Insight into the truffle brûlé: tripartite interactions between the black truffle (Tuber melanosporum), holm oak (Quercus ilex) and arbuscular mycorrhizal plants

Aim Tuber melanosporum is an ectomycorrhizal (ECM) fungus from Mediterranean transitional ecosystems where ECM trees start to dominate among arbuscular-mycorrhizal (AM) shrubs and herbs (companion plants). Its presence entails the development of ‘brules’, where vegetation is scarce for unknown reasons. Current T. melanosporum production comes from plantations where management often suppresses the understory vegetation, although empirical knowledge advocates a positive role of some companion plants in truffle production. This study aimed at (i) experimentally testing the reciprocal interaction between T. melanosporum and companion plants and (ii) examining T. melanosporum-mediated soil feedback involved in the dynamics of truffle ground vegetation.