Restoration of North American Salt Deserts: A Look at the Past and Suggestions for the Future

Abstract

North American salt deserts are typically characterized by slow-growing Atriplex shrubs and perennial grasses with biological soil crusts (BSC) important in shrub interspaces. Disturbance due to heavy livestock use, wildfire, and recreation and energy development has increased the need for restoration of salt deserts in the western United States. However, restoration often fails due to invasive annual species and poor native plant establishment. In addition to a literature review, we surveyed restored salt desert sites in National Conservation Areas and other public lands in western Colorado ranging in age (3–63 yr) and restoration methods to assess approaches that were more or less successful. We used non-parametric ordination techniques to compare plant communities to environmental and restoration explanatory variables. Restored communities tended to move toward reference condition over time, but soil type, seeding, and type of disturbance also influenced plant community recovery. Overgrazed sites passively restored by long-term livestock exclusion were most similar to reference sites, while sites affected by wildfire and soil-related disturbances were most different from reference with non-native invasive annual grass (primarily Bromus tectorum) and forbs being common. These undesirable species were also more abundant on seeded sites than non-seeded or references sites, although mixes with a higher proportion of native species tended to improve outcomes. Results suggest that disturbance type and management approaches can have a large impact on restoration success in Intermountain West salt deserts, though many questions require further research.