Arbuscular mycorrhizal fungus identity and diversity influence subtropical tree competition

Arbuscular mycorrhizal (AM) fungi can influence plant nutrient uptake and, therefore, may alter inter specific plant competition. However, the role of AM fungi in subtropical tree competition is poorly understood. In this study, we investigated the effects of AM fungus identity (four species) and diversity (a mixture of the same four species) on the competitive relationships between seedlings of a pioneer tree Rhus chinensis and a late-pioneer tree Celtis sinensis, and between R. chinensis and a mid-successional tree Cinnamomum camphora. In seedlings, AM fungi significantly promoted a competitive advantage of chinensis over both Ce. sinensis and Ci. camphora. Furthermore, the extent to which AM fungi affected interspecific plant competition outcomes was dependent on AM fungus identity, and the effect of AM fungus diversity on interspecific competition outcomes may derive from the most beneficial AM fungal species. (C) 2015 Elsevier Ltd and The British Mycological Society. All rights reserved.