The ecological need for prescribed fire in Sequoia and Kings Canyon National Park, United States of America

Introduction. Forests throughout the West may require prescribed fire or thinning to reduce fire hazard and restore ecological processes.; Aim. The purpose of this study is to identify areas outside the range of historical variability based on the Time Since Last Fire (TSLF) relative to pre-Euroamerican fire return intervals. These areas with long TSLF relative to the historic fire return interval have high fire hazard and would be given high priority for prescribed burns.; Location. This study was performed in topographically rugged terrain ranging in elevation from 485 to 4,392m in the Sequoia and Kings Canyon National Park, California, USA.; Methods. Fire Return Interval Departures (FRIDs) were calculated from TSLF and historic fire return intervals to determine if the 12 dominant vegetation classes of Sequoia and Kings Canyon National Park have maintained pre-Euroamerican fire return intervals. FRIDs were used to help identify the ecological need for prescribed burning within the park.; Results. Two maps of FRIDs were created based on minimum and maximum estimates of the historic fire return intervals. These maps depict the risk of fire across the park based on historic fire return intervals. Areas with extreme risk of fire are concentrated in the north-central areas of the park and sporadically along the western border with high levels of concentration clustered around major roads and trails. Also, ponderosa pine and white fir forests have a greater percent of FRIDs > 5 than the other 9 vegetation classes.; Main conclusions. FRID Analysis is a useful method of evaluating the ecological need for prescribed burn. FRID Analysis identifies areas that are likely at risk of severe fire and in need of management ignited prescribed burning.