A systematic review of management efforts on goatgrass (Aegilops spp) dominance.
Goatgrass (Aegilops) species are some of the most aggressive invasive plants in the Western U.S. Despite intense management efforts, goatgrass continues to reduce the ecological and economic integrity of natural and agroecological systems. The mismatch between current research outcomes and practical needs of land managers is likely a result of limitations associated with generalizing from single location, treatment, or season studies. We conducted a systematic review of experiments testing control of two dominant goatgrass invaders (A. cylindrica and A. triuncialis) to identify general patterns in treatment efficiency. Using data from 391 separate experiments, we found that experimental treatments were more successful at controlling the dominance of A. cylindrica compared to A. triuncialis. For A. cylindrica, no treatment demonstrated particular utility for control. Treatment of A. cylindrica in the vegetative stage was more effective for control than treatment at other stages. For A. triuncialis, burning and grazing demonstrated effective overall control among all treatments, although grazing produced variable results. Treatment in the fruiting stage of A. triuncialis was more effective for control than treatment at other stages. For both species, multiple applications of a management treatment within a year resulted in no better control than a single application within a year. Additionally, treatments deployed in two consecutive years resulted in better control of both species, than a treatment deployed in a single year. This work highlights promising avenues for more intensive research on goatgrass weed control and suggests that management funding is most effectively utilized when employed across years rather than focused on a single year.