Restoring native plants to crested wheatgrass stands

Abstract

Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a nonindigenous grass introduced to North America for improving degraded rangelands. It is often criticized for forming nearly monotypic stands. Our objective was to determine the feasibility of restoring native plant species to crested wheatgrass-dominated rangeland. We investigated methods for suppressing crested wheatgrass followed by revegetation with a mix of native species. We tested five suppression treatments: undisturbed, low rate of glyphosate (0.25x recommended rate), high rate of glyphosate (recommended rate), 1-pass mechanical (disked once), and 2-pass mechanical (disked twice). Procedures were repeated in two trials in separate years. We sampled density and canopy cover of crested wheatgrass and density of seeded species for three (trial 1) and two (trial 2) years. Mechanical treatments increased crested wheatgrass density by 30-50%, whereas most other treatments were similar to the undisturbed (6.8 plants/m2). Crested wheatgrass cover decreased in mechanical and full herbicide treatments in trial 1 and was variable across treatments in trial 2. Seeded species density in all treatments (29 plants/m2) was greater than in the undisturbed treatment (18 plants/m2) 1 year after seeding in trial 1 and was similar across treatments (26 plants/m2) in trial 2. By the end of the study, though, all treatments resulted in similar seeded species density (

Citation

Fansler, Valerie A.; Mangold, Jane M. 2010. Restoring native plants to crested wheatgrass stands. Restoration Ecology. doi 10.1111/j.1526-100X.2010.00678.x