Friday, August 10, 2007: 8:20 AM
Blrm Salon V, San Jose Marriott
Significant degradation of public rangeland ecosystems has occurred throughout the Southwest as a result of historic overgrazing by livestock, setting off a heated debate over the appropriate role of grazing in these semi-arid environments. Still, current research suggests that regionally complicated and interdependent relationships between grazing, climate and a site’s ecological characteristics may best explain the agroecosystem dynamics of these rangelands. Without having to resolve this debate we can still agree on the widespread need for landscape-level restoration. However, efforts to conduct ecosystem restoration within the West’s public rangelands are constrained by a dual policy mandate to manage for both ecosystem health and food production. Our experiment, on a remote part of the Arizona Strip, examined the effects of eight different restoration treatments on the germination success of seeded, cool-season native grasses. The effects of livestock grazing, seeding technique, various climate regimes, as well as the interactive effects of these treatments, were analyzed. Results indicate that mesic micro-environments and abundance of surface litter best explain germination success. These results are being used to plan larger scale experiments across local ecological gradients in order to develop maps of restoration potential. When coupled with background data on range productivity and degradation, and plant diversity, these restoration potential maps produce a decision-tree model that informs managers on where to locate grazing and restoration activities across the study region. Ultimately, this model produces well-informed decisions about how to reconcile ecological restoration with sustainable ranching practices.