Kauf Zorica, Fangmeier Andreas, Rosavec Roman, Španjol Željko
Institute of Landscape and Plant Ecology, University of Hohenheim, August-von-Hartmann Str. 3, 70599, Stuttgart, Germany,
Environ Manage. 2015 Mar;55(3):687-701. doi: 10.1007/s00267-014-0427-3. Epub 2014 Dec 24.
One of the suggested management options for reducing fire danger is the selection of less flammable plant species. Nevertheless, vegetation flammability is both complex and dynamic, making identification of such species challenging. While large efforts have been made to connect plant traits to fire behavior, seasonal changes and within species variability of traits are often neglected. Currently, even the most sophisticated fire danger systems presume that intrinsic characteristics of leaf litter stay unchanged, and plant species flammability lists are often transferred from one area to another. In order to assess if these practices can be improved, we performed a study examining the relationship between morphological characteristics and flammability parameters of leaf litter, thereby taking into account seasonal and local variability. Litter from six Mediterranean tree species was sampled throughout the fire season from three different locations along a climate gradient. Samples were subjected to flammability testing involving an epiradiator operated at 400 °C surface temperature with 3 g sample weight. Specific leaf area, fuel moisture content, average area, and average mass of a single particle had significant influences on flammability parameters. Effects of sampling time and location were significant as well. Due to the standardized testing conditions, these effects could be attributed to changes in intrinsic characteristics of the material. As the aforementioned effects were inconsistent and species specific, these results may potentially limit the generalization of species flammability rankings. Further research is necessary in order to evaluate the importance of our findings for fire danger modeling.
降低火灾风险的一种建议管理方法是选择易燃性较低的植物物种。然而，植被的易燃性既复杂又具有动态性，这使得识别此类物种具有挑战性。尽管人们已经做出了巨大努力将植物特征与火灾行为联系起来，但性状的季节变化和物种内的变异性常常被忽视。目前，即使是最复杂的火灾风险系统也假定落叶的内在特征保持不变，而且植物物种易燃性列表常常从一个地区转移到另一个地区。为了评估这些做法是否可以改进，我们进行了一项研究，考察落叶的形态特征与易燃性参数之间的关系，从而考虑到季节和局部变异性。在火灾季节期间，从沿着气候梯度的三个不同地点采集了六种地中海树种的落叶。对样品进行了易燃性测试，测试使用表面温度为400°C的红外辐射器，样品重量为3克。比叶面积、燃料含水量、单个颗粒的平均面积和平均质量对易燃性参数有显著影响。采样时间和地点的影响也很显著。由于测试条件标准化，这些影响可归因于材料内在特征的变化。由于上述影响不一致且具有物种特异性，这些结果可能会限制物种易燃性排名的普遍适用性。为了评估我们的研究结果对火灾风险建模的重要性，还需要进一步研究。
