Baeza M J, De Luís M, Raventós J, Escarré A
Fundación CEAM (Centro de Estudios Ambientales del Mediterráneo), Parque Tecnológico, C/Charles Darwin, 14. Paterna, Valencia 46.980, Spain.
J Environ Manage. 2002 Jun;65(2):199-208. doi: 10.1006/jema.2002.0545.
Fire behaviour under experimental conditions is described in nine Mediterranean gorse shrublands ranging from 3-12 years of age with different fuel loads. Significant differences in the fire-line intensity, fuel load and rate of fire spread have been found to be related to the stage of development of the communities. Fire spread is correlated with fuel moisture using multiple regression techniques. Differences in fuel moisture between mature and young communities under moderate weather conditions have been found. The lower moisture content identified in the mature shrubland is due both to the decreasing moisture content of senescent shrubland in some species, mainly in live fractions of Ulex parviflorus Pour. fuel, and to a substantial increase in dead fuel fractions with low percentages of moisture content. The result is that the older the shrubland is, the greater will be the decrease in the total moisture content of the vegetation. In these moderate weather conditions, the fire intensity of the mature community was as high as the maximum intensity recommended for prescribed fires. This fact seems to indicate that, even under moderate conditions, prescribed burning as an alternative management tool in the mature shrubland must always take into account fuel control; on the other hand, this technique could be applied more easily when the shrubland is at an intermediate growth stage (4-5 years of age). Therefore, more frequent low-intensity prescribed fires are indicated to abate the risk of catastrophic fire.
本文描述了在实验条件下，9个年龄在3至12年、具有不同燃料负荷的地中海金雀花灌木丛中的火灾行为。研究发现，火线强度、燃料负荷和火灾蔓延速度的显著差异与群落的发育阶段有关。利用多元回归技术，火灾蔓延与燃料湿度相关。在中等天气条件下，已发现成熟群落和年轻群落之间的燃料湿度存在差异。成熟灌木丛中较低的水分含量，一方面是由于一些物种中衰老灌木丛的水分含量下降，主要是小花乌蔹莓（Ulex parviflorus Pour.）活部分的燃料，另一方面是由于低水分含量的死燃料部分大幅增加。结果是，灌木丛年龄越大，植被总水分含量的下降幅度就越大。在这些中等天气条件下，成熟群落的火灾强度高达规定火烧推荐的最大强度。这一事实似乎表明，即使在中等条件下，在成熟灌木丛中作为一种替代管理工具的规定火烧也必须始终考虑燃料控制；另一方面，当灌木丛处于中间生长阶段（4至5年）时，这种技术应用起来可能更容易。因此，建议更频繁地进行低强度规定火烧，以降低灾难性火灾的风险。
