Relative performance of native cultivar and wild collected seed for grassland restoration

Abstract

Availability of native plant materials for grassland restoration is limited. Even when available in sufficient quantities for ecological restoration projects, seed germination and establishment in relatively arid environments is often low. Poor revegetation results in soil erosion, invasion by non-native plant species and reduced aesthetics. Therefore, development and use of native plants bred for traits favourable for restoration should be considered. This study addressed whether native cultivar seed, commercially selected for advantageous growth characteristics, could improve native grass species reestablishment relative to wild collected seed. Cultivar and wild seed types of four cool season native grass species were investigated at three foothills fescue grassland reclamation sites: Bromus carinatus (mountain brome), Elymus trachycaulus (slender wheatgrass), Festuca idahoensis (Idaho fescue) and Koeleria macrantha (June grass). Seeding and transplanting were conducted and germination, emergence, density, height and health were determined from 2011 to 2013. No significant differences were detected between cultivar and wild seed types except laboratory germination, which was greater in the Elymus trachycaulus cultivar and in the wild collected Koeleria macrantha. Bromus carinatus performed poorly as a seedling from either seed type. Consistent trends in cultivar and wild seed performance, that reflected seed germination, were found for each species although results were not significant due to high variability. Results show that for these common grass species, seed type may not influence initial establishment. Differences among species were significant and varied with response measured, suggesting species characteristics are a key factor affecting native grass reestablishment. Species specific responses to seed type highlight the importance of making seed source decisions on a species basis.