Biodiv Sci ›› 2009, Vol. 17 ›› Issue (1): 43-50.  DOI: 10.3724/SP.J.1003.2009.08148

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Multiple-scale spatial analysis of community structure in a mountainous mixed evergreen-deciduous broad-leaved forest, southwest China

Anjiu Zhao, Tingxing Hu*(), Xiaohong Chen   

  1. Key Laboratory of Ecological Forestry Engineering of Sichuan Province, Sichuan Agricultural University, Ya’an, Sichuan 625014
  • Received:2008-06-20 Accepted:2008-12-29 Online:2009-01-20 Published:2009-01-20
  • Contact: Tingxing Hu

Abstract:

To investigate the spatial-dependence of heterogeneity at multiple scales for a community, we selected a representative plot of 100 m × 100 m in the mountainous evergreen and deciduous mixed broad-leaved forest in Sichuan, southwest China (102°50´E, 30°02´N). The location of every tree was mapped by compass, and all-scale analysis of spatial structure of forest community was conducted by the method of PCNM (principal coordinates of neighbor matrices). The results showed that Pielou evenness index, gap-fraction, openness, stand basal area, and stand density were influenced by spatial structure of the community at a broad scale. At the same time Pielou evenness index was impacted significantly by stand density, direct radiation, and leaf area index at all scales, while soil organic matter contents were markedly influenced by stand density, biomass, direct radiation, and gap-fraction at each scale. It could be concluded that community structure and environmental factors are markedly influenced by spatial sampling procedures. Our results highlighted that PCNM analysis could achieve a spectral decomposition vector of the spatial relationships among sampling sites, and that the significant PCNM variables could be directly interpreted in terms of spatial scales, or including variation decomposition with respect to spatial and environmental components. Canonical correlation analysis also indicated that forest community structure variables were correlated significantly with light factors, and both were interacted with each other and correlated well with PCNM variables. Therefore, the method of PCNM could help to understand the scale-dependence of heterogeneity at the community level.

Key words: ecological community, spatial patterns, principal coordinates of neighbor matrices (PCNM), scale, spatial model