Root herbivory reduces species richness and alters community structure of root-colonising arbuscular mycorrhizal fungi

Abstract

Belowground insect herbivory is an important interaction that can shape ecological communities above- and belowground. A key component of belowground ecosystems are the arbuscular mycorrhizal (AM) fungi that associate with roots of most terrestrial plants. Despite the shared ecological significance of root herbivores and AM fungi, there is an absence of data on how insect root herbivory affects root-colonising AM fungal diversity. This study explored the impacts of root herbivory (from Dermolepida alborhirtum) on the diversity and community composition of AM fungi colonising plant roots (Dichanthium sericeum) and assessed the effects on plant growth and nutrient uptake. Belowground herbivory significantly altered AM fungal community structure and reduced species richness, potentially removing fungal taxa sensitive to root-herbivore disturbance. Meanwhile, herbivory also reduced root biomass and aboveground phosphorus. These findings demonstrate how belowground herbivores can directly shape AM fungal communities in plant roots.