Mycorrhizal Symbioses and Plant Invasions

The factors that influence a plant's ability to invade are not well understood. Many mechanisms are involved and the relative importance of different mechanisms depends on the specific invasion. Here we consider one factor—mycorrhizal symbioses. These symbioses are ubiquitous interactions involving the plants and soil fungi of most terrestrial ecosystems. We develop a conceptual framework for considering mycorrhizal symbioses in plant species invasions. The most critical aspects of this framework are: (a) the mycorrhizal status and (b) the growth response of the invading plant, (c) the ability of the plant to associate with different fungi, (d) the quality of the plant as a host for local fungi and feedback dynamics, (e) the biogeography and dispersal of the fungi, (f) the introduction and spread of the fungi, and (g) the ecological consequences of the creation of novel mycorrhizas. These aspects can critically influence the trajectory of a plant invasion, and this symbiosis deserves more attention in plant invasion biology.