[Scenario simulation of ecosystem service trade-offs in bay cities: A case study in Quanzhou, Fujian Province, China]

Bay cities have abundant land-sea resources and higher environmental carrying capacity. The high density of population and industry surrounding the bay makes bay cities a type of ecologically fragile areas. With Quanzhou, a typical bay city, as an example, we simulated the land use and landscape pattern change in 2030 based on multiple data sources (land use data, meteorological site data, topographic data and statistical data) using Logistic-CA-Markov coupling model to set natural scenarios, planning scenarios and protection scenarios. Four key ecosystem service (ES) including water retention, soil conservation, carbon sequestration (NPP), food supply and their trade-offs were calculated and predicted. Under the three scenarios, the area of cultivated land and construction land in Quanzhou City would increase in 2030. Forest land, grassland and water area would be reduced in varying degrees. The fragmentation of land use would be serious. In comparison with 2015, except for soil conservation service, water retention, carbon sequestrtion and food supply of Quanzhou City would decline to varying degrees in 2030. Ecosystem service function in natural scenario would be more decreased, with the decline under the protection scenario being lower than the planning scenario. In the protection and planning scenarios, the synergy between water conservation and soil conservation, water conservation and carbon sequestrtion, soil conservation and carbon sequestrtion in 2030 would be enhanced and the trade-offs would be weakened.