元宝山冷杉群落学特点的研究

元宝山冷杉群落3000m^2样方统计到107种，隶属52科，81属。种类组成中，单种科、少种属占的比例相当大，含单种的科有27科，占51．9％。单种的属有63属，占77．8％；含两种的属为12属，占14．8％，两者共占92．6％。乔木层种类除了南方铁杉外，其它优势种类都为稳定型种群。乔木层的优势区系成分相当稳定，表明该群落为一种顶极群落。71个种子植物属只有11个分布区类型和8个变型，仅占所有变型的26．7％，地理成分不复杂，其中热带分布27属，占39．7％，温带分布38属，占55．9％。热带分布以泛热带和热带亚洲为主，温带分布与东亚、东亚和北美洲间断分布密切相关。乔木层16个优势种中，属中亚热带地理分布类型的有13种，占81．3％，其中重要值排列前4位的种类均为中亚热带类型，所以元宝山冷杉群落为亚热带性质。元宝山冷杉不同群丛元宝山冷杉种群结构的差异反映了群落的演替过程。107种组成种类中，常绿成分占62．6％，落叶成分占37．4％，其中矮高位芽植物最多，占20．6％，叶级以小型叶为主，占57．9％，叶型以单叶比例最大，占81．6％。各样地的物种多样性水平均较高，表明元宝山冷杉群落是一个处于稳定地位的顶极群落。

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.