Title: Landscape-scale rehabilitation of medusahead (Taeniatherum caput-medusae)dominated sagebrush steppe Authors
Submitted to: Journal of Invasive Plant Science and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2013
Publication Date: October 1, 2012
Citation: Sheley, R.L., Vasquez, E., Chamberlain, A., Smith, B.S. 2012. Landscape-scale rehabilitation of medusahead (Taeniatherum caput-medusae)dominated sagebrush steppe. Journal of Invasive Plant Science and Management. 5:436-442. Interpretive Summary: Managing invasive annual grass infestations on a large scale remains a major impediment for successful rangeland restoration. The high cost of treatments with low percentage of success rates often keep managers from initiating management plans where large scale infestations are present. In this experiment we utilized a single entry treatment of herbicide application and seeding on landscape scale plots of medusahead and cheatgrass infested rangeland. We were interested in determining if this method would provide acceptable levels of control for the invasive grasses and establishment of desired species. Our results suggest that the one-pass system may be suitable method for restoring invasive annual grass infestations and lower the cost of treatment by completing an herbicide application and seeding in a single entry into the field.
Technical Abstract: Producers facing infestations of invasive annual grasses regularly voice the need for practical revegetation strategies that can be applied across broad landscapes. Our objective was to determine the potential for scaling-up the single-entry approach for revegetating medusahead (Taenitherum Taeniatherum caput-medusae (L.) Nevski infested rangeland to broader, more heterogeneous landscape-scale revegetation of winter annual-grass infested rangeland. We hypothesized when applied on a highly variable landscape-scale, the combination of imazapic and seeding would provide highest abundance of perennial grasses and lowest amount of annual grasses. Treatment included a control, seeding crested wheatgrass (Agropyron cristatum X desertorum ‘Hycrest’) and Sandberg’s bluegrass (Poa secunda)(at 17.86 kg/ha; spraying imazapic, and simultaneously applied combination spraying and seeding. The treatments were applied to large plots (3.5-25 1.4 to 8 hectares) and replicated five times with each replication located in different watersheds throughout southeastern Oregon. This study shows that the entry approach can be scaled-up to larger landscapes, but variation within established areas will likely be high. This procedure should reduce the costs of multi-entry treatment applications and make revegetating annual grass-infested rangeland across landscapes more affordable.