The good, the bad, the salty: Investigation of native plants for revegetation of salt-impacted soil in the northern Great Plains, United States

Salt-impacted soils are formed through anthropogenic or natural causes. In the northern Great Plains region of North America, salts that occur in the soil parent materials move upward through the soil profile due to changing land-use and precipitation regimes. If these salts accumulate in the surface soil layer, they impact the ecological integrity of a site, creating the need for ecological restoration. Common methods for addressing salt-impacted soil were developed in the irrigated soils of the southwestern United States and are often ineffective in noncrop areas and the northern Great Plains due to differences in soil properties, elevated gypsum concentrations, and poor soil drainage. Therefore, the objective of this study was to identify native plant species suited for revegetation in salt-impacted soils in the northern Great Plains region of North America. This field study evaluated the survival and performance of eight native plant species in soils with high, medium, or low salt concentrations. Survival was evaluated at summer and end-of-season sampling (five months total) and performance variables (plant height, basal diameter, number of flowering heads, number of tillers/stems, and aboveground biomass) were evaluated at end-of-season sampling. Seven of the eight species evaluated exhibited some salt tolerance and could be suitable for the revegetation of moderately salt-impacted soil. Overall, Asclepias speciosa, Gaillardia aristata, and Helianthus maximiliani grew in minimally salt-impacted soils, whereas Elymus canadensis, Elymus trachycaulus, and Pascopyrum smithii grew in moderately salt-impacted soils, and only Sporobolus airoides grew in highly salt-impacted soils. As these native plants establish and grow, they will spur autogenic recovery by stabilizing soil structure and improving water movement in the soil. These results indicate that salt tolerance must be considered when selecting species that could revegetate these areas.