| 摘要: |
| 【目的】阐明秦岭南坡油松林、锐齿栎林及其混交林3种典型次生林群落各层物种组成与环境因子之间的关系，探讨不同植被层对同一环境因子的响应差异，并确定影响群落各层物种组成的主要环境因子。【方法】在秦岭南坡火地塘林区和黄柏塬自然保护区等5个松栎林典型分布区共设置45块样地，分草、灌、乔3层进行群落学调查，并运用CCA排序法分析3种群落各层物种组成与海拔、坡度、坡向、坡位、林分郁闭度和枯枝落叶层厚度等6种环境因子之间的关系。【结果】（1）所调查的45块样地中共记录维管植物321种，隶属于73科183属，其中乔木78种，灌木（含木质藤本）105种，草本植物138种。（2）海拔和坡度与草、灌、乔3层的物种组成均显著相关，坡向和枯枝落叶层厚度对草本层物种组成有显著影响，坡向与乔木层物种组成也有较显著的相关性。【结论】草、灌、乔3个层次的物种组成对环境因子的响应有差异，海拔是影响群落草本层和灌木层物种组成最主要的环境因子，其次是坡度；影响乔木层物种组成最主要的环境因子为坡度。 |
| 关键词: 次生林群落 物种组成 环境因子 秦岭 |
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| 基金项目:林业公益性行业科研专项（20100400206）；国家自然科学基金项目（31070570） |
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| Effects of environmental factors on the species composition of three typical secondary forests in Qinling Mountains |
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ZHANG Zi-liang,YU Fei,WANG De-xiang
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| Abstract: |
| 【Objective】This study clarified the relationship between environmental factors and species composition of three typical secondary forests,i.e.,Pinus tabuliformis forest,Quercus aliena var.acuteserrata forest,and their mixed forest in Qinling Mountains,to test whether different vegetation layers response differently to the same environmental variables and determine the dominating factors.【Method】A total of 45 vegetation plots were set up in 5 typical pine-oak-forest areas including Huoditang Forest District on the south slope of Qinling Mountains and Huangbaiyuan Nature Reserve to conduct coenological investigation in the herb,shrub and tree layers separately.Canonical correspondence analysis (CCA) was used to rank and determine the 6 main environmental factors (elevation,slope,aspect,slope position,canopy density,and thickness of litter layer) relating to species composition of different vegetation layers.【Result】(1) A total of 321 vascular plants species belonging to 183 genera and 73 families were recorded in the plots investigated,among which there were 138 herbs,105 shrubs (including woody climbers),and 78 trees.(2) Species composition in all vegetation layers of 3 communities showed a statistically significant correlation with elevation and slope.In contrast,species composition in herb layer showed a correlation with slope aspect and the litter layer thickness,and slope aspect also presented a correlation with species composition in tree layer.【Conclusion】Species composition in each layer responded distinctly to different environmental factors.Elevation was the main factor affecting species composition both in herb and shrub layers among the six factors,followed by the slope.Slope was the dominating factor of species composition in tree layers of typical secondary forests in Qinling Mountains. |
| Key words: secondary forest community species composition environmental factors Qinling Mountains |
