Abstract: The assessment of forest ecosystem integrity dynamics can reflect changes in structure and function of forest ecosystems, which is of great significance for establishing longterm effective ecosystem management measures. Here, we developed an indicator system to assess forest ecosystem integrity of the Changbai Mountain National Nature Reserve with surrounding 8km radii in 2005, 2030, 2070, and 2100 by combining the ecosystem integrity assessment framework (EIAF) and a forest landscape model (LANDIS PRO). The results showed that forest ecosystem integrity of Changbai Mountain had a slight decline in 2005-2030 and a continuous increase in 2030-2100. The transfer area among various levels of forest ecosystem integrity continuously reduced over time, while the pattern of forest ecosystem integrity with different levels tended to be stable. Spatially, the overall integrity of the Changbai Mountain forest ecosystems was relatively high. However, there were some patches with low ecosystem integrity in this region due to historical typhoon and anthropogenic disturbance. The ecosystem integrity was higher within than outside the nature reserve. The forest ecosystem integrity of the north and west sides was higher than that of the east side of Changbai Mountain. In the future, it is necessary to strengthen management in areas with low forest ecosystem integrity to facilitate forest recovery.

Key words: forest landscape model, ecosystem integrity assessment framework, spatial principal component analysis, Changbai Mountain.