【摘要】 研究了2年生、4年生、6年生位于粤北的第二个轮伐期桉树人工林的林下植物生物多样性,选择了天然次生林和4年生的针叶混交林作为对照。在对几种森林类型乔木层、灌木层和草本层样方进行了植物生物多样性调查的基础上,对物种丰富度、Shannon-Wiener指数、Simpson指数和Pielou均匀度指数进行了分析。结果表明,桉树林植物共有105种,隶属55科91属,其中2年生桉树林有植物37种、隶属26科35属,4年生桉树林有植物64种、隶属37科59属,6年生桉树林共有植物65种、隶属41科59属,随着桉树林的生长,林内物种数呈现增加趋势。天然次生林与其它几种森林类型相比,物种丰富度最高,有植物85种、隶属46科64属,但与6年生桉树林并没有显著差异。针叶混交林有植物39种、隶属24科33属,物种丰富度不及同年生的桉树林,与2年生桉树林相近。几种森林类型的Shannon-wiener指数,Simpson指数分析,Pielou均匀度指数基本表现为2年生桉树林<针叶混交林<4年生桉树<6年生桉树林<天然次生林。入侵植物马樱丹仅在4年生的桉树林中出现,在其它年龄桉树林、针叶混交林及近自然林中均没有发现,表明马缨丹已经开始入侵粤北山区,但尚未形成大面积危害。研究表明,粤北现有的桉树人工林经营模式对林下植被多样性影响不大。更多还原

【Abstract】 The plant biodiversity of understorey species in different forest types in Northern Guangdong were investigated in this study. The forest types included a natural secondary forest(hereafter referred as NSF) and a 4-year-old mixed conifer plantation(hereafter referred as MCP) as two control, as well as 2-, 4- and 6-year-old Eucalyptus plantations(hereafter referred as EP2, EP4 and EP6, respectively). The plant biodiversity of tree, shrub and herb layer, respectively, were analyzed with species richness, Shannon-Wiener index, Simpson index and Pielou evenness index. The results indicated that there were 105 species belonging to 55 families and 91 genera in the Eucalyptus plantations. A number of 37(26 families, 35 genera), 64(37 families, 59 genera) and 65(41 families, 59 genera) species were found in EP2, EP4 and EP6, respectively. The species number showed an increasing trend with plantations growth. The NSF with 39 species(24 families and 33 genera) had the highest species richness among forest types, but the difference between NSF and EP6 was not significant. The species richness of MCP with 39 species(24 families, 33 genera) was lower than that of EP4, and close to EP2. The Shannon-Wiener index, Simpson index and Pielou evenness index followed the same order of EP2 < MCP < EP4 < EP6 < NSF. The invasive species Lantana camara were found in EP4 only, which indicated that L. camara had invaded Northern Guangdong and harmed slightly. This study indicated that the management modes of eucalyptus plantations in Northern Guangdong had insignificant influence on plant biodiversity of understorey species.更多还原