Cultural methods for establishing Wyoming big sagebrush on mined lands.

Abstract

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle &Young) is one of the most widely distributed shrub species in Wyoming and the Rocky Mountain and Northern Plains region. Its reestablishment on mined lands has generally proven difficult however, because of low seedling vigor, an inability to compete with herbaceous species, poor seed quality, and altered edaphic conditions. Field research evaluating the effect of topsoil management, mulching practice, and plant competition have shown that all of these factors significantly influence initial sagebrush establishment. Greater sagebrush establishment occurred on fresh topsoil compared to 5-year-old stockpiled topsoil. Stubble, surface-applied mulch, and elimination of herbaceous competition also significantly increased establishment in the first growing season. A cool, wet second-year growing season (April-September) resulted in large increases in sagebrush seedling density across all treatments; however, soil management and competition treatment effects were still apparent in the second year. Mulch type had limited effects on sagebrush seedling density by the third year of the study. This research indicates that big sagebrush seed viability in the soil is longer than previously thought and that seed dormancy, safe site development, and climactic conditions play important roles in germination, establishment, and seedling survival of this species.