[Ecologically critical areas of broad-leaved Korean pine mixed forest in Changbai Mountains, China].

In order to improve the protection system to reduce the damage of biodiversity and protect broad-leaved Korean pine mixed forest, 64 forest farms from 6 Forestry Bureaus around Changbai Mountains Nature Reserve were investigated and analyzed. A total of 41 plants were selected as key protected plants, and felling area, cropland, mining area, highway, railway and residential area were considered as the disturbance factors. GAP and GIS spatial analysis were used to draw the indicator plant and disturbance intensity distribution maps. The results showed that the indicator species distribution was uneven. The indicator plant enrichment regions were located on the north western and southern slopes centered with Shengli and Lenggouzi forest farms of Quanyang County, respectively, and single distributions of the endemic plants were found in Baoshan, Henshan, Lenggouzi and Heishan forest farms. The different disturbance severities were observed in the different forest farms, among which the north part in Lushuihe and Baihe forest farms were severely disrupted. Two ecologically critical areas, Quanyang-Lushuihe-Baihe on the north slope of Changbai Mountains and the east part of Changbai County on the south slope, were determined based on the comprehensive analysis.