Final Report: Impact of Temporal Landcover Changes in Southeastern Idaho Rangelands Fire Effects on Wind Erosion in Sagebrush Steppe Rangelands of the Snake River Plain

Wind erosion of soil is an appreciable but unstudied event following fires in cold desert. We examined aeolian transport of sediment for one year following fire in semiarid shrub steppe of southern Idaho. Sediment collectors were used to determine horizontal mass transport of soil ( ) and saltation sensors and anemometers were used to determine saltation activity (# seconds saltation is detected per 300 seconds) and threshold wind speed in an unburned control site and an area burned in August. Horizontal mass transport (per 30 d periods) was negligible in the unburned area, but in the burned area was 5.40 kg m in October and decreased to 2.80 kg m in November and 0.32 kg m in December. Mean threshold wind speeds were between 10.0 and 10.6 m s at the burned site during fall. A lack of saltation precluded determination of thresholds thereafter at the burned site and for the entire course of the study at the unburned site. Differences in sediment flux and saltation activity at burned and unburned sites became much less pronounced following the emergence of herbaceous vegetation in the spring. Our results indicate that the burned shrub steppe was prone to aeolian sediment transport in the first months following summer wildfire and became less so by early winter, through spring and summer. 1 1 2