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 ℃ 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

Fire Investigation via Analysis of Ignition Characteristics and Carbon Emissions of Fire–prone Surface Fuels in Korea

This study focuses on the identification of ignition characteristics and carbon discharge resulting from combustion of surface fuels vulnerable to forest fire. Four withered surface fuels, including dead leaves and cones of Pinus densiflora, dead leaves of Quercus variabilis, and Castenea crenata burs; and six biofuel herbs, including Agsstache rugosa, Oplismenus undulatifolius, Pueraria thunbergiana, Cirsium japonicum var. ussuriense, Festuca ovina L., and Osmundaceae were selected for analysis. Also, monthly carbon emissions (Jun. -Oct. 2008) from Festuca ovina were analyzed. As a result of tests, it was confirmed that dead leaves and cones of P. densiflora and C. crenata burs were instantly ignited with flame, which lasted quite a while. The total CO_2 and CO emissions from the 10 different kinds of surface fuels analyzed on this study were 28–98 g and 0.76–4.08 g per 50 g of each fuel, respectively, indicating that the amount of carbon emissions vary depending on the type of fuel. The results also demonstrated that there is a great difference between withered fuels and biofuels in terms of carbon emissions. More specifically, the four withered types of fuels, compared to the six biofuel herbs, were found to emit more CO_2 and CO. In particular, dead cones of P. densiflora emitted more carbon dioxide (CO_2) and carbon monoxide (CO) than the rest of the surface fuels. Also, the carbon emissions were found high during the period of from August to September. Consequently, in the case of a forest fire, dead cones and leaves of P. densiflora are expected to emit up to 3.5 times more CO_2 and CO than the other surface fuels. The area covered with dead leaves and pine cones is thought to have a high risk of ignition, high fire intensity because of relatively long lasting flame, and rapid fire spread. Herbs and living fuels with high moisture content are expected to elucidate the course of fire in that they produce large amount of combustion products such as smoke and carbon discharge resulting from nonflame-ignition

Changes in the Combustion Characteristics of Living Quercus Mongolica Leaves with Altitude Variation

In this study, combustion tests were conducted on living Q. mongolica leaves to compare their combustion characteristics at different altitudes. Leaf moisture content was measured and combustion characteristics were then studied using an ignition temperature tester, a cone calorimeter, and a smoke density chamber. The samples contained 117-145% moisture. The temperature of non-flame ignition was 275-308℃ and did not vary with altitude. Samples from 1,300m and 1,500m ignited more quickly than the others, but went out after 2 and 4 seconds, respectively. Heat release increased and reached its peak at 1,100 m, thereafter decreasing. Smoke release decreased and smoke density increased in proportion to altitude. The mean release density of CO rose gradually with increasing altitude while that of CO2 increased from 1,200 m

Study on Fire Identification using Combustion Pattern Analysis of Pine Trees According to Climate Change in Korea

This study monthly combustion tests were conducted on pine green leaves during June 2008 ～ May 2012 (4 years) for combustion pattern analysis of forest fires according to climate change in Korea. As result of research, fuel humidity of 75～178% was shown for 4 years in which much difference was shown according to climate. Period of frequent forest fires with high risk was shown to be in April and November, and it was shown that influence of fuel humidity was shown. Especially, April showed pattern of relatively higher risk of forest fires than October and range of auto ignition temperature was 270～355˚C in which temperature difference of 85˚C was shown according to climate change. Total heat release was shown in range of 11～72 MJ/m^2 for 4 years, as April showed 41～56 MJ/m^2 and November showed 21～33 MJ/m^2 that April which had low fuel humidity showed relatively high heat release. Total smoke release was shown in range of 159～951m^2/m^2 for 4 years, as April showed 311～951m^2/m^2 and November showed 246～322m^2/m^2. Therefore, it could be known that April relatively releases more smoke than October. For carbon release, CO showed 1.6586～26.1460 g range and CO_2 showed 36.412～100.01 g range for 4 years and this concentration of combustion product has severe change by season that high release of CO and CO_2 is shown in April through May