ARS | Publication request: PRESCRIBED FIRE EFFECTS ON UNDERSTORY COMPONENTS IN A WYOMING BIG SAGEBRUSH COMMUNITY

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2006
Publication Date: February 9, 2007
Citation: Rhodes, E., Bates, J.D. 2007. Prescribed fire effects on understory components in a wyoming big sagebrush community [abstract]. Society for Range Management Meeting. Paper No.356.

Technical Abstract: Historically, fire was a naturally occurring disturbance in the Wyoming big sagebrush alliance (Artemisia tridentata ssp. wyomingensis Beetle & Young), temporarily shifting plant community dominance from sagebrush to perennial grasses. Research efforts have been focused on fire effects on sites with an established invasive species component. However, extensive areas of the Wyoming big sagebrush alliance in eastern Oregon contain intact native understories with minimal presence of invasive species. The impact of prescribed fire on composition and production of herbaceous vegetation in an intact Wyoming big sagebrush community was evaluated for three years following a prescribed fall burn. Herbaceous biomass, canopy cover, and species richness, were compared in a randomized block design with two treatments: burned and unburned Wyoming big sagebrush steppe. Native understory vegetation was either improved or not affected by prescribed fire. Total herbaceous cover was greater in the burn the second year (P =0.0155), but was not different in the first and third years (P >0.05). Thurbers needlegrass cover was greater in burned treatments by the third year post burn (P =0.0149). In all three post burn years, both total herbaceous biomass (P 0.05). Annual forb biomass was 2.80 times higher (P =0.0212) in the burned treatment the first year post burn, but did not differ significantly thereafter (P >0.05). Total species richness did not differ between treatments during the study (P >0.05). Our results suggest that prescribed fire in an intact Wyoming big sagebrush community is not detrimental to native understory species when invasive species are not predominant in the pre burn community.