Start Date: Apr 14, 2008
End Date: Apr 13, 2013
Subobjective 1.A. CTE imagery will be collected in 2 yr before and after grazing to determine whether this imagery can be used to accurately assess changes in vegetation due to grazing. The CTE method will be compared with more conventional methods. VLSA imagery will be collected at several scales from pastures that differ with respect to burning and postfire grazing rest to determine the efficiency and degree of specificity that vegetation classification can be accurately made with this methodology. Likewise the VLSA method will be compared with conventional methods. Subobjective 2.A. Prescribed fire in the spring, fall, or an unburned control will be the main plot treatments, and the burns will cause a shift in vegetation composition for the mountain big sagebrush community at the research location. Following the fire disturbances, different periods of postfire grazing rest will be imposed on subplots which may alter the rate of succession toward the preburned state for the burned main plots. Measurements of soil erosion due to wind and simulated rainfall, soil nutrient dynamics, and plant productivity, and animal productivity and behavior will be measured in each burn/postfire grazing rest treatment combination to determine what effect the resulting shifts in vegetation composition have on ecological function of this plant community. Subobjective 2.B. Data from Subobjective 2.A and other collaborators' data will be used to develop parameterization algorithms for RHEM. Multiple regression techniques will be used to develop algorithms that utilize plant and soil characteristics to estimate soil erodibility and hydraulic roughness. Subobjective 2.C. Sheep will be bedded on bedgrounds at our summer range. Measurements of infiltration, erosion, and runoff water quality will be measured from three treatments. The three treatments will be within the bedground and bedded in the measurement year, within the bedground but not bedded in the measurement year, outside the bedground in a similar site but only grazed in the measurement year.