Artemisia tridentata (sagebrush) is the most widely distributed shrub in North America and is the local dominant in many communities, due in part to physiological and genetic characteristics. The relationships of A. tridentata with its mycorrhizal fungal communities will be examined to determine if local adaptations of the endophyte-host relationship have a role in the wide distribution of the shrub. These facts are of special interest in this relationship. The shrub has up to a 2.5 times increase in biomass with mycorrhizal infection. Associated species of mycorrhizal fungi are of tropical origin in southern sites and of temperate origin in the northern sites. Different species of mycorrhizal fungi have different physiological effects on this host so local fungal communities may explain the success of the shrub. Both descriptive and functional approaches, including an examination of vesicular-arbuscular mycorrhizal fungal communities in stands of A. tridentata throughout its distribution and reciprocal transplants of A. tridentata and its associated fungi between sites in Southern California and Southwestern Wyoming, will be taken. An interdisciplinary team of researchers will measure morphological, anatomical, physiological, and fungal parameters to determine success of the transplants. The measurements will be integrated using a conceptual hierarchical model. These data will be used to sort out differences between sites, plant populations, and fungal populations and genera on local adaptations of A. tridentata and its ability to persist in geographically remote sites.
