Soil Burn Severity Report for Archie Creek Fire

When a wildfire burns through an area, the severity and impact to the land and soil is not always equal. Sometimes there is just minimal impact, and other times the impact is severe. Here is a break down of how severe the Archie Creek Fire on the 131k acres that it burned. Archie Creek (131,419 acres) Unburned: 11,682 (9%) Low: 18,666 (14%) Moderate: 57,855 (44%) High: 43,216 (33%) Severity Indicators Low soil burn severity: Surface organic ­layers are not completely consumed and are still recognizable. Structural aggregate stability is not changed from its unburned condition, and roots are generally unchanged because the heat pulse below the soil surface was not great enough to consume or char any underlying organics. The ground surface, including any exposed mineral soil, may appear brown or black(lightly charred), and the canopy and understory vegetation will likely appear “green.” Moderate soil burn severity: Up to 80 percent of the pre-fire ground cover (litter and ground fuels) may be consumed but generally not all of it. Fine roots (~0.1 inch or 0.25 cm diameter)maybe scorched but are rarely completely consumed over much of the area. The color of the ash on the surface is generally blackened with possible gray patches. There may be potential for recruitment of effective ground cover from scorched needles or leaves remaining in the canopy that will soon fall to the ground. The prevailing color of the site is often “brown” due to canopy needle and other vegetation scorch. Soil structure is generally unchanged. High soil burn severity: All or nearly all of the pre-fire ground cover and surface organic matter (litter, duff, and fine roots) is generally consumed, and charring may be visible on larger roots. The prevailing color of the site is often “black” due to extensive charring. Bare soil or ash is exposed and susceptible to erosion, and aggregate structure may be less stable. White or gray ash (up to several centimeters in depth) indicates that considerable ground cover or fuels were consumed. Sometimes very large tree roots (> 3 inches or 8 cm diameter) are entirely burned extending from a charred stump hole. Soil is often gray, orange, or reddish at the ground surface where large fuels were concentrated and consumed. Short video explaining what the Burned Area Emergency Response Team does and why. https://www.roseburgtracker.com/posts/5f84be794520d70004b0205c Field Guide from USFS on mapping post-fire soil burn severity (recommend reading!) https://www.fs.fed.us/rm/pubs/rmrs_gtr243.pdf Sample burn severity comparisons came from this document. BAER main page: https://inciweb.nwcg.gov/incident/7222/?fbclid=IwAR3TzioFFJYgl9Ak3zE5rogK3IowZita1tPKmqGjpmzSJwq9ortRzsm6vFQ