1a.Objectives (from AD-416)
Provide BLM with a decision matrix to be utilized in selecting treatment protocol to increase native diversity in three-awn dominated plant communities.
1b.Approach (from AD-416)
Examine the effects of fire and nitrogen addition on three-awn dominated communities. Increased nitrogen availability will likely improve the ability of other species to establish and compete with three-awn. Late growing season fire should be detrimental to red three-awn because of the plant's growth pattern and bunchgrass habit. Treatments will be combinations of fire vs. no fire and nitrogen addition vs. no nitrogen addition and assigned in a completely randomized design with factorial arrangement and replicated 5 times. Treatment effects will be evaluated by measuring standing crop, plant species composition and plant diversity before treatment and 2 years post-treatment.
First-year post-treatment data have been collected. Pre-treatment data have been collected for the repeated experiment and sites are ready for BLM treatment application late in FY2011. Simulated grazing treatments have been applied to determine utilization effects on three-awn and coexisting species and half of the laboratory analyses of fire and fertilizer effects on three-awn diet quality have been conducted. This project supports NP 215 Rangeland, Pasture and Forages Action Plan under Component I (Rangeland Management Systems to Enhance the Environment and Economic Viability) and supports ARS strategic plan Objective 5.1 (Provide Science-Based Knowledge and Education To Improve the Management of Forest, Rangelands, and Pastures). More specifically, experiments in this project target the following objectives of the NP 215 Action Plan: A.2, Determine impact of livestock grazing, fire, mechanical treatments, and drought on ecological integrity and watershed structure and function; and Objective C.1, Understand mechanisms of weed invasion and develop management strategies that can be used to restore rangelands that have been degraded by weeds and other disturbances.