Effects of post-wildfire mechanical seeding on soil in WY big sagebrush

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Here, we compared the effects of mechanical seeding techniques on soil properties following two wildfires occurring in similar climates with contrasting soil textures (silty loam and gravelly loam soils). Using either a rangeland or minimum-till drill to create furrows or mix broadcasted seeds into soils, we quantified wind erosion risk for unburned sites, burned nonseeded sites, and seeded sites according to soil aggregate stability, horizontal sediment flux, surface microtopography, and soil compaction. Effects of mechanical seeding were small relative to those created by wildfire. For burned areas, differences in site stability were greatest between sites. Following wildfire, the largest decrease in site stability occurred in fine-textured soils, where horizontal sediment transport was increased by nearly five orders of magnitude relative to unburned areas. Despite these initial differences, site stability in fine-textured soils may have improved to a greater degree than stability at the coarse-textured site. Furthermore, we found minimal differences between drill types on site stability but, instead, observed that the largest differences in soil properties were created by furrow versus broadcast seeding. The different outcomes of rehabilitation on site stability found here, paired with the spatial extent to which wildfire affects landscapes, highlights the importance of postfire monitoring of site stability in more locations that vary by soil, plant, landscape, and climatic variables.