Abstract: Northeast China forest belt is an important part of the national ecological function regionalization “two screens and three zones”, which is of regional and national significance for ecological security. The construction of ecological security network in this region is an important basis for the optimization of ecological pattern and its function improvement. We used the habitat quality analysis module in InVEST model and the circuit theory to identify the ecological sources, corridors, barriers and pinch points, and constructed the ecosystem service security network of Northeast China forest belt. The results showed that there were 30 ecosystem service sources in the study area, with a total area of 16.40×10⁴ km², accounting for 27.3% of the study area, and that woodland, wetland and other ecological lands were the main components. There are 42 key ecological corridors with a total length of 2475.55 km, and 20 potential ecological corridors with an average length of 420.55 km. The area of the ecological improvement zone is 56.45×10⁴ km². According to the improvement degree of accumulated current value, the  restoration area is classified into three levels, with the first and second level restoration zones accounting for 12.8% and 24.3%, respectively. Based on distribution pattern of the ecological sources, ecological corridors, ecological pinch points, ecological barriers, and ecological restoration zones, we constructed the ecosystem service security network of the study area, and provided suggestions for restoration and improvement according to its characteristics. Our results would provide scientific basis for its ecological pattern optimization and function improvement in the study area.

Key words: ecosystem service security pattern, ecological source, ecological corridor, Northeast China forest belt.