广州闽楠-樟人工混交林物种组成与多样性研究

为了解人工混交林群落结构特征和物种多样性关系，对广州龙眼洞林场内闽楠（Phoebe bournei）-樟（Cinnamomum camphora）人工混交林进行群落结构分析。结果表明，0.37 hm²样地内共有128种植物9 563株，隶属于57科99属；其中乔木35种，灌木61种，草本98种。在乔木层中，重要值排名前5的植物分别是山乌桕（Triadica cochinchinensis）（33.86%）、闽楠（17.24%）、樟（12.96%）、三桠苦（Melicope pteleifolia）（7.92%）和山苍子（Litsea pungens）（3.70%）；灌木层以茜草科（Rubiaceae）植物为主；草本层以禾本科（Poaceae）植物为主。乔木层、灌木层和草本层的Shannon-Wiener指数分别为1.230、1.708和1.754，Simpson指数分别为0.635、0.680和0.707，表明该人工混交林下草本物种丰富。非度量多维尺度分析（NMDS）表明，不同样方的物种组成相似性并不一致，部分样方含有偶见种。群落的径级结构呈倒“J”型，其中11.64%为幼苗，苗木占比6.08%，小树占比55.34%，壮树占比25.28%，大树占比仅为0.70%，因此推测闽楠-樟人工混交林仍处于演替初期。

Studies on Species Composition and Diversity of Phoebe bournei-Cinnamomum camphora Plantation in Guangzhou

In order to understand the relationship between community structure with species diversity of artificial mixed forest, the community structure of Phoebe bournei-Cinnamomum camphora mixed plantation in Longyandong Forest Farm in Guangzhou was analyzed. The results showed that there were 128 species 9 563 plants in 0.37 hm² quadrat, belonging to 57 families and 99 genera, in which there were 35 tree, 61 shrub, and 98 herb species. In tree layer, the species with importance value at top 5 were Triadica cochinchinensis (33.86%), Phoebe bournei (17.24%), Triadica cochinchinensis (12.96%), Melicope pteleifolia (7.92%), and Litsea pungens (3.70%), the shrub layer was dominated by Rubiaceae, and did the herb layer by Poaceae. The Shannon-Wiener indexes of tree, shrub and herb layers were 1.230, 1.708, and 1.754, respectively, and the Simpson indexes were 0.635, 0.680, and 0.707, indicating that artificial mixed forest was rich in herbaceous species. The non-metric multidimensional scale (NMDS) analysis showed that the similarity of species composition was not consistent in different plots, and some plots contained occasional species. The diameter class structure of the community showed an inverted "J" type, of which 11.64% were seedlings, and saplings, small trees, strong trees and large trees account for 6.08%, 55.34%, 25.28%, and 0.70%, respectively. Therefore, it was suggested that the Phoebe bournei-Cinnamomum camphora mixed plantation was still in the early successional stage.