2012 Annual Report
2) Determine if crested wheatgrass displaces native vegetation from plant communities.
Sampling: Management history will be determined from historic records and personal knowledge of the land manager. Management history that will be collected includes year established, method of seeding, kind of brush control used, grazing history, and additional disturbances.
Vegetation characteristics will be determined using 60 x 50 m plot to sample each site. Four 50 m transects will be deployed at 20 m intervals along the 60 m transect. Herbaceous vegetation cover and density will be visually estimated by species inside 40 x 50 cm frames located at 3 m intervals on each transect line (starting at 3 m and ending at 45 m), resulting in 15 frames per transect and 75 frames per plot. Shrub canopy cover by species will be measured by line intercept (Canfield 1941). Canopy gaps less than 15 cm will be included in the canopy cover measurements. Shrub density will be determined by counting all rooted individuals in five, 2 X 50 m belt transects at each plot.
Soil texture, water holding capacity, pH, and profile description will also be collected at each site. Topographical position, aspect, elevation, and slope will be recorded at each site.
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. Crested wheatgrass and native perennial bunchgrass cover will be measured in 15 randomly placed 0.2m2 frames in each plot. Density will measured across the entire plots to be able to compare to density in 1989.