|Nafus, Aleta - Oregon State University|
|Ganskopp, David - Retired ARS Employee|
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2014
Publication Date: 5/6/2015
Publication URL: http://handle.nal.usda.gov/10113/60851
Citation: Nafus, A.M., Svejcar, A.J., Ganskopp, D.C., Davies, K.W. 2015. Abundances of coplanted native bunchgrasses and crested wheatgrass after 13 years. Rangeland Ecology and Management. 68(2):211-214. doi: 10.1016/j.rama.2015.01.011.
Interpretive Summary: There is substantial interest in establishing native plants in crested wheatgrass, an introduced bunchgrass, dominated plant communities, but little is known about the long-term dynamics of co-planted crested wheatgrass and native species. We evaluated the abundance of crested wheatgrass and seven native bunchgrasses 13 years after being co-planted at equal densities in nine plots. Crested wheatgrass became the dominant bunchgrass species with a ten-fold increase in density. About half of the native bunchgrass species maintained their original densities and the other half decreased over the 13 years. Our results suggest that densities of native bunchgrasses planted with crested wheatgrass are unlikely to increase and that some species may only persist at low levels. The high recruitment of crested wheatgrass suggests that it is likely a good choice to seed after disturbances in areas at risk of exotic plant invasion.
Technical Abstract: Crested wheatgrass (Agropyron cristatum [L] Gaertm) has been seeded on over 5 million hectares in western North America because it more readily establishes than native bunchgrasses. Currently, there is substantial interest in re-establishing native species in sagebrush steppe, but efforts to reintroduce native grasses into crested wheatgrass stands have been largely unsuccessful, and little is known about the long-term dynamics of crested wheatgrass/native species mixes. We examined the abundance of crested wheatgrass and seven native sagebrush steppe bunchgrasses planted concurrently at equal densities in non-grazed and unburned plots. Thirteen years post-establishment, crested wheatgrass was the dominant bunchgrass, with a ten-fold increase in density. Idaho fescue (Festuca idahoensis Elmer), Thurber’s needlegrass (Achnatherum thurberianum (Piper) Barkworth), and Sandberg bluegrass (Poa secunda J. Presl) maintained their density, whereas bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A. Löve), needle-and-thread (Hesperostipa comata (Trin. & Rupr.) Barkworth), squirreltail (Elymus elymoides (Raf.) Swezey) and basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Löve) densities declined. Our results suggest that densities of native bunchgrasses planted with crested wheatgrass are unlikely to increase and that some species may only persist at low levels. The high recruitment of crested wheatgrass suggests that it might be a good choice to seed after disturbances in areas at risk of exotic plant invasion.