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Abstract(s)
Os fogos florestais são uma realidade presente com graves consequências ambientais, sociais e económicas. Em Portugal a ocorrência de fogos florestais tem-se vindo a agravar, verificando-se considerável aumento na média anual de área ardida; nos últimos dez anos, mais de 1,5 milhões de hectares arderam. As questões relacionadas com a gestão da floresta e as condições climáticas, nas quais se chega a atingir temperaturas superiores a 40°C, com escassez de água no solo, nos meses mais quentes, serão fatores chave neste problema. Estes fogos, com as mais variadas intensidades, provocam danos graves nos ecossistemas, causando efeitos nefastos no solo, pondo em causa as suas funções e serviços ao ecossistema. Assim, o estudo das propriedades físico-químicas do solo, antes e após o fogo, é relevante, o seu conhecimento permite uma melhor compreensão e previsão do comportamento do solo e, ainda, planear e adotar estratégias mais eficazes na mitigação dos danos causados pelo fogo. O presente trabalho teve como objetivo principal a avaliação do impacto de um fogo prescrito nas propriedades físicas e químicas de um solo florestal da zona do Parque de Montesinho em Bragança (NE de Portugal), avaliando o seu impacto ao longo do tempo, a quatro profundidades diferentes, entre os 0 e os 20 cm. Para o efeito, foi realizada amostragem antes do fogo prescrito, imediatamente após o fogo e dois messes após. Em cada um destes momentos, foram realizados ensaios laboratoriais sobre as amostras colhidas para determinação da granulometria, teor em água, condutividade elétrica, pH, teor em matéria orgânica, conteúdo em carbono orgânico total e análise química elementar. Na presente dissertação é apresentada uma síntese teórica da problemática em estudo, as metodologias de trabalho utilizadas durante os estudos realizados, os resultados obtidos nos vários ensaios e respetiva análise. Por fim, são tecidas considerações finais e apresentadas algumas perspetivas para trabalhos futuros.
Wildfires are a present reality with serious environmental, social, and economic consequences. In Portugal, wildfires have been worsening, with a considerable increase in the average annual area burnt; in the last ten years, more than 1.5 million hectares have burnt. Issues related to forest management and climatic conditions, in which temperatures can reach over 40°C, with a shortage of water on the ground in the hottest months, are key factors in this problem. Furthermore, these fires, with the most varied intensities, cause severe damage to ecosystems, causing harmful effects on the soil, calling into question their functions and services to the ecosystem. Thus, the study of soil physical and chemical properties before and after the fire is relevant. Its knowledge allows a better understanding and prediction of soil behaviour and plans and adopts more effective strategies to mitigate damage caused by fire. The main objective of the present work was to evaluate the impact of prescribed fire on the physical and chemical properties of forest soil in the Montesinho Park area (Bragança, NE Portugal), assessing its impact over time, at four different depths, between 0 and 20 cm. For this purpose, sampling was carried out before the prescribed fire, immediately after the fire and two months after. At each moment, laboratory tests were performed on the samples collected to determine granulometry, water content, electrical conductivity, pH, organic matter content, total organic carbon content, and elemental chemical analysis. This dissertation presents a theoretical synthesis of the problem understudy, the work methodologies used during the studies carried out, the results obtained in the various tests, and their analysis. Al last, final remarks are made, and some perspectives for future work are presented.
Wildfires are a present reality with serious environmental, social, and economic consequences. In Portugal, wildfires have been worsening, with a considerable increase in the average annual area burnt; in the last ten years, more than 1.5 million hectares have burnt. Issues related to forest management and climatic conditions, in which temperatures can reach over 40°C, with a shortage of water on the ground in the hottest months, are key factors in this problem. Furthermore, these fires, with the most varied intensities, cause severe damage to ecosystems, causing harmful effects on the soil, calling into question their functions and services to the ecosystem. Thus, the study of soil physical and chemical properties before and after the fire is relevant. Its knowledge allows a better understanding and prediction of soil behaviour and plans and adopts more effective strategies to mitigate damage caused by fire. The main objective of the present work was to evaluate the impact of prescribed fire on the physical and chemical properties of forest soil in the Montesinho Park area (Bragança, NE Portugal), assessing its impact over time, at four different depths, between 0 and 20 cm. For this purpose, sampling was carried out before the prescribed fire, immediately after the fire and two months after. At each moment, laboratory tests were performed on the samples collected to determine granulometry, water content, electrical conductivity, pH, organic matter content, total organic carbon content, and elemental chemical analysis. This dissertation presents a theoretical synthesis of the problem understudy, the work methodologies used during the studies carried out, the results obtained in the various tests, and their analysis. Al last, final remarks are made, and some perspectives for future work are presented.
Description
Keywords
Fogo prescrito Solo Solo queimado Geoambiente Prescribed fire Soil Burnt soil Geoenvironment