A fundamental question in arid land management focuses on understanding the long-term effects of fire on desert ecosystems. To assess the effects of fire on surface topography, soil roughness, and vegetation, terrestrial (ground-based) lidar was used to quantify the differences between burned and unburned surfaces by creating a series of high-resolution vegetation structure and bare-earth surface models for six sample plots in the Grand Canyon-Parashant National Monument, Arizona. Eleven years after prescribed burns, mound volumes, plant heights, and soil-surface roughness were substantially lower on burned plots than on unburned plots. Results also suggest a link between vegetation and soil mounds, either through accretion or erosion mechanisms such as wind and/or water erosion. The biogeomorphic implications of fire-induced changes are important. Reduced plant cover and altered soil surfaces from fire likely influence seed residence times, inhibit seed germination and plant establishment, and affect other ecohydrological processes.
Optech terrestrial lidar scanner overlooking a fenced study plot in the Grand Canyon-Parashant National Monument, Arizona.