Spatial patterns and controls on wind erosion in the Great Basin

Authors: TREMINIO, RONALD - New Mexico State University; Webb, Nicholas - Nick; EDWARDS, BRANDON - New Mexico State University; FAIST, AKASHA - University Of Montana; Newingham, Beth; KACHERGIS, EMILY - Bureau Of Land Management

Submitted to: Journal of Geophysical Research-Biogeosciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2023
Publication Date: 1/8/2024
Citation: Treminio, R.S., Webb, N.P., Edwards, B.L., Faist, A., Newingham, B.A., Kachergis, E. 2024. Spatial patterns and controls on wind erosion in the Great Basin. Journal of Geophysical Research-Biogeosciences. 129(1). Article e2023JG007792. https://doi.org/10.1029/2023JG007792.
DOI: https://doi.org/10.1029/2023JG007792

Interpretive Summary: The Great Basin in the western United States is experiencing increasing disturbances due to wildfire exacerbated by the invasion of non-native plant species, which can potentially accelerate wind erosion. We used a wind erosion and dust emission model to identify regions in the Great Basin susceptible to wind erosion. We investigated the relationship between indices of plant cover and amount of bare ground that control wind erosion to the outputs from the wind erosion model. Lastly, we investigated how wildfire frequency and invasive plant species cover were related to the probability of wind erosion in the Great Basin. We found areas with large wind erosion rates were in dry, low elevation areas, with large bare gaps between plants. High total foliar cover resulted in low magnitudes of wind erosion. The number of repeat wildfires and increasing invasive plant species cover reduced the probability of wind erosion. However, post-fire wind erosion can be extremely high in areas with invasive annual grass cover. We demonstrated the complex interactions among plant cover and composition, wildfire and wind erosion in the Great Basin.

Technical Abstract: The Great Basin of the western United States is experiencing dramatic increases in wildfire and Bromus species invasion that potentially accelerate wind erosion and plant community change. We used a wind erosion model parameterized for rangelands and standard ecological monitoring data sets collected at 10,779 locations from 2011 to 2019 to characterize potential wind erosion in the Great Basin, assess relationships between factors affecting wind erosion, and quantify effects of wildfire and invasive Bromus species on aeolian horizontal sediment flux, Q. There were 403 monitoring plots (~3.7% of plots) with Q > 100 g m-1 d-1. Median values for the highest Q category (>100) ranged from 196.5 to 308.5 g m-1 d-1. Locations with Q > 100 g m-1 d-1 were associated with dry, low elevation areas of the Great Basin with low perennial grass and perennial forb cover, and with large bare gaps between plants. Areas with high perennial grass, perennial forb, and shrub cover had small Q (=10 g m-1 d-1). Substantial wind erosion was predicted in areas that have experienced wildfires, but areas with multiple wildfires had a lower predicted probability of Q particularly as invasive Bromus species cover increased. Modeled Q was up to two orders of magnitude higher post-wildfire (median 44.2 g m-1 d-1) than in intact or annual grass-invaded regions of the Great Basin (median 0.4 g m-1 d-1). Our results reveal the complex interplay among plant community composition, wildfire, and the amount of bare ground controlling wind erosion on Great Basin rangelands.