Shortcomings of Present Studies on the Effects of Invasive Plants on Soil Microbial Communities

One of the principal reasons for the successful invasion of invasive plants is that these invaders can facilitate the succession of soil microbial communities in their rhizosphere. This study presents a summary of the effects of invasive plants on soil microbial communities. The effects of invasive plants on soil microbial communities encompass both indirect and direct effects. These include changes in the physicochemical properties (e.g., pH, moisture, and electrical conductivity); alterations in enzyme activities related to nutrient (especially nitrogen) cycling, and nutrient (especially nitrogen) availability levels in soil; variations in the growth performance of invasive and native plants, and the species composition of native plant communities; and changes in the alpha diversity, the relative abundance, the metabolic activity, and the community structure of soil microorganisms (especially the dominant microbial species). In general, invasive plants can cause changes in the structure of soil microbial communities (particularly functional microorganisms, such as the mycorrhizal fungi and N-fixing bacteria) in invaded ecosystems in ways that provide positive feedback for their invasiveness and negative feedback for the growth performance of native plants. This review also considers the limitations of existing studies on the effects of invasive plants on soil microbial communities. The results will provide a solid theoretical basis for elucidating the role of the interactive feedback between invasive plants and soil microbial communities in driving the successful invasion of invasive plants.