Floristic Analysis of Seed Plants in Xiaoqiaogou Region of Laojun Mountain National Nature Reserve

The vegetation in Xiaoqiaogou region of Laojun Mountain National Nature Reserve has been monitored since 2016. The characteristics and status of the flora in this area have been studied based on the field survey. Our investigation shows that the forest vegetation in this region is monsoon evergreen broad-leaved forest and dominated by Fagaceae, Lauraceae, Magnoliaceae and some other families. There has a large amount of seed plants, with 706 species in 274 genus and 106 families, which average species density is up to 42 species/100 m². There also has 15 species of ancient gymnosperms belonging to 8 genus and 6 families, 30 species of Magnoliaceae belonging to 8 genera, and plenty of tertiary relict plant such as Diploganax and Rhoiptelea chiliantha, which indicates that the flora of this region has an ancient origin. The R/T of families, genus and species are 2.27, 2.58 and 6.36 respectively, which indicates that the floristic elements have obvious tropical properties. And the temperate plant families and genus account for 1/3 of the total, reflecting transitional properties. The east-west direction is the western edge of the China-Japan flora, which meets the China-Himalayan flora. The geographical location of the flora is very unique.