Objectives are to evaluate patterns in litter/duff biomass and moisture associated with different micro-site conditions and apply the information to burn conditions and ignition patterns. At
Results/Conclusions: Duff was deeper near trees (11.4 +/- 3.1cm) compared to away (4.1 +/- 2.8 cm). Duff moisture was predicted to be higher near longleaf compared to away but this was not the case. Preliminary results revealed little difference in overall moisture content of total litter or duff. However, except immediately following rain, near longleaf, the top 1cm of duff was significantly drier by ~11% compared to paired sites away from trees. In addition there were small but consistent differences between duff moisture within 1m down-slope of longleaf trees compared to paired up-slope points.
Drier near-surface duff is expected to increase likelihood of smoldering near compared to away from longleaf. We consider how chances of duff ignition near longleaf may be decreased by employing ignitions pattern that minimizes flaming front residence time and so lessen additional drying and ignition potential for the top layer of duff. Better understanding of micro-site fuel differences may be increasingly important under some climate change scenarios. Even slightly warmer and/or drier conditions are expected to limit the number of days appropriate for burning in stands with duff accumulation in a wide range of ecosystems, including not only pine but also hardwood forests.