Objective  Songnen Plain, as the concentrated distribution area of typical black land in northeast China, is faced with the problems of soil erosion and soil fertility decline. Comprehensive evaluation of land ecological vulnerability in Songnen Plain can provide a basis for land resource utilization and food security in this region.

  Method  The evaluation index system of land ecological vulnerability in Songnen Plain of Heilongjiang Province was constructed by using Sensitivity-ecological, Resilience-ecological Pressure model (S-R-P model) and GIS technology, combined with Analytic Hierarchy Process (AHP) and comprehensive index method. The land ecological vulnerability in the study area was evaluated in 2005, 2010, 2015 and 2020. It also classified the calculated land ecological vulnerability index to express their spatial and temporal distribution and its hierarchical transformation characteristics.

  Result  The study showed that the overall land ecological vulnerability in Songnen Plain was presented in a slightly vulnerability state and the comprehensive index of land ecological vulnerability fluctuated. From 2005 to 2020, the areas of micro and slightly vulnerable area increased by 3.37% and 5.16%, respectively. Moderate, severe and extremely vulnerable areas decreased by 7.04%, 1.46% and 0.03%, respectively. The proportion of micro vulnerable and slightly vulnerable area was the largest, accounting for 80.97%, mainly distributed in the northeast and central part of Songnen Plain. Moderate, severe and extremely vulnerable area were mainly distributed in the midwest and south of Songnen Plain, accounting for 19.03% in total. The areas of land ecological vulnerability remained unchanged, but the increased and decreased areas accounted for 5.52% and 18.04% of the total area.

  Conclusion  The overall land ecological vulnerability in the study area is in a slightly vulnerability state, but the spatial difference is obvious. So the ecological protection measures should be continuously improved to strengthen the protection of black land and the guarantee of food security. This study can provide reference for local zoning management and sustainable development.