habitat suitability of the community and its disturbance status can not only effectively determine the suitable areas for Suaeda salsa ecological restoration, but also can propose targeted solutions according to the interference factors. Moreover, this way can greatly improve the survival rate and coverage area of Suaeda salsa restoration, reduce unnecessary input and loss, enhance the ability to resist coastal wetland shoreline erosion and degradation, and maintain the stability and integrity of the coastal wetland ecosystem. In this study, based on the data of 180 sampling points in the Liaohe estuary wetland, habitat suitability was identified, and the MaxEnt model (habitat suitability model) was used to analyze the suitable distribution area. The interannual changes in Suaeda salsa and reclamation activities in the Liaohe estuary wetland during the past 30 years were extracted from Landsat remote sensing images, and the temporal and spatial dynamic relationship between the distribution of Suaeda salsa and reclamation was analyzed. The dominant factors affecting the distribution of Suaeda salsa were water salinity as well as soil Cd and Zn levels, with influence weights of 49.1%, 28.9%, and 18.0%, respectively, and a total weight of 96%. Compared with the existing 596 hm2 of Suaeda salsa vegetation in the Liaohe estuary wetland, the area highly suitable for growth was 12,306 hm2, whereas the area with medium suitability was 12,100 hm2. Reclamation and aquaculture areas accounted for 33.31% of the highly suitable area and were the main reasons for habitat fragmentation. The study explained the reasons for the difficulty of ecological restoration of Suaeda salsa due to unsuitable habitat quality, and revealed a strong conflict between coastal reclamation and environmental protection, suggesting that the protection of coastal wetlands should consider changes in industrial model strategy. The restoration, reconstruction, and sustainable management of Suaeda salsa communities can be achieved by reducing the proportion of reclamation areas. This study improves the ecological restoration theory of degraded wetlands and provides a theoretical basis for coastal wetland protection and nature-based restoration programs.
