Ecosystem services, trade-offs and synergy analysis in Tianjin under different land use scenarios

  Objective  Land use change is an important factor leading to changes in ecosystem services and their relationships. It is significant to explore the impact of land use on ecosystem services.

  Method  This study is based on the land use data of Tianjin in 2000 and 2015, combined with regional development planning, using the GeoSOS-FLUS model to predict the land use structure under three different situations in 2030, and using the InVEST model to evaluate ecosystem services and trade-offs.

  Result  (1) From 2015 to 2030, under the business as usual, cities continued to expand, construction land increased by 27.68%, and cultivated land decreased by 11.47%. Under the ecological planning, urban expansion slowed down, construction land increased by 7.97%, and woodland, grassland, waters and shrubs increased by 2.02%. Under the rapid urban development, construction land and cultivated land remained stable, and the water area increased by 4.78%. (2) From 2015 to 2030, the comprehensive ecosystem service index of Tianjin under different situations showed a downward trend. In 2030, the total ecosystem service indexes of business as usual, ecological planning and rapid urban development were 0.172, 0.181 and 0.180, respectively. (3) From 2015 to 2030, the direction of the synergy of the four ecosystem services under different situations had not changed, but the strengths and weaknesses had undergone complicated changes. In general, the synergy relationship was stronger under the ecological planning and weaker under the business as usual.

  Conclusion  This study suggests that Tianjin City should slow the urban expansion, optimize the current land use structure, and enhance the ecological environment construction in the future. The research results can provide a theoretical basis of ecosystem management in Tianjin.