老君山国家级自然保护区小桥沟片区森林种子植物区系分析

2016年以来，对文山老君山国家级自然保护区小桥沟片区的植被进行监测，基于实地调查资料，对本区植物区系的特点和地位进行研究。结果表明：其森林植被是以壳斗科、樟科、木兰科等为优势组成的季风常绿阔叶林，种子植物丰富有106科274属706种，平均种密度最高达42种/100 m²；有古老的裸子植物6科8属15种、木兰科植物8属30种，及马蹄参属和马尾树等第三纪孑遗植物，表明本区植物区系起源古老；科、属、种R/T分别为2.27、2.58和6.36，表明植物区系成分具有明显的热带性质，温带性质的植物科、属占总数1/3，反映出具有过渡性质。东西方向是中国—日本植物区系的西缘，与中国—喜马拉雅植物区系交汇，植物区系地理区位十分独特。

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.