Influence of weather on production dynamics in Wyoming big sagebrush steppe across plant associations

Authors: Copeland, Stella; Davies, Kirk; Hardegree, Stuart; Moffet, Corey; Bates, Jonathan - Jon

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2022
Publication Date: 10/13/2022
Citation: Copeland, S.M., Davies, K.W., Hardegree, S.P., Moffet, C., Bates, J.D. 2022. Influence of weather on production dynamics in Wyoming big sagebrush steppe across plant associations. Rangeland Ecology and Management. 85:48-55. https://doi.org/10.1016/j.rama.2022.09.002.
DOI: https://doi.org/10.1016/j.rama.2022.09.002

Interpretive Summary: Highly variable production across years is common in semi-arid rangelands like sagebrush steppe due to weather. However, few observational studies have described this variability across space and time and with relationship to specific seasonal weather patterns and vegetation types. We measured production across 10 years to associate weather and site vegetation characteristics with weather-driven dynamics in 44 undisturbed intact Wyoming big sagebrush steppe sites. We also examined whether patterns were similar across functional groups and sites. Spring precipitation was the most consistent predictor of production, however, weather in previous years and various seasons also drove production patterns, particularly for perennial groups. High synchrony across vegetation types and functional groups suggests that these characteristics are unlikely to stabilize dynamic weather-driven production patterns in intact sagebrush steppe sites in the northern Great Basin.

Technical Abstract: High interannual variability in production occurs in many semiarid rangelands, including the perennial-dominated sagebrush steppe, in response to variable weather conditions. Describing the effects of weather on the dynamics of sagebrush steppe has implications for a broad set of management objectives including forage and wildlife habitat. Here, we investigated the effects of seasonal weather and plant associations, related to abiotic characteristics, on herbaceous production dynamics across 44 intact, representative sagebrush steppe sites across eastern Oregon from 2003 to 2012. We tested for the effects of sampling year, lagged precipitation, and potential evapotranspiration predictors, as well as prior year biomass and plant association on production of major herbaceous functional groups. We also tested for synchrony across functional groups and plant associations. We found that spring precipitation was the most consistent predictor of production. However, several other variables including prior year weather significantly affected production. Production sensitivity to weather was combined with high synchrony across functional groups and associations, suggesting low potential for production stability associated with these factors in sagebrush steppe in the northern Great Basin.