Effects of fuel load and moisture content on fire behaviour and heating in masticated litter-dominated fuels
Mechanical fuels treatments are being used in fire-prone ecosystems where fuel loading poses a hazard, yetlittle research elucidating subsequent fire behaviour exists, especially in litter-dominated fuelbeds. To address this deficiency, we burned constructed fuelbeds from masticated sites in pine flatwoods forests in northern Florida with palmetto-dominated understoreys and examined the effects of fuel load and fuel moisture content (FMC) on fire behaviour. Flame lengths (49–140 cm) and fireline intensity (183–773 kJm 1 s 1) increased with loading (10-30 Mg ha 1) and were reduced by 40 and 47% with increasing FMC from 9 to 13%. Rate of spread was not influenced by fuel load, but doubled under drier FMC. Fuel consumption was.90% for all burns. Soil temperatures were influenced by both fuel load and FMC, but never reached lethal temperatures (608C). However, temperatures of thermocouple probes placed at the fuelbed surface reached 274–5038C. Probe maximumtemperature and duration at temperatures $608C (9.5–20.08C min) both increased with fuel load, but were unaffected by FMC. The fire behaviour observed in these unique litter-dominated fuelbeds provides additional insight into the burning characteristics of masticated fuels in general.