Invasive Non-native Plants Alter the Occurrence of Arbuscular Mycorrhizal Fungi and Benefit from This Association

Abstract

We investigated the influence of three aggressive non-native invasive plants (pale swallow-wort [Vincetoxicum rossicum], kudzu [Pueraria lobata], and Chinese privet [Ligustrum sinense]) on arbuscular mycorrhizal fungi (AMF). Our findings from central New York and southeastern Alabama forest habitats confirm that each species formed symbiotic associations with native AMF populations. Mycorrhizal dependency of kudzu was high when grown in invaded (85 percent) and non-invaded (83 percent) soil. The results indicate that invasion into new areas by non-native plant species may alter the occurrence of AMF in the resident soil. Evidence for a possible alteration in the AMF community was obtained largely from a Mycorrhiza Infection Potential bioassay. The bioassay indicated that root colonization levels by AMF of bait plants grown in soil collected from areas where the non-native plants formed pure stands were in general significantly greater than root colonization levels in soils collected from adjacent areas where the invasive plants were not present. Furthermore, the number of AMF spores in soil collected from areas invaded by pale swallow-wort was significantly higher than for nearby non-invaded soil. High colonization levels of pale swallow-wort roots with hyphae were observed during most of the growing season. The presence of arbuscules in pale swallow-wort roots was most evident in July and corresponds with the pre-flowering period of this species.