A sand dune area in Santa Catarina, Brazil, was surveyed every 3 months to determine species composition and seasonal variation of arbuscular mycorrhizal fungi populations associated with Spartina ciliata. Spores from 12 fungal species were recovered. Overall species richness was 5.9. A plot of rank versus abundance provided an indirect measure of the structure of the fungal community and showed a linear relationship among species. A mean of 298 spores/100 g soil were extracted from sand dune samples, with Acaulospora scrobiculata forming 50.9% of the total population. The most frequently recovered species at all sampling dates were Gigaspora albida, Scutellospora weresubiae, A. scrobiculata, and one undescribed Scutellospora species. Spore abundance ranged from 0 to 69 spores/100 g soil for all species except A. scrobiculata (60–247 spores/100 g). Spore abundance of each species did not vary significantly through the season. However, several general trends were observed. The number of spores of Glomus constrictum, Glomus etunicatum, and Acaulospora sp. (No. 2) was maximal in winter, whereas that of Gigaspora albida peaked in spring. Species composition and richness of arbuscular fungi in Brazilian dunes appear to be similar to those in sand dunes along the Atlantic coast of the United States. Key words: arbuscular mycorrhizal fungi, ecology, sand dunes, spore populations, Brazil.
Arbuscular mycorrhizal fungi (Glomeromycota) of soils of the Lubuskie province
