Abstract: Qinglong River Nature Reserve lies in western Liaoning Province, the crunodes of Liaoning, Hebei, and Inner Mongolia, and is the connection of Yanshan Mountain, Qilaotu Mountain, and Nuluerhu Mountain. For protecting the plant diversity in North and Northeast China, it is of significance to study the floral composition in Qinglong River Nature Reserve and its adjacent nature reserves. Based on the investigation data from 95 sampling plots in the Qinglong River Nature Reserve, this paper analyzed the floral composition and distribution type of vascular plants in the Reserve, and a comparison was made with the flora in adjacent nature reserves. In the Reserve, a total of 656 vascular plant species were recorded, belonging to 108 families and 362 genera, among which, 21 species were of fern plants, belonging to 14 families and 16 genera, 2 species were of gymnosperm, belonging to 2 families and 2 genera, and 633 species were of angiosperms, belonging to 92 families and 344 genera. The genera of seed plants in the Reserve could be divided into 15 distribution types. The floristic characteristics were ancient origin, abundant species, and obvious temperate feature. The comparison of the flora in Qinglong River Nature Reserve and in five adjacent reserves showed that the proportion of the floral composition in a reserve was greatly associated with its geographical location. Overall, the floral composition was affected by latitude (temperature), i.e., the higher the latitude, the higher the proportion of the temperate floristic composition, and also, affected by the distance to the ocean. The proportion of the floral composition in Qinglong River Nature Reserve had great relevance to the latitude.

Key words: ecological security, northeast old industrial area., ecological coordination coefficient, sustainability, emergy-ecological footprint approach