Renovating cool-season rangelands: A comparison of five restoration techniques. Hendrickson, John ^*,1, Hanson, Jon¹, Liebig, Mark¹, Johnson, Holly¹, ¹ USDA-ARS, Mandan, North Dakota

ABSTRACT- Renovating rangelands in the Northern Great Plains can present special challenges since often both native vegetation and the invaders are cool-season perennial grasses. A project was initiated near Mandan North Dakota to evaluate the effectiveness of different restoration techniques in altering species density on a 40-acre rangeland invaded by cool-season perennial grasses. Ten sites were selected and 5 treatments and a control were randomly applied to 10 x 20 m plots within each site. Treatments were: 1) control, 2) late-April burn, 3) late-April burn followed by application of imazapic, 4) spring application of imazapic, 5) spring mowing and 6) a spring mowing followed by litter removal. Three 1/8 m quadrats were established in each plot and the total number of tillers of smooth bromegrass, Kentucky bluegrass, other invaders and native grasses and forbs were counted in the fall of 2002 and used to determine species composition. This was repeated in July 2003. Percent smooth bromegrass increased in all the treatments during this time period except for the raking treatment while percent Kentucky bluegrass was reduced in all treatments and the control. Burning plus imazapic application significantly increased the percent of native grasses in the species composition compared with application of imazapic only, mowing and the control. Burning plus imazapic appeared to reduce productivity of the site. Data collection is continuing on this project to further evaluate the impact of treatments on species composition and productivity.

KEY WORDS: Bromus inermus , Fire, Poa pratensis