Functional stability of mycorrhizal interactions in woody natives and aliens facing fire disturbance

Abstract

Changes in soil biota following fire and its successive influence on their interactions with plants may have direct implications on the invasion successof woody alien species in fire-prone ecosystems. In this work, we experimentally addressed if soil biota from burned and unburned areas differentially affectgrowth and nutrition of two dominant woody natives (Lithraea molleoides and Vachellia caven) and three woody invaders (Gleditsia triacanthos, Ligustrumlucidum and Pyracantha angustifolia) that occur on fire-prone ecosystems of central Argentina. Our results indicate that growth and P content in tissuesof both woody natives Lithraea and Vachellia were generally benefited by arbuscular mycorrhizal fungi (AMF) and that these effects did not strongly differ between AMF communities from burned and unburned soils. In the case of alien species, differences in growth and nutrition in response to AMF wererelated more to the identity of the invader than on the provenance of the soil biota. This study provides evidence on the important role that soil biota may have in the success of woody aliens in these ecosystems and on the functional stability of AMF communities facing disturbances.