An experimental test of small mammal dispersal of arbuscular mycorrhizal fungi spores

Abstract

Arbuscular mycorrhizal fungi (AMF) affect the structure of plant communities by influencing plant survivorship, growth, and diversity. Many AMF species produce spores below ground that have no obvious means of dispersal. Small mammals feed on AMF spores and those spores can still inoculate plants after passing through digestive systems. For this reason, small mammals are hypothesized to disperse AMF spores; however, few data exist to support this idea. I tested the ability of small mammals to disperse AMF spores by examining their impact on mycorrhizal inoculum potential in a northeast mesophytic forest. A field survey determined that small mammals sporadically consumed AMF spores. In a field experiment, more plots that were accessible to small mammals contained AMF than control plots, which excluded small mammals. This study provides experimental evidence that small mammals disperse AMF spores in a patchy manner, and wind dispersal also plays a role in AMF dispersal.