Authors: Gregory W Hamby; Jesse K Kreye; J. Morgan VarnerImpacts of fire exclusion in eastern U.S. hardwood forests include overstory compositional changes that have been hypothesized to dampen fire behavior via altered forest structure and forest floor fuels, resulting in a so-called “mesophication” effect. We examined the potential for expected changes in litter composition to alter forest floor flammability in a southeastern U.S. oak-hickory forest using laboratory burn experiments. Results indicated that increasing the relative contribution of litter from fire-sensitive mesophytic species (Liquidambar styraciflua, Ulmus alata, and Cornus Florida) slowed moisture loss and reduced litter flammability (flame height, flame duration, fuel consumption). Differences in fire behavior were also evidenced when moisture was held constant (dry conditions). The combined effects of increased moisture retention and less flammable litter highlights an important synergy that may result from increased dominance of fire-sensitive species in these fire-prone oak forests. Restoration efforts aimed at reintroducing fire in fire-suppressed hardwood forests may require altering stand composition to limit mesophytic litter input or ensuring that burning conditions result in desired surface fire behavior.