FLORISTIC CHARACTERISTICS AND GEOGRAPHIC DISTRIBUTION OF THE FERNS IN THE QINLING MOUNTAIN RANGE, CHINA

The horizontal distribution patherns of ferns frequently correspond to those of the forests in Qinling. The vertical distribution on the northern slope of Taibaishan can be divided into 4 altitudinal belts, among which the belt at elevation of 800—2600m is the region where the most species of ferns exist. Among 77 genera of ferns in the Qinling, 36 genera are tropical and subtropical genera, and occupy 46.9 percent of the whole genera. Among them, there are 17 genera and each is represented by only 1 species. The others include 2—3 species distributed on southern slope of the Qinling. The above figures indicate that the southern slope is northern margin of subtropical region. The fact proves that the fern group of the Qinling mountains can be considered as the same fern flora of Himalaya. The fern flora of S. -W. -China to Japan has been named as "Polysticho-Dryopteris flora"