A variety of public and private land agencies have attempted to restore salt deserts following natural disturbances such as wildfire or drought in the western U.S. over the past 50 years, but with limited success. New Colorado State University research demonstrates that a delicately balanced approach is essential for the future of restoring these extreme environments in the western U.S.
Salt deserts, which comprise large swaths of land found in Utah, Nevada and the Four Corners area, are uniquely harsh environments with hot summers, cold winters and minimal precipitation, all factors that create a difficult environment for plant life. The unusually high salt content in the soil intensifies water stress on plants and limits their growth even further. It may take decades for these areas to recover enough from disturbances like wildfire and overgrazing to be used for recreation and livestock grazing.
Jayne Jonas-Bratten, a research scholar in the Forest and Rangeland Stewardship department, led a review article recently published in the journal Ecological Restoration. Her team found that successful restoration includes multiple factors found both above and below ground in these areas.
“What makes restoration more challenging in this system, is that ‘natural’ conditions don’t really exist anymore,” said Jonas-Bratten. “One of the challenges with this project was to recognize that different types of disturbance vary in their impacts on salt desert systems.”
Her research team reviewed past restoration research and government reports to understand the current state of salt desert restoration. They also collected their own data across 19 salt desert sites on the Western Slope of Colorado. Sixteen of these sites had restoration work previously done on them, while three were untreated reference sites. Along with vegetation measurements, they analyzed the results of seeding methods, rates, and mixture compositions from previous restoration records.
“By combining a literature review with on-the-ground measures of sites the Bureau of Land Management has restored over the years, we were able to determine what recommendations from the past actually worked,” said Mark Paschke, a co-author on the study and Warner College Research Associate Dean.
Based on their results, the team made recommendations aimed at improving restoration success of salt deserts in the future. These include planting diverse seed mixtures from a variety of native plants, using shrub transplants, performing revegetation during years of predicted above average precipitation, and pre-treating sites to remove or reduce competing non-native plants. Careful livestock management in restoration areas, along with replicating and recording treatments, can also help achieve more successful outcomes.
They found that severe soil disturbance especially makes seeding efforts difficult to establish. Additional projects the team is conducting with the BLM will look at plant species in soil seedbanks of disturbed and reference sites. If native seeds are found in the soil after a disturbance, restoration efforts could focus on providing the environmental conditions native plant communities need to reestablish in salt deserts.