Processes underlying the effect of mycorrhizal symbiosis on plant-plant interactions

Mycorrhizal symbiosis has important implications for the diversity and productivity of plant communities. However, our mechanistic understanding of its influence on the outcome of plant-plant interactions is still expanding. In this review we propose a framework that might be useful to efficiently approach the effects of mycorrhizal fungi (MF) on plant-plant interactions. We propose several scenarios that can theoretically result in different outcomes of plant-plant interactions based on the combination of two processes: the diversity of resources provided by MF taxa to their host (resource dissimilarity) and contrasting ways of distributing those resources (resource distribution). Then, we illustrate our arguments with different ecological contexts where certain combinations of these two processes are prone to occur. The proposed framework suggests testable hypotheses that can contribute to elucidate relevant processes underlying the effects of mycorrhizal symbiosis on plant-plant interactions. (C) 2018 Elsevier Ltd and British Mycological Society. All rights reserved.