Coupling duff development with tree litter and downed fuel inputs, decomposition and fire consumption in a long-term prescribed fire experiment in Florida

Background Mapping surface and ground fuels is key to predicting fire behavior and effects. Remote sensing effectively describes tree canopy attributes, but it is less effective for surface and ground fuels because they are partially obscured by vegetation. Aims We mapped duff loads by leveraging the coupled relationship between canopy, surface and ground fuels: canopy fuels provide the source material for surface fuels, which serve as the material for duff formation. Methods We mapped annual surface fuel production from tree components that contribute to duff formation using airborne laser scanning data. We adjusted a forest soil organic carbon model to simulate duff development under environmental factors constraining decomposition, and included consumption rates accounting for prescribed burning fuel removal. We tested the workflow in southeastern US pine flatwoods where a long-term prescribed burning experiment has been running since 1958. Key results Comparison between modeled duff estimates and field observations provided good agreement, showing low bias and high coefficient of determination. Conclusions This approach allows surface and ground fuels mapping at high spatial resolution (≤5 m) using airborne laser scanning. Implications This integrated modeling workflow improves on current methods to describe heterogeneous duff layers and shows that surface and ground fuels can be mapped using remote sensing and ecological modeling.