Abstract: Mangrove forest is a woody community occurring in the intertidal zone of tropical and subtropical coasts, with important ecological functions. Guangdong Province has the largest area of mangrove in China, and thus is critical for mangrove protection. Maximum entropy model (MaxEnt), a species distribution model, is extensively applied in biodiversity conservation. This study compiled a dataset of mangrove distribution and key environmental variables in Guangdong Province. With this dataset, a mangrove MaxEnt was built, which was used to predict the potential suitable zones of mangroves in Guangdong Province and to identify the key environmental variables influencing mangrove distribution. Outcomes of the modeling were further used to assess conservation gaps. The results showed that the most important environmental variables affecting mangrove distribution were temperature, sea surface temperature, and precipitation. The suitable range for annual mean temperature was 22.37-23.58 ℃, for mean sea surface temperature of the coldest quarter was 23.15-23.34 ℃, for annual precipitation was 1647.14-1809.61 mm, and for precipitation of driest month was 23.6-27.2 mm. The most suitable areas for mangrove in Guangdong were mainly concentrated in Pearl River Estuary to Daya Bay coast, and Leizhou Peninsula to Yangjiang coast. Conservation gaps of mangrove were mainly located in Yangjiang Port, Zhenhai Bay, Pearl River Estuary, and Red Bay. Our findings could provide a scientific basis for improving and advancing the spatial layout of mangrove protection and restoration in Guangdong Province.

Key words: species distribution model, conservation gap, suitable area, potential distribution, restricting factor.