U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 48, May 2009


US government work.


After wildfire and when planning prescribed burns, those who tend the land must try to predict tree death. Managers and planners need to know the level of fire intensity required to meet tree mortality objectives, decide if and which trees to salvage, and predict future post-fire stand conditions. Models play a vital role in helping take the guesswork out of predicting post-fire tree mortality. One such model—the Ryan and Amman model—is perhaps the most widely used tree mortality model in the United States. It is used in the First Order Fire Effects Model (FOFEM), BehavePlus, and other similar software programs. Sharon Hood, along with a team of researchers that included two of the original authors of the fi rst widely used treemortality model, have evaluated the Ryan and Amman model and improved it. They have created species-specific models for many western conifers that give managers more options for predicting tree mortality. With their large data set, they also evaluated the use of bark char codes for predicting cambium status. Already, FOFEM (version 5.7) has incorporated the results of their new modeling efforts, and management guidelines are available for using bark char codes.