Influence of Alternanthera philoxeroides invasion on species diversity and stability in the herbaceous community in southern Henan Province

To explore the influence of Alternanthera philoxeroides invasion on herbaceous plant communities in southern Henan Province, we set up 20 invaded plots and 20 control plots in Xinyang City. Using mathematical statistics and quantitative ecological methods, we studied the differences in species structure between invaded and control communities, as well as the coupling relationships among morphological characteristics, biomass of A. philoxeroides, species diversity, and community stability, which could provide references for biological control and native biodiversity protection. The results were as follows: 1) Four α-species diversity indices and species distribution uniformity of DCA ordination of the invaded community were all higher than those for the control community. 2) As A. philoxeroides coverage increased, the Shannon-Wiener (R² = 0.569, P = 0.001) and Simpson (R² = 0.749, P < 0.001) diversity index all showed a significant binomial trend. 3) Simpson, Shannon-Wiener index, and the Pielou evenness index all had a significant negative regression relationship with A. philoxeroides biomass. 4) The invaded community stability rose with the increase in A. philoxeroides relative height, whereas it declined with the A. philoxeroides root-shoot ratio and the Pielou index increased. Our study indicated that the A. philoxeroides invasion seriously decreased the herbaceous species diversity and destroyed the stability of the native plant community in southern Henan Province; thus, we should develop effective control measures for preventing the spread of the invasion.