Louise E. Ashmun

Tools to aid post-wildfire assessment and erosion-mitigation treatment decisions

A considerable investment in post-fire research over the past decade has improved our understanding of wildfire effects on soil, hydrology,erosion and erosion-mitigationtreatment effectiveness. Using thisnew knowledge, we have developed several tools to assist land managers with post-wildfire assessment and treatment decisions, such as prediction models, research syntheses, equipment and methods for field measurements, reference catalogues and databases of past-practice, and spreadsheets for calculating resource valuation and cost-benefit analysis. These tools provide relevantscience topost-fireassessment teams andlandmanagers informats that often canbe directly enteredinto assessment and treatment decision-making protocols. Providing public access to these tools through the internet not only has increased their dissemination, but also has allowed them to be updated and improved as new knowledge and technology become available. The use of these science-based tools has facilitated a broader application of current knowledge to post-fire management in the United States and in other fire-prone areas around the world. Additional keywords: burn severity, erosion modeling, remote sensing, resource valuation.

Erosion Risk Management Tool (ERMiT) user manual (version 2006.01.18)

The decision of where, when, and how to apply the most effective post-fire erosion mitigation treatments requires land managers to assess the risk of damaging runoff and erosion events occurring after a fire. To aid in this assessment, the Erosion Risk Management Tool (ERMiT) was developed. This user manual describes the input parameters, input interface, model processing, and output files for version 2006.01.18. ERMiT is a web-based application that uses Water Erosion Prediction Project (WEPP) technology to estimate erosion, in probabilistic terms, on burned and recovering forest, range, and chaparral lands with and without the application of erosion mitigation treatments. User inputs are processed by ERMiT to combine rain event variability with spatial and temporal variabilities of soil burn severity and soil properties, which are then used as WEPP input parameters. Based on 20 to 40 individual WEPP runs, ERMiT produces a distribution of rain event sediment delivery rates with a probability of occurrence for each of five post-fire years. In addition, event sediment delivery rate distributions are generated for post-fire hillslopes that have been treated with seeding, straw mulch, and erosion barriers such as contour-felled logs or straw wattles.

Measuring duff moisture content in the field using a portable meter sensitive to dielectric permittivity

Duff water content is an important consideration for fire managers when determining favourable timing for prescribed fire ignition. The duff consumption during burning depends largely on the duff water content at the time of ignition. A portable duff moisture meter was developed for real-time water content measurements of non-homogenous material such as forest duff. Using circuitry developed from time and frequency domain reflectometry (TDR and FDR) technologies, this sensor measures a change in frequency that is responsive to the dielectric permittivity of the duff material placed in a sample chamber and compressed. Duff samples from four forest cover types—Douglas fir, larch, lodgepole pine and spruce/alpine fir—were used to calibrate the frequency output to volumetric water content. A second-order polynomial (R2 = 0.97) provides the best fit of the data to volumetric water content. The accuracy of the duff moisture meter is ±1.5% at 30% volumetric water content and ±4% at 60% volumetric water content. The volumetric water content can readily be converted to gravimetric water content, which is used more frequently by fire managers and as an input to predictive models of duff consumption.

Production and aerial application of wood shreds as a post-fire hillslope erosion mitigation treatment

Guidelines for the production and aerial application of wood shred mulch as a post-fire hillslope treatment were developed from laboratory and field studies, several field operations, and the evaluations of professionals involved in those operations. At two early trial sites, the wood shred mulch was produced off-site and transported to the area of use. At the 2010 Schultz Fire in Arizona, the wood mulches were produced on-site from burned hazard trees that were felled and skidded to a processing area where the logs were shredded by a horizontal grinder and piled. The subsequent aerial applications of the wood shreds were staged from the same landings where they were produced. At the 2010 Fourmile Canyon, 2012 High Park, and 2012 Waldo Canyon Fires in Colorado, wood shreds were produced from various combinations of on- and off-site burned and green trees that were generally shredded near the harvest or storage site. The wood shreds were transported by chip trucks to aerial application staging areas. The most challenging aspect of wood shred production was adjusting the grinder screens and through-put speed to maximize the proportion of shreds that were 2 to 8 inches (50 to 200 mm) in length. The same equipment and techniques used for aerial mulching with agricultural straw worked, with some adjustments in flight altitude and speed, for wood shreds. The Heli-Claw, an experimental device designed to replace the cargo net in aerial mulching, was tested and used to apply 80 percent of the wood shred mulch at the Beal Mountain mine reclamation site. Because wood shreds are four to six times heavier than agricultural straw, wood shred mulch took longer to apply than agricultural straw for the same area (25 to 35 ac [10 to 14 ha] per day for wood shreds; approximately 200 ac [81 ha] per day for straw). The additional flight time makes mulching with wood shreds cost three to four times more than with agricultural straw (

Post-fire mulching for runoff and erosion mitigation Part I: Effectiveness at reducing hillslope erosion rates

1700 to

Post-fire mulching for runoff and erosion mitigation; Part II: Effectiveness in reducing runoff and sediment yields from small catchments

2200 per ac [

Post-fire treatment effectiveness for hillslope stabilization

4200 to

Postfire rehabilitation of the Hayman Fire

5500 per ha] for wood shreds;

Evaluating the effectiveness of wood shred and agricultural straw mulches as a treatment to reduce post-wildfire hillslope erosion in southern British Columbia, Canada

500 to

Emergency post-fire rehabilitation treatment effects on burned area ecology and long-term restoration

700 per acre [