UC Davis

Weedy species invasions are a huge problem in rangeland and natural areas as they degrade the quality and quantity of forage for livestock and reduce biodiversity. Weed suppression using native grasses is an ecologically driven method of weed management, representing an opportunity for low-input and management over long temporal scales if these systems can be successfully established. A systemic literature review was conducted to explore the interactions between native grasses and weeds, and revealed the potential of native grasses to provide a reduction in weed presence through interactions with other biological communities. We proposed the merging of agronomic and breeding techniques with restoration efforts such as using specialized seeding techniques to establish native grasses in these systems. A generalized planning framework for land managers is also presented, emphasizing the consideration of functional traits for competitive advantage against weeds and germplasm availability as the main considerations for species selection. Management strategies that provide advantages to native grasses such as land clearance and strategic disturbances were also discussed. Suppression can occur through a variety of mechanisms including direct competition with weeds, indirect interactions through trophic levels of arthropods and grazers, and human-induced disturbances. From our results, we believe that native grasses can potentially play an important role in efficacious weed suppression if utilized tactfully.