Floristic Composition and Ecological Characteristics of Pinus kwangtungensis Forest in Nanling

This paper analyzed the floristic composition of Pinus kwangtungensis forest and its ecological characteristics by investigating the sample plots of 7 200 m^2 P. kwangtungensis forest in Nanling. The resuit shows that there are 76 families, 138 genera and 227 species of vascular plants in which the arbors are the main components and the dicotyledon takes up the majority. As far as the distribution of plant genera is concerned, the seed plants of P. kwangtungensis forest in Nanling can be divided into 12 distribution areal types and 7 subtypes, which are the world distribution, the tropical distribution, temperate region distribution and the temperate region dominated distribution. Among these three distribution areas, the tropical distribution is the biggest one and it also has temperate region features. P. kwangtungensis is dominant in the canopy layer, but the tree height is obviously lower than that of other trees in subcanopy layer. The clustering analysis result shows that the physiognomy and distribution in the stratified frequency of the coniferous tree species-P, kwangtungensis is obviously distinguished from the broadleaf tree species. But there are no significant distinction between the two broadleaf tree species, Cyclobalanopsis glauca and Lit, sea elongata. The height, the diameter at breast height, the bole height under the first branch and the tree number of stratified frequency index of the two species have no significant differences.