Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2013
Publication Date: N/A
Technical Abstract: In the last 50 years, the exotic annual grass, Bromus tectorum, has come to dominate rangelands over northern Nevada. Long-term occupation of soil by B. tectorum has the potential to alter soil processes particularly carbon and nitrogen cycles. Using a paired design, we compared surface soil properties (0-5, 5-10 cm) between cheatgrass invaded and nearby similar soil occupied by native vegetation for 9 sites in northern Nevada. Response variables quantified included: total C and N, mineral N, labile C, and soil-solution anions. Pooled over site and depth, soils invaded by B. tectorum had significantly greater total C (1.78 vs. 0.93 %), total N (0.145 vs. 0.080 %), labile C (551 vs. 348 mg kg-1), and solution phase ortho-P (71.6 vs. 36.5 µmol L-1). Mineral N was much higher in soil beneath B. tectorum than soil beneath native vegetation (0.64 vs. 0.36 mmol kg-1), but statistically similar. These data indicated invasion by B. tectorum affects soil C and N cycles relative to native plant communities. Higher levels of labile C in invaded sites suggest faster turnover of C. These data were collected during a below average precipitation year and the study will be duplicated in a more normal year.