Search Results (899)

This study presents a comprehensive analysis of climate evolution in the Porto region (Northern Portugal) using 148 years (1863–2010) of continuous meteorological data from the Serra do Pilar weather station (WMO station 08546). The research employs both traditional linear statistical methods and advanced non-linear analysis techniques, including polynomial trend fitting and multidecadal oscillation analysis, to accurately characterize long-term climate patterns. Results reveal that linear trend analysis is misleading for this dataset, as both temperature and precipitation follow parabolic (U-shaped) distributions with minima around 1910–1970. The early period (1863–1900) exhibited higher values than the recent period, contradicting linear trend interpretations. Advanced analysis shows that the mean temperature follows a parabolic pattern (R² = 0.353) with the minimum around 1935, while precipitation exhibits similar behavior (R² = 0.053) with the minimum around 1936. Multidecadal oscillations are detected with dominant periods of 46.7, 15.6, and 10.0 years for temperature, and 35.0, 17.5, and 4.5 years for precipitation. Maximum temperatures show complex oscillatory behavior with a severe drop around 1890. Seasonal analysis reveals distinct patterns across all seasons: winter (+0.065 °C/decade) and autumn (+0.059 °C/decade) show warming trends in maximum temperatures, while spring (−0.080 °C/decade) and summer (−0.079 °C/decade) demonstrate cooling trends in minimum temperatures, with no significant trends in spring (+0.012 °C/decade) and summer (+0.003 °C/decade) maximum temperatures or winter (−0.021 °C/decade) and autumn (−0.035 °C/decade) minimum temperatures. The study identifies a significant change point in mean temperature around 1980, which occurs approximately one decade earlier than the global warming acceleration typically observed in the 1990s, suggesting regional Atlantic influences may precede global patterns. Extreme event analysis indicates stable frequencies of hot days (averaging 3.6 days/year above 25.0 °C) and heavy precipitation events (averaging 1.2 days/year above 234.6 mm) throughout the study period. These findings demonstrate that the Porto region’s climate is characterized by natural multidecadal variability rather than monotonic trends, with the climate system showing oscillatory behavior typical of Atlantic-influenced coastal regions. The results contribute to understanding regional climate variability and provide essential baseline data for climate change adaptation strategies in Northern Portugal. The results align with broader patterns of natural climate variability in the Iberian Peninsula while highlighting the importance of non-linear analysis for comprehensive climate assessment. Full article

Atmospheric aerosols are recognized as a major air pollutant with significant impacts on human health, air quality, and climate. Yet, the chemical composition and seasonal variability of aerosols remain underexplored in several Western Mediterranean regions. This study presents a year-long investigation of PM_2.5 and PM₁₀ in Tetouan, Northern Morocco, where both local emissions and regional transport influence air quality. PM_2.5 and PM₁₀ samples were collected and analysed for total mass and comprehensive chemical characterization, including organic carbon (OC), elemental carbon (EC), water-soluble ions (WSIs), and sugar tracers (levoglucosan, arabitol, and glucose). Concentration-weighted trajectory (CWT) modelling and air mass back-trajectory analyses were used to assess potential source regions and transport pathways. PM_2.5 concentrations ranged from 4.2 to 41.8 µg m⁻³ (annual mean: 18.0 ± 6.4 µg m⁻³), while PM₁₀ ranged from 11.9 to 66.3 µg m⁻³ (annual mean: 30.8 ± 9.7 µg m⁻³), with peaks in winter and minima in spring. The PM_2.5-to-PM₁₀ ratio averaged 0.59, indicating a substantial accumulation of particle mass within the fine fraction, especially during the cold season. Carbonaceous aerosols dominated the fine fraction, with total carbonaceous aerosol (TCA) contributing ~52% to PM_2.5 and ~34% to PM₁₀. Secondary organic carbon (SOC) accounted for up to 90% of OC in PM_2.5, reaching 7.3 ± 3.4 µg m⁻³ in winter. WSIs comprised ~39% of PM_2.5 mass, with sulfate, nitrate, and ammonium as major components, peaking in summer. Sugar tracers exhibited coarse-mode dominance, reflecting biomass burning and biogenic activity. Concentration-weighted trajectory and back-trajectory analyses identified the Mediterranean Basin and Iberian Peninsula as dominant source regions, in addition to local urban emissions. Overall, this study attempts to fill a critical knowledge gap in Southwestern Mediterranean aerosol research by providing a comprehensive characterization of PM_2.5 and PM₁₀ chemical composition and their seasonal dynamics in Tetouan. It further offers new insights into how a combination of local emissions and regional transport shapes the aerosol composition in this North African urban environment. Full article

Historic earthen architecture—particularly rammed earth—is underrepresented in digital heritage initiatives despite its widespread historical use and vulnerability to degradation. This paper presents a novel methodology for integrating semantic, geometric, and geospatial information from earthen heritage into a unified digital environment, bridging Heritage Building Information Modeling (HBIM) and Geographic Information Systems (GIS) through an object-relational database. The proposed workflow enables automated and bidirectional data exchange between Revit (via Dynamo scripts) and open-source GIS tools (QGIS and PostgreSQL/PostGIS), supporting semantic alignment and spatial coherence. The method was tested on seven fortified rammed-earth sites in the southwestern Iberian Peninsula, chosen for their typological and territorial diversity. Results demonstrate the feasibility of multiscale documentation and analysis, supported by a structured database populated with geometric, semantic, diagnostic, and environmental information, enabling enriched interpretations of construction techniques, material variability, and conservation status. The approach also facilitates the integration of HBIM datasets into broader territorial management frameworks. This work contributes to the development of scalable, open-source digital tools tailored to vernacular heritage, offering a replicable strategy for bridging the gap between building-scale and landscape-scale documentation in cultural heritage management. Full article

Holm oak groves of Quercus ilex subsp. ilex are one of the most characteristic environmental elements of the Cantabrian strip of the Iberian Peninsula. The Cantabrian holm oak forest does not have a clear origin. There is a possibility that it has a relict character, and it could also respond more to human activity over the last 10,000 years. Nowadays, it is a rare, scarce, and finicultural forest in this demarcation, but it provides many ecosystem services. To carry out a comparative analysis and assessment of its potential as Green Infrastructure and of its coastal facies (Urdaibai, Bizkaia), 10 random and stratified inventories were carried out. These plots were monitored regularly for more than 2 years and in seasonal visits to avoid phenological bias. The resulting synthetic syninventories were then assessed according to the LANBIOEVA (Landscape Biogeographical Evaluation) Methodology, which has been applied for more than 35 years in different ecosystems and landscapes at a global scale. Scores for various parameters related to ecosystem services are of high conservation interest, and the cultural services are medium to high. Concerning conservation priority, the low records of the three threat parameters result in mean values that are in the first quartile for this parameter, which attests to a good level of conservation. The conclusion is clear: the Biosphere Reserve status has had a positive influence on the proper management and conservation of the Cantabrian holm oak forest and its associated ecosystem services. However, certain threats that still weigh on this ecosystem need to be addressed. Full article

Maritime traffic accounts for more than 90% of world trade. Noise, pollution, and litter are its drawbacks, affecting especially vulnerable migratory fish. Here, a motivated team of citizen scientists analyzed maritime traffic from three estuaries of the south Bay of Biscay and three from the south of the Iberian Peninsula, where the European eel is critically endangered, during the season of the entrance of glass eels. More than 164,000 data points about ship types and positions were collected. The results showed that traffic differences between estuaries would explain, at least partially, the different eel conservation statuses. The participants appreciated learning about ships and nature conservation and acquiring an awareness of the real volume of shipping and its potential impacts. All the citizen scientists, new and experienced, would like to get involved in ocean research again. Full article

The Yucatán Black Hairless Pig (YBHP) is a native Mexican breed with cultural and agricultural importance in the Yucatán Peninsula. This study explored the genetic diversity and population structure of YBHP using a genome-wide single-nucleotide polymorphism (SNP) from the porcine GGP 50K chip, comparing it with native and cosmopolitan breeds worldwide. Genetic diversity analyses revealed an observed heterozygosity (HO) of 0.3602 ± 0.032 and an inbreeding coefficient (F_IS) of 0.1517 ± 0.076, indicating moderate diversity and a relatively low level of inbreeding for an endangered native breed. ADMIXTURE analyses revealed a predominant and distinctive ancestry component exclusive to YBHP, along with shared ancestry with European breeds, particularly those of presumed Iberian origin. Principal Component Analysis (PCA) and phylogenetic network clustering supported its genomic singularity while confirming ancestral proximity to traditional European pigs. These findings highlight the dual nature of the YBHP: a genetically distinct native breed shaped by local adaptation yet retaining ancestral signals from Old World lineages. This genomic insight provides a scientific basis for conservation planning, supports the breed’s recognition as a unique genetic resource, and promotes its sustainable use in regional production systems. Full article

The Muschelkalk sedimentary cycle in the northwestern region of the Iberian Range (central Spain) lies within a transitional area between the Iberian and Hesperia type Triassic domains. To improve the understanding of its paleopalynological record, fifty samples were analyzed from ten stratigraphic sections corresponding to the Tramacastilla Dolostones Formation (TD Fm.), Cuesta del Castillo Sandstones and Siltstones Formation (CCSS Fm.), and Royuela Dolostones, Marls and Limestones Formation (RDML Fm.). Despite previous studies in the area, palynological data remain scarce or insufficiently detailed, highlighting the need for a systematic reassessment. Based on the identified palynological assemblages, the succession is assigned to an age spanning from the Fassanian to the Longobardian, with a possible extension into the base of the Julian (early Carnian). The results confirm that the siliciclastic unit (CCSS) represents a lateral facies change with respect to the carbonate formations of the upper Muschelkalk (TD and RDML). From a paleoecological perspective, the assemblages indicate a warm and predominantly dry environment, dominated by xerophytic conifers, although evidence of more humid local environments, such as marshes or coastal plains, is also observed. Full article

The capture of Jerusalem during the First Crusade, the extirpation of various heresies in the twelfth and thirteen centuries, the gradual expansion of Christian rule in the Iberian peninsula, and the mass conversion of Jews to Christianity there during the fourteenth century, all seemed to support a Christian triumphalism that imagined that as the End Time approached, Jews and other infidels would inevitably be absorbed into the Church. Nonetheless, an expanding medieval awareness of the many ‘Others’ beyond Christendom contributed to Christian anxieties that Jews (or Muslims) might expand their number through mass conversion, and not Christians. This paper will examine some sources of this anxiety. Full article

During the Pleistocene, the successive ice ages prompted the southward expansion of the “Mammoth Steppe” ecosystem, a prevalent habitat that supported species adapted to cold environments such as the mammoth, woolly rhinoceros, and reindeer. Previously, the earliest evidence for such cold-adapted species in the Iberian Peninsula dated back to Marine Isotope Stage 6 (MIS 6, ~191–123 ka). This paper reports the discovery of a reindeer (Rangifer) tooth from Unit GIII of the Galería site at the Atapuerca-Trinchera site complex, dated to MIS 8 (~300–243 ka). This find is significant as it represents not only the oldest evidence of glacial fauna in the Iberian Peninsula but also the southernmost occurrence of reindeer in Europe of this age. The presence of Rangifer at this latitude (42°21′ N) during MIS 8 suggests that the glacial conditions affected the Iberian fauna earlier and with greater intensity than previously understood. Over the subsequent climatic cycles, cold-adapted species spread further south, reaching Madrid (40°20′) during the penultimate glacial period and the province of Granada (37°01′) during the last glacial maximum. The coexistence of human fossils and lithic artefacts within Units GII and GIII at Galería indicates that early humans also inhabited these glacial environments at Atapuerca. This study elaborates on the morphological and archaeological significance of the reindeer fossil, emphasizing its role in understanding the biogeographical patterns of glacial fauna and the adaptability of Middle Pleistocene human populations. Full article

Quercus faginea Lam., a winter-deciduous oak native to the Iberian Peninsula, typically grows under a Mediterranean climate. To identify the main drivers influencing radial wood increment, we analyzed the climatic signals in tree-ring width and wood anatomical traits using increment cores. Winter conditions influenced both latewood width and earlywood vessel size in the first row. Latewood was positively correlated with precipitation and temperature, with the long-term positive effect of winter water supply supported by SPEI. In contrast, vessel size showed negative correlations, also reflecting a long-term negative effect of winter precipitation. Consequently, conditions that enhanced latewood width and overall tree-ring growth appear to be associated with the formation of smaller earlywood vessels. Although ample winter precipitation replenishes soil water reserves and supports prolonged wood formation, it may also induce anaerobic soil conditions that promote root fermentation, depleting carbohydrates needed for cell turgor and expansion, and ultimately regulating earlywood vessel size. This physiological decoupling may help explain the lack of a significant correlation between latewood width and earlywood vessel size, underscoring their independent responses to environmental influences. Our findings highlighted the complex interplay between various climatic conditions affecting Q. faginea, with implications for understanding its adaptive capacity in changing climates. Full article

Biochar is an amendment that can enhance both soil fertility and sequester carbon. However, its historical applications continue to be underexplored. In this overview, we investigate the formiguer method of burning woody biomass to create agricultural biochar for use as fertilizer in Catalonia, Spain, within the context of historical biochar use. A literature review targeted searches of scholarly databases to compare the formiguer method to Amazonian terra preta and other traditional biochar use. We identified sources covering biochar properties, soil impacts, and historical agricultural practices within the Iberian Peninsula and briefly described the main methods or treatments used during this process. Past research demonstrates that the formiguer method, which involves pyrolytic combustion of biomass within soil mounds, improves microbial activity, increases soil phosphorus and potassium availability from soil structure, and leads to long-term carbon stabilization, even though it can result in short-term decreases in soil organic carbon and nitrogen losses. Despite being abandoned in Europe with the rise of chemical fertilizers, the use of formiguers exemplifies a decentralized approach to nutrient and agroecosystem management. The literature highlights the relevance that these traditional biochar practices can have in informing modern soil management and sustainable agricultural strategies. Understanding the formiguer can offer critical insights to optimize contemporary biochar applications and historical techniques into future sustainability frameworks. Full article

Host genetic variability is relevant to understanding how parasites modulate natural selection in wild fish populations. Coastal lagoons are transitional ecosystems where knowledge lacks on relationships between genotypic diversity with parasitism. The aim of this study was to assess the effect of genetic diversity on host health and parasitological traits in fish inhabiting a Mediterranean lagoon. Black-striped pipefish Syngnathus abaster were collected in August 2023 and 2024 from the Mar Menor (Iberian lagoon, SE Spain). Genetic diversity was measured as Internal Relatedness (IR: a homozygosity index from microsatellite markers). Population frequency was lower for the medium IR level. For this same category, both health indices (external body condition and internal organs) indicated a worse status. Parasite prevalence, abundance and an index of life-cycle complexity (heteroxenous species) were greater for the medium level of genetic diversity. Such results are explained under a scenario of parasite-mediated disruptive selection: a higher disease pressure against the phenotypically intermediate individuals. Two contrasting strategies were detected to better control parasitism at the host genotypic level: (1) high homozygosity, and (2) high heterozygosity, which probably reflects better immuno-competence as a phenotypic trait. From an evolutionary perspective, parasites play a crucial role in shaping genetic diversity within host populations. Full article

Climate change poses a major threat to forests, impacting the distribution and viability of key species. Quercus pyrenaica Willd., a marcescent oak endemic to the Iberian Peninsula (Portugal and Spain) and southwestern France and a structural species in submediterranean forests, is particularly susceptible to shifts in temperature and precipitation patterns. Aiming to assess its potential loss of suitable area under future climate scenarios, we developed high-resolution spatial distribution models to project the future habitat suitability of Q. pyrenaica under two climate change scenarios (SSP3-7.0 and SSP5-8.5) for the periods 2070 and 2100. Our model, which has an excellent predictive performance (AUC of 0.971 and a TSS of 0.834), indicates a predominantly northward shift in the potential distribution of the species, accompanied by substantial habitat loss in southern and lowland regions. Long-term potential suitable area may shrink to 42% of that currently available. This, combined with the limited natural dispersal capacity of the species, highlights the urgency of targeted management and conservation strategies. These results offer critical insights to inform conservation strategies and forest management under ongoing climate change. Full article

Hybridization of solar and wind energy sources is a promising solution to enhance the dispatch capability of renewables. The complementarity of wind and solar radiation, as well as the sharing of transmission lines and other infrastructures, can notably benefit the deployment of renewable power. Mapping of hybrid solar–wind potential can help identify new emplacements or existing power facilities where an extension with a hybrid system might work. This paper presents an analysis of a hybrid solar–wind potential by considering a reference power plant of 40 MW in the Iberian Peninsula and comparing the hybrid and non-hybrid energy generated. The generation of energy is estimated using SAM for a typical meteorological year, using PVGIS and ERA5 meteorological information as input. Modeling the hybrid plant in relation to individual PV and wind power plants minimizes the dependence on technical and economic input data, allowing for the expression of potential hybridization analysis in relative numbers through maps. Correlation coefficient and capacity factor maps are presented here at different time scales, showing the complementarity in most of the spatial domain. In addition, economic analysis in comparison with non-hybrid power plants shows a reduction of around 25–30% in the LCOE in many areas of interest. Finally, a sizing sensitivity analysis is also performed to select the most beneficial sharing between PV and wind. Full article

The Sierra Minera de Cartagena-La Unión, located in southeast of the Iberian Peninsula, has been significantly impacted by historical mining activities, which resulted in environmental degradation, including acid mine drainage (AMD) and heavy metal contamination. This study evaluates the potential of PRISMA hyperspectral imagery for multi-temporal mapping of AMD-related minerals in two mining-affected drainage basins: Beal and Gorguel. Key minerals indicative of AMD—iron oxides and hydroxides (hematite, jarosite, goethite), gypsum, and aluminium-bearing clays—were identified and mapped using band ratios applied to PRISMA data acquired over five dates between 2020 and 2024. Additionally, Sentinel-2 data were incorporated in the analysis due to their higher temporal resolution to complement iron oxide and hydroxide evolution from PRISMA. Results reveal distinct temporal and spatial patterns in mineral distribution, influenced by seasonal precipitation and climatic factors. Jarosite was predominant after torrential precipitation events, reflecting recent AMD deposition, while gypsum exhibited seasonal variability linked to evaporation cycles. Goethite and hematite increased in drier conditions, indicating transitions in oxidation states. Validation using X-ray diffraction (XRD), laboratory spectral curves, and a larger time-series of Sentinel-2 imagery demonstrated strong correlations, confirming PRISMA’s effectiveness for iron oxides and hydroxides and gypsum identification and monitoring. However, challenges such as noise, striping effects, and limited image availability affected the accuracy of aluminium-bearing clay mapping and limited long-term trend analysis. Full article