9.º Congresso Nacional Florestal

Aline Oliveira apresentou, no dia 11/10/2022, a comunicação "Questioning current fuel management practices in Portugal - the InduForestFire project", veja abaixo um resumo do que foi apresentado:

The InduForestFire project seeks mitigation solutions to avoid damage caused by large fires in industrial areas through scientific studies that explore the phenomena associated with these damages. For this, the project involves two approaches of very different nature, but complementary. The first is a forest-based approach, aimed at understanding fire behavior around industrial zones. The second refers to fire safety, based on assessments of the characteristics of the structures that make up these zones. Regarding the first approach, the legislation requires fuel management around industrial perimeters according to criteria that are not scientifically-based. The structure and composition of the surrounding vegetation decisively influences the behavior of fire, but the existing knowledge in this regard is still insufficient to guide effective and more adequate fuel management. Based on fire behavior simulations and in situ data collection, some important results have already been achieved by the InduForestFire project. Here, we present some of this evidence that assesses current management and supports the creation of new management approaches to prevent fire damage at the industrial-forest interface in the future. Our first results indicate that the expansion of megafires, like those of 2017, can be locally interrupted by patches of native broadleaved forest. Through spatiallyexplicit fire behavior simulations, we identified that replacing the current vegetation present in the WUI with broadleaved forests can reduce fire intensity by up to five times, even in extreme weather conditions. Our estimates for the interface of six industrial zones (Mira, Oliveira do Hospital, Oliveira de Frades, Tocha, Mortágua, and Pedrogão Grande) indicate that fires that abruptly exceed the suppression capacity in pine and eucalyptus forests (flame length of 1.3 m and fireline intensity above 3,000 Kw/m) can be suppressed effectively in broadleaved forests in extreme weather (1.41 m and 607 Kw/m, respectively) and easily suppressed in broadleaf forests in standard weather (0.77 m and 176 KW/m, respectively). Through the development of fuel models and simulations of surface fire behavior, we also evaluated the effect of fuel management on the secondary management network, in different types of forests. We sampled 30 pairs of Managed Areas vs. Unmanaged Areas, in eucalyptus, maritime pine, and mixed stands. Our results showed a trade-off between the beneficial reduction in fuel load and fuel bed depth, which supposedly justified the management criteria, and the more severe weather conditions (higher wind speed and lower relative humidity) in managed areas. Despite the fuel breaks being an important instrument to support the suppression of forest fires, it remains to be evaluated whether these areas present any difference for crown fires and for more severe climate scenarios. New data will be collected for fire behavior evaluations in different adjacent forest compositions and for crown fire simulations in the areas already sampled. We hope, through InduForestFire, to support fuel management in the country through robust results that integrate more efficient strategies to face extreme weather. This includes, mainly, reinforcing the role of forest legislation to include, in a more comprehensive way, measures for the introduction of native species into the territory.