Factors driving natural recruitment of Wyoming big sagebrush are poorly understood. Wyoming big sagebrush is a mid to late seral species, is not fire adapted, and can take decades to return to pre-fire densities. Wyoming big sagebrush communities have significantly declined due to changes in fire and climate regimes over the last century. We observed rare, natural recruitment events in 2016 and 2017 near Reno, Nevada, USA. We measured canopy gap, plant species and ground cover, shrub richness and size, distance to nearest adult sagebrush, and juvenile sagebrush density at fourteen paired burned and unburned sites. Additionally, seedlings were marked to determine survivorship and growth over time. Aspect, slope, and elevation were measured using a 10-meter elevation model. Seasonal temperature and precipitation were calculated using PRISM monthly models. The 2016 recruitment event was 136 times greater than 2017, but only 3% of the 2016 seedlings survived. Ninety-nine percent of seedlings were located within unburned stands. Growing season maximum temperature, winter precipitation, distance to adult sagebrush, and West-facing aspects were negatively associated with seedling density. Seedlings averaged 1.5 m from the nearest adult sagebrush, with a maximum distance of 14 m. When the high recruitment year (2016) was isolated, litter and rock cover had a positive effect on seedling density. Seedling height was positively associated with perennial, native species cover, which suggest more productive sites with low invasion promote growth. In two winters with above average precipitation, increased precipitation, presumably as snow cover, may have resulted in seed dormancy and reduced germination. Higher growing season temperatures and UV radiation on western slopes may have resulted in seed or seedling desiccation. We will continue monitoring sagebrush seedlings in relation to weather, topography, abiotic conditions, and plant community structure. Understanding the natural recruitment of sagebrush may inform restoration efforts.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.