| 摘要: |
| 桉树Eucalyptus spp.是我国南方最主要的速生树种之一，由于长期掠夺式经营，桉树林出现了地力衰退、病虫害严重、生物多样性下降等一系列生态问题，营造桉阔复层混交林是平衡经济效益与生态效益的有益尝试。研究通过调查粤西桉阔复层混交林，分析不同桉树密度下林分结构、物种组成的差异，筛选不同桉树密度下林分结构更加稳定、生物多样性更高、林木生长更优的桉阔复层林。研究结果表明：低桉树密度林分中，天然更新物种占优势，黄牛木Cratoxylum ligustrinum、土蜜树Bridelia tomentosa、破布叶Microcos paniculata是林分中主要的先锋树种；在高桉树密度林分，栽植物种占据优势，尾巨桉Eucalyptus urophylla×E.grandi、樟树Cinnamomum camphora是主要的栽植树种；桉树密度越接近的林分，其科属种组成差异越小，反之差异越大；不同桉树密度林分间的物种丰富度、个体密度没有显著差异，胸高断面积、平均高度、平均胸径则有显著差异（P < 0.01）；从径级结构来看，随着桉树密度的升高，林分的径级结构从倒“J”型分布向峰型分布发展。低桉树密度林有着稳定的天然林更新替代，但所处的演替阶段较早，高桉树密度林能更早到达林分成熟期，所处的演替阶段更高，可获取的林木资源更丰富。 |
| 关键词: 桉树密度 桉阔复层林 桉阔混交林 林分结构 物种组成 |
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| 基金项目:广东省森林生态综合示范园（省德庆林场森林质量提升示范园）项目 |
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| Structure and Composition of Eucalyptus-broadleaved Compound Forest with Different Eucalyptus Densities |
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WANG Feng1, SU Yongxin2, GONG Yiguang1, XU Mingfeng3, HE Chunmei3, LIANG Yuxing1, WANG Kai1, LI Chunyong1
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1.Deqing Forest Farm of Guangdong Province;2.Guangdong Pearl River Estuary National Nature Reserve Administration of Chinese White Dolphin;3.Guangdong Academy of Forestry
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| Abstract: |
| Eucalyptus spp. is one of the most important fast-growing tree species in south China. Due to long-term plundering management, eucalyptus forest had been confronted with a series of ecological problems, such as soil degradation, serious diseases and declining biodiversity. It is a beneficial attempt to balance economic benefit and ecological benefit to build eucalyptus-broadleaved compound forest. In this study, we investigated eucalyptus-broadleaved compound forests in western Guangdong province, analyzed the stand structure, species composition and stand differences under different eucalyptus densities, and then screened eucalyptus-broadleaved compound forests with more stable stand structure, higher biodiversity and better forest growth. The resultsshowed that, in low eucalyptus density forest, the naturally refreshed species were dominant, and Cratoxylum ligustrum, Bridelia tomentosa, and Microcos paniculata were the main pioneer species. In high eucalyptus density forest, planting tree species were dominant, such as Eucalyptus urophylla×E.grandi and Cinnamomum camphora. The closer the eucalyptus density was, the smaller the difference in family, genera and species composition was, and vice versa, the larger the difference was. There was no significant difference in species richness and individual density among different eucalyptus densities, but there were significant differences in basal area, average height and average DBH. In terms of size distributions, with the increase of eucalyptus density, the size distributions developed from inverse J-shape to peak-shape. The low density eucalyptus forest had a stable replacement of natural forest, but it was in an earlier succession stage. High eucalyptus density could reach the maturity stage earlier. It was at a higher stage of succession and had more abundant wood resources. |
| Key words: eucalyptus density eucalyptus-broadleaved compound forest eucalyptus-broadleaved mixed forest stand structure species composition |
