Native arbuscular mycorrhizal fungi (AMF) from mountain grassland (Córdoba, Argentina) I. Seasonal variation of fungal spore diversity

Arbuscular mycorrhizal fungi (AMF) were studied in the rhizosphere of 3 Poaceae with meta- bolic pathway C3 (Briza subaristata Lam., Deyeuxia hi- eronymi (Hack.) Turpe and Poa stuckertii (Hack.) Par- odi), 2 Poaceae with C4 metabolic type (Eragrostis lu- gens Nees and Sorghastrum pellitum (Hack.) Parodi.), and a Rosaceae (Alchemilla pinnata Ruiz & Pav.) from a natural mountain grassland in Central Argentina (South America). Host species, their metabolic type, seasonal changes, and grazing effects over AM fungal diversity were analyzed. Seventeen mycorrhizal fungi taxa were found, widespread in all families of Glom- ales. Density of endomycorrhizal fungi was found to be strongly influenced with seasons and host meta- bolic pathway, although biodiversity (H), richness (S) and evenness (E) did not change. In most cases graz- ing did not affect these variables.