Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 27, 2007
Publication Date: September 1, 2007
Citation: Davies, K.W., Bates, J.D., Miller, R. 2007. Short-term effects of burning wyoming big sagebrush steppe in southeast oregon. Rangeland Ecology and Management.60:515-522. Interpretive Summary: The impact of prescribed fall burning relatively intact Wyoming big sagebrush communities on total vegetation production and cover, availability of resources to herbaceous vegetation, and potential for exotic annual grass invasion has not been well quantified. Treatments were burning (burned) and not burning (control). Vegetation production and cover, perennial herbaceous vegetation diversity, soil water content, soil inorganic nitrogen, total soil nitrogen and carbon, and soil organic matter were compared between treatments. Total vegetation production and cover were greater in the control than the burned treatment. However, greater herbaceous production and cover in the burned than the control treatment suggests that resources were more available to herbaceous vegetation in the burned than the control treatment. Annual exotic grass cover and production did not increase with burning. These results indicate herbaceous vegetation can be increased with prescribed burning relatively intact Wyoming big sagebrush communities without exotic annual grass invasion.
Technical Abstract: Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh) plant communities of the Intermountain West have been greatly reduced from their historic range as a result of wildfire, agronomic practices, brush control treatments, and weed invasions. The impact of prescribed fall burning Wyoming big sagebrush has not been well quantified. Treatments were sagebrush removed with burning (burned) and sagebrush present (control). Treatments were applied to 0.4 ha plots at six sites. Biomass production, vegetation cover, perennial herbaceous vegetation diversity, soil water content, soil inorganic nitrogen (NO3-, NH4+), total soil nitrogen (N), total soil carbon (C), and soil organic matter (OM) were compared between treatments in the first two years post-burn. In 2003 and 2004, total (shrub and herbaceous) aboveground annual biomass production was 2.3 and 1.2 times greater, respectively, in the control compared to the burned treatment. In the upper 15 cm of the soil profile, inorganic N concentrations were greater in the burned than control treatment, while soil water, at least in the spring, was greater in the control than burned treatment. Regardless, greater herbaceous aboveground annual production and cover in the burned treatment indicated resources were more available to herbaceous vegetation in the burned than control treatment. Exotic annual grasses did not increase with the burn treatment. Our results suggest in some instances that late seral Wyoming big sagebrush plant communities can be prescribed fall burned to increase livestock forage or alter wildlife habitat without exotic annual grass invasion in the first two years post-burn. However, long-term evaluation at multiple sites across a larger area is needed to better quantify the effects of prescribed fall burning on these communities. Thus, caution is advised because of the value of Wyoming big sagebrush plant communities to wildlife and the threat of invasive plants.