Effects of Disturbance on Silver Sagebrush Communities in Dry Mixed-Grass Prairie

Abstract

Restoration specialists are increasingly interested in re-establishing silver sagebrush ( Artemisia cana ) communities due to the large number of wildlife species that are partial sagebrush obligates. Energy development within native grasslands can contribute to habitat loss through introduction of invasive species. In this study, pipeline and reclaimed well site footprints were assessed relative to undisturbed sample units to identify management practices that achieve effective restoration of silver sagebrush communities on disturbed sites. Our objectives were to compare silver sagebrush communities on energy disturbances with undisturbed areas in two ecological range sites in dry mixed-grass prairie: blowouts (hard-packed bare ground) and overflows (mesic sedimentation). Our hypothesis was that moisture, greater nutrient values, and potential seed banks found in overflows may benefit silver sagebrush growth. We were also interested in plant communities resulting from of various seeding treatments, hypothesizing that silver sagebrush may be negatively impacted by some seeding treatments. We used a paired transect design to measure variations in plant species cover in each ecological range type. We found similar silver sagebrush cover values to adjacent undisturbed areas following disturbances on both overflow and blowout ecological range types; however, silver sagebrush was significantly reduced in disturbed areas that were seeded with grass species compared to sites that were allowed to recover naturally. We recommend minimum disturbance practices with natural recovery, avoidance of seeding agronomic cultivars, and in particular preventing introduction of invasive species such as crested wheatgrass.