Forest management and seasonal effects on the diversity and ecological function of soil fungi in a Northwestern Patagonian shrubland

GARIBALDI, L.A.; FONTENLA, SONIA; CARRON, AYELEN

BARILOCHE - SAN CARLOS DE BARILOCHE

Simposio; II International Symposium Mycorrhizal Symbiosis in South America; 2019

Forest management and seasonal effects on the diversity and ecological function of soil fungi in a Northwestern Patagonian shrublandA.I. Carron1,2*, L.A. Garibaldi3,4 and S. Fontenla11Laboratorio de Microbiología Aplicada y Biotecnología vegetal y del suelo, CRUB, Universidad Nacional del Comahue. 2IPATEC (Universidad Nacional del Comahue-CONICET)3Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural (IRNAD), Sede Andina, Universidad Nacional de Río Negro (UNRN) 4Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).*Email: ayecarron@gmail.comThe shrublands of the Andean-patagonian region present high biodiversity and provide multiple ecosystem services, being one of the ecosystems with higher forestry activities in the region. Several natural and anthropogenic factors influence the soil fungus community. These microorganisms play a central role in ecosystem functioning and interaction with different species. Our objective was to evaluate the effects of forest management and season (autumn vs. summer) in the soil fungal community and their ecological function. Eight experimental plots were established in a native shrubland combining: thinning intensity (basal area removed 70, 50, 30 and 0%) and implantation of native tree species (implanted and not implanted). A soil sample/plot was collected in autumn and summer, one year after the forest management. We determined soil community characteristics and ectomycorrhizal occurrence of a dominant native tree (N. antarctica). The fungal soil community analysis was performed with the Roche Sequencing using the entire ITS region of fungal nrDNA (ITS1F-ITS4). The taxonomic classification were RAPD with UNITE/QIIME database and were assigned a trophic mode using FUNGuild database. Then, a NMDS test was performed using Bray-Curtis dissimilarity. All N. antarctica adults had high values of ectomycorrhizal colonization (~80%) with non-significant differences between plots. At fungal classes, only a correlation was observed between taxonomic diversity and the season. The abundance of Tremellomycetes and Dothideomycetes (including other mycorrhizal fungi, such as Cenococccum) was higher in autumn, while Sordariomycetes, Eurotiomycetes and Leotiomycetes abundance was higher in summer. When the trophic modes were analyzed there were no correlation between them, the season, the thinning or the implantation. The saprotrophs and sapro-simbiotrophs were the most abundant trophic mode, represented by the genera Hygrocybe and Mortierella in both seasons. After this general behavior, the pathogens and symbionts that followed them in abundance presented different trends between seasons. Autumn was associated with the pathogen mode and summer with the symbiotrophic mode, particularly represented by ectomycorrhizal fungi with greater abundance of Cortinarius, Descomyces and Inocybe. The results suggest that in a Patagonian shrubland seasonal factors influence fungal diversity, at the class and gender level, and ecological function. Management factors do not appear to be determinant after one year of established thinning intensity and implantation of native tree species.Keywords: ectomycorrhizal fungi, Nothofagus antarctica, seasons and soil characteristics