Occurrence of Arbuscular Mycorrhiza in Herbaceous Plants in Communities Invaded by Acer negundo (Sapindaceae, Sapindales)

We tested whether one of the consequences of alien plant invasions predicted by the “degraded mutualism” or “mutualism disruption” hypothesis was revealed in relation to the invasive tree ash-leaved maple (Acer negundo L.). The aim of the work was to assess the occurrence of arbuscular mycorrhiza in the roots of Taraxacum sect. Taraxacum F.H. Wigg. (Taraxacum officinale F.H. Wigg.) and Poa angustifolia L. in communities invaded (An+) and not invaded by A. negundo, dominated by other woody plant species (An–). The study was performed in urban habitats of Yekaterinburg. Root samples of T. sect. Taraxacum and P. angustifolia were collected from 7 An+ and 7 An– habitats. The occurrence of arbuscular mycorrhiza and root hairs were recorded microscopically. In T. sect. Taraxacum, an increased occurrence of mycorrhiza was found in communities invaded by A. negundo. In P. angustifolia, no differences of mycorrhiza formation depending on A. negundo dominance were observed. Therefore, we have not found a confirmation of the “degraded mutualism” or “mutualism disruption” hypothesis regarding A. negundo.