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Authors
Abstract(s)
O fogo produz efeitos adversos no solo, alterando as suas propriedades físicas, químicas, biológicas e mineralógicas. O Parque Natural de Montesinho (PNM), apresenta 1/3 da sua área coberto por áreas de matos, que são altamente inflamáveis, e combinado as características mediterrânicas do ambiente, elevam o risco de incêndios. O fogo controlado é uma medida preventiva do risco de incêndio, diminuindo a biomassa combustível, que admite-se ter baixo impacto sobre o solo, face à sua baixa intensidade.
Este estudo focou-se nas alterações das propriedades e processos físicos do solo, após a aplicação de fogo controlado numa área de matos do PNM, vizinha de um povoamento florestal de resinosas. As propriedades físicas foram analisadas em três momentos: antes, imediatamente pós fogo e dois meses pós fogo. Em 11 pontos de amostragem foram tomadas amostras não perturbadas na camada 0-5 cm, em anéis metálicos 100 cm3. As determinações laboratoriais incluíram permeabilidade saturada, densidade aparente, capacidade máxima para a água, capacidade de campo, porosidade (macro-, micro- e total).
A densidade aparente e os macroporos aumentaram significativamente, assim como a capacidade máxima para água, a capacidade de campo, e o armazenamento de água, sofreram uma diminuição; para além disso, a porosidade total e a permeabilidade diminuíram, mesmo que não significativamente. Contudo, a combinação de todas essas mudanças consta que a dinâmica hidrológica do solo se alterou após o fogo, entretanto, tendendo a voltar ao estágio anterior ao fogo controlado, no momento dois meses após o fogo.
A perda de solo e o escoamento foram monitorados durante 3 meses após a queima, através da inserção de 8 microparcelas de 4m², 4 delas localizadas em um declive mais acentuado e 4 em declive menor. A precipitação total durante o monitoramento foi de 80,2 mm, resultando em uma média de 0,616 mm em escoamento e 19,51 (g.m-2) em perda de solo, para o declive mais baixo e 2,39 mm e 22,95 (g.m-2) para o declive mais acentuado. Embora o período de monitoramento fosse curto, pode-se notar que houve uma perda de solo ocasionada pelo fogo e um efeito do declive, quanto ao escoamento.
Entende-se que a contribuição deste trabalho para a investigação dos impactos do fogo controlado nas propriedades e processos físicos do solo em áreas de matos permite um conhecimento mais amplo dos efeitos a curto prazo no Parque Natural de Montesinho, NE Portugal.
Fire produces adverse effects on soil, altering its physical, chemical, biological, and mineralogical properties. The Montesinho natural park (MNP), has 1/3 of its area covered by shrublands, which are highly flammable, and combined by the Mediterranean characteristics of the environment, increase the risk of fires. Prescribed fire is a preventive measure of the risk of wildfire, reducing fuel biomass, which is admitted having low impact on the soil, given its low intensity. This study focused on changes in soil physical properties and processes after the application of prescribed fire in a shrubland area of MNP, neighboring a resinous forest settlement. The physical properties were analyzed in three moments: before, immediately after fire and two months after fire. At 11 sampling point, undisturbed samples were taken in the 0 – 5cm layer, in 100 cm3 metal rings. Laboratory determinations included saturated permeability, bulk density, maximum water capacity, field capacity and porosity (macro-, micro-, and total). The bulk density and macropores increased significantly, as well as the maximum water capacity, field capacity, and water storage, decreased; in addition, total porosity and permeability decreased, even if not significantly. However, the combination of all these changes is reported that the hydrological dynamics of the soil changed after the fire, however, tending to return to the stage prior to the controlled fire, at the moment two months after the fire. Soil loss and runoff were monitored for 3 months after burning, through the insertion of 8 microplots of 4m², 4 of them located on a steeper slope and 4 on a flatter slope. The total precipitation during monitoring was 80.2 mm, resulting in an average of 0.616 mm in runoff and 19.51 (g.m-2) in soil loss, for the lower slope and 2.39 mm and 22.95 (g.m-2) for the steepest slope. Although the monitoring period was short, it can be noted that there was a soil loss caused by fire and a slope effect on runoff. It is understood that the contribution of this work to the investigation of the impacts of controlled fire on the properties and physical processes of the soil in shrublands areas allows a broader knowledge of the short-term effects in the Natural Park of Montesinho, NE Portugal.
Fire produces adverse effects on soil, altering its physical, chemical, biological, and mineralogical properties. The Montesinho natural park (MNP), has 1/3 of its area covered by shrublands, which are highly flammable, and combined by the Mediterranean characteristics of the environment, increase the risk of fires. Prescribed fire is a preventive measure of the risk of wildfire, reducing fuel biomass, which is admitted having low impact on the soil, given its low intensity. This study focused on changes in soil physical properties and processes after the application of prescribed fire in a shrubland area of MNP, neighboring a resinous forest settlement. The physical properties were analyzed in three moments: before, immediately after fire and two months after fire. At 11 sampling point, undisturbed samples were taken in the 0 – 5cm layer, in 100 cm3 metal rings. Laboratory determinations included saturated permeability, bulk density, maximum water capacity, field capacity and porosity (macro-, micro-, and total). The bulk density and macropores increased significantly, as well as the maximum water capacity, field capacity, and water storage, decreased; in addition, total porosity and permeability decreased, even if not significantly. However, the combination of all these changes is reported that the hydrological dynamics of the soil changed after the fire, however, tending to return to the stage prior to the controlled fire, at the moment two months after the fire. Soil loss and runoff were monitored for 3 months after burning, through the insertion of 8 microplots of 4m², 4 of them located on a steeper slope and 4 on a flatter slope. The total precipitation during monitoring was 80.2 mm, resulting in an average of 0.616 mm in runoff and 19.51 (g.m-2) in soil loss, for the lower slope and 2.39 mm and 22.95 (g.m-2) for the steepest slope. Although the monitoring period was short, it can be noted that there was a soil loss caused by fire and a slope effect on runoff. It is understood that the contribution of this work to the investigation of the impacts of controlled fire on the properties and physical processes of the soil in shrublands areas allows a broader knowledge of the short-term effects in the Natural Park of Montesinho, NE Portugal.
Description
Mestrado de dupla diplomação com a Universidade Tecnológica Federal do Paraná - UTFPR
Keywords
Áreas ardidas Recuperação pós fogo Matos Propriedades físicas do solo Erosão