We studied trends of species diversity along the sere of Acacia confusa plantations of Nanjenshan area. Using the method of time-space mutual substitution, sixteen 0.05ha plots of 28-60 year A. confusa plantations and four 0.05ha plots in natural forests were sampled. A total of 340 vascular plant species in 230 genera and 106 families were recorded. Applying Two Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) on the basal areas of 155 woody plants, three successional phases were classified: early phase of secondary forest, intermediate phase of secondary forest, and natural forest phase. Based on their distribution along the sere, the 155 woody plants were classified into five ecological species groups: pioneering species, early successional secondary species, late successional secondary species, early recovering natural forest species, and late recovering natural forest species. Alpha diversity was highest in natural forest phase and lowest in intermediate phase of secondary forest. Alpha diversity of tree layer was highest in natural forest phase and, in contrary, lowest in early phase of secondary forest. Alpha diversity of shrub layer did not show significant difference among phases. Beta diversity was highest in 29-year and 55-year A. confusa plantation. Our results revealed that A. confusa plantations need high turnover of species and approximately 177 years to have species composition near natural forest.
We studied trends of species diversity along the sere of Acacia confusa plantations of Nanjenshan area. Using the method of time-space mutual substitution, sixteen 0.05ha plots of 28-60 year A. confusa plantations and four 0.05ha plots in natural forests were sampled. A total of 340 vascular plant species in 230 genera and 106 families were recorded. Applying Two Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) on the basal areas of 155 woody plants, three successional phases were classified: early phase of secondary forest, intermediate phase of secondary forest, and natural forest phase. Based on their distribution along the sere, the 155 woody plants were classified into five ecological species groups: pioneering species, early successional secondary species, late successional secondary species, early recovering natural forest species, and late recovering natural forest species. Alpha diversity was highest in natural forest phase and lowest in intermediate phase of secondary forest. Alpha diversity of tree layer was highest in natural forest phase and, in contrary, lowest in early phase of secondary forest. Alpha diversity of shrub layer did not show significant difference among phases. Beta diversity was highest in 29-year and 55-year A. confusa plantation. Our results revealed that A. confusa plantations need high turnover of species and approximately 177 years to have species composition near natural forest.