In flammability assessment, the terpene effect is usually studied using their total or subgroup content, missing, therefore, the information that could be provided by the molecules themselves. In this study, the specific role of terpenes on leaf flammability was sought comparing different levels of terpene identification—total, subgroup (i.e. mono-, sesqui-, and diterpene), and single compound—as well as their interactions with fuel moisture content (FMC) in four species common in Mediterranean Wildland–Urban Interfaces (Pinus halepensis, Cupressocyparis leylandii, Hesperocyparis arizonica, Cupressus sempervirens). Pinus halepensis was the most flammable species (low FMC and higher sesquiterpene content but low terpene diversity) while Cupressocyparis leylandii presented the highest terpene diversity and total terpene content (higher mono- and diterpene content). Flammability was differently affected according to the terpene identification level used in the models. The effects ranged from non-significant for most species studied, using subgroup or total terpene content, to mostly significant, using single compound content. Regarding the former, the lack of significant results could be due to opposite effects of different single compounds within a terpene subgroup. For the latter, terpene molecules driving flammability and their effects (positive or negative) differed among species. A cumulative effect with FMC was also highlighted in some cases but terpenes mostly remained the main flammability drivers regardless of the species. Using the refined terpene level in modelling allowed a better understanding of the compounds’ role on flammability, which is useful in the identification of plant traits linked to flammability.

在可燃性评估中，萜烯效应通常使用其总或亚组含量来研究，因此缺少分子本身可以提供的信息。在这项研究中，通过比较萜烯的不同识别水平（总，亚组（即单萜，倍半萜和二萜）和单一化合物）及其与燃料水分的相互作用，寻求萜烯对叶片可燃性的特定作用（ FMC）的四种常见于地中海荒地，城市界面（地中海松，Cupressocyparis leylandii，Hesperocyparis arizonica，地中海柏木）。哈尔滨松是最易燃的物种（低FMC和较高的倍半萜烯含量，但萜烯多样性低），而Cupressocyparis leylandii呈现出最高的萜烯多样性和总萜烯含量（较高的单萜和二萜含量）。根据模型中使用的萜烯鉴定水平，可燃性受到不同的影响。对于使用亚组或总萜烯含量的大多数研究物种，影响范围不明显，而使用单一化合物含量，则影响范围最为显着。关于前者，缺乏重要结果可能是由于萜亚组中不同单一化合物的相反作用。对于后者，驱动可燃性的萜烯分子及其作用（正或负）在物种之间是不同的。在某些情况下，还强调了FMC的累积作用，但萜烯仍然是主要的可燃性驱动因素，而与物种无关。