Fungal communities associated with the rhizosphere and bulk soil of Gaultheria mucronata

This study investigates the fungal communities associated with Gaultheria mucronata (Ericaceae) colonizing volcanic scoria soils in Conguillio National Park, La Araucania, Chile. Volcanic scoria represents an extreme edaphic environment characterized by low nutrient availability, high porosity, and minimal organic matter, making it a challenging substrate for plant establishment. G. mucronata is among the pioneer shrub species capable of colonizing such substrates, suggesting potential functional associations with soil fungi that may facilitate nutrient acquisition and stress tolerance. Using ITS amplicon sequencing (metabarcoding), we compared the fungal diversity and community composition between the rhizospheric soil (directly influenced by root activity) and bulk soil (distant from roots) of G. mucronata. This rhizosphere vs. bulk soil comparison allows identification of plant-driven selection of fungal taxa, including potential mycorrhizal partners, saprotrophic fungi, and other functionally relevant guilds. Alpha and beta diversity analyses, as well as differential abundance testing, were applied to characterize community structure and identify indicator taxa enriched in each soil compartment.