Restoration of native vegetation in dryland ecosystems, which encompass over 40% of terrestrial ecosystems, is a persistent and growing challenge for land managers. The difficulty in part stems from low and variable precipitation, combined with a lack of understanding of the impact of weather conditions and variability on restoration outcomes. Big sagebrush, a foundational species which once covered over 62 million ha of western North American, is a prime example of a pressing dryland restoration challenge for which restoration success has been variable. We analyzed field data on restoration outcomes collected at 771 plots across the western range of big sagebrush and process-based ecohydrological modeling to identify factors leading to reestablishment of big sagebrush.
Results/Conclusions
Our results indicate big sagebrush reestablishment is most strongly associated with availability of cool temperatures and ample spring soil moisture, but not total precipitation. In particular, interactions among temperature, precipitation and snowpack are critical for restoration success. We also find that there can be considerable weather-driven inter-annual variability in the probability of sagebrush establishment (up to 40% variation in probability of establishment). Adaptive management strategies that target seeding during favorable years or mitigate the effects of variability through repeated seeding may improve successful restoration of foundational native shrubs in dryland ecosystems.