Responses of Soil Bacterial Communities to Conyza canadensis Invasion with Different Cover Classes Along a Climatic Gradient

Abstract

Some invasive species can trigger shifts in soil microbial communities in their rhizosphere to facilitate the invasion process. Meanwhile, some invasive species can display different cover classes in the invaded ecosystems and even cross many climatic zones. This study aims to address the effects of the notorious invasive species Conyza canadensis with different cover classes along a climatic gradient in China on soil bacterial communities. All cover classes of C. canadensis increased the Shannon's diversity index and the abundance‐based coverage estimator (ACE) index but decreased the operational taxonomic richness and the Good's coverage of soil bacterial communities, although this change was not significant. Thus, C. canadensis invasion can raise the diversity and richness of soil bacterial communities but also leads to the extinction of some soil microbial species to create a microenvironment that facilitates its further invasion. The increased diversity and richness of soil bacterial communities induced by C. canadensis invasion with different cover classes may play an important role in its successful invasion across multiple climatic zones. This may be due to the fact that soil microbial communities can influence plant communities and higher soil bacterial diversity can improve soil functions and plant nutrient acquisition. Meanwhile, the effect size and the significance level of climatic gradient on the ACE index and the Chao1 index of soil bacterial communities was obviously higher than other indices of soil bacterial communities. Thus, species richness of soil bacterial communities was primarily changed under C. canadensis invasion along a climatic gradient.