Abstract: Poyang Lake Basin is an important agricultural production area in China and a globally important wetland reserve. Ecosystem services of this region play a pivotal role in China’s and even the global sustainable deve-lopment. Studying the responses of trade-offs and synergies of ecosystem services to the regional land-use changes in Poyang Lake Basin is of great significance in guiding the management of national land space, and in enhancing ecosystem services. We used the InVEST model to quantitatively assess carbon storage service (CSS), food provisioning service (GP) and water purification service (SWP) of Poyang Lake Basin in 2000, 2010 and 2020. Two sampling transects, i.e., transect 1 and 2, were delineated for the main terrain of plains and hills in the basin. Based on this, we used wavelet coherence analysis to measure the trade-offs and synergies between several ecosystem services, and applied linear regression to identify their responses to land use changes in Poyang Lake Basin. The results showed that, in the transect 1 and transect 2, the proportion of samples with positive correlation between CSS and SWP in 2000, 2010, 2020 were 82.3% and 92.9%, 79.0% and 94.8%, 91.2% and 94.1%, respectively, showing synergistic relationship, the proportion of samples with negative correlation between CSS and GP were 86.8% and 96.8%, 81.0% and 96.7%, 76.0% and 92.5%, and the sample proportion of negative correlation between SWP and GP were 80.5% and 91.5%, 80.9% and 91.9%, 100% and 99.8%, respectively, which showed a trade-off relationship. In the plains, woodlands had the strongest influence on ecosystem service trade-offs and synergies, with wavelet coherence means of -0.54, -0.77, and 0.62 for CSS and GP, SWP and GP, and CSS and SWP, respectively. In hilly areas, unutilized land had the strongest impact on the synergistic relationship between CSS and SWP with a wavelet coherence mean of 0.84, and built-up land had the greatest impact on the trade-off relationship between CSS and GP, and SWP and GP with wavelet coherence means of -0.79 and -0.72, respectively. The response of ecosystem service trade-off/synergistic relationship to land use conflict was not significant. In the plain area, the synergistic relationship between CSS and SWP was negatively correlated with land use intensity, and the trade-off relationship between CSS and GP, and SWP and GP was positively correlated with land use intensity. The pattern in the hilly area was the opposite to the plain area. The protection of ecosystem services and spatial control of land in Poyang Lake Basin should be managed according to different land types.

Key words: ecosystem service, wavelet coherence, trade-offs and synergies, land use, Poyang Lake Basin