Reestablishing cold-desert grasslands: A seeding experiment in Canyonlands National Park, Utah
Proceedings: Wildland Shrub and Arid Land Restoration Symposium
U.S. Department of Agriculture, Forest Service, Intermountain Research Station
Eighteen different treatments were applied to an area seeded with the native grasses Stipa comata and S. (Oryzopsis) hymenoides. Plots received supplemental water up to annual rainfall levels. Treatments included 30% cover of native grass mulch (Hilaria jamesii); nitrogen and phosphorus fertilizer; cyanobacterial inoculant from an adjacent, undisturbed area; sugar (to stimulate microbial activity); no water; and various combinations of these treatments. Plots were evaluated one year later for number of grass seedlings established, number of grass seedlings eaten, and cover and biomass of the exotics Salsola kali and S. iberica. Different treatments resulted in strikingly different establishment rates of the seeded grasses, with any treatment using mulch having only 15 to 25% as many seedlings as the most successful treatment. Fertilized plots tended to have fewer seedlings as well. Sugar, by limiting nitrogen availability, was effective at reducing Salsola biomass and cover, as well as in encouraging perennial seedling establishment. Salsola cover had a small negative effect on total Stipa plants present. However, herbivory was significantly reduced for Stipa plants growing in Salsola canopies. Consequently, biomass was enhanced in plots with Salsola. In spite of precipitation during the growing season being below the 50-year average, plots without supplemental water did as well as those with supplemental water. As measured by overall native plant establishment, the most successful treatments were seed only (with and without supplemental water), the combination of sugar and springspread cyanobacteria, and native grass straw mixed in with fallspread cyanobacterial inoculant.
Belnap, J., and Sharpe, S., 1995, Reestablishing cold-desert grasslands: A seeding experiment in Canyonlands National Park, Utah, in Roundy, B. A., McArthur, E. D., Haley, J. S., and Mann, D. K., eds., Proceedings: Wildland Shrub and Arid Land Restoration Symposium, October 19- 21, 1993, Las Vegas, Nevada, General Technical Report No. INT-GTR-315: Ogden, Utah, U.S. Department of Agriculture, Forest Service, Intermountain Research Station, p. 46-51.