Background/Question/Methods
Serpentine soils harbor many endemic plant species worldwide and are of considerable conservation interest.  We know very little about how their microbial communities differ from surrounding soil types, however.  It has been suggested that serpentine adapted arbuscular mycorrhizal fungi (AMF) may increase plants' tolerance to the low nutrient and high heavy metal concentrations present in serpentine soil.  To explore this possibility we surveyed the AMF community of northeastern Portugal on both serpentine and non-serpentine soil.  Using molecular markers we identified those AMF present in the roots of a local species of grass, Avenula sulcata, which grows on both soil types.
Results/Conclusions
Our results indicate that serpentine soil has very little influence on AMF community composition.  Not a single species found more than once was restricted to either serpentine or non-serpentine soils.  Moreover, the communities did not differ in richness, diversity, or evenness.  Ordination techniques gave stronger yet still equivocal support for distinct community composition between soil types.  While serpentine soils exert a large and obvious impact on plant communities, it appear that AMF are largely unaffected by this seemingly extreme environment.  Our results indicate that an endemic serpentine adapted mycorrhizal community is not an important component of plant tolerance to serpentine soil.