Although introduced species such as crested wheatgrass (Agropyron cristatum) have been widely used for post-fire rehabilitation seedings in semiarid Great Basin ecosystems, native species such as bluebunch wheatgrass (Pseudoroegneria spicata), western wheatgrass (Pascopyrum smithii) and big sagebrush (Artemisia tridentata) now play an increasingly important role in seeding efforts. Seed mixes containing only native species are ideal for areas where natural vegetation recovery is a long-term objective, but the ability of native seedings to meet other objectives such as weed suppression has often been questioned.
An operational-scale seeding experiment was initiated at two study sites following the 1999 Railroad wildfire in Tintic Valley, Utah, to compare native seed mixes with conventional mixes dominated by introduced species. Short-term effects of these seed mix treatments during the first three years of seedling growth were examined and reported by Thompson et al. (2006). In 2015, a team of researchers from the USDA Forest Service Rocky Mountain Research Station and Utah Department of Natural Resources returned to the study site to examine longer-term effects. They were interested in documenting changes in cover and density of key plant species to determine whether the seed mix treatments had been effective at re-establishing perennial cover and suppressing exotic annuals over the longer term.