[Trade-offs/Synergies and Driving Mechanism between Ecosystem Regulation Services and Various Ecosystem Cultural...

Ecosystem services are the products of human values integrated into ecosystem processes and functions， with obvious natural and social characteristics， and the analysis of ecosystem service trade-offs/synergies is a key scientific issue in the synergistic development of regional socio-ecology. Taking the Chengdu-Chongqing urban agglomeration as the research object， the study constructs the InVEST-MaxEnt-XGBoost-SHAP multi-modeling framework to quantify the spatial patterns of ecosystem regulation services （ERS） and ecosystem cultural services （ECS） and reveals the trade-offs/synergies relationship and driving mechanism between ERS and various ECS [aesthetic landscape service （AL）， science education and leisure service （SE）， and spiritual and faith service （SF）]. The results show that： ① ERS such as carbon sequestration， water conservation， soil conservation， and habitat quality had a highly positive correlation， with R² ranging from 0.53 to 0.77， and their spatial distributions tended to be consistent， which was mainly manifested as high in the surroundings and low in the middle. ② The spatial heterogeneity of the ECS was obvious， and the R² were all less than 0.37， with AL in a sporadic dispersal state and SE and SF in the form of multinucleated clusters in the built-up areas of the towns. ③ There were significant differences in the trade-offs/synergies between ERS and various ECS： ERS and AL were dominated by a synergistic relationship， with a synergistic area accounting for 52.07%， while ERS and SE and SF were in a trade-off relationship （trade-off areas accounting for 55.75% and 58.99%）. ④ Land use type， population density， and normalized vegetation index were dominant moderating factors of trade-off synergism between ERS and ECS services. Among them， cropland promoted the development of the ERS-ECS synergistic relationship. Moderate population density （<20 people·hm^-2） and vegetation cover （NDVI>0.69） were the key thresholds for ERS-AL synergy development， and AL depended on the spatial coupling of natural substrate integrity and human landscape accessibility. Moreover， socio-economic factors， such as road density （>1.3 km·km^-2 or >1 km·km^-2） and GDP （>500 000 yuan·km^-2）， influenced ERS through the marginal regressive effect of the synergistic pattern of ERS-SE and ERS-SF， indicating that the ECS function was subject to the double constraints of economic agglomeration intensity and spatial accessibility. Based on this， the study proposes a differentiated governance path of "ecological restoration in the central part and cultural value-added in the edge，" which provides a scientific basis for the sustainable development of the Chengdu-Chongqing urban agglomeration.