1a.Objectives (from AD-416)
1) Determine what factors (management, site/environmental characteristic, etc) promote native plant recruitment in crested wheatgrass plant communities.
2) Determine if crested wheatgrass displaces native vegetation from plant communities.
1b.Approach (from AD-416)
To accomplish the first objective, we propose to sample 100 crested wheatgrass plant communities across the northern Great Basin to determine what factors promote native plant recruitment in crested wheatgrass plant communities. Private and public land managers will be contacted to locate near-monoculture of crested wheatgrass and crested wheatgrass with native vegetation recruitment. Site, environmental, and management characteristics will be collected to determine their relationships with native plant recruitment into crested wheatgrass communities.
To determine if crested wheatgrass displaces native vegetation we will measure the densities and cover of perennial bunchgrasses in plots established in 1989 with specific densities of crested wheatgrass and seven native perennial bunchgrasses. Eight plots will be used to determine if crested wheatgrass density has increased and native perennial bunchgrass densities have decreased since the plots were established.
ARS scientists in Burns, OR sampled plots established in 1998 that had known densities of crested wheatgrass and seven native perennial bunchgrasses in 2010. We presented the results of this sampling at the 2011 Society for Range Management Meetings in Billings, Montana. We sampled these plots again in 2011. We have also been locating crested wheatgrass seedings across south eastern Oregon, but will not sample these seedings until next summer. These seedings will be used to determine what factors promote native vegetation recruitment.