De Luis M, Raventós J, González-Hidalgo J C
Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, Rozna Dolina, Cesta VIII/34, SI-1000 Ljubljana, Slovenia.
J Environ Manage. 2005 Jul;76(2):159-66. doi: 10.1016/j.jenvman.2005.01.014. Epub 2005 Apr 7.
In Western Mediterranean areas, fires are frequent in forests established on old croplands where woody resprouting species are scarce and post-fire regeneration is limited to obligate-seeder species, such as Mediterranean gorse (Ulex parviflorus), that accumulate a great deal of fine dry fuel, increasing the risk of other severe fires. Under these conditions, fuel control techniques are required in order to prevent fires of high intensity and severity and the subsequent economic and ecological damage. Prescribed fires present an alternative to fuel control, and recent studies demonstrate that, under optimum climatic conditions, fire-line intensity values fall within the limits of those recommended for fire prescription. However, a better understanding of the consequences of fire on the regeneration of vegetation is needed in order to evaluate the suitability of prescribed fires as a technique for fuel reduction in Mediterranean gorse ecosystems. This paper analyses the factors controlling seedling germination after fire to make an evaluation from an ecological perspective of whether fire prescription is a suitable technique for fuel control in mature Mediterranean gorse shrublands. The results show that small differences in the composition of vegetation play a decisive role in fire behaviour, and have a decisive influence on the system's capacity for regeneration. Fire severity is low in mixed Mediterranean gorse communities with a low continuity of dead fine fuel (including Cistus sp., Rosmarinus sp., etc.) and fire creates a wide range of microhabitats where seedling emergence is high. In contrast, where U. parviflorus is more dominant, fire severity is higher and the regeneration of vegetation could be hindered. Our conclusions suggest that detailed studies of the composition of plant communities are required in order to decide whether prescribed burning should be applied.
在西地中海地区，老农田上形成的森林火灾频发，这些地方木本萌蘖物种稀少，火灾后的再生仅限于专性种子植物物种，如地中海金雀花（Ulex parviflorus），它们积累了大量细小的干燥燃料，增加了发生其他严重火灾的风险。在这种情况下，需要采用燃料控制技术以防止高强度和高严重程度的火灾以及随后的经济和生态破坏。计划火烧是燃料控制的一种替代方法，最近的研究表明，在最佳气候条件下，火线强度值在火灾计划建议的范围内。然而，为了评估计划火烧作为地中海金雀花生态系统中减少燃料的一种技术的适用性，需要更好地了解火灾对植被再生的影响。本文分析了火灾后控制幼苗萌发的因素，以便从生态角度评估计划火烧是否是成熟地中海金雀花灌木丛中燃料控制的合适技术。结果表明，植被组成的微小差异在火灾行为中起决定性作用，并对系统的再生能力产生决定性影响。在地中海金雀花与死亡细小燃料（包括岩蔷薇属、迷迭香属等）连续性较低的混合群落中，火灾严重程度较低，火灾创造了广泛的微生境，幼苗出土率较高。相比之下，在地中海金雀花占主导地位的地方，火灾严重程度较高，植被再生可能会受到阻碍。我们的结论表明，需要对植物群落组成进行详细研究，以决定是否应采用计划火烧。
