Percorrer por autor "Barroso, Ana"
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- A comparison of analytical methods for the determination of soil pH: case study on burned soils in Northern PortugalPublication . Faria, Maria; Bertocco, Tamires; Barroso, Ana; Carvalho, Manuela; Fonseca, Felícia; Matos, Cristina Delerue; Figueiredo, Tomás de; Braga, Amalia Sequeira; Valente, Teresa; Jimenez-Ballesta, RaimundoWildfires can cause serious imbalances in ecosystems, primarily at the soil level, making it vulnerable to degradation processes such as erosion. During and after a fire, changes occur in soil properties, including pH, which affects the solubility and availability of nutrients. Currently, there is a great diversity of protocols, some involving normalized standards, to determine soil pH, but there is no consensual or universal analytical method for this parameter, especially in burned soils, in which mineral and organic fractions could have been modified. Therefore, the objective of the present work is to evaluate the effect that variations in these analytical protocols may have on pH results. For this, five methods commonly found in the international bibliography for the analysis of pH of soil in water (pH(H2O)) were selected and compared to propose the most precise procedure. The analytical methods were applied to 43 soil samples, collected in a plot subjected to prescribed burning in the Parque Natural de Montesinho (Northern Portugal). The studied methods differ in the following protocol items: water suspension ratio (1:2.5 or 1:5), mechanical stirring time in the suspension (10 min or 1 h), and in the resting time for the solid particles to settle (15 min or 8 h). The obtained results point to the suitability of the five methods used for soil pH analysis, indicating that there are no statistically significant differences. However, results also allow suggesting a more appropriate method concerning practical reasons, such as labor in a lab. Thus, to make the analysis process more profitable, M2 is a good option because it uses a small amount of sample (5 g), short agitation (10 min) and settling time (15 min). In turn, M1 and M5, which use a lower proportion of soil (1:2.5) show lower pH variation in the measurements. This fact may be explained by a smaller dilution effect. Considering that these two methods differ in the settling time, it is suggested to apply M1, because only 15 min are required. Therefore, the main conclusion reached with this work is that the measurement of soil pH using M1, i.e., a soil:water ratio of 1:2.5, with agitation of 10 min and settling time of 15 min, is a robust and more expeditious protocol to be applied to soil samples after a fire.
- Deteção remota apoiada por veículos aéreos não tripulados (VANT) aplicada à monitorização de áreas sujeitas a incêndios florestaisPublication . Barroso, Ana; Royer, Ana Carolina; Alves, Leonardo Kipper; Piovesan, Eloiza de Lima; Fernandes, M.; Teixeira, Bruno Rafael Silva; Alves, Diogo; Santos, Patrícia; Fonseca, Felícia; Pamplona, Jorge Manuel; Carvalho, Manuela; Henriques, Renato; Hernández, Zulimar; Delerue-Matos, Cristina; Figueiredo, Tomás de; Valente, TeresaOs incêndios florestais, nas últimas décadas, têm aumentado em termos de frequência, intensidade e extensão. Em consequência, têm também crescido as preocupações pelos efeitos ambientais negativos destes eventos, nomeadamente nas propriedades dos solos. A gravidade das modificações depende, entre outros aspetos, da intensidade e/ou severidade do fogo, topografia local e tipo de vegetação. A monitorização das áreas ardidas é pois essencial para compreender a evolução das propriedades do solo e sua interação com a vegetação, bem como as tendências de recuperação ao longo do tempo. É neste contexto que se reforça a utilidade das técnicas de deteção remota, proporcionando ferramentas eficazes para o acompanhamento de áreas florestais queimadas. Mais frequentemente, esta monitorização faz-se com recursamento ao processamento de imagens de satélite, antes e pós incêndio. As aplicações mais comuns referem o mapeamento ara obtenção de modelos digitais de superfície (MDS) e cálculo de índices de vegetação (NDVI) ou de áreas ardidas (NBR) e volume de biomassa. No entanto, as imagens de satélite apresentam algumas limitações, nomeadamente quanto à resolução espacial e temporal, condicionando assim a qualidade dos dados. Estas limitações são ultrapassadas com a utilização de veículos aéreos não tripulados (VANT), que possibilitam uma maior resolução espacial. No presente trabalho mostra-se um caso de aplicação deste tipo de tecnologia numa área situada no Parque Natural de Montesinho (Aveleda, Bragança, Portugal). São apresentados os resultados de levantamentos fotogramétricos, realizados antes e após um fogo controlado, que proporcionaram imagens obtidas com um VANT Dji Phantom 4RTK. O tratamento dos dados resultantes dos voos permitiu a obtenção de ortofotomapas e MDS, abrindo a possibilidade de estimar o volume de biomassa e avaliar a evolução do processo de revegetação natural. A realização de voos de pormenor, em pequenas secções da parcela, permite ainda um acompanhamento de elevada resolução do efeito do fogo em termos de perda de solo por erosão.
- TERRAMATER project: a tool for post-fire rehabilitation and restoration of soilsPublication . Macías, Felipe; Antelo, Juan; Verdes, P.V.; Figueiredo, Tomás de; Fonseca, Felícia; Hernández, Zulimar; Valente, Teresa; Barroso, Ana; Henriques, Renato; Carvalho, Manuela; Fernandes, Maria João; Teixeira, Salomé; Delerue-Matos, Cristina; Macías-García, FelipeIn recent years the risk of wildfires in the regions located in the Portuguese-Spanish border varied between moderate to high or very high. The loss of the vegetation cover and the presence of huge areas of unprotected soil due to the occurrence of large wildfires, as well as the limited post-fire protection actions, have increased the risk of soil erosion to catastrophic levels. Thus, it is crucial to act immediately to restore the ecosystem, avoid or minimize the soil erosive processes and the impact to the forest masses in the affected areas. The main objective of the TERRAMATER project is the recovery of the environmental, ecological and productive functions of burnt areas, reducing soil losses due to erosion and increasing soil resilience to future episodes of wildfire. The improvement of ecological functions in the recovered areas also aims to reduce the threat of pests in the neighboring forest masses. This will be achieved by remediation actions conducted in soils affected by wildfires or prescribed fires, including the application of soil amendments based on the use of technosols obtained from organic wastes and industrial byproducts. The soil plots selected for the study correspond to areas in the north of Portugal and northwest of Spain, dominated by either Atlantic-type or Mediterranean-type shrublands. The amendments will be previously formulated and tested under controlled conditions according to the soil information obtained and the local knowledge of post-fire ecological conditions. Also, the biogeochemical processes associated with the recovery and improvement of the quality of the affected soils will be taken into account. The application of the technosol amendments, will produce an increase in the organic carbon pools and promote the protection and improvement of the soil quality, which will result in an opportunity for ecological restoration of burnt areas and the subsequent reduction in emissions of greenhouse gases. Finally, this application will help to minimize the pollution of water bodies close to the burnt areas resulting from the runoff of nutrients and suspended materials from ashes.