Spatial-temporal Changes and Trade-offs and Synergies of Ecosystem Services in the Thousand-island Lake Basin

Based on 6 periods of multi-source data and ecosystem service evaluation model from 1995 to 2019, we evaluated the ecosystem of water yield, soil conservation, carbon storage and habitat quality in the Thousand-island Lake Basin, and then studied the trade-off and the trade-off and synergy between ecosystem service functions are explored by combining hot spot analysis and correlation analysis. The results show that the water yield and soil conservation in the Thousand-island Lake Basin has the same change trend characteristics, which is a trend of first decreasing, then increasing, and then decreasing. Carbon storage and habitat quality have increased. In addition to water yield services, the high calue region of the other 3 services have certain overlap on the whole, the high calue region of water yield services are mainly concentrated in the western and Central Lake coastal areas of the basin. In general, the area of non hot spots accounts for the highest proportion, and the area of category Ⅳ hot spots accounts for the lowest proportion. The multi ecosystem service supply areas are mainly distributed in the medium and high gradient areas, and the non hot spots and single service supply areas are distributed in the low gradient areas. In the Thousand-island Lake Basin, synergy is the dominant relationship between ecosystem services, in which water production and carbon storage are trade-offs, and the trade-off synergies between habitat quality and soil conservation are different in different years. Land use type, vegetation coverage, and elevation are the main influencing factors for the trade-off between ecosystem services. The spatial distribution of ecosystem services in the Thousand-island Lake Basin is obviously heterogeneous, and there are differences in the trade-off synergy. The research results can provide important data support for watershed ecological planning and socio-economic development.