Restoration of semi-arid lands in the western U. S. is hindered by invasion of exotic species such as�Bromus tectorum(cheatgass) and highly variable weather. Decreasing soil moisture variability in may promote establishment of a native species over invasive species. With their ability to absorb moisture when it is abundant and slowly release it over time, superabsorbent polymers (SAP) may increase overall soil moisture and decrease soil moisture variability during restoration. In this study, we aimed to investigate the interactive effects of precipitation timing, drought,�B. tectorum,�and SAP on soil resources and developing restoration plant communities. The study was established in 2014 at two sites in Colorado. Two levels of three treatments (drought: exclusion of 66% of ambient rainfall or ambient rainfall;�B. tectorum�presence: 465 seeds m-2�or none; SAP: 26 g m-2�or none) were fully crossed in three blocks at each site. After one year of monitoring, we observed significant effects of drought at both sites on soil moisture and plant communities. Independent and interactive effects of drought and SAP at the Eastern Slope site and drought and�B. tectorum�at the Western Slope site influenced plant communities and soil moisture.�At the Eastern Slope site, drought limited seeded species recruitment late in the season and SAP improved seeded species establishment under ambient precipitation. At the Western Slope site, total seedling densities were lower under drought and native seedling densities were lower with�B. tectorum. At the Western Slope site,�B. tectorum�under ambient precipitation had a stronger negative impact on soil moisture at 30 cm depth than drought treatments. Our results suggest that the effectiveness of SAPs is likely affected by antecedent soil moisture and precipitation patterns.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.