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

CARRON AI; GARIBALDI LA; FONTENLA S

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

The shrublands ofthe Andean-Patagonian region present high biodiversity and providemultiple ecosystem services, being one of the ecosystems with higherforestry activities in the region. Several natural and anthropogenicfactors influence the soil fungus community. These microorganismsplay a central role in ecosystem functioning and interaction withdifferent species. Our objective was to evaluate the effects offorest management and season (autumn vs. Summer) in the soil fungalcommunity and their ecological function. Eight experimental plotswere established in a native shrubland combining: thinning intensity(basal area removed 70, 50, 30 and 0%) and implantation of nativetree species (implanted and not implanted). A soil sample/plot wascollected in autumn and summer, one year after the forest management.We determined soil community characteristics and ectomycorrhizaloccurrence of a dominant native tree (N. antarctica). The fungal soilcommunity analysis was performed with the Roche Sequencing using theentire ITS region of fungal nrDNA (ITS1F-ITS4). The taxonomicclassification were RAPD with UNITE/QIIME database and were assigneda trophic mode using FUNGuild database. Then, a NMDS test wasperformed using Bray-Curtis dissimilarity. All N. antarctica adultshad high values of ectomycorrhizal colonization (~80%) withnon-significant differences between plots. At fungal classes, only acorrelation was observed between taxonomic diversity and the season.The abundance of Tremellomycetes and Dothideomycetes (including othermycorrhizal fungi, such as Cenococccum) was higher in autumn, whileSordariomycetes, Eurotiomycetes and Leotiomycetes abundance washigher in summer. When the trophic modes were analyzed there were nocorrelation between them, the season, the thinning or theimplantation. The saprotrophs and sapro-simbiotrophs were the mostabundant trophic mode, represented by the genera Hygrocybe andMortierella in both seasons. After this general behavior, thepathogens and symbionts that followed them in abundance presenteddifferent trends between seasons. Autumn was associated with thepathogen mode and summer with the symbiotrophic mode, particularlyrepresented by ectomycorrhizal fungi with greater abundance ofCortinarius, Descomyces and Inocybe. The results suggest that in aPatagonian shrubland seasonal factors influence fungal diversity, atthe class and gender level, and ecological function. Managementfactors do not appear to be determinant after one year of establishedthinning intensity and implantation of native tree species.p { margin-bottom: 0.25cm; line-height: 120%; }