关键词: 东灵山, 植物区系, 植物区系谱, PCA, 排序

Abstract: There are 997 species of higher plants which belong to 127 families and 476 genera. Among them 935 species of 101 families and 430 genera are seed plants. The largest family of seed plants is Compositae which includes 116 species. Besides, the families with more than 25 species are as follows: Gramineae,Leguminosae, Rosaceae, Liliaceae, Labiatae and Caryophyllaceae. There are 457 species in the 8 families, which accounts for 46% of the total number of the seed plants in Dongling Mountain area. The 430 genera of seed plants, excluding 50 cosmopolitan genera and 8 genera endemic to China, can be grouped into * 15 distributional types as proposed by Wu Zhengyi. Of the 15 types, North temperate type with 155 genera is at the first position. The total number of genera belonging to various temperate types comes to 298 and that for tropical and subtropical types is only 76. These show clearly that the flora of Dongling Mountain area has a strong temperate feature. Some modification of the concept and analyzing methods of floristic spectrum were made in this paper, based on the principles proposed by Prof. Wu Zhengyi and other experts. Principal Component Analysis (PCA) was used for the first time to quantitatively analyse the floras of areas of Dongling Mountain and 28 other mountains in China, so as to find out the position of the flora in a series of floras of the country and some good Its have been obtained. Floristic spectrum analysis is a good method for the comparison of similarities between different floras. The result of quantitative analysis on 29 floras in China including Dongling Mountain showed that the method of dimension-minimization was useful, because accumulative contribution rate of the first two axes was about 80%, and that of the first three axes was higher than 92%. The similar result was obtained through the calculation of R/T ratio (tropical genera/temperate genera ratio). The values of R/T ratio decrease as latitude increases according to the data from 29 mountainous floras, which is the good expression for the latitudinal zonation of floristic variation.

Key words: Dongling Mountain Area, Flora, Floristic speetrum, PCA, Ordination