Revegetation Controls Dust in Antelope Valley

 

Helicopter Seeding of Barren Desert Areas

A long drought in the 1980s had reduced vegetation cover in Antelope Valley in the western Mojave Desert. Dust storms had wiped out crops and forced farmers to reseed fields repeatedly. Suspended soil had blown into Lancaster, Palmdale and surrounding rural areas, causing unhealthy levels of airborne particulate matter. Reduced visibility had caused traffic accidents and disrupted operations at military facilities. Exacerbating matters, wind erosion had increased the barren areas.

 

 
Beginning in early 1992, a collaborative effort of UC Cooperative Extension (UCCE), USDA Soil Conservation Service (now Natural Resources Conservation Service), the Los Angeles County Fire Department, the Antelope Valley Resource Conservation District and local air pollution districts instituted a massive revegetation campaign. Seeds were flown in by fire department helicopters and planted on 2,500 acres by local contractors. Throughout the 1990s, UCCE conducted plant density measurements to identify the most successful native shrub species. UCCE planted replicated trials of alternative revegetation practices to determine optimal seeding and transplanting techniques and to identify ways to reduce revegetation costs. Combination strategies of revegetation and wind-fencing were developed, and UCCE measurements validated their ability to suppress dust emissions.
 

 
The 300,000 or so residents of the area obtained more healthful air to breathe, farmers experienced fewer problems, and dust-related traffic accidents declined. Maximum daily particulate matter concentrations in Lancaster declined from 780 micrograms per cubic meter of air in 1991 to an average of 75.6 during the next 10 years, with many fewer instances in which state and federal air quality standards were exceeded. Drought conditions returned in the mid-1990s, but the revegetation held the soil in place.
 

Supporting Unit: UCR Botany and Plant Sciences Dept. and Kearney Agricultural Center
 
David Grantz
UC Riverside, Botany & Plant Sciences
Kearney Agricultural Center
9240 S. Riverbend Avenue, Parlier, CA 93648
559-646-6599 (Voice)
559-646-6593 (Fax)
david@uckac.edu