Yu Chen ^1* Xinyu Zhao ¹ Song Wu ¹ Zhiqiang Tong ²

• ¹ Jilin Agriculture University, Changchun, China
• ² Mudanjiang Natural Resources Comprehensive Investigation Center, Mudanjiang, China

Typical black soil region in Northeastern China (TBSN) are facing problems of degradation of ecosystem services, spatial conflicts between cropland and ecological land.Ecological protection redline (EPR) policy is one of the first national policy utilizing multiple ecosystem services (ESs). However, there is no standardized framework of delineation and validation for TBSN. In this study, the framework of ecological protection redline delineation was further improved in three aspects of ecosystem service function, ecological sensitivity and biodiversity. Specifically, the framework considered the conflict between high quality cropland and ecological land in the TBSN. We examined EPR effectiveness by comparing ESs and trade-off/synergistic relationship of different land use scenarios for 2035. The results show that: (1)The ecological protection redline delineation threshold for each key indicator was determined to be 15% under considering the quality level of cropland. The ecological redline area of 89,593.63km 2 was identified, which was concentrated in the southwestern part of the Mengdong typical black soil subzone and Songnen typical black soil subzone. (2) Compared to the currently ecological protection scenario and currently ecological protection redline scenario, the optimized ecological protection redline scenario was the best solution to guarantee the sustainable development of TBSN, which maximizing ESs, weakening trade-off and strengthening synergistic between them. The results of the study provided a theoretical basis for land use planning and scientific management of ecosystems in TBSN.