Location: Forage and Range ResearchTitle: Influence of land-use legacies following shrub reduction and seeding of big sagebrush sites
|JONES, ALLISON - Wild Utah Project|
|PENDERGAST, MARY - Wild Utah Project|
|THACKER, ERIC - Utah State University|
|GREENHALGH, LINDEN - Utah State University|
Submitted to: Rangeland Ecology and Management
Publication Type: Research Notes
Publication Acceptance Date: 6/5/2018
Publication Date: 7/18/2018
Citation: Monaco, T.A., Jones, A., Pendergast, M., Thacker, E.T., Greenhalgh, L. 2018. Influence of land-use legacies following shrub reduction and seeding of big sagebrush sites. Rangeland Ecology and Management.
Technical Abstract: Big sagebrush (Artemisia tridentata Nutt.) plant communities provide important economic and ecosystem values, but often require management to reduce shrub density and rehabilitate understory vegetation. We studied vegetation structure and plant community responses to a two-way chain harrow treatment and broadcast seeding of 12 herbaceous species at eight Wyoming big sagebrush (A. tridentata Nutt. subsp. wyomingensis Beetle & Young) sites. These sites differed in land-use history; five were cultivated for dryland wheat production during the 1950-1980s then seeded with introduced forage grasses (C-S), while three had not been exposed to this land-use legacy (non C-S). Our objective was to evaluate whether the C-S legacy influences the magnitude of vegetation change following contemporary treatment. Prior to treatment, C-S sites had lower sagebrush cover, higher dead sagebrush cover, and higher broom snakeweed (Gutierrezia sarothrae [Pursh] Britton & Rusby) cover than adjacent non C-S sites. Plant community change three years after treatment, determined with multivariate ordination analysis of species composition, varied between site histories, and response to treatment was most strongly correlated with reductions in sagebrush cover, increases in the perennial bulbous bluegrass (Poa bulbosa L.), and increases in 10 other herbaceous species-four of which were seeded in 2010. Five years after treatment, mature sagebrush cover remained reduced for both land-use histories, yet density of sagebrush seedlings and broom snakeweek increased in C-S sites during the second and third year after treatment. In addition, perennial forb cover increased for C-S sites, while perennial grass biomass increased for non C-S sites. Our results emphasize that broad variability in plant community responses to sagebrush reduction and seeding is possible within the same ecological site classification, and that legacy effects due to the combination of past cultivation and seeding should be considered when planning restoration projects.