Time to ignition is influenced by both moisture content and soluble carbohydrates in live Douglas fir and Lodgepole pine needles
Time to ignition is influenced by both moisture content and soluble carbohydrates in live Douglas fir and Lodgepole pine needles
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发表时间：
2010
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通讯作者：
Matthieu Jolly;S. McAllister;M. Finney;Ann M. Hadlow
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作者：
Matthieu Jolly;S. McAllister;M. Finney;Ann M. Hadlow
活的植物通常是野外火灾中燃烧的主要燃料，但对控制其点火行为的因素知之甚少。长期以来，水分含量一直被假设为确定在活性燃料中蔓延的火灾的特征，但水分含量本身无法解释在一年中不同时间观察到的各种物种点火的差异。此外，很少有人关心活燃料的水分含量和化学成分之间的平衡，以及这种平衡可能如何影响产生火焰燃烧所必需的可燃气体混合物所需的净能量。在这里，我们研究的时间点燃的两个物种的活燃料，道格拉斯冷杉（花旗松）和美国黑松（松扭）。整个季节都在收集活燃料，并量化其点燃时间。此外，我们评估每个样品的水分含量和碳水化合物组成。我们发现，点火时间与水分含量显着相关，但水分含量单独只解释了约46%的变异性，两个物种的点火时间。然而，当水分含量与一个简单的度量可用的碳水化合物相结合，85%的点火时间的变异解释使用相同的模型为两个物种。这些结果表明，虽然水分含量起着重要的作用，在确定的时间点燃的活植物，额外的信息，碳基化合物在树叶中的分布同样重要。这个指标可以作为一个简单的方法来评估树叶的易燃性，并确定的特点，使一些植物比其他更容易点燃。
Living plants are often the primary fuels burning in wildland fire but little is known about the factors that govern their ignition behavior. Moisture content has long been hypothesized to determine the characteristics of fires spreading in live fuels but moisture content alone fails to explain observed differences in the ignition of various species at different times of the year. Furthermore, little concern has been given to balance between the moisture content and chemical composition of live fuels and how this balance of might affect the net energy required to produce the combustible mixture of gases that is necessary for flaming combustion. Here we examine the time to ignition of two species of live fuels, Douglas Fir (Pseudotsuga menzeseii) and Lodgepole Pine (Pinus contorta). Live fuels are collected throughout the season and their time to ignition quantified. Additionally, we assess the moisture content and carbohydrate composition of each sample. We found that time to ignition was significantly correlated with moisture content but that moisture content alone only explains about 46% of the variability in time to ignition for both species. However, when moisture content is combined with a simple metric of available carbohydrates, 85% of the variability in ignition timing was explained using the same model for both species. These results suggest that while moisture content plays an important role in determining the time to ignition of live plants, additional information about the distribution of carbon-based compounds in the foliage is equally as important. This metric may serve as a simple way to assess the flammability of foliage and to determine the characteristics that make some plants more easily ignited than others.