Project Info

Squirrels and fires: how do biotic agents influence post-fire erosion?

Danica Roth

Project Goals and Description:

Prolonged drought conditions and intensifying winter storms in the Western US have dramatically increased wildfire occurrence and associated hazards in recent decades—a trend that climate forecasts indicate will continue in coming years. As megafires and megadroughts spread up the west coast, the historic reference frames in which we have come to understand post-fire processes are shifting rapidly, and our ability to model and predict the effects of fire on erosional processes and hazards are quickly falling behind. This is largely a reflection of fundamental gaps in our understanding of the processes and variables that control sediment transport and landscape evolution. For example, sediment transport laws are currently unable to account for dry ravel—the rolling, sliding and bouncing downhill motion of sediment, often mobilized by burrowing animals or tree fall, or by the incineration of vegetation and other surface roughness elements during fires—which is a primary postfire erosional process in many steep landscapes and known to play a role in postfire hazards like landslides and debris flows. We are also currently unable to bridge the gap between small-scale sediment transport processes such as those that occur in dynamic post-fire settings, and the long-term, large-scale evolution of landscapes and topographic features like slope or relief, which must both influence and eventually be influenced by sediment transport. Without connecting these scales, we cannot accurately predict the long-term effects of a changing fire regime on whole landscapes. This project will use a range of approaches to examine erosion rates and topographic characteristics associated with sediment transport caused by biotic agents (i.e., “bioturbation”), including CA ground squirrels, Botta’s pocket gopher and invasive wild boar. This work will contribute to better understanding of the role of bioturbation-driven dry ravel and regional variables like lithology, vegetation, hillslope aspect, and seasonal rainfall in controlling both long-term landscape evolution and shorter-term erosion and hazards after wildfire.

More Information:

Grand Challenge: Engineer the tools of scientific discovery.
CSM Surface Processes & Geomorphology Lab Group Website:   Recent Landscapes Live online seminar by Simon Mudd ("If you don’t like the stream power law, wait until you get a load of what we do on hillslopes”):   McLauchlan, Kendra K., Philip E. Higuera, Jessica Miesel, Brendan M. Rogers, Jennifer Schweitzer, Jacquelyn K. Shuman, Alan J. Tepley et al. "Fire as a fundamental ecological process: Research advances and frontiers." Journal of Ecology 108, no. 5 (2020): 2047-2069.   Gabet, Emmanuel J., O. J. Reichman, and Eric W. Seabloom. "The effects of bioturbation on soil processes and sediment transport." Annual Review of Earth and Planetary Sciences 31, no. 1 (2003): 249-273.   Perreault, Lauren M., Elowyn M. Yager, and Rolf Aalto. "Effects of gradient, distance, curvature and aspect on steep burned and unburned hillslope soil erosion and deposition." Earth Surface Processes and Landforms 42, no. 7 (2017): 1033-1048.   Roth, Danica L., Tyler H. Doane, Joshua J. Roering, David J. Furbish, and Aaron Zettler-Mann. "Particle motion on burned and vegetated hillslopes." Proceedings of the National Academy of Sciences 117, no. 41 (2020): 25335-25343.

Primary Contacts:

Danica Roth,

Student Preparation


The student should have basic familiarity with geology and geomorphology, and interest in learning about the project focus area(s) and gaining the skills involved in project execution (students interested in contributing to/learning about multiple aspects of project goals, or with interests in a specific project component will be considered equally). A strong work ethic, attention to detail/instruction, creative thinking, note-taking, communication and collaborative skills will be required. Experience with field work, GIS software, topographic data and maps, soil sample analysis, radionuclide analysis, spectral/Fourier analysis, hydrological property characterization, and/or ecological/environmental monitoring and characterization would be beneficial but are not required.




Student will assist with various field, lab and computational work, which may include (depending on project needs and student interests): collecting, prepping and analyzing soil samples in the gamma spectroscopy lab to assess short-term erosion and deposition rates, measuring post-fire soil water infiltration, collecting and processing high resolution topographic data (terrestrial lidar and photogrammetry), conducting rock drop experiments to measure particle travel distances over variable post-fire topography, field and digital mapping, conducting surveys to count and measure burrow characteristics, manipulating topographic data in ArcGIS, transporting and installing field gear and equipment, overnight travel to remote field sites in the western US, and contributing to various outreach efforts with K12 students.


Student will have weekly to biweekly meetings to discuss progress, challenges and questions, as well as email, Slack and drop-in availability. The student will also be included in weekly lab group meetings conducted jointly with research groups at the University of Minnesota and Minnesota State University, and will be invited to attend lab journal reading groups, which will provide exposure to a collegial research environment and provide networking and professional development opportunities. Depending on student interests, goals and performance, this project may also lead to student co-authorship on scientific publications and presentation at scientific conferences, and additional research, internship and teaching or field assistantship opportunities with the group going forward.


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