A 16-year case study of bluebunch wheatgrass and Snake River wheatgrass plant materials in Idaho’s Snake River Plain

Abstract

While plant material releases have typically undergone some level of testing, long-term comparisons and evaluations are relatively few. Understanding long-term environmental adaptation of species and plant releases is critical for achieving persistent site restoration and rehabilitation. Idaho NRCS established a multi-species display nursery in the semi-arid Snake River Plain at Orchard, Idaho, in 2004. The display nursery included 9 entries of bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) Á. Löve [Poaceae]) and 4 entries of Snake River wheatgrass (Elymus wawawaiensis J. Carlson & Barkworth [Poaceae]), which were evaluated yearly for plant density from 2005 through 2008, and again in 2021. In this non-replicated case study, we found several bluebunch and Snake River wheatgrass accessions and releases adapted to local site conditions while not being of local origin. Our observations further support the commonly accepted belief that Anatone bluebunch wheatgrass is better adapted to lower precipitation areas than ‘Goldar’. We did not see evidence that Snake River wheatgrass was more drought tolerant than bluebunch releases at the Orchard study site, but rather, we saw significant variation among releases or accessions of each species.