Factors mediating cheatgrass invasion of intact salt desert shrubland

Abstract

Cheatgrass (Bromus tectorum) has recently displaced salt desert shrubland in many areas of the Great Basin. We studied the dynamics of cheatgrass invasion into an intact shadscale-gray molly community in Dugway Valley, Utah, by adding seeds and manipulating disturbance regime and resource availability. Shrub clipping or cryptobiotic crust trampling on large plots increased cheatgrass recruitment and biomass production slightly in a favorable moisture year (1997 to 1998), whereas in a less favorable moisture year (1998 to 1999) these disturbance treatments had a significant negative effect. In 1998 to 1999 small plot studies, recruitment was similar in intact shrub clumps and openings, but biomass and, therefore, seed production was three times greater in shrub clumps. Disturbance decreased recruitment but had no significant effect on biomass per plant. Added water had no effect in openings, but added N increased and reduced N decreased biomass. In shrub clumps, fertility manipulation had little effect, but added water increased biomass.

Parent Publication

• Shrubland ecosystem genetics and biodiversity: proceedings

Citation

Meyer, Susan E.; Garvin, Susan C.; Beckstead, Julie. 2001. Factors mediating cheatgrass invasion of intact salt desert shrubland. In: McArthur, E. Durant; Fairbanks, Daniel J., comps. Shrubland ecosystem genetics and biodiversity: proceedings; 2000 June 13-15; Provo, UT. Proc. RMRS-P-21. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 224-232.