Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The role of soil arbuscular mycorrhizal fungal community in plant invasions.

Abstract

Some 90% of terrestrial plant species form mycorrhizal associations with fungi of which arbuscular mycorrhizas (AM) are the most common type. In this symbiosis, host specificity is low and many AM fungi are cosmopolitan. Based on these traits, it was long assumed that AM does not play an important role in plant invasions. In the last two decades a host of studies showed that AM fungi can indeed influence plant invasions by either facilitating or hindering the success of the invader. Invasive species may be less dependent on AM than native species as they are either non-mycorrhizal or facultative mycorrhizal forming associations with cosmopolitan, generalist fungi. Exotic plants may take advantage of the local AM community to enhance their competitive ability (e.g. by drawing assimilates from resident species through common mycorrhizal network). Through various mechanisms (e.g. allelopathy, mineral nutrient enrichment, fungal or host plant phenology, rapid growth, high abundance) invasive species can alter the composition of the AM community in the invaded habitat for their own benefit and that can have a negative influence on resident plants if dependent on native AM fungi. Often, the resident AM community is an important component in the defence of plant communities against plant invasion. Therefore, protection against invasive plants or restoration of invaded habitats may require direct manipulation of the soil AM community (through e.g. spore inonculation or topsoil replacement). For this, a thorough knowledge of both the AM association of the invasive plant and the resident AM community is required.