ARS | Publication request: Simulating Effects of Cheatgrass Invasion on Native Bunchgrass Productivity Under Different Precipitation Scenarios

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 2009
Publication Date: February 7, 2010
Citation: Johnson, M., Kiniry, J.R., Weltz, M.A., Spanel, D.A., Finzel, J., Launchbaugh, K., Rodriguez-Barahona, L., Rollins, K. 2010. Simulating Effects of Cheatgrass Invasion on Native Bunchgrass Productivity Under Different Precipitation Scenarios [abstract]. Society for Range Management and Weed Science Society of America Annual Meeting Program Guide. O-103.

Technical Abstract: Preventing the spread of cheatgrass is a high priority for natural resource managers in the western United States. Cheatgrass invasion is deleterious in numerous ways, including diminishing local biodiversity, increasing fire risks, and lowering carrying capacity. Because management is expensive, it is important to direct post-invasion eradication efforts to areas where they have the most chance of success, and direct pre-invasion efforts to areas under the highest threat of invasion. The Agricultural Land Management Alternatives with Numerical Assessment Criteria model (ALMANAC) is capable of realistic simulation of interspecies competition as well as process-based simulation of the water balance and nutrient balance of competing species, factors that influence species success and productivity. ALMANAC is an assessment tool being utilized in the Rangeland Conservation Effects Assessment Project (R-CEAP). In this project, we simulated cheatgrass productivity and bunchgrass productivity across multiple years at sites in Idaho, Nevada, and Utah. We further considered how prolonged drought periods or prolonged wet periods might influence cheatgrass persistence and success. We compared results to those reported in the Natural Resource Conservation Service (NRCS) ecological site productivity for these sites. This report of preliminary results demonstrates the potential usefulness of ALMANAC for predicting cheatgrass infestation potentials in this region, which should lead to better management strategies.