Canada goldenrod invasion cause significant shifts in the taxonomic diversity and community stability of plant communities in heterogeneous landscapes in urban ecosystems in East China

Abstract

Invasive plant species (invaders hereafter) have led to larger shifts in the structure and functions of native ecosystems. Landscape heterogeneity in urban ecosystems can alter the invasion process mediated by the invaders. Thus, it is important to evaluate the effects of the invaders on the taxonomic diversity and stability of plant communities to better understand the mechanisms underlying successful plant invasion, especially in heterogeneous landscapes in urban ecosystems. This study aims to address the effects of the notorious invader Canada goldenrod (Solidago canadensis L.; goldenrod hereafter) on the taxonomic diversity and stability of plant communities by using a comparative study in heterogeneous landscapes in urban ecosystems in East China. Heterogeneous landscapes played a more obvious role in driving changed taxonomic diversity and stability of plant communities as compared to goldenrod invasion. The phenomenon may be most probably caused by the differences in environmental selection pressures in different types of landscape types. The taxonomic diversity (especially diversity and evenness) of plant communities were strongly correlated with the stability both in the uninvaded and invaded plant communities as well as the most types of urban ecosystems. Accordingly, the results of this study support the diversity hypothesis. There was a significantly negative correlation between the relative abundance of the most dominant species and the stability both in the uninvaded and invaded plant communities as well as in the all types of urban ecosystems. Thus, the results of this study did not support the mass ratio hypothesis. The relative abundance of goldenrod was not a primary driver in the stability of plant communities mainly due the fact that goldenrod invasion did not trigger noticeable impacts on the taxonomic diversity and stability of plant communities.