LAUSR

Abstract Implementing the policy of returning farmland to lakes (RFL) led to land use/land cover (LULC) changes and affected ecosystem service trade-offs. Consequently, the implementation intensity of RFL has become an important issue. The LULC of the Jianghuai Ecological Economic Zone (JHEEZ) has transformed significantly because of the implementation of RFL. In this study, we simulated the LULC change of the JHEEZ in 2030 and then analyzed the trade-offs and synergies of ecosystem services under four RFL intensity scenarios. Our results showed that water yield first increased and then decreased, and crop production decreased; in contrast, carbon storage, habitat quality, and water purification continuously increased. The levels of the five ecosystem services were most balanced in the mild RFL scenario. In this scenario, water yield and crop production decreased by 0.46% and 5.95%, respectively. In contrast, carbon storage, habitat quality, and water purification increased by 0.35%, 3.49% and 3.20%, respectively. Under the moderate and strong RFL scenarios, increases in regulation services were at the expense of significant reductions in supply services. In all RFL scenarios, carbon storage, habitat quality and water purification increased in synergy, except for natural RFL scenarios. These three ecosystem services were in a trade-off relationship with water yield and crop production. However, under the natural RFL scenario, water yield was synergistic with these three ecosystem services. Therefore, the implementation of RFL may enhance ecosystem service trade-offs. Our results reveal the impact of different intensities of RFL on ecosystem service trade-offs and suggest that the intensity of RFL implementation should be factored into policy making and ecosystem management. This study can provide a useful reference for decision makers to choose the optimal restoration intensity of lake and wetland.