A preliminary study of interactions between species of vesicular-arbuscular fungi in a sand dune

Abstract

Interactions between five species of VA mycorrhizal fungi sporulating in association with the dominant plants on a single barrier dune were examined. The observed frequency of simultaneous occurrence of any two species did not differ significantly from the expected value in any pairing. Spore densities of individual fungal species in the same sample were analyzed to determine if a stimulation or inhibition of sporulation resulted from high or low levels of sporulation by other VA species. The effect of host species on occurrence of VA species and spore density in the rhizosphere also was studied. Two fungi were absent or rare on three hosts, and spore production by Acaulospora scrobiculata was significantly greater in association with Ammophila breviligulata than with Lathyrus japonicus var. glaber. It was concluded that interaction between VA fungi is of less importance in determining species presence and spore density than are the species of host plant and other environmental factors.