Broad-scale alterations of historical fire regimes and vegetation dynamics have occurred in many landscapes in the U.S. through the combined influence of land management practices, fire exclusion, ungulate herbivory, insect and disease outbreaks, climate change, and invasion of non-native plant species. The LANDFIRE Program produces maps of historical fire regimes and vegetation conditions using the disturbance dynamics model VDDT. The LANDFIRE Program also produces maps of current vegetation and measurements of current vegetation departure from simulated historical reference conditions. These maps support fire and landscape management planning outlined in the goals of the National Fire Plan, Federal Wildland Fire Management Policy, and the Healthy Forests Restoration Act. Data Summary: The Historical Percent of Replacement Severity Fires data layer quantifies the percent of all fires that were of low severity. Replacement severity fires cause greater than 75% average replacement of dominant overstory aboveground biomass within a typical fire perimeter. This data layer is derived from vegetation and disturbance dynamics model VDDT. This layer was created by linking the BpS layer to the Percent of Replacement Severity Fires rulesets. This layer is intended to describe one component of historical fire regime characteristics in the context of the broader historical time period represented by the LANDFIRE Biophysical Settings layer and LANDFIRE Biophysical Settings Model documentation. This layer is created by linking the BpS Group attribute in the BpS layer with the Refresh Model Tracker (RMT) data and assigning the Historical Percent of Replacement Severity Fires attribute. This geospatial product should display a reasonable approximation of Historical Percent of Replacement Severity Fires, as documented in the Refresh Model Tracker. Historical percents of mixed severity fires were classified into 20 categories using 5% increments. Additional data layer values were included to represent Water (111), Snow / Ice (112), Barren (131), and Sparsely Vegetated (132). Vegetated areas that never burned during the simulations were included in the category Indeterminate Fire Regime Characteristics (133); these vegetation types either had no defined fire behavior or had extremely low probabilities of fire ignition. Metadata and Downloads