Soil mycobiome structure across central and peripherial zones in a pecan nut agroecosystem [Carya illinoinensis (Wangenh.) K. Koch]

Using ITS1-based metabarcoding, we investigated the structure of the soil fungal communities in the central and peripheral zones of a 25-hectare pecan nut (Carya illinoinensis) orchard located in the arid region of Coahuila, Mexico. While environmental conditions such as soil moisture and temperature varied between zones, physicochemical soil properties (pH, organic carbon, total carbon, organic matter, electrical conductivity, and zinc) remained homogeneous. A total of 4,443 fungal OTUs were detected at 97% similarity. Alpha diversity indices did not differ significantly between zones. The fungal community was dominated by the phyla Ascomycota and Basidiomycota, with Pezizomycetes, Dothideomycetes, and Agaricomycetes as dominant classes. No statistically significant differences in beta diversity or community composition were found between zones (PERMANOVA p = 0.662). Redundancy analysis also revealed no clear clustering by zone, though localized differences were observed. Our findings suggest that agronomic management in this system promotes environmental homogeneity, leading to relatively uniform fungal communities. This exploratory study highlights the need for future research incorporating comparisons with adjacent natural ecosystems to better assess spatial patterns and potential edge effects in agroecosystems.