Changes in the combustion characteristics of living leaves of pinus densiflora by altitude

Combustion tests were conducted with living leaves of P. densiflora to examine the combustion characteristics of this species at different altitudes. An ignition temperature tester, cone calorimeter, and smoke density chamber were used for the tests. Leaf moisture content was measured prior to combustion, yielding a range of between 148 and 177%. The temperature of non-flame ignition was 300-310 °C and did not vary with altitude. Flame ignition occurred in the samples taken at 900 m and 1300 m, but lasted for only 7 and 8 s, respectively. These two samples released similar heat, with the sample from 1300 m producing slightly more heat. The sample from 1400 m released more than twice the smoke yielded by the other samples. Maximum smoke density was highest for the higher altitude samples, and the amount of smoke released varied proportionately with altitude. The mean release density of CO increased abruptly at 1100 m and decreased after that point before an abrupt increase at 1500 m, and that of CO₂ showed almost the same pattern as for CO.