In the Antelope Valley of the Mojave Desert, tillage and seeding of native shrubs reduced emissions of fugitive dust from disturbed lands by more than 95 percent, achieving ground cover comparable to surrounding old field successional areas. Wind fences, furrowing across the wind and widely spaced roughness elements were also found to be effective for suppression of fugitive dust emissions. Revegetation by direct seeding was successful in one year with high rainfall but was not reproducible in other years using the same techniques, nor in small plot trials of many species with or without irrigation. Rangeland drilling or broadcast seeding on untilled surfaces were as effective in some years as tillage and seeding, and were less disruptive to natural shrub establishment processes. The use of transplants of nursery-grown native shrubs did not guarantee plant survival and was more expensive than direct seeding. Plant survival exhibited large location effects, attributed to level of previous soil disturbance, which affected bulk density, nutrient status, and microorganism populations. Plastic cones placed over transplants increased plant survival. Land managers should consider minimally disruptive seeding protocols, but should not rely on successful shrub establishment in any given year. Mechanical mitigation strategies such as scattered roughness elements, wind fences or furrowing, provide more rapid and reliable mitigation of fugitive dust emissions, but may be less sustainable than extensive shrub establishment.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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