Seasonal dynamics of the vesicular-arbuscular mycorrhizal fungi in Chilean central-south sand dune ecosystems

Belcy González S.1, Roberto Godoy B.1 y Heriberto Figueroa S.2

A study was carried out at the litoral of Mehufn, central-south of Chile (39º 26' S) to determine the seasonal variation of the mycorrhizal colonization grade in Ambrosía chamíssonís (Less) Greene and Ammophila arenarla (L.) Link. A. chamíssonís shows an increase in the colonization grade from the embryonic dunes to the more stabilized ones during all seasons, with top values in spring. The mycorrhizal colonization grade of A. arenaría which does not grow in embryonic dunes, is higher in secondary dunes than in primary dunes during all seasons with top values in summer. Fungal spores production is related to vegetal extension and dunes stabilization and the maximum values were observed in secundary dunes in summer with 1,235 spores in 100 g of substrate. The genera Glomus and Aeaulospora are the most frequent taxa of mycorrhizal fungi found. The numbers of viable propagules obtained by the "most-probable-number-method" show a close correlation with results obtained by direct spore counts.

Keywords: vesicular-arbuscular mycorrhizal fungi, sand dunes, Chile.
1 Instituto de Botánica, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
2 Instituto de Estadistica, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.