FUNCTIONAL DIVERSITY OF NATIVE MYCORRHIZAE DURING EARLY DEVELOPMENT OF BIG SAGEBRUSH; A STEP(PE) TOWARDS RESTORING SAGEBRUSH ECOSYSTEMS

Disturbance of sagebrush ecosystems by human activities has decreased the economic and ecological services that these rangelands can provide. Reseeding and improved management practices aim to restore sagebrush ecosystems and balance human use with conservation of wildlife habitats. Wyoming big sagebrush plays a critical role in determining the structure of many sagebrush ecosystems and in providing forage and habitat for other species. Reintroduction of Wyoming big sagebrush in burned areas has proven difficult due in part to high seedling mortality. A key factor in improving the success of restoration efforts may be a better knowledge of the associations between sagebrush seedlings and fungi that can have beneficial effects on the seedlings, in particular arbuscular mycorrhizal fungi (AMF). In burned areas that have been occupied by exotic annual grasses, the density of these fungi may be low and/or the AMF species present may not be the most beneficial to sagebrush seedlings. Under this scenario, practices that combine sowing with addition of the appropriate fungal inoculums may improve seedling establishment. Experiments described in this proposal will begin to investigate these possibilities and help launch a larger research and training program dubbed "VAMoSS", Vesicular Arbuscular Mycorrhizae of Sagebrush Steppe. Logical first steps will be to multiply and identify native AMF. Subsequently, we will test the effects of native mycorrhizal addition on colonization and establishment of sagebrush seedlings under natural conditions; native AMF will be added as both mixed and single species. Enhanced seedling establishment by any of the AMF treatments will aid the development of new approaches to sagebrush habitat restoration, ultimately improving the productivity and environmental quality of these rangelands. In addition, the proposed study will increase our knowledge of AMF species inhabiting sagebrush habitats, their ecological interactions with Wyoming big sagebrush, as well as compositional and functional biodiversity of the steppe.