Author
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/24/2018 Publication Date: 1/9/2019 Citation: Bates, J.D., Davies, K.W. 2019. Characteristics of intact Wyoming big sagebrush associations in southeastern Oregon. Rangeland Ecology and Management. 72(1):36-46. https://doi.org/10.1016/j.rama.2018.07.015. DOI: https://doi.org/10.1016/j.rama.2018.07.015 Interpretive Summary: There is a lack of information that describes vegetation characteristics, diversity, and heterogeneity of the Wyoming big sagebrush alliance which may hamper development of management plans and habitat criteria. We sampled 48 Wyoming big sagebrush plant communities over a 10 year period and delineate six major vegetation associations and described their key vegetation characteristics including canopy cover, density, richness and structure. This information provides important vegetation potentials of forage and habitat capabilities to develop grazing plans and manage habitat. Habitat suitability criteria for sage-grouse indicated that Wyoming big sagebrush associations at the stand/site level will generally meet marginal requirements for the breeding period and suitable requirements for their other life stages. Technical Abstract: The Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) alliance is the most extensive of the big sagebrush complex in the Intermountain West. There is a lack of information that describes vegetation characteristics, diversity, and heterogeneity of the Wyoming big sagebrush alliance. We sampled 48 Wyoming big sagebrush plant communities over a 10 year period to delineate major vegetation associations and describe their major vegetation characteristics including canopy cover, density, richness and structure. Six associations were identified, using MRPP analysis, based on dominant or co-dominate perennial bunchgrass species: ARTRW8 (Wyoming big sagebrush)/PSSP6 (Pseudoroegneria spicata [Pursh] A. Löve, bluebunch wheatgrass), ARTRW8/ACTH7 (Achnatherum thurberianum [Piper] Barkworth, Thurber’s needlegrass), ARTRW8/FEID (Festuca idahoensis Elmer, Idaho fescue), ARTRW8/HECO26 (Hesperostipa comata [Trin. & Rupr.] Barkworth, needle-and-thread), ARTRW8/PSSP6-ACTH7, and ARTRW8/PSSP6-FEID-ACTH7. On average, PSSP6 and FEID associations had the highest total herbaceous cover and annual yields and the HECO26 and ACTH7 associations the lowest. Perennial forb cover averaged over 5 % in PSSP6 and FEID associations and from 0.3% to 3.5% in the other associations. Sagebrush cover was greatest in ACTH7 and PSSP6-ACTH7 and lowest in FEID and HECO26 associations. Habitat suitability criteria for sage-grouse indicated that Wyoming big sagebrush associations at the stand/site level will generally meet marginal requirements for the breeding period and suitable requirements for their other life stages. |