Restoration of cheatgrass (Bromus tectorum) invaded rangelands is among the largest management challenges in the Intermountain West. In an effort to reduce the conversion of native sagebrush steppe into annual communities, the Bureau of Land Management reseeds rangelands after fire at very large scales, seeding tens of thousands of acres per year in extreme fire years. These seeding efforts have mixed success.
One factor that may affect the establishment of seeded species in invaded areas is the choice of seeds used in restoration.
We have demonstrated that plants vary in their ability to tolerate competition with cheatgrass, with traits such as seedling root to shoot ratio and the production of fine and coarse roots affecting the survival and performance of native grasses such as squirreltail (Elymus elymoides), big squirreltail (E. multisetus), and sandberg bluegrass (Poa secunda).
This research is comparing the relative performance of native grasses, collected from field sites close to the area to be restored, with commercially-available seeds.
Two types of native seeds will be grown in these experiments: a randomly selected pool of native plants, and a pool of plants that possess traits we have found to be particularly beneficial for surviving in invaded areas. Seeds will be planted in 5 field sites in four states, and survival and growth will be monitored for three growing seasons.
Additionally, seeds will be collected from surviving plants and compared with the original seeding mix to further determine which traits increase survival in invaded systems.
Finally, we will establish an increase garden at UNR for plants collected from Nevada, which will give us the ability to
- test these seeds in realistic rangeland drill seedings in future projects and
- share seeds with collaborators who may be interested in releasing these plants for use in the Great Basin.
Benefits to rangelands will be the potential for improvement of restoration of the most invaded of our Great Basin plant communities.