Seasonal dynamics of selected species of V-A mycorrhizal fungi in a sand dune

Abstract

Seasonal dynamics of five vesicular-arbuscular mycorrhizal fungi ( Acaulospora scrobiculata, Gigaspora gigantea, Scutellospora calospora, S. pellucida and S. persica ) occurring in a Massachusetts sand dune were examined to determine the period of maximum sporulation. Although the maximum spore population was found in October, three distinct seasonal patterns were evident. Spore abundance of A. scrobiculata and G. gigantea was highest in October samples, and that of S. calospora was greatest in the August collection. A bimodal trend of peak spore abundance in October and May, was detected for S. pellucida and S. persica . Statistically significant seasonal trends were demonstrated for A. scrobiculata and S. persica . No statistically significant linear or curvilinear relationship could be demonstrated between spore abundance and edaphic factors (pH, organic matter or chloride). High levels of spore abundance for one species in a sample were associated with significantly lower levels of sporulation by the other species in the same sample (with the exception of S. pellucida ), suggesting antagonistic interactions between species.