摘要
基于野外调查和室内实验数据,采取主成分分析和典型相关分析相结合的方法,分析了广西平果县喀斯特山地蚬木(Excentrodendron hsienmu)生存群落物种多样性与土壤养分和地形因子间的关系。结果表明:群落各层的物种数、Shannon-Wiener指数和Pielou均匀度指数表现为乔木层>灌木层>草本层。主成分分析的前3个主成分解释了总变异的78.8%,第一主成分的特征值为5.29,方差贡献率为44.0%,主要反映了土壤养分的综合信息。典型相关分析显示乔木层多样性能敏感指示土壤养分变化,与土壤全磷间呈负相关、与全氮间呈正相关;灌木层物种多样性对地形变化更为敏感,与坡位和海拔间均表现为正相关关系;土壤与地形因子间存在较为密切的耦合关系,土壤全磷与坡位间呈正相关、土壤pH与岩石裸露率间呈负相关。
Excentrodendron hsienmu is a species endemic to tropical limestone areas. It is one of the constructive species in north tropical limestone seasonal rainforest. The mixed forest dominated by E.hsienmu is very important to the karst ecosystem. So far, little is know about the main environmental factors affecting the plant diversity in this community. To explore the effects of variations in soils and topography on the species diversity in this community, woody plants with diameter at breast height （DBH） ≥1.0 cm, shrubs, herbs, soils, and topographic factors were investigated in 15 plots in the karst mountains of Pinguo County, located in Guangxi, south China. α diversity indexes were calculated, and 7 soil properties were measured. Principal component analysis （PCA） and canonical correlation analysis （CCA） were employed in this study. It was observed that the community composition was simple, and the α diversity indexes were low. All the species richness, Shannon-Wiener and Pielou index in tree layer were the greatest, followed by shrub and herb layer. Results of PCA showed the accumulative variance contribution of the first three principal components was 78.8%. The eigenvalue of first principal component was 5.29, and it encompassed 44.0% of the total variation, which mainly reflected the variation in soil nutrients. Results of CCA showed α diversity of tree layer was sensitive to the variation of soil nutrients. Shannon-Wiener diversity index of tree layer was negatively correlated with total phosphorus （TP） and positively with total nitrogen. Shannon-Wiener diversity index of shrub layer was sensitive to the topography gradient. It was positively related to both slope position and elevation. Meanwhile, there was close coupling relationship between soils and topography. TP was positively correlated with position, and pH negatively with per. of covered rock.
出处
《植物研究》
CAS
CSCD
北大核心
2014年第2期204-211,共8页
Bulletin of Botanical Research
基金
广西林业科学研究院基本科研业务费资助项目(林科201201号)
广西自然科学基金资助项目(2012GXNSFAA053042)
关键词
土壤
地形
主成分分析
典型相关分析
蚬木
soil
topography
principal component analysis
canonical correlation analysis
Excentrodendron hsienmu
