Location: Rangeland Resources & Systems ResearchTitle: Induced biological soil crust controls on wind erodibility and PM10 emissions
|FICK, STEPHEN - Us Geological Survey (USGS)|
|BARGER, NICHOLE - University Of Colorado|
|DUNIWAY, MICHAEL - Us Geological Survey (USGS)|
Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2019
Publication Date: 1/24/2020
Citation: Fick, S.E., Barger, N., Tatarko, J., Duniway, M. 2020. Induced biological soil crust controls on wind erodibility and PM10 emissions. Earth Surface Processes and Landforms. 45:224-236. https://doi.org/10.1002/esp.4731.
Interpretive Summary: Biological organisms such as mosses, lichens, algae, and bacteria can form patches of crust on the soils of drier regions. These biological crusts can protect soil surfaces from wind erosion, and promoting their development is emerging as a way to restore sites disturbed by human and animals. Using a portable device, we evaluated dust emissions from surfaces with either added biological soil crust, a plant-based soil stabilizer, or both at varying simulated wind speeds. After only four months, we found that combinations of added biological crust plus stabilizer provided greater wind erosion resistance, resulting in nearly twice as much dust reduction than either of the treatments alone. When biological crust plus stabilizer was added, dust production did not differ from the untreated flat, soil-crust covered control areas, even though treated areas had greater surface roughness and captured windblown sediment over the four-month establishment period. We show how erodible sediment changes with increasing wind and the added controls, and how occasionally observed spikes in fine dust may be related to dislodged biological soil crust aggregates striking the surface. The relatively rapid soil-building activity and improved stability of the added biological crust and soil stabilizer mixtures provide a promising method for dryland dust control.
Technical Abstract: Promoting the development of biological soil crusts (biocrusts) remains an appealing restoration approach in drylands due to the resistance biocrusts can provide against erosion. Using a portable device, we evaluated dust emissions from surfaces either inoculated with biocrust, amended with a plant-based soil stabilizer, or both at varying wind friction velocities. Only four months after application, we found that combinations of inoculant and stabilizer provided greater erosion resistance than either of the treatments alone, resulting in a nearly 2-fold reduction in estimated emissions across simulations. Emissions from inoculum-with-stabilizer plots did not differ from the flat, physical-crust covered control plots, even though treated plots had greater surface roughness and captured windblown sediment over the four-month establishment period. We show how available erodible sediment limitation shifts with increasing friction velocity and treatment, and how occasionally observed spikes in PM10 concentration may be related to dislodged biocrust aggregates striking the surface. The relatively rapid soil-building activity and enhanced integrity of biocrust inoculum and soil stabilizer mixtures provides a promising methodology for dryland dust mitigation.