Cordoba, A.S., M.M.de Mendonça, S.L. Stürmer and P.T. Rygiewicz. 2001. Diversity of arbuscular mycorrhizal fungi along a sand dune stabilization gradient: A case study at Joaquina Beach on the Island of Santa Catarina, South Brazil. Mycoscience 42:379-387. WED-00-121
Species diversity of abuscular mycorrhizal fungi (AMF) was assessed along a dunes stabilization gradient (embyonic dune, foredune and fixed dune) at Praia da Joaquina (Joaquina Beach), Ilha de Santa Catarina. These dunes served as a case study to assess whether diversity and mycorrhizal inoculum potential increase along the gradient. Ten soil samples were collected from each stage, pooled, and then six, 100g soil sub-samples taken to identify and enumerate spores. Twelve AMF species were detected, and all three families in Glomales were represented. Gigasporaceae species dominated in the embryonic dune while Glomaceae species dominated in the fixed dune. Total spore numbers and richness increased as the dunes became more stabilized. However, indices of Margalef, Simpson and Shannon reached maximal values at different stages suggesting that species abundance distributions were different at each stage. In both embryonic and fixed dunes, species abundance data fit the broken stick model while in the foredune, the log series model best described the data. Mycorrhizal inoculum potential followed spore numbers and increased along the gradient suggesting that spores are important in initiating root colonization in this system. Relationships between edcaphic factors and functional roles of Glomales families as determinants of AMF distribution are discussed.