Start Date: Jan 31, 2008
End Date: Jan 30, 2013
The planned research is designed to improve sustainability of rangeland production by addressing the interacting effects of disturbances on stability and integrity of rangelands and efficiency of livestock nutrient conversion. Objectives are to: 1) Develop strategies and decision tools to proactively manage livestock grazing, fire, and drought impacts on Great Plains community structure and function; 2) Improve animal productivity and product quality based on predicted nutrient intake, forage dynamics, and diet selection processes in the northern Great Plains; and 3) Develop management strategies to restore rangelands degraded by weeds and prevent weed invasions in the northern Great Plains. Experiments are integrated across objectives and will determine the interacting effects of grazing, fire, drought, and invasive plants on plant communities (production, species composition, diversity, heterogeneity, propagation, and survival) and the effects of changes in vegetation and animal physiology on livestock (weight gain, distribution, diet quality, diet selection, diet diversity, foraging efficiency, forage intake, and rumen microbial diversity). Two experiments are replicated across three locations (Miles City, MT, Nunn, CO and Woodward, OK) to determine ecological ramifications of fire seasonality, return interval, and grazing interactions in semiarid rangelands on a north-south gradient across the western Great Plains. Understanding the mechanisms that control disturbance effects on rangelands and animal responses to alterations in the plant community will promote development of proactive management strategies for improved stability in rangelands and rangeland livestock production systems.