Site, competition and plant stock influence transplant success of Wyoming big sagebrush

Authors: MCADOO, J - University Of Nevada; Boyd, Chad; Sheley, Roger

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2013
Publication Date: 5/1/2013
Citation: Mcadoo, J.K., Boyd, C.S., Sheley, R.L. 2013. Site, competition and plant stock influence transplant success of Wyoming big sagebrush. Rangeland Ecology and Management. 66(3):305-312. https://doi.org/10.2111/REM-D-12-00136.1.
DOI: https://doi.org/10.2111/REM-D-12-00136.1

Interpretive Summary: Sagebrush is critical to ecological function and maintaining wildlife habitat in many plant communities of the western United States, however, re-establishing Wyoming big sagebrush on depleted sites has been largely unsuccessful using conventional techniques centered on broadcast seeding. We quantified the success of an alternative restoration method, transplanting, relative to transplant stock (nursery seedlings vs. wildlings) across a variety of ecological sites and tested the hypothesis that reduction of herbaceous vegetation would increase survival of transplanted sagebrush. Our results indicate that transplanting seedling or juvenile sagebrush is a viable technique for establishing sagebrush on a variety of ecological sites and that establishment can be increased substantially by using herbicide to remove competing vegetation at the time of planting. High labor and plant material investments may limit the size of restoration projects for which sagebrush transplants are practical, however, dramatically increased success, relative to traditional broadcast seeding techniques, indicates transplants are an important technique for restoring Wyoming big sagebrush on depleted sites, particularly on smaller restoration projects or when establishing sagebrush islands to develop a seed source for a larger area.

Technical Abstract: Within the sagebrush steppe ecosystem, sagebrush plants influence a number of ecosystem properties, including nutrient distribution, plant species diversity, soil moisture and temperature, and provide habitat for a wide variety of wildlife species. Recent increases in frequency and size of wildfires and associated annual grass expansion within the Wyoming big sagebrush alliance have increased the need for effective sagebrush restoration tools and protocols. Our objectives were to quantify the success of Wyoming big sagebrush transplants relative to transplant stock (nursery seedlings vs. wildlings) across a variety of ecological sites and to test the hypothesis that reduction of herbaceous vegetation would increase survival of transplanted sagebrush. We used a randomized block (reps = 5) design at each of three sites (1) cheatgrass-dominated, 2) native plant-dominated, and 3) crested wheatgrass-dominated) near Elko, NV. Treatments included plant stock (nursery stock or locally-harvested wildlings) and herbicide (glyphosate) to reduce competing vegetation. Transplants were planted in the spring of 2009 and 2010 and monitored for survival. Data were analyzed for site and treatment effects using mixed model ANOVA. Surviving plant density at one and two years post-planting was generally highest (up to 3-fold) on the native site (p < 0.05). Density of surviving plants was almost 3-fold higher for nursery stock on most sites for the 2009 planting, but differences in survival by planting stock were minimal for the 2010 planting. Glyphosate application increased surviving plant density up to 300% (depending on site) for both years of planting. High labor and plant material investments (relative to traditional drilling or broadcasting) may limit the size of projects for which sagebrush transplants are practical, but these costs can be offset by high success relative to traditional methods. Our data indicate that sagebrush transplants can be effective for establishing sagebrush on depleted sites.