Studies on the phytocoenological features of Abies yuanbaoshanensis community in Yuanbaoshan, Guangxi

According to a statistics in 3 000 m2 field of 6 samples,there are totally 107 species belonging to 81 genera of 52 families in the Abies yuanbaoshanensis community. The families with only one species and the genera with few species dominated. 51.9% of the families were found with one species,77.8% of the genera contain one species and 14.8% of the genera with two species,both account for 92.6%. In the arborous layer,the dominant species except Tsuga tchekiangensis were stable populations,so the dominant community floristic were stable,the result showed that it was a climax community. There are only 11 area types and 8 sub-types in 71 seed plant genera,only accounts for 26.7% of all the sub-types,so the geographical elements are discomplex. In 71 seed plant genera,27 genera belong to tropical, account for 39.7%,38 genera belong to temperate,account for 55.9%,and tropical genera mainly constituted by Pantropic and Tropic Asian,temperate genera constituted by East Asian and E. As-N. America disjointed.In the dominant species of arborous layer,83% is middle subtropical zonal type,of which the first 4 positions of important value index were all middle subtropical zonal types. This showed that the community was subtropical characteristic. The different population structures of Abies yuanbaoshanensis in different associations reflected the process of succession of community. There are 62.6% evergreen and 37.4% deblade in 107 species,of which the Na.ph was the first position accounts for 20.6%. Meanwhile,the leaf size class of the vegetation was mainly microphylla(57.9%),and 81.6% of the leaf pattern was simple leaf. The level species diversity in different samples are also high,this showed Abies yuanbaoshanensis community was a stable climax community.