ISA - Dissertações de Mestrado
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The Master Dissertations is the collection of academic works produced to obtain the Master degree at the School of Agriculture.
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- Agrivoltaico em viticultura: Caracterização do microclima luminoso e avaliação da resposta fisiológica nas castas Encruzado e ViosinhoPublication . Lisboa, Madalena Dargent Eurico; Lopes, Carlos Manuel Antunes; Victorino, Gonçalo Filipe dos SantosNos últimos anos, tem-se registado um crescente interesse na integração de painéis fotovoltaicos na agricultura, particularmente na viticultura em regiões mediterrânicas, como estratégia de adaptação às alterações climáticas. O presente estudo foi conduzido numa vinha de castas brancas, localizada em Lisboa, com o principal objetivo de avaliar o efeito do sombreamento intermitente gerado por um sistema agrivoltaico no microclima luminoso e na resposta fisiológica das videiras, nas castas Viosinho e Encruzado. Para este fim, foram implementados três tratamentos, com base na posição relativa dos painéis em relação às plantas: painel sobre a videira (PVT), painel sobre as entrelinhas adjacentes (PVL) e sem painéis (controlo). O estudo acompanhou o ciclo vegetativo e reprodutivo das videiras, avaliando variáveis como a radiação solar incidente, as trocas gasosas, a maturação das uvas e a produtividade. Os resultados demonstraram que o sombreamento provocado pelos painéis influenciou a resposta fisiológica das videiras em determinados períodos do dia, dependendo do tratamento, com diferenças significativas na radiação incidente, especialmente em momentos de stress térmico e luminoso. Às 13h, os valores médios de radiação fotossinteticamente ativa foram cerca de 16% no tratamento PVT e 44% no tratamento PVL, em comparação com o controlo. Às 15h, esses valores foram de 71% no PVT e 20% no PVL. Não se observaram diferenças significativas nos valores de potencial hídrico entre os tratamentos, com ambas as castas a apresentarem valores entre -0,75 MPa e -0,96 MPa, não havendo um efeito claro do sistema sobre o estado hídrico das plantas. De igual modo, a condutância estomática variou entre 73,0 e 191,5 mmol H₂O m⁻² s⁻¹, sem diferenças significativas entre os tratamentos. O sombreamento causado pelos painéis fotovoltaicos atrasou a vindima em 11 dias para a casta Viosinho e 31 dias para a casta Encruzado. Apesar das diferenças nas datas de vindima entre os tratamentos, não se verificaram diferenças significativas na composição dos mostos finais. Os resultados deste estudo sugerem que o sistema AgriPV apresenta elevado potencial como ferramenta de adaptação às alterações climáticas, com capacidade para equilibrar a produção vitícola e energética. Contudo, são necessários mais estudos de longo prazo, em diferentes regiões e condições climáticas, para confirmar o seu impacto na produtividade e qualidade do vinho.
- Green, Scorched, or Consumed? Classifying fire effects on forest canopies with Satellite data and Machine learningPublication . Thomas, Aswin; Pereira, José Miguel Cardoso; Campagnolo, Manuel Lameiras FigueiredoThis study develops a highly accurate model to assess the impact of wildfire severity on forest canopies in Portugal using remote sensing techniques based on training data extracted from 11 large fires, integrating Landsat satellite data, the Random Forest (RF) algorithm, and the Tasseled Cap Transformation (TCT). The model distinguishes between three levels of fire severity: green (low), scorched (moderate), and consumed (high). The three main TCT components - brightness, greenness, and wetness - are used in the research to characterize the effect of fire on forest canopies. The Copernicus Tree Cover Density (TCD) dataset was utilized to create a forest mask, which guaranteed that the categorization was limited to forested regions. The model demonstrated its effectiveness with a classification accuracy of over 90%, highlighting the usefulness of combining RF and TCT for fire severity mapping. Fires in locations such as Gois, Pedrogão, and Leria exhibited more accurate classification results compared to other regions, with the greenness component being the most significant predictor of fire severity. Fire severity maps for seven large fire occurrences between 2013 and 2019 were created using the model. Maritime pine and eucalyptus, the dominant species in these forests, were particularly impacted by high-severity fires, especially in regions prone to recurrent wildfires. This study provides important information for ecological preservation and post-fire management. The generated fire severity maps can assist in planning restoration efforts, implementing species-specific rehabilitation, and developing strategic forest management practices to mitigate future fire risks. The study further suggests the potential for using higher-resolution datasets, such as Sentinel-2, spaceborne LiDAR data from the GEDI and ICESat-2 missions to refine future assessments of fire impacts.
- Designing a spatiotemporal fuel break maximizing wildfire resistancePublication . Saha, Sajal; Marques, Susete Maria Gonçalves; Tóth, Sándor F.Wildfires that are not under control pose a major threat, leading to significant loss of human life, destruction of economic assets, and irreversible damage to natural ecosystems, underscoring the urgent need for improved fire management and prevention strategies. Fuel treatment, together with wildfire resistance indices, is a valuable technique to lessen wildfire devastation. In this research, we propose an approach to design a spatiotemporal fuel break to reduce the spatial connectivity of fuel hazards integrating wildfire resistance. A mixed integer programming (MIP) model is formulated in such a way that it breaks the connectivity of high-risk regions as a means to maximize wildfire resistance in the landscape. To test the modeling approach, we considered Vale do Sousa as our case study area, which is in Northwestern Portugal and spans three districts: Paiva, Paredes, and Penafiel. We put our method to the test in Paiva County. The model was considered for a five 10-year periods planning horizon and up to a total of 47,448 prescriptions, an average of 69 prescriptions per stand for maximizing wildfire resistance. The research area encompasses 7,487 hectares and split into 686 stands; among them 5 stands are isolated. A total of 770 prescriptions were selected to maximize wildfire resistance. This difference resulted because of selecting two prescriptions for the mixed stands comprising two species. The model comprised 16,883 constraints and 56,591 variables. Among them 54,283 were binary variables. The objective of the problem was to maximize the average landscape-level fire resistance score. The optimization resulted in an objective function value of 4.08. This indicator's values ran from 1 (low resistance) to 5 (highest resistance). Results showed that the model can locate fuel break patches in the case study area during five planning periods. The result directed a species wise conversion in the landscape level from beginning of the planning horizon to end of the planning horizon. In eucalyptus-dominated stands, for instance, the prescription advised species conversion to cork oak and chestnut, which are less flammable and have longer rotation years, therefore lowering the overall fire risk as well as increasing the wildfire resistance in the landscape. The innovation of the model is the attempt to incorporate wildfire resistance indicators to find the fuel break places. Our approach effectively sustained the adjacency issues and implicitly maintained connectivity between fuel breaks. The model also successfully constrained the area of harvested stands, ensuring the fuel break remained within the specified minimum and maximum limits set in the model. The study added a new dimension to fuel break optimization by integrating wildfire resistance indicator, spatial dynamics and temporal planning.
- Determination of gluconic acid in grape must by enzymatic methodPublication . Puppo, Laura; Catarino, SofiaGluconic acid is a key indicator of grape health and wine quality, particularly in musts and wines affected by noble or grey rot caused by Botrytis cinerea. High concentrations, often reaching several grams per liter, indicate the severity of infection and can negatively impact fermentation, clarity, and stability. However, noble rot can also enhance desirable sensory characteristics, such as honey and apricot aromas, in certain wine styles like Tokaji and Sauternes. This study aimed to study and validate an enzymatic method for determining gluconic acid in must, in accordance with OIV guidelines, for future implementation at ISA's Laboratory. The main parameters studied were analytical limits, precision (repeatability and intralaboratorial reproducibility), and accuracy (recovery). A calibration curve was constructed using gluconic acid standards from 0 to 2 g/L, with absorbance being measured at 340 nm. The resulting equation, y = 1.1991x - 0.0072 (R² = 0.999), demonstrated excellent linearity. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.101 g/L and 0.268 g/L, respectively, confirming the method’s sensitivity for low concentrations. Precision was evaluated through repeatability studies, with coefficients of variation (CV%) ranging from 5.06% to 13.616% for red must and around to 26% for white must. Accuracy was evaluated through recovery studies, with unsatisfactory results for both musts, likely due to issues in spiking trials. In conclusion, while the enzymatic method demonstrated good sensitivity and precision, its performance in terms of accuracy showed significant limitations. Refinements in sample preparation and more rigour in addition trials will be necessary to properly evaluate this characteristic. Moreover, as the results were obtained using only a white and a red must from a single vintage, further trials on different grape varieties and vintages are essential to draw more consistent conclusions about the method’s performance across various matrices, ensuring robustness for broader applications.
- The role of 'M Series' rootstocks in the adaptation of sparkling wine viticulture in Franciacorta Wine Region to climate change (North Italy)Publication . Cavalli, Roberto; Cola, Gabriele; Costa, Joaquim Miguel Rangel da CunhaNew adaptation strategies and techniques are needed to increase resilience of vineyards to the effects of climate change. Currently, most of the vineyards are grafted onto few century-old rootstocks, selected from a relatively small gene pool. The development of new biotypes can represent a turning point for modern viticulture. In fact, the rootstock choice from an enriched pool of genotypes, could represent a winning adaptive solution, positively influencing the behaviour of the scion by increasing its performance, considering the specific environmental context and oenological target. The M series rootstocks, developed by the University of Milan in the eighties, when the first signs of climate change effects appeared and officially registered in 2014, were tested in different environments and with different grafting combinations. This work focuses on the evaluation of rootstocks performances in combination with Chardonnay in the specific context of sparkling wine production in Franciacorta (Lombardy, Italy). The four M rootstocks (M1, M2, M3, M4) and the widely adopted SO4 and 1103P were analysed considering drought stress tolerance, vegetative growth (vigour), yield and berry quality. Microvinifications of grapes from each scion-rootstock combination were made in 2022 and 2023 and analysed and evaluated by a tasting panel. The rootstock 1103P showed good tolerance to water stress condition and was characterized by late ripening and a balanced sugar and acidity profile. However, it did not perform well in terms of sensorial analysis of wine. SO4 demonstrated a very good tolerance to water stress and maintained a stable but average sugar/acidity ratio along the four seasons. The M4 revealed to be the most interesting of the M-series showing a good water stress tolerance, a high acidity-sugar ratio, concurrent with an earlier ripening that allows for a more balanced ripening in terms of aromas, as confirmed by the tasting panel scores.
- Shoot topping and training system as adaptation strategies in a climate change context in Franciacorta Vine Growing Region (North Italy)Publication . Crescini, Francesco; Gabriele, Cola; Costa, Joaquim Miguel Rangel da CunhaThe present research work focuses on the results of the first year of evaluation of two different adaptation measures to climate change analysing the impact of shoot hedging and the training system adopted on berry grape ripening, yield and wine parameters. The experiment was performed using plants of the variety Chardonnay grafted on SO4 , in Franciacorta vine growing region (North Italy) in 2023. Two trials were carried out. The first trial evaluated shoot hedging and 4 treatments were applied : 1)long hedging, 2) short hedging, 3) hedging at veraison and 4) no hedging. The second trial evaluated the effect of the training system experiment. Three systems were studied: Geneva Double Curtain (GDC), Guyot and Sylvoz. The results of the study show a significant effect of the treatments on the measured parameters. In the case of shoot hedging, the weather conditions favoured a high vegetative response which resulted in a vegetative-reproductive imbalance. In 2023 vintage shoot hedging resulted in delayed maturation. Moreover, the highest berry’s total acidity was found with the smaller canopy wall treatment, while higher sugar levels were obtained in the no hedging treatment .The sensorial analysis of the resulting wine mainly differs in shoot wrapping treatment, being the more complex and reporting more mature sensorial traits. With reference to the training system trial , a delayed ripening of grapes was observed for GDC, which was not able to reach full ripeness due to the high bunch load and low leaf area. Sylvoz resulted in the highest sugar accumulation, with the highest yield per plant but the lowest yield per hectare. From the evaluation of the vegetative-productive balance Guyot resulted as the most balanced treatment, able to maintain the acidity in both, must and wine. The sensorial analysis of the resulting wine doesn’t show sharp differences except for Sylvoz that results with slightly greater aromatic intensity, with more pronounced floral and tropical notes. The meteorological conditions of the 2023 vintage were not limiting for grapevine growth and production quality, as it is expected to be the case in the future due to climate change. Thereby the finding needs to be implemented with the future results allowing to have a broader perspective of the studied adaptation measures in a climate change context.
- Vineyard Management in Château Petit-Village in Pomerol, FrancePublication . Bellido, Leopoldo Félix Tena; Lopes, Carlos Manuel Antunes; Pedco, ChiaraThis thesis provides an in-depth analysis of vineyard management practices conducted during an internship at Château Petit-Village, a 10.5-hectare vineyard in Pomerol, Bordeaux. The internship, from March to August, involved various operations from pruning to pre-harvest maturity control. Due to an unusually rainy season, grape ripening was delayed, requiring increased phytosanitary treatments and highlighting the complexity of managing a vineyard under challenging weather conditions. Key focus areas included soil management, canopy control, and the use of cover crops to improve soil health and prevent erosion. The introduction of the Vitibot Bakus, a semi-autonomous electric tractor, was vital in optimizing labor efficiency. However, the year’s heavy rainfall necessitated 23 phytosanitary treatments, including organic-approved copper and sulfur-based solutions. The vineyard’s organic certification posed challenges, as the limited range of treatments complicated disease management. It also shows the efforts to optimize vine health through canopy management techniques like leaf and shoot thinning, which improved sunlight exposure and reduced disease risks. Cover crops, tailored to each plot’s needs, enhanced soil structure and biodiversity, aligning with the vineyard’s commitment to sustainable agriculture and its High Environmental Value (HVE) certification. Additionally, the thesis examines the vineyard’s disease monitoring program, particularly focusing on the Esca complex and Fanleaf Disease, both of which threaten vine longevity. In the last chapter a critical evaluation of the vineyard’s management strategies is done, suggesting that the labor force structure and organic certification be re-evaluated in light of the challenges posed by extreme weather conditions. A more flexible approach, potentially incorporating conventional farming techniques, may be necessary to ensure both grape quality and economic sustainability.
- Qualidade nutricional, bioativa e microbiológica de farinhas de inseto edíveis, alimentados com subprodutos de origem vegetal e de pescadoPublication . Dias, Rafaela Andrade; Abreu, Marta; Martins, Maria Luisa LouroNeste estudo, avaliou-se a adequação de dietas alternativas como substitutos parciais ou totais de alimentos comerciais (RC) na criação em cativeiro de grilos da espécie Acheta domesticus. Foram testados alimentos compostos formulados a partir de subprodutos (hortofrutícolas- HF e pescado- SP), com o objetivo de produzir farinhas de inseto para consumo alimentar. Foram testadas três formulações: RI (50% HF + 50% RC), RII (33% HF + 33% RC + 33% SP) e RIII (50% HF + 50% SP), e as farinhas produzidas a partir dos grilos criados com essas dietas. As características composicionais dos alimentos compostos e das farinhas foram avaliadas considerando atributos nutricionais, bioativos e microbiológicos. Os resultados permitiram concluir que as RI e RII, mostraram-se adequadas para a criação de grilos, permitindo a conversão eficiente dos alimentos compostos em massa corporal. A comparação das RI e RII revelou diferenças significativas na composição, com a RI apresentando maior teor de hidratos de carbono, enquanto a RII destacando-se pelos teores mais elevados de humidade, lípidos, fibra bruta, cinzas e minerais. A RIII, resultou num desenvolvimento limitado inviabilizando a produção de farinha. As farinhas FI e FII apresentaram elevado teor proteico ( 60%). Independentemente da dieta, demonstraram elevada qualidade proteica, com um perfil de aminoácidos diversificado, incluindo todos os essenciais, elevado teor de minerais (K, P, S, Na, Ca e Mg), superando fontes proteicas tradicionais. Além disso, as contagens microbiológicas e os níveis de cádmio, chumbo e gordura saturada, foram compatíveis com o Regulamento (UE) 2022/188. Contudo, os níveis de mercúrio na FII excederam o limite referido no Regulamento (UE) 2023/915. A composição das farinhas foi, no entanto, influenciada pela dieta dos insetos: a FI destacou-se pela capacidade antioxidante e maior teor de ácidos gordos saturados e aminoácidos; enquanto a FII apresentou maior teor de proteína, cinzas, minerais e ácidos gordos monoinsaturados.
- Are threats to Iberian freshwater fish species affecting specific trait characteristics?Publication . Sêco, Juliana Pessoa; Duarte, Gonçalo Filipe Fernandes; Branco, Paulo José de LemosThe Iberian Peninsula has one of the highest levels of biodiversity and endemicity of freshwaterdependent fish in Europe. However, due to significant natural and anthropogenic pressures, it has one of the most endangered freshwater-dependent fish communities. Management actions tend to rely on taxonomic-centered assessments, where existing alterations are generally a delayed consequence of longer habitat disruption. Few studies have explored the link between various traits of freshwater fish and their threat status on the Iberian scale. This study aims to determine if the threat level of this group of species is biased towards specific functional trait characteristics and if species with distinct conservation categories have a distinctive pool of functional traits. Data from 62 Iberian freshwaterdependent fish species were gathered and related to their International Union for Conservation of Nature (IUCN) Red List conservation status. These categories also allowed a categorization of threatened versus non-threatened species. Ecological traits include climate zone, critical thermal maxima, adult size, longevity, length of the breeding season, female maturity, adult trophic status and level, habitat spawning and feeding preferences (hydrology and substrate type) and migratory behavior. Morphological traits consist of ratio measurements of body characteristics and body shape. Additionally, the influence of the number of basins and the species’ total distribution area was also analyzed. Results showed that threatened species were associated with smaller body size, shorter longevity, and higher thermal tolerance. Diadromous species' threat levels were more correlated to morphological traits linked to dispersal capacity, critical for their life cycles. There are no differences in the functional space of species with different conservation statuses, possibly due to the intense pressures affecting these species. The present work demonstrates that conservation strategies should consider functional diversity losses and focus not only on conserving individual species but also on maintaining the ecological balance of ecosystems.
- Utilização de corretivos derivados de resíduos na recuperação de solos afetados por atividades mineiras (Mina de Aljustrel - Faixa Piritosa Ibérica)Publication . Athayde, João Pedro Ramos; Alvarenga, Paula; Mourato, Miguel BarbosaO uso de corretivos derivados de resíduos constitui uma alternativa sustentável, com potencial para melhorar as propriedades de solos afetados por metais, contribuindo para estratégias de remediação de solos e para a promoção da economia circular. Este trabalho teve como principal objetivo a avaliação da eficácia da aplicação de concha de ostra moída (em substituição do carbonato de cálcio tradicional), combinada com corretivo proveniente da fração orgânica de resíduos sólidos urbanos na recuperação de um solo ácido proveniente da zona mineira de Aljustrel. O estudo foi dividido em três partes, que completam esse objetivo: (i) a avaliação da correção da acidez do solo utilizando concha de ostra moída; (ii) a capacidade de melhoria das propriedades físico-químicas do solo, incluindo o aumento do pH e a correção da fertilidade, através da aplicação combinada de concha de ostra moída e composto de resíduos sólidos urbanos (RSU), visando a revegetação da área; e (iii) a capacidade da combinação de concha de ostra moída e composto de RSU na imobilização dos elementos tóxicos presentes no solo contaminado. Os resultados obtidos demonstram o potencial da utilização da concha de ostra moída como agente alcalinizante sustentável na calagem do solo da Mina de Aljustrel, com pH muito ácido (pH 4,3), tendo sido possível nas doses 20 e 30 t/ha elevar o pH para valores entre 5,8 e 6,2, respetivamente. Com a aplicação simultânea de 50 t/ha de composto de RSU (Classe I), essa correção de pH mantém os valores de pH próximos de 6, para além de elevar significativamente os teores de matéria orgânica, e teores em N total, P e K extraíveis, o que poderá aumentar a fertilidade do solo. As análises dos teores em elementos potencialmente tóxicos totais corroboraram as análises iniciais: os valores totais de Cu, Zn, Cd, As e Pb permaneceram acima dos limites de referência preestabelecidos no Guia Técnico da Agência Portuguesa do Ambiente de 2022, mas a aplicação dos tratamentos permitiu a sua imobilização para teores muito baixos, por vezes abaixo do limite de deteção da técnica, o que diminui a sua biodisponibilidade e o risco da sua lixiviação.