Mima Mounds, Crust & Fire
Document Type
Poster
Event Website
https://source2022.sched.com/
Start Date
16-5-2022
End Date
16-5-2022
Keywords
Geology, Fire, Biology
Abstract
In September 2020 the Evans Canyon Fire partially burned areas on Umtanum ridge south of Ellensburg, Washington. In the burn area are mima mounds, a geologic formation composed of piles of silt about one meter tall and 5-50 meters across that occasionally have rock rings around the base. We conducted a pilot study to look at the potential relationships between the fire and biological soil crust (BSC) coverage on mounds and intermounds. BSC is a layer composed of small organisms such as algae and mosses that forms on top of soils in our climate. We hypothesized that BSC coverage would be greater on mounds than intermounds, and that crusts would be disproportionately affected by fire across mounds and intermounds. We took photographs of the crust in a 1 by ¼ meter quadrat frame, then analyzed the image through the program ‘SketchandCalc’ to determine the percent area covered by BSC within the frame. Results showed that burnt intermounds had the greatest BSC coverage, while unburnt intermounds had the least. Data additionally suggest that intermound BSC is more strongly affected by fire, but since many of the unburnt mounds were too covered with other vegetation to accurately measure the BSC coverage, the significance of this is slightly retracted. From this data we were not able to conclusively determine whether BSC coverage is greater on mounds or intermounds but it was found that fire disproportionately affects BSC cover between mounds and intermounds.
Recommended Citation
Crowe, Abbey; Siguenza, Philip; and Smith, Anthony, "Mima Mounds, Crust & Fire" (2022). Symposium Of University Research and Creative Expression (SOURCE). 32.
https://digitalcommons.cwu.edu/source/2022/COTS/32
Department/Program
Geological Sciences
Additional Mentoring Department
Geological Sciences
Mima Mounds, Crust & Fire
In September 2020 the Evans Canyon Fire partially burned areas on Umtanum ridge south of Ellensburg, Washington. In the burn area are mima mounds, a geologic formation composed of piles of silt about one meter tall and 5-50 meters across that occasionally have rock rings around the base. We conducted a pilot study to look at the potential relationships between the fire and biological soil crust (BSC) coverage on mounds and intermounds. BSC is a layer composed of small organisms such as algae and mosses that forms on top of soils in our climate. We hypothesized that BSC coverage would be greater on mounds than intermounds, and that crusts would be disproportionately affected by fire across mounds and intermounds. We took photographs of the crust in a 1 by ¼ meter quadrat frame, then analyzed the image through the program ‘SketchandCalc’ to determine the percent area covered by BSC within the frame. Results showed that burnt intermounds had the greatest BSC coverage, while unburnt intermounds had the least. Data additionally suggest that intermound BSC is more strongly affected by fire, but since many of the unburnt mounds were too covered with other vegetation to accurately measure the BSC coverage, the significance of this is slightly retracted. From this data we were not able to conclusively determine whether BSC coverage is greater on mounds or intermounds but it was found that fire disproportionately affects BSC cover between mounds and intermounds.
https://digitalcommons.cwu.edu/source/2022/COTS/32
Faculty Mentor(s)
Lisa Ely