广东石门台国家级自然保护区老虎山次生林群落特征

Community Characteristics of Tiger Mountain Secondary Forest in Shimentai National Nature Reserve, Guangdong

为了解在广东石门台国家级自然保护区的老虎山南坡建设的大型林冠模拟氮沉降野外控制试验平台的植被组成特征,开展了18个样方的每木调查和分析研究。结果表明,在面积0.72 hm^(2)中有维管束植物53科86属127种;胸径(DBH)≥1.0 cm的立木有2 465株,平均密度为0.34 ind./m^(2),最高达25 m。群落以锥(Castanopsis chinensis)、罗伞树(Ardisia quinquegona)、木荷(Schima superba)等为主要优势种类,且以高位芽、中小型叶、革质和非全缘叶植物为主要种类组成的常绿阔叶次生林。热带-亚热带区系成分在群落中占明显优势,具有热带向亚热带过渡的特征。18个样方乔木层的Simpson指数(0.851~0.936)和Shannon-Wiener指数(3.504~4.494)相近,Pielou均匀度指数较高(0.780~1.000),但Gleason和Margalef丰富度指数差异较大(分别为3.209~7.738和16.760~40.806),样方间有10~26种共有种(Sorensen相似性系数为0.377~0.722),而灌木层则相反,物种多样性指数均变化较大,样方间只有0~10种共有种(Sorensen相似性系数为0~0.714)。因此,灌木层的密度和种类差异对群落结构的影响应充分考虑。

A large canopy simulation and nitrogen deposition field control experimental platform was established on southern slope of Tiger Mountain in Shimentai National Nature Reserve, Guangdong Province, China. To further understand the characteristics of vegetation composition at the platform, 18 plots covering a total area of 0.72 hm^(2) were set up. The results showed that there were 127 vascular species, belonging to 86 genera and 53 families. Furthermore, there were 2 465 individuals with diameter at breast height(DBH)≥1.0 cm. The tree density was 0.34 ind./m^(2), and the tallest up to 25 m. The dominant species in the community was Castanopsis chinensis, Ardisia quinquegon, and Schima superba, which was a secondary evergreen broad-leaved forest consisting of phanerophytes, medium-and small-leaf, leathery, and unentire leaf as main species. The tropical-subtropical floristic elements were dominant in the community, with the characteristics of transition from the tropical to subtropical. Among 18 plots at tree layer, the Simpson index(0.851-0.936) and Shannon-Wiener index(3.504-4.494) were similar;the Pielou’s evenness index was high(0.780-1.000);and the Gleason and Margalef richness indexes were rather variable(3.209-7.738 and 16.760-40.806, respectively). The plots shared 10-26 species with Sorensen similarity coefficient of 0.377-0.722. On the contrary, in shrub layers, the above indexes all varied greatly, and only 0–10 common species among plots with Sorensen similarity coefficient of 0-0.714. Therefore, the effect of shrub layer density and species difference on community structure should be considered.