Soil and endophytic fungal associations with grama at the Sevilleta LTER

Plant and soil fungi are fundamental in different ecological processes. However, our current knowledge of plant-associated and soil fungal communities is limiting our capacity of understanding main roles of fungi in ecosystems. The main objective of this research was to study diversity, composition and the effect of nitrogen fertilization on fungal communities at the Sevilleta semiarid grasslands. We collected plant-associated and soil fungal communities at the Niwot and Sevilleta LTER. Fungi were sequenced using fungal-specific primers. About 50% of the Operational Taxonomic Units were considered novel (less than 97% similarity with respect to sequences in the NCBI database). Rarefaction curves and diversity estimators do not show saturation. Root fungi were dominated by dark septate fungi and at least 10 different orders including endophytic, coprophilous, mycorrhizal (AMF), saprophytic and plant pathogenic fungi were found colonizing the roots of dominant plants. Major and most diverse groups belong to the order Pleosporales including potential novel families. Soil and root communities showed significant differences and AMF fungi were affected by nitrogen fertilization.  Potential ecological roles of these symbionts, their diversity, and biogeographical distributions will be discussed.