Systematic conservation planning of freshwater wetlands in Pearl River Basin

Wetland distribution data were used to conduct comprehensive evaluation of wetland protection status in the Pearl River Basin, an important socio-economic development area．Aiming at protection of wetland biodiversity, theories and methods of systematic protection planning were used to consider comprehensively socioeconomic factors such as GDP and population density．Spatial optimization model Marxan was used to construct priority pattern of wetland protection in the Pearl River Basin．A total of 87 protection units covering a total area of 27 681.79 km² were established, a protection network was formed, each sub-basin was evaluated to determine wetland protection vacancies．The Pearl River Basin protection system was found to be seriously lacking and needs to be reconstructed urgently．Wetland protection vacancies in the upper reaches were found to be mainly concentrated in areas where plateaus, mountain lakes and river wetlands were widely distributed．In the middle and lower reaches of the Pearl River, large-scale nature reserves for large-scale wetland vacancies need to be established to strengthen protection and restoration of important ecological reserve resources．The Pearl River Delta region has been subject to strong human disturbance and experienced prosperous economic activities, construction of wetland parks or wetland communities in the protection space of the Guangdong-Hong Kong-Macao Greater Bay Area should be an urgent focus, to launch targeted coastal wetland restoration projects to ease reclamation．Wetland protection vacancies in Hainan and the rivers of the South China Sea islands are mainly located in parts of the east and west of Hainan Island．Different types of nature reserves and natural parks should be established depending on protection intensity and development levels in the region．These data could be applied to the adjustment of the Pearl River Basin wetland protection system, for overall protection, rational development and utilization of the Pearl River wetland from a macro level．Our work will be useful for key economic developments such as the Guangdong-Hong Kong-Macao Greater Bay Area．