Plant invasion has limited impact on soil microbial alpha-diversity : a meta-analysis

Plant invasion has proved to be a significant driver of ecosystem change, and with increased probability of invasion due to globalization, agricultural practices and other anthropogenic causes, it is crucial to understand its impact across multiple trophic levels. With the strong linkages between above and belowground processes, the response of soil microorganisms to plant invasion is the next logical step in developing our conceptual understanding of this complex system. In our study, we utilized a meta-analytical approach to better understand the impacts of plant invasion on soil microbial diversity. We synthesized 70 independent studies with 23 unique invaders across multiple ecosystem types to search for generalizable trends in soil microbial a-diversity following invasion. When possible, soil nutrient metrics were also collected in an attempt to understand the contribution of nutrient status shifts on microbial a-diversity. Our results show plant invasion to have highly heterogenous and limited impacts on microbial a-diversity. When taken together, our study indicates soil microbial a-diversity to remain constant following invasion, contrary to the aboveground counter parts. As our results suggest a decoupling in patterns of below and aboveground diversity, future work is needed to examine the drivers of microbial diversity patterns following invasion