Assessment of the habitat suitability and restoration potential of mangroves in Xiamen Bay, China

In order to quantitatively explore the impacts of multiple environmental factors on the mangrove distribution, and predict the regional spatial pattern of mangrove habitat suitability and restoration potential, the maximum entropy model was applied to assess the habitat suitability of mangroves in Xiamen Bay, overlaying with the land use and land cover data to analyze the restoration potential. The results showed that among the five environmental variable groups of bioclimate, topography, water quality, substrate type, and hydrology, the main factors that affected the distribution of mangroves in Xiamen Bay were temperature, topography and water quality. Among the single environmental factors, the distance from shoreline, the nutrient concentration and the salinity were the decisive factors. The areas with higher suitability and restoration potential are mainly located in Jiulong River Estuary, Xiatanwei, Xiang′an, and Dongyu, Haicang. Apart from the existing mangrove areas, we predicted 406.4 hm² with high restoration potential and 1 001.2 hm² with medium restoration potential in Xiamen Bay. Existing protected areas and restoration projects have covered the most of these areas. In the future, areas along the coast of Anhai Bay, Jiulong River Estuary, Zhangzhou Port and islands nearby may be considered for mangrove restoration. This study attempted to adopt the modelling method to determine the comprehensive suitable conditions of mangroves, and to achieve spatial and quantitative assessment. The results can provide important scientific basis for the site selection of mangrove restoration and decision support for the regional protection and restoration management of mangroves.