Northeastern Portugal Research Articles

Foliar application of biostimulants improves nutritional and bioactive quality of walnuts.

Owing to their health benefits, walnuts are attracting interest as a good option for nutritious meals, thereby promoting their production. Furthermore, the adoption of ecologically and environmentally friendly agriculture strengthens biostimulant use as a sustainable complement to traditional fertilizers. This study evaluated the effects of different foliar-applied biostimulants in walnut tree orchards, in northeastern Portugal, on walnuts' chemical composition and bioactivity. Walnut samples were rich in fat (particularly the polyunsaturated linoleic acid), dietary fiber and protein. Sucrose was the most prevalent soluble sugar, followed by glucose and fructose. Studied samples also showed an antioxidant activity comparable (or superior) to that of Trolox. Some plant biostimulants (e.g. Sprint Plus®) had a positive impact on the nutritional composition of walnuts, more specifically by boosting tocopherol levels, besides improving the bioactivity of walnut extracts against specific bacteria. Overall, this research demonstrated that important quality traits of walnuts can be improved using sustainable agricultural bioproducts and practices. © 2024 Society of Chemical Industry.

Prevalence of Type 2 Diabetes Risk in a Higher Education Community of North-Eastern Portugal: a Prospective Cross-sectional Observational Analysis

Objectives: Type 2 diabetes (T2D) is considered one of the most prevalent diseases worldwide. The aim of this study was to analyse the risk of developing T2D in a higher education community of Bragança, North-Eastern Portugal.Methods: The observational, cross-sectional and prospective sample comprised 3021 individuals, aged between 18 and 64 years old, of whom 1759 were women (mean age 24.16 ± 8.80 years) and 1263 were men (mean age 23.37 ± 8.70 years). The Finnish Diabetes Risk Score (FINDRISC) questionnaire was employed to estimate the risk of developing T2D over the next 10 years.Results: The results indicated that approximately 37 (1%) participants in the sample exhibited a high risk of developing T2D, 117 (4%) participants exhibited a moderate risk, 660 (22%) participants exhibited a slight risk, and 2206 (73%) participants exhibited a low risk. A higher T2D risk was observed in the staff group in comparison with the other groups (p < 0.001). Furthermore, body mass index (BMI) and waist circumference (WC) were the variables that most contributed to the increased risk of developing T2D (X2 = 1034.5; p < 0.001).Conclusions: In conclusion, the study reported a low T2D risk for the higher education community of Bragança in the Portuguese North-Eastern region. However, the risk of T2D was found to be higher in the staff group than in the student group. The FINDRISK questionnaire may be applied for the early diagnosis of T2D risk factors.

Changes in bryophyte functional composition during post-fire succession

Climate and land-use changes are altering fire regimes in many regions around the world. To date, most studies have focused on the effects of altered fire regimes on woody and herbaceous communities, while the mechanisms driving post-fire bryophyte succession remain poorly understood, particularly in Mediterranean-type ecosystems. Here, we examined changes in bryophyte functional composition along a post-fire chronosequence (ranging from 1 to 20+ years) in Pyrenean oak woodlands (northeastern Portugal). To do so, we defined bryophyte functional groups based on seven morphological, reproductive, and life history traits. Then, we fitted linear and structural equation models to disentangle the direct and indirect effects of fire (time since fire and fire intensity), vegetation structure, climate, topography, and edaphic conditions on the abundance of each group. We identified two main functional groups: early colonizers (species with traits associated with strong colonization ability and desiccation tolerance) and perennial stayers (species with high competitive ability, i.e., large perennial mosses). Overall, the abundance of early colonizer species decreased with time since fire and increased with fire intensity, while the opposite was observed for perennial stayers. Thus, successional dynamics reflected a trade-off between species' competitive and colonization abilities, highlighting the role of biotic interactions later in succession. Patterns of functional composition were also consistent with changes in environmental conditions during succession, suggesting that species may experience stressful conditions (i.e., high radiation and low water availability) in early stages of post-fire succession. Our results also indicate that increased fire intensity may alter successional trajectories, leading to long-term changes in bryophyte communities. By understanding the response of bryophyte communities to fire, we were able to identify species with potential use as soil restoration materials.

Leishmania Seroprevalence in Dogs: Comparing Shelter and Domestic Communities.

Canine leishmaniosis (CanL) is a chronic, systemic, and often severe disease. The main causative agent of CanL is a protozoan parasite, Leishmania infantum, with phlebotomine sand flies acting as vectors. In Europe and other continents, L. infantum is also responsible for leishmaniosis in other animals, such as cats, horses, and humans. In Portugal, animal and human leishmaniosis is endemic, and high prevalence levels of infections and disease have been reported in dogs. There is a prejudice against stray animals and also those housed in shelters, assuming they have higher levels of infection with vector-borne pathogens, including L. infantum, when compared to domestic animals. In northeastern Portugal, serum samples were obtained from March to May 2022 in three shelters (n = 179) and thirteen veterinary clinics (n = 164), resulting in 343 dogs being analyzed for antibodies to Leishmania spp. by the direct agglutination test (DAT). The overall seroprevalence was 9.9%, with 15.2% seroprevalence in domestic dogs and 5.0% in the shelter ones (p = 0.003). The fact that shelter dogs had a lower seroprevalence could be explained by more regular veterinary care provided in shelters regarding preventive measures, including insecticides with an antifeeding effect, in comparison with domestic dogs.

Evaluation of historical and future thermal conditions for almond trees in north-eastern Portugal

The Trás-os-Montes agrarian region (TM; north-eastern Portugal) is a traditionally growing area of almond trees. However, climate change may significantly alter the current growing conditions and threaten sustainability. Chilling and forcing conditions in TM are assessed herein, also considering different varietal phenological timings. The dynamic model/chill portions (CP) and chilling hour (CH) models are used to assess the chilling phase. For the forcing phase, growing degree hours (GDH) and growing degree days (GDD) models are selected, hinting at differences between simpler (CH and GDD) and more complex models (CP and GDH). Furthermore, the climate change projections for these models are assessed. The models are computed using daily temperatures for baseline (Iberia01, 1971–2015) and two future periods (EURO-CORDEX: medium-term, 2041–2060, and long-term, 2061–2080), following two anthropogenic forcing scenarios (RCP4.5 and RCP8.5). For the future, a five-member ensemble of regional-global climate model chains is used. Projections for CP and CH show decreases, mostly for RCP8.5, whereas projections for GDH and GDD reveal an increase in heat conditions until the beginning of summer. GDH shows that potentially damaging high temperatures during summer, effectively lead to a decrease in heat accumulation for almond trees. CP and GDH, more biologically effective, seem to be more accurate in capturing climate change impacts. For the three varietal groups, the late cultivar may experience a greater reduction of CP and GDH compared to early and mid-season varieties. Nonetheless, the increase in heat forcing should be more detrimental than the decrease in chilling conditions. Although almond production may be compromised in the future, adequate adaptation options are suggested to mitigate future losses of yield/quality and warrant its sustainability.

How Can a Changing Climate Influence the Productivity of Traditional Olive Orchards? Regression Analysis Applied to a Local Case Study in Portugal

Nowadays, the climate is undoubtedly one of the main threats to the sustainability of olive orchards, especially in the case of rainfed traditional production systems. Local warming, droughts, and extreme weather events are some of the climatological factors responsible for environmental thresholds in relation to crops being exceeded. The main objective of this study was to investigate the influence of microclimatic variability on the productivity of traditional olive orchards in a municipality located in northeastern Portugal. For this purpose, official data on climate, expressed through agro-bioclimatic indicators, and olive productivity for a 21-year historical period (2000–2020) were used to evaluate potential correlations. In addition, a comprehensive regression analysis involving the dataset and the following modeling scenarios was carried out to develop regression models and assess the resulting predictions: (a) Random Forest (RF) with selected features; (b) Ordinary Least-Squares (OLS) with selected features; (c) OLS with correlation features; and (d) OLS with all features. For the a and b scenarios, features were selected applying the Recursive Feature Elimination with Cross-Validation (RFECV) technique. The best statistical performance was achieved considering nonlinearity among variables (a scenario, R2 = 0.95); however, it was not possible to derive any model given the underlying methodology to this scenario. In linear regression applications, the best fit between model predictions and the real olive productivity was obtained when all the analyzed agro-bioclimatic indicators were included in the regression (d scenario, R2 = 0.85). When selecting only the most relevant indicators using RFECV and correlation techniques, moderate correlations for the b and c regression scenarios were obtained (R2 of 0.54 and 0.49, respectively). Based on the research findings, especially the regression models, their adaptability to other olive territories with similar agronomic and environmental characteristics is suggested for crop management and regulatory purposes.

Children’s Perception of Climate Change in North-Eastern Portugal

Despite the impact that climate change is having on our planet and considering its consequences for future generations, much of the academic literature focuses on adolescent and adult perceptions, giving little relevance to children’s perceptions. Children’s voices have the potential to influence public opinion, which may in turn determine the direction of a new policy on the climate crisis. In this context, it is urgent that we understand how children perceive this problem. This quantitative study was based on the application of 245 questionnaires to children aged between 9 and 13 years old from five schools in north-eastern Portugal, more specifically in the region of Trás-os-Montes. We can say that this study was a convenience study because we delivered the surveys in the schools closest to the working area of the researchers. We used a questionnaire with 26 questions, 24 of which had closed responses (like the Likert type), one open response, and one with multiple choices. In this work, we conducted a descriptive and inferential statistical analysis, and prepared a database, using the statistical software IBM SPSS, which allowed us to conduct some statistical tests, selected according to variables. For the descriptive analysis, several parameters were used for the distribution of variables, namely, frequency, percentage, mean, and standard deviation. We rejected the null hypothesis (H0) and assumed for the inferential analysis that the sample does not follow a normal distribution, considering the fulfillment of the necessary criteria for parametric tests and after performing the Kolmogorov–Smirnov normality test, whose null hypothesis (H0) is that data are normally distributed, and given that the p-value for the variables under study was p < 0.05. In this regard, non-parametric tests were used. The Mann–Whitney test was used to compare the degree of agreement with climate change statements as a function of the student’s gender and year of schooling, which is a non-parametric test suitable for comparing the distribution functions of an ordinal variable measured in two independent samples. The results show that most of the children expressed concern about the study’s potential problem, and (42%) said they are concerned about climate change. However, they show some doubts and a lack of knowledge about some of the themes, like (33.5%) cannot name only one consequence of climate change. We also found differences between the two study cycles, with children in the 6th grade having a higher average in their understanding of the phenomenon (p = 0.049), as well as the level of education of the parents being positively correlated with a more ecocentric posture, we can see this when we considering the variable parents. We also found that 46.6% of the students say that television is where they learn more about climate change. From the results obtained, we can open new paths for future research and contribute to the definition of policies and educational practices since the school has the responsibility to cooperate in the production of values, attitudes, and pro-environmental behaviors.

Technological Innovation in the Traditional Olive Orchard Management: Advances and Opportunities to the Northeastern Region of Portugal

In Portugal, the olive orchard is the most representative agricultural crop and one of the most impactful on the national economy. Therefore, a production structure accompanying the technological advances in this field would be expected; however, such a structure has not yet been realized, especially within traditional systems. Thus, taking northeastern Portugal as a case study, where a great expression of traditional orchards is visible, the following aspects are addressed within this paper: the region’s biophysical framework, the olive orchard’s environmental and socio-economic importance and its current management practices and associated pressures. As a result of that assessment, which demonstrates a low level of sustainability for traditional olive orchards, mainly in terms of economic viability, the most effective and simple solution is to act appropriately on factors that interfere with the crop yield, namely, irrigation and fertilization issues. With that purpose, a multiscale precision oliviculture system is also presented that is being developed in order to support decision making in traditional olive orchard management, aiming to obtain economically efficient productions based on eco-friendly cultural practices. Throughout the entire process, it is essential to ensure stakeholder engagement, in particular, olive growers, so that they recognize the effectiveness of potential measures that may avoid the reconversion/abandonment of the traditional olive production system.

Celtic Music Festivals in Portugal: Europeanisation, Urban Regeneration, and Regional Development

AbstractThis article addresses the interceltic festivals of Porto (1986–2008) and Sendim in Terra de Miranda (since 2000), situated in northwestern and northeastern Portugal, respectively, from the perspective of European heritage festivals. It examines how these two festivals were used to promote tourism, urban regeneration, rural development, image-making, and place branding. We argue that the interceltic festivals of Porto and Sendim are entangled with the Europeanisation of Portugal, involving new possibilities for identification with Europe’s Atlantic fringe, a space that is symbolised by the Celtic imaginary.

Excessive Delay in Nutrient Release by Controlled-Release Fertilizers Can Reduce Chestnut Yield

Farmers are increasing the use of fertilizers in chestnut, the only cash crop produced in the mountainous areas of northeastern Portugal. This calls for more studies to guide them towards a more ecological intensification. The effects of three controlled-release fertilizers, two that release nutrients over three months (BoskGrow 20:05:20_3m, Exactyon 18:05:13_3m) and one over six months (Exactyon 18:05:12_6m), and an organic amendment authorized for organic farming (Humix 12:03:05) were compared with an untreated control during a three-year field trial (2019–2021). BoskGrow 20:05:20_3m, Exactyon 18:05:13_3m and Humix 12:03:05 gave significantly higher nut yields (90.6 to 97.0 kg tree−1, average 2019 + 2021) than Exactyon 18:05:12_6m (66.3 kg tree−1) and the control (69.5 kg tree−1). Leaf concentrations of nitrogen and potassium tended to be higher in the BoskGrow 20:05:20_3m and Exactyon 18:05:13_3m treatments, and they were stated as the most important causes in the establishment of the two productive groups. Humix 12:03:05, although less concentrated in nutrients, led to a chestnut yield at the level of the most productive treatments, possibly due to the multiple positive effects of organic matter on soil and plants. Under the conditions of this experiment, where rainfall is low in the summer, fertilizers whose nutrient release takes a long time, such as Exactyon 18:05:12_6m, seem not to be a good fertilization option due to reduced nutrient uptake and increased levels of soil inorganic nitrogen at the end of the growing season. Humix 12:03:05 emerged as a possible solution for organic producers.

A diagnostic framework for assessing land-use change impacts on landscape pattern and character – A case-study from the Douro region, Portugal

Mediterranean rural landscapes are experiencing multiple changes which imperil the preservation of landscape pattern and character. Despite the abundance of land-use change studies, most approaches do not evaluate the impact of land-use change on landscape character.This study presents a diagnostic framework focused on two main phases: i) the quantification of landscape pattern and analysis of the significant transition processes that occur, and ii) a qualitative appraisal of land-use transitions, classifying them based on whether the landscape character is maintained, neglected, enhancing, or diverging. Four land-use maps from 1995, 2007, 2010 and 2015 covering the Douro region (northeastern Portugal) were analyzed. This region has heterogeneous landscape characters and includes areas classified for their natural and cultural values.Most of the change was compatible with the landscape character (87%), though there was a reduction in heterogeneous agriculture, bare land, and pastureland associated with agricultural abandonment. Landscape patches were more complex and less isolated until 2007, but there has been an opposite trend in recent years. The main change processes are afforestation, loss of forests, and vineyard expansion. The Douro region shows similar trends to other Mediterranean areas, namely the polarization of human influence, driven mainly by depopulation, agricultural policies and wildfires.In conclusion, this diagnostic framework quantified and spatialized the main trends, constituting the first step to analyzing a vast and heterogeneous territory. This study emphasizes the importance of monitoring this landscape in the future to make better-informed decisions regarding landscape planning and maintenance to address challenges such as climate change and depopulation.

Physical and Thermal Properties Analysis of Hematite for Thermal Heat Storage.

Energy sustainability represents an important research topic for aiding decreasing energy dependence and slowing down climate changes. In this context, solutions using thermal energy storage through rock start to emerge, due to its natural benefits, when compared to more polluting alternatives. To understand whether a rock material can be considered a good thermal energy storage material for such solutions, it is necessary to evaluate the physical, chemical and thermal properties of such materials. Therefore, it becomes essential to understand how heat propagates in the rock and how voids influence the thermal properties. To achieve these goals, hematite ore from Moncorvo, Northeastern Portugal was used, in particular, to study the effect of grain size on thermal properties for three different sized lots. Chemical and physical changes between heated and unheated lots were detected using X-ray diffraction and particle size, as well as X-ray fluorescence analysis. Regarding thermal properties, a hot wire method approach was used with seven thermocouples. Additionally, a thermal inversion model to simulate the heat exchanges was also proposed, allowing changing the properties of the constituents, to fit the theoretical and experimental temperature curve. Furthermore, the model reveals how heat propagates inside the reservoir filled with hematite ore.

The Assemblage of Beetles in the Olive Grove and Surrounding Mediterranean Shrublands in Portugal

The olive tree is perfectly adapted to the Mediterranean region, where it represents high economic, social, and landscape importance, olive orchards being an important repository of biodiversity. The order Coleoptera encompasses families that provide important ecosystem services, such as pest limitation. The objective of this work was to compare the assemblage of families of Beetles between the olive grove and their surrounding semi-natural landscape in Trás-os-Montes. The ground beetles on four olive groves and their adjacent shrubland areas were sampled using pitfall traps near Mirandela (Northeastern Portugal) in May and June of 2015 and 2016. Anthicidae, Staphylinidae, and Scarabaeidae dominated the community. The richness of the families was significantly greater in the olive grove in both years of study. On the contrary, the overall diversity did not significantly differ. In both years, the complementarity between the areas was low, reflecting similar communities in terms of families. Predators were dominant in both habitats; therefore, the surrounding landscape could act as shelter and provide alternative resources to the community of Coleoptera inhabiting the olive grove during disturbances derived from agricultural management.

Functional diversity of epigeal spiders in the olive grove agroecosystem in northeastern Portugal: a comparison between crop and surrounding semi‐natural habitats

AbstractThe olive grove agroecosystem (Olea europaea L., Oleaceae) is very important in terms of economy and culture throughout the Mediterranean region. In Trás‐os‐Montes (Portugal), olive groves are commonly surrounded by semi‐natural areas consisting of Mediterranean shrublands. Understanding the role of potential predators of olive pests is crucial to enhancing biological control in sustainable agriculture. This study aimed to investigate the community structure of ground‐inhabiting spiders (Arachnida: Araneae) in the olive grove and their surrounding shrublands in Trás‐os‐Montes. We found that the community of spiders was dominated by ground hunters such as Lycosidae and Gnaphosidae. Lycosidae were more abundant in olive groves than in surrounding shrublands in 2015 only, whereas Gnaphosidae were more abundant in olive groves in both years of the study (2015 and 2016). Hence, the two habitats displayed a low complementarity of spider families. The Mediterranean shrubland areas could act as a reservoir and refuge for potential pest biocontrol agents. Conservation of surrounding semi‐natural areas may contribute to the natural limitation of pests exerted by spiders in the olive grove agroecosystem. Nevertheless, further long‐time and species‐level studies are needed to provide insights into the role of spiders as natural enemies.

The prevalence of metabolic syndrome and its components in Bragança District, North-Eastern Portugal: A retrospective observational cross-sectional study

The prevalence of metabolic syndrome and its components in Bragança District, North-Eastern Portugal: A retrospective observational cross-sectional study

The influence of domestic heating systems in indoor air quality in homes of a region of Northeastern Portugal

The influence of domestic heating systems in indoor air quality in homes of a region of Northeastern Portugal

The influence of domestic heating systems in indoor air quality in homes of a region of northeastern Portugal

The influence of domestic heating systems in indoor air quality in homes of a region of northeastern Portugal

Contribution to the knowledge of Portuguese serpentine flora: ecological characteristics, endemic plants, and implications for biodiversity conservation

Serpentine areas are scarce in the world, but contain a large number of endemic taxa. These areas have, in many cases, been little or not at all surveyed from a vegetation and biodiversity conservation point of view. The most important Portuguese serpentine outcrops are found in northeastern Portugal, particularly in the Bragança-Vinhais and Morais massifs. Here, we present a complete ecological-floristic check-list of serpentinophites that are found in these areas since this knowledge is essential for their evaluation, management and conservation. A total of 25 taxa, classified into three categories with different grades of serpentinophily, were included in the list: (1) obligate serpentinophytes (exclusively on serpentine), (2) endemic or widespread taxa that in Portugal occur exclusively in ultramafic outcrops, and (3) preferential serpentinophytes (most of the distribution range, at least 90% of populations, are found on serpentine). Genera common to other Iberian serpentine areas (Andalusian serpentine flora) are Odontarrhena, Arenaria, Armeria, Asplenium, Paragymnopteris, Saxifraga and Silene. The majority of the studied serpentinophytes (72%) occurred in endemic and highly specialized plant communities. About half of the studied serpentinophytes (48%) are assigned in some IUCN threat category. Consequently, it is necessary to implement conservation measures to guarantee the protection of these habitats. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.2013337 .

A tritrophic interaction model for an olive tree pest, the olive moth — Prays oleae (Bernard)

The olive tree (Olea europaea L.) is among the oldest and most widespread crops in the Mediterranean basin. Portugal is the third olive producer in the European Union, and Trás-os-Montes region, located in northeastern Portugal, is the second Portuguese producing olive region.The olive moth, Prays oleae (Bernard) (Lepidoptera: Praydidae) is a key olive pest in Trás-os-Montes. This pest is a natural host/prey of several organisms which include larvae of generalist and specialist parasitoids as well as generalist predators and entomopathogens. Its most abundant parasitoid is the specialist Ageniaspis fuscicollis (Dalman) (Hymenoptera: Encyrtidae) and this, in Trás-os-Montes region, is commonly followed by the facultative hyperparasitoid Elasmus flabellatus (Fonscolombe) (Hymenoptera: Eulophidae). Spiders represent a relevant group of generalist predators in olive agroecosystems and encompass an important predatory action in agroecosystems as well as an ability to reduce the populations of various insect pests. In this context, a mathematical model, considering the population of the olive moth, the two parasitoids populations and the spider population as the variables in our system, was constructed. The ecosystem steady states for feasibility and stability were assessed. The possible pesticide effects, that represent essentially extra mortality rates for each one of the insect populations, and potential abundance variations on their populations under a climate change scenario were included. Results indicate that the most important natural control agent is A. fuscicollis but in certain conditions E. flabellatus or spiders may be relevant contributors for the pest reduction. This approach may provide a useful tool to assist the field researchers on this pest system and its management.

Hop dry matter yield and cone quality responses to amino acid and potassium-rich foliar spray applications

The use of amino acid and K-rich foliar sprays was evaluated in a commercial hop field in North-eastern Portugal. Four applications of an amino acid-rich foliar spray were performed in place of a second side dress N application of ⁓70 kg N ha−1, which is usually applied by the farmer. The K-rich foliar spray was applied once at the cone developing stage as a supplement to the farmer’s fertilization plan. The amino acid-enriched foliar spray maintained crop dry matter yield at the levels of the control treatment and increased cone alpha-acids concentration (41.8% in 2018 and 9.3% in 2019). Foliar K did not increase cone dry matter yield, cone size or bitter acid concentration. Tissue K concentration was not significantly affected by foliar treatments whereas the application of K seemed to increase N uptake, with leaves and stems being the predominant allocation tissues. Both foliar treatments increased leaf and stem Mg concentrations. The results seem to emphasize the importance of amino acids in the biosynthesis of bitter acids, while K and Zn seemed to play an important secondary role, maybe related to N metabolism and its reduction into amino acids. The concentrations of total phenols in cones and leaves were lower in the foliar treatments in comparison to the control, and the higher values registered in leaves. In this study, the use of amino acids as a foliar spray provided an interesting result, since they maintained cone dry matter yield and increased cone bitter acid concentration with reduced N use.