This document summarizes a long-term study of channel morphology and large wood dynamics in mountain streams after wildfires in the Bridger-Teton National Forest. Surveys were conducted in 2001, 2002, 2003, 2007, 2008, and 2013 to census large wood, map channel changes, and document increases in wood recruitment and log jams leading to bank migration and channel shifts. The project was funded by the Geologic Society of America, GeoCorps America, US Forest Service, and National Fire Plan to understand post-fire impacts to fluvial geomorphology.

1. BOULDER CREEK FIRE FLUVIAL GEOMORPHOLOGY GEOCORPS
POSITIONS: A LONG TERM ASSESSMENT OF CHANNEL
MORPHOLOGY AND LARGE WOOD DYNAMICS IN POST-FIRE
MOUNTAIN STREAMS ON THE BRIDGER-TETON NATIONAL
FOREST
Ryan T. Richardson1
, Ben S. Kraushaur1
, Sandra E. Ryan2
,
Kathleen A. Dwire2
, Mark Dixon2
1
GeoCorps America, Geologic Society of America, 3300
Penrose Place, Boulder, CO 80301-1806
2
US Forest Service, Rocky Mountain Research Station, 240
W. Prospect Rd., Fort Collins, Colorado 80526

9. Project Goals
Large In-stream Wood Census Channel Morphology

10. Large In-Stream Wood Census
• Length
• Diameter
• Channel Type
• Structural Association
• Burn/Age

11. Wood Recruitment
Figures from upcoming publication by Dr. Sandra Ryan

12. Boulder Reach 36 (2001)

13. Boulder Reach 36 (2007)

14. Boulder Reach 36 (2013)

15. Channel Morphology
• Stream Survey
– Longitudinal Profiles
– Banks
– Cross Sections
• Instrumentation
– Total Station Instrument
– Prism Poles

16. 0 6 12 18 243
Meterst
Legend
Old cutbank
Logs 2001
Centerline 2001
Early banks
Reach 36 2001
0 6 12 18 243
Meters
t
Legend
New logs in 2002
Old cutbank
Remained in place 2001
Centerline 2001
Early Banks
Reach 36 2002
0 6 12 18 243
Meterst
Legend
Logs moved in 2003
Logs new in 2003
Logs in place
Old cutbank
Centerline
Early banks
Reach 36 2003
0 6 12 18 243
Meterst
Legend
Logs missing 2007
Logs new 2007
Logs moved 2007
Logs Inplace 2007
Old cutbank
Early banks
2007_Centerline
2007_Banks
Reach 36 2007
0 6 12 18 243
Meterst
Legend
Missing in 2008
New recruits 2008
Moved within reach 2008
Buried 2008
Remained in place 2008
2007 Banks
2007 Centerline
2008 Newly eroded area
2008 New centerline
Old cutbank
Reach 36 2008
0 6 12 18 243
Meterst
Legend
Missing in 2008
New recruits 2008
Moved within reach 2008
Buried 2008
Remained in place 2008
2007 Banks
2007 Centerline
2008 Newly eroded area
2008 New centerline
Old cutbank
Reach 36 2008
0 6 12 18 243
Meterst
Legend
New recruits 2013
Broken in 2013
Missing in 2013
Buried in 2013
Moved within reach 2013
Remained in place 2013
2013 Centerline
2013 Banks
Old cutbank
Reach 36 2013

17. 0 6 12 18 243
Meterst
Legend
Old cutbank
Logs 2001
Centerline 2001
Early banks
Reach 36 2001
0 6 12 18 243
Meterst
Legend
All large wood 2013
2013 Centerline
2013 Banks
Old cutbank
Reach 36 2013
All existing wood

18. http://www.inciweb.org/incident/map/3726/2/

19. Future Research

20. Conclusion
• Wood recruitment increases 4-7 years post
fire
• This increase in large in-stream wood form log
jams in channel
• These log jams create depositional areas that
eventually cause bank migration and channel
avulsions

21. Acknowledgements
• Geologic Society of America
• GeoCorps America
• Bridger Teton National Forest
• Rocky Mountain Research Station
• US Forest Service
• National Fire Plan

22. References
• Rim Fire BAER Team, Soil Burn Intensity Map,
http://www.inciweb.org/incident/map/3726/2/
• Mortiz, Max. Climate change and disruptions to global fire
activity. Ecosphere. V3(6). June 2012. Article 25.