Get reliable science

Using seeding to restore degraded rangelands of the northern Great Plains is a major challenge.� Often, seeded species fail to establish and areas remain/become dominated by downy brome and other unwanted plants.� Even where some seeded species establish, species diversity is typically low, and big sagebrush and other shrub are nearly nonexistent.� We gathered vegetation data on >350 seeded fields on nine strip coal mines in Wyoming and Montana and then paired these vegetation data with management (e.g. seeding rate) and environmental (e.g. 1st growing season precipitation) data in order to better understand factors regulating seeding outcomes.� We found seeding aggressive, cool-season grasses, such as western wheatgrass and green needlegrass, reduced annual weed cover.� These grasses became similarly abundant whether sown at low or high rates, so low rates could likely be safely used to reduce seed costs.� More importantly, reducing grass seed rates reduced the onset of intense grass competition and thereby increased cover of shrubs, the plants most difficult to restore to our system.� Grass competition had the potential to be so intense that seeded shrubs established at higher densities in dryer-than-average years, presumably because dry conditions reduced seeded grass establishment and competition.� These results point to cost-effective management strategies that could be used to improve restoration outcomes in mixed grass prairie.� In addition to our large-scale observational study, we briefly discuss a study strategically using seed mix diversity to buffer seeding outcomes against weather variation.