Changes in ecosystem services and their tradeoffs and synergies in the Yangtze River Basin from 2000 to 2020

Abstract

[Objective] The Yangtze River is an important ecological security barrier in China. Analyzing the spatial-temporal changes of ecosystem services and the driving force of land use change in the Yangtze River Basin is conducive to the coordinated development of ecology and economy in the region. [Methods] Based on remote sensing data from 2000 to 2020, the RUSLE model and the InVEST model were used to calculate the amount of soil retention, water yield, and carbon sequestration in the Yangtze River Basin. The Sen trend method and hotspot analysis method were used to analyze changes in ecosystem services. Partial correlation analysis was used to analyze the tradeoff-synergy relationships between services, and the reasons for change in ecosystem services were analyzed from the perspective of land use change. [Results] (1) From 2000 to 2020, the trends of change of average annual soil retention, water yield, and carbon sequestration in the basin were about 1.75 t/(hm2·a), -1.33×103 m3/(km2·a), and 1.62 gC/(m2·a). Except for water yield, which showed a decreasing trend in some areas, other services showed an increasing trend in most areas. The overall area of ecosystem services hotspots was expanded, especially those dominated by carbon sequestration and water yield services. (2) Soil retention and water yield were mainly in an insignificant tradeoff relationship, soil retention and carbon sequestration were mainly in a significant synergistic relationship, and carbon sequestration and water yield were mainly in an insignificant synergistic relationship. (3) The conversion from cropland to forestland had a greater impact on soil conservation services, the conversion from cropland to grassland had a greater impact on carbon sequestration services, and the conversion from grassland to cropland had a greater impact on water yield services. (4) Soil retention, water yield, and carbon sequestration services tended to be synergistic when cropland was converted to forest and grass areas, and tended to be tradeoff when the forest and grass areas were turned to cropland. [Conclusion] The ecosystem services in the Yangtze River Basin have improved in general. The increase in forest and grass area in land use change had a positive effect on the improvement of ecosystem services and the coordinated development between services. The game between land development and ecological protection has led to dynamic changes in ecosystem services. Considering the importance of regional economic development, it is necessary to balance development and protection, and achieve green and sustainable development.

Keywords

• ecosystem services|land use|spatiotemporal variation|tradeoff and synergy|the yangtze river basin