Restoration of mountain big sagebrush steppe following prescibed burning to control western juniper

Authors: Davies, Kirk; Bates, Jonathan - Jon; Madsen, Matthew; NAFUS, ALETA - Oregon State University

Submitted to: Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2014
Publication Date: 4/3/2014
Publication URL: http://handle.nal.usda.gov/10113/58787
Citation: Davies, K.W., Bates, J.D., Madsen, M.D., Nafus, A.M. 2014. Restoration of mountain big sagebrush steppe following prescibed burning to control western juniper. Environmental Management. 53:1015-1022. DOI: 10.1007/s00267-014-0255-5

Interpretive Summary: Western juniper encroachment of mountain big sagebrush steppe has degraded wildlife habitat, reduced forage production, and increased erosion risk. Western juniper can be successfully controlled with partial cutting followed by prescribed burning, but the recovery of the herbaceous understory and sagebrush may be slow. We evaluated the effectiveness of seeding perennial herbaceous vegetation and sagebrush at five sites where juniper was controlled with partial cutting and prescribed burning. Sagebrush and perennial grass density and cover were much greater where they were seeded. These results suggest that seeding after juniper control can accelerate the recovery of mountain big sagebrush steppe and provide habitat for sagebrush-associated wildlife species. With the wide spread loss of sagebrush habitats and associated declines in sagebrush-associated wildlife, these results are important to land and wildlife managers and restoration ecologists.

Technical Abstract: Western juniper (Juniperus occidentalis ssp. occidentalis Hook) encroachment into mountain big sagebrush (Artemisia tridentata spp. vaseyana (Rydb.) Beetle) steppe has degraded sagebrush-associated wildlife habitat, reduced livestock forage production, and increased erosion risk. The loss of sagebrush as juniper cover increases has exacerbated the plight of sage-grouse and other sagebrush-associated wildlife species. Western juniper has been successfully controlled with partial cutting followed by prescribed burning, but the herbaceous understory and sagebrush may be slow to recover. We evaluated the effectiveness of seeding perennial herbaceous vegetation and sagebrush at five sites where juniper was controlled by partially cutting and prescribed burning. Treatments tested at each site included an unseeded control, herbaceous seed mix (aerial seeded), and the same herbaceous seed mix plus mountain big sagebrush seed (broadcasted to simulate aerial seeding). In the third year post-treatment, perennial grass cover and density were twice as high in plots receiving the herbaceous seed mix compared to the control plots. Sagebrush cover and density in the sagebrush seeded plots were between 74- and 290-fold and 62- and 155-fold greater than the control and herbaceous seeded plots. By the third year after treatment, sagebrush cover was as high as 12% in the sagebrush seeded plots and between 0% and 0.4% where it was not seeded. These results indicate that aerial seeding perennial herbaceous vegetation can accelerate the recovery of perennial grasses and probably stabilize the site and limit opportunities for invasive plants. Our results also suggest that seeding mountain big sagebrush after prescribed burning encroaching western juniper can rapidly recover sagebrush cover and density and thereby provide habitat for sagebrush-associated wildlife species. In areas where sagebrush habitat is limited, we hypothesize that seeding sagebrush after juniper control could be used to increase sagebrush habitat and decrease the risks to sagebrush-associated species.