Objective To quantify the effects of different management measures on the resilience of Mongolian oak (Quercus mongolica) secondary forests in northeastern China, and to provide a scientific basis for adaptive forest management and ecological restoration in the region.

Method Twelve permanent 1-ha plots were established in the Changbai Mountain area and arranged in a randomized block design with four treatments: traditional management (TM), crop-tree release with a target density of 80 trees per hectare (CTR1), crop-tree release with a target density of 120 trees per hectare (CTR2), and an untreated control (CK). Forest inventories were conducted in 2013, 2018, and 2023. Based on the theoretical framework of forest resilience, eight indicators were selected from three dimensions: Resistance (dominant tree diameter, weighted height–diameter ratio, uniform angle index), Recovery (size diversity, tree species diversity, canopy cover), and Adaptability (species composition, and competitiveness of climax species) to construct a comprehensive evaluation index system. A combined subjective–objective weighting approach and the unit-circle method were applied to calculate the Resilience Composite Index (RCI) and to assess the effects of different management measures on forest resilience after 5 and 10 years.

Result (1) The proposed indicator system was ecologically and statistically robust, with low inter-indicator correlations and strong information complementarity, and the combined weighting method effectively distinguished resilience responses among management treatments. (2) Both crop-tree release and traditional management significantly increased size diversity, weighted height–diameter ratio, and canopy cover (p < 0.05), while crop-tree release further promoted the diameter growth of dominant trees. (3) Five years after cutting, CTR2 showed the largest and significant increase in RCI; ten years after cutting, both crop-tree treatments exhibited significant improvement, whereas TM and CK showed no significant enhancement of resilience. (4) The improvement of forest resilience in the short and medium term mainly comes from the enhancement of resistance and resilience..

Conclusion Low-intensity crop-tree release, particularly CTR2 with a crop-tree density of 120 trees per hectare, demonstrated optimal short-and medium-term effects. By optimizing size structure, improving the growth conditions of dominant trees, and enhancing functional redundancy, this approach simultaneously strengthens resistance and recovery of Quercus mongolica secondary forests and represents an effective pathway to improve resilience in temperate secondary forests. Enhancement of adaptability, however, depends on longer-term structural adjustment and successional processes.