Southwestern Iberian Peninsula Research Articles

Molecular identification of the invasive subterranean termite Reticulitermes grassei (Blattodea: Rhinotermitidae) outside its known distribution: introduction routes and implications for pest management strategies.

Despite providing important ecosystem services, termites are also serious pests of wooden structures. Termites are highly adaptive organisms that cause concern as an invasive species. Predictions of the future spread of their distribution range due to factors such as climate change, urban growth, and global trade present new challenges to our capacity to protect our wood and wood-based materials and structures effectively. Reticulitermes grassei Clément, 1978 (Blattodea: Rhinotermitidae) is a subterranean termite native to the Iberian Peninsula and France, whose global distribution has widened over recent years. This article updates the distribution range of this species, confirming its identification in the Azores, Madeira, and Morocco through molecular analysis. The origin and consequences of these putative invasive populations are discussed in light of previously available data. The resulting network showed a highly structured base consisting of many haplotypes from the southern and southwestern Iberian Peninsula (Spain and Portugal), including those from Morocco (in natural landscapes) and Switzerland (in infrastructures). The more derived part of the network includes the haplotypes from southwest France, the northwest Iberian Peninsula, the United Kingdom, Azores, and Madeira, the last 3 being linked probably to human-mediated transportation events. The potential impacts of invasive subterranean termite populations expanding into new regions are concerning, especially in urban environments, and remain uncertain in natural areas. The challenges posed by these termites could be especially worrying in island ecosystems. Hence, it is crucial to implement early warning systems and monitoring programs in regions susceptible to subterranean termite invasions.

Networks of geometrically coherent faults accommodate Alpine tectonic inversion offshore southwestern Iberia

Abstract. The structural styles and magnitudes of Alpine tectonic inversion are reviewed for the Atlantic margin of southwestern (SW) Iberia, a region known for its historical earthquakes, tsunamis and associated geohazards. Reprocessed, high-quality 2D seismic data provide new images of tectonic faults, which were mapped to a depth exceeding 10 km for the first time. A total of 26 of these faults comprise syn-rift structures accommodating vertical uplift and horizontal advection (shortening) during Alpine tectonics. At the regional scale, tectonic reactivation has been marked by (a) the exhumation of parts of the present-day continental shelf, (b) local folding and thrusting of strata at the foot of the continental slope, and (c) oversteepening of syn- and post-rift sequences near reactivated faults (e.g. “passive uplift”). This work proves, for the first time, that geometric coherence dominated the growth and linkage of the 26 offshore faults mapped in SW Iberia; therefore, they are prone to reactivate as a kinematically coherent fault network. They form 100–250 km long structures, the longest of which may generate earthquakes with a momentum magnitude (Mw) of 8.0. Tectonic inversion started in the Late Cretaceous, and its magnitude is greater close to where magmatic intrusions are identified. In contrast to previous models, this work postulates that regions in which Late Mesozoic magmatism was more intense comprise thickened, harder crust and form lateral buttresses to northwest–southeast compression. It shows these structural buttresses to have promoted the development of early stage fold-and-thrust belts – typical of convergent margins – in two distinct sectors.

Beware of trees: Pine afforestation of a naturally treeless habitat reduces flower and pollinator diversity

Planting three billion trees to capture carbon and seeking measures to reverse pollinator decline are two key pledges of the EU Biodiversity Strategy for 2030. Although planting trees could be adequate to restore biodiversity in degraded landscapes and mitigate anthropogenic carbon emissions, it can also negatively impact biodiversity of naturally treeless habitats. To explore whether these two pledges might conflict, we focused on the European dry heathland, a treeless habitat frequent in the southwestern Iberian Peninsula, where it is locally known as herriza. The herriza stands out by its high plant biodiversity and profuse flowering that supports a wide range of insect pollinators. Yet, the herriza has been heavily afforested with pine trees until the onset of the 21st century. This past activity provides a unique natural experiment to assess the effect of afforestation on flower abundance and associated pollinator diversity. We conducted a two-year field study of the diversity and abundance of flowers and pollinators in five selected sites, each consisting of two adjacent plots of open and afforested herriza. Afforested herriza plots had consistently lower diversity and abundance of flowers and insect pollinators than open herriza plots. Our results highlight the negative impact of afforestation of a treeless habitat on its flowering pattern and associated insect pollinator guilds. We thus suggest seeking alternatives to afforesting naturally treeless habitats in order to avoid conflicts between carbon sequestration and pollinator conservation.

High-resolution downscaling of CMIP6 Earth system and global climate models using deep learning for Iberia

Abstract. Deep learning (DL) methods have recently garnered attention from the climate change community for being an innovative approach to downscaling climate variables from Earth system and global climate models (ESGCMs) with horizontal resolutions still too coarse to represent regional- to local-scale phenomena. In the context of the Coupled Model Intercomparison Project phase 6 (CMIP6), ESGCM simulations were conducted for the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) at resolutions ranging from 0.70 to 3.75∘. Here, four convolutional neural network (CNN) architectures were evaluated for their ability to downscale, to a resolution of 0.1∘, seven CMIP6 ESGCMs over the Iberian Peninsula – a known climate change hotspot, due to its increased vulnerability to projected future warming and drying conditions. The study is divided into three stages: (1) evaluating the performance of the four CNN architectures in predicting mean, minimum, and maximum temperatures, as well as daily precipitation, trained using ERA5 data and compared with the Iberia01 observational dataset; (2) downscaling the CMIP6 ESGCMs using the trained CNN architectures and further evaluating the ensemble against Iberia01; and (3) constructing a multi-model ensemble of CNN-based downscaled projections for temperature and precipitation over the Iberian Peninsula at 0.1∘ resolution throughout the 21st century under four Shared Socioeconomic Pathway (SSP) scenarios. Upon validation and satisfactory performance evaluation, the DL downscaled projections demonstrate overall agreement with the CMIP6 ESGCM ensemble in magnitude for temperature projections and sign for the projected temperature and precipitation changes. Moreover, the advantages of using a high-resolution DL downscaled ensemble of ESGCM climate projections are evident, offering substantial added value in representing regional climate change over Iberia. Notably, a clear warming trend is observed in Iberia, consistent with previous studies in this area, with projected temperature increases ranging from 2 to 6 ∘C, depending on the climate scenario. Regarding precipitation, robust projected decreases are observed in western and southwestern Iberia, particularly after 2040. These results may offer a new tool for providing regional climate change information for adaptation strategies based on CMIP6 ESGCMs prior to the next phase of the European branch of the Coordinated Regional Climate Downscaling Experiment (EURO-CORDEX) experiments.

Fitness consequences of feeding-by-remating interactions in female Cerambyx welensii (Coleoptera: Cerambycidae: Cerambycinae)

Abstract The longhorn beetle, Cerambyx welensii (Küster) (Coleoptera: Cerambycidae), is considered a critical factor in oak decline in southwestern Iberia, but populations vary over space and time, depending on several ecological factors. Adults feed on ripe fruits and tree exudates, and evidence suggests that feeding could impact fitness in hot, dry summers, especially under climate change. In the present study, we assessed the impact of adult feeding (sugar-fed, water-fed, or unfed) and remating (monandrous versus polyandrous) on female reproductive output. Lifetime fecundity increased with female size in most feeding–remating combinations. Sugar-fed females achieved the highest longevity and fecundity, unfed females the lowest, and water-fed females had intermediate values. The daily fecundity pattern was strongly dependent on female feeding. Longevity and fecundity of once-mated and remated females were similar in both unfed and water-fed groups; however, in sugar-fed females, remating enhanced fecundity and shortened life span. Preoviposition, oviposition, and postoviposition periods were distinctly affected by both diet and remating. Results show that females require sugar to maximise reproductive output and that a water supply may partially mitigate the fitness decline of unfed females. We conclude that female feeding must be considered to explain C. welensii spatio-temporal occupancy–abundance patterns in oak woodlands.

Mapping the risk of exposure to Crimean-Congo haemorrhagic fever virus in the Iberian Peninsula using Eurasian wild boar (Sus scrofa) as a model

Crimean-Congo haemorrhagic fever (CCHF) virus (CCHFV) is a tick-borne zoonotic pathogen that can cause a lethal haemorrhagic disease in humans. Although the virus appears to be endemically established in the Iberian Peninsula, CCHF is an emerging disease in Spain. Clinical signs of CCHFV infection are mainly manifested in humans, but the virus replicates in several animal species. Understanding the determinants of CCHFV exposure risk from animal models is essential to predicting high-risk exposure hotspots for public health action. With this objective in mind, we designed a cross-sectional study of Eurasian wild boar (Sus scrofa) in Spain and Portugal. The study analysed 5,291 sera collected between 2006 and 2022 from 90 wild boar populations with a specific double-antigen ELISA to estimate CCHFV serum prevalence and identify the main determinants of exposure probability. To do so, we statistically modelled exposure risk with host- and environment-related predictors and spatially projected it at a 10 × 10 km square resolution at the scale of the Iberian Peninsula to map foci of infection risk. Fifty-seven (63.3 %) of the 90 populations had at least one seropositive animal, with seroprevalence ranging from 0.0 to 88.2 %. Anti-CCHFV antibodies were found in 1,026 of 5,291 wild boar (19.4 %; 95 % confidence interval: 18.3–20.5 %), with highest exposure rates in southwestern Iberia. The most relevant predictors of virus exposure risk were wild boar abundance, local rainfall regime, shrub cover, winter air temperature and soil temperature variation. The spatial projection of the best-fit model identified high-risk foci as occurring in most of western and southwestern Iberia and identified recently confirmed risk foci in eastern Spain. The results of the study demonstrate that serological surveys of CCHFV vector hosts are a powerful, robust and highly informative tool for public health authorities to take action to prevent human cases of CCHF in enzootic and emergency settings.

Unravelling the mosquito-haemosporidian parasite-bird host network in the southwestern Iberian Peninsula: insights into malaria infections, mosquito community and feeding preferences.

Vector-borne diseases affecting humans, wildlife and livestock have significantly increased their incidence and distribution in the last decades. Because the interaction among vectors-parasite-vertebrate hosts plays a key role driving vector-borne disease transmission, the analyses of the diversity and structure of vector-parasite networks and host-feeding preference may help to assess disease risk. Also, the study of seasonal variations in the structure and composition of vector and parasite communities may elucidate the current patterns of parasite persistence and spread as well as facilitate prediction of how climate variations may impact vector-borne disease transmission. Avian malaria and related haemosporidian parasites constitute an exceptional model to understand the ecology and evolution of vector-borne diseases. However, the characterization of vector-haemosporidian parasite-bird host assemblages is largely unknown in many regions. Here, we analyzed 5859 female mosquitoes captured from May to November in five localities from southwestern Spain to explore the composition and seasonal variation of the vector-parasite-vertebrate host network. We showed a gradual increase in mosquito abundance, peaking in July. A total of 16 different haemosporidian lineages were found infecting 13 mosquito species. Of these assemblages, more than 70% of these vector-parasite associations have not been described in previous studies. Moreover, three Haemoproteus lineages were reported for the first time in this study. The prevalence of avian malaria infections in mosquitoes varied significantly across the months, reaching a maximum in November. Mosquito blood-feeding preference was higher for mammals (62.5%), whereas 37.5% of vectors fed on birds, suggesting opportunistic feeding behavior. These outcomes improve our understanding of disease transmission risk and help tovector control strategies.

Creating frames of reference for chert exploitation during the Late Pleistocene in Southwesternmost Iberia.

Southwestern Iberia has played a key role in characterizing Late Pleistocene human ecodynamics. Among other aspects of human behavior, chert procurement and management studies in this region have received increasing attention in the past two decades, especially focusing on the sites showing repeated human occupation, such as the case of Vale Boi (Southern Portugal). However, these studies have been very limited in their geographical scope, and mostly focused on brief macroscopic descriptions of the raw materials. To further our knowledge of the relationship between regional availability of raw materials and its impact on human adaptations and mobility, a more detailed approach to characterizing geological sources is needed. This paper characterizes chert raw materials location, diversity, and availability in a geologically well-defined region of southern Portugal - the Algarve. Through macroscopic and petrographic approaches, we provide a detailed characterization of geological chert sources to build a frame of reference for chert exploitation in the region. Our results show that there are four main chert formations in Algarve, and that despite the within-source variability, sufficient differences at macroscopic and petrographic levels are present to allow clear source attribution. These results provide a baseline for raw material studies in archaeological assemblages across southwestern Iberia, that will be essential to further characterize the dynamics of human behavior in some of the most important eco-cultural niches.

Dynamics of CO2, CH4, and N2O in Ria Formosa coastal lagoon (southwestern Iberia) and export to the Gulf of Cadiz

A first characterization of greenhouse gases had been carried out to study their role and impact in a productive transitional coastal system of the southern Portugal – Ria Formosa lagoon. To this purpose, the partial pressure of CO2 (pCO2) and the concentration of dissolved CH4 and N2O have been measured. Two surveys were carried out during 2020, at low tide under typical conditions of Spring (March) and end of Summer (October). The samplings sites were distributed along the costal lagoon covering: i) inner areas with strong human impact (influence of different flows of treated wastewater discharges); and ii) main channels in connection with the main inlets to study the exchanges with the ocean. In general, the highest values of the three greenhouse gases were found at the inner studied areas, especially affected by the disposal of treated effluents from wastewater treatment plans, in October. The mean water - atmosphere fluxes of the CO2, CH4 and N2O are positive, showing that the study area acts as a source of these gases to the atmosphere. On the other hand, it was calculated a rough estimation of the three gases globally exported from Ria Formosa to the ocean, through the main six inlets to evaluate the magnitude of the supply of these gases from Ria Formosa to the adjacent ocean. The mean CO2, CH4 and N2O horizontal water fluxes exported from all the inlets of Ria Formosa to the Gulf of Cadiz for both seasons, during low water, are 8.7 ± 3.9 mmol m−2 s−1, 8.0 ± 3.5 μmol m−2 s−1 and 3.2 ± 1.5 μmol m−2 s−1, which corresponds to a mass transport through the inlets section of 0.7 ± 0.7 kg s−1, 0.2 ± 0.2 g s−1 and 0.2 ± 0.3 g s−1 respectively. From these estimates, as expected, the higher mass transport was found at the larger and deeper inlets (Faro-Olhão and Armona).

Unveiling High-Tech Metals in Roasted Pyrite Wastes from the Iberian Pyrite Belt, SW Spain

The Iberian Pyrite Belt (IPB), in the southwestern Iberian Peninsula, is a large metallogenic province exploited since ancient times. As a result of historical and current mining activity, a vast volume of metallic mineral waste, mainly derived from the processing of pyrite, is still in situ and polluting the environment. A specific mine waste residuum locally known in the area as “morrongos”, which was produced during pyrite roasting mainly in the 19th century, is evaluated here in order to unravel untapped resources of high-tech metals commonly used in high-tech devices. Applying a combination of whole-rock geochemical (ICP-AES, ICPMS, FA-AAS) and single-grain mineralogical techniques (EPMA, LA-ICP-MS, FESEM, and FIB-HRTEM) on the “morrongos”, we unhide the still-present remarkable concentrations of Au, Ag, Pb, Zn, and Cu in them. The mineralogical expressions for these economic metals include oxides (hematite, magnetite, and hercynite), arsenates, sulfates of the jarosite group, native metals, and, to a lesser extent, relictic sulfides. This first-ever estimation of these economic metals in this type of residue allows their revalorization, highlighting them as suitable sources for the exploitation and recovery of metals necessary for the clean energy transition.

Founder events and subsequent genetic bottlenecks underlie karyotype evolution in the Ibero-North African endemic Carex helodes.

Despite chromosomal evolution being one of the major drivers of diversification in plants, we do not yet have a clear view of how new chromosome rearrangements become fixed within populations, which is a crucial step forward for understanding chromosomal speciation. In this study, we test the role of genetic drift in the establishment of new chromosomal variants in the context of hybrid dysfunction models of chromosomal speciation. We genotyped 178 individuals from seven populations (plus 25 seeds from one population) across the geographical range of Carex helodes (Cyperaceae). We also characterized karyotype geographical patterns of the species across its distribution range. For one of the populations, we performed a detailed study of the fine-scale, local spatial distribution of its individuals and their genotypes and karyotypes. Synergistically, phylogeographical and karyotypic evidence revealed two main genetic groups: southwestern Iberian Peninsula vs. northwestern African populations; and within Europe our results suggest a west-to-east expansion with signals of genetic bottlenecks. Additionally, we inferred a pattern of descending dysploidy, plausibly as a result of a west-to-east process of post-glacial colonization in Europe. Our results give experimental support to the role of geographical isolation, drift and inbreeding in the establishment of new karyotypes, which is key in the speciation models of hybrid dysfunction.

Small Houses of the Dead: A Model of Collective Funerary Activity in the Chalcolithic Tombs of Southwestern Iberia. La Orden-Seminario Site (Huelva, Spain)

Abstract This study analyses the funerary activity of small collective tombs with a limited number of individuals in the southwest of the Iberian Peninsula during the Copper Age. These small burial spaces are one of the most frequent funerary manifestations and one of the most common forms of megalithic monumentality in the complex societies of this geographical area. The necropolis of La Orden-Seminario is put forward as a detailed case study, applying a multi-method approach that integrates the interrelated analysis of architecture, stratigraphy, funerary deposits, bioanthropological indicators, and chronological sequences. The research makes it possible to identify the overarching features that characterise these collective funerary activity: (a) the architectural and functional similarity between the hypogea and tholoi; (b) the periodic remodelling and reorganisation of the burial spaces; (c) the formation of superimposed funerary levels articulated in various phases; (d) the short periods of time in each level, with a concentration of 1–5 generations; (e) the coexistence of primary and secondary funerary deposits; (f) the low minimum number of individuals and the non-existence of dissymmetric practices according to sex and/or age; (g) the uniformity of the grave goods, the fragmentation of the objects, and the deposition of offerings; and (h) reuse during the Early Bronze Age.

Composition and manufacture of a rare gold example of the Mesopotamian “tree of life” iconography and coeval jewellery in southwestern Iberian Peninsula

Composition and manufacture of a rare gold example of the Mesopotamian “tree of life” iconography and coeval jewellery in southwestern Iberian Peninsula

Numerical modelling for the seismic assessment of complex masonry heritage buildings: the case study of the Giralda tower

Existing heritage buildings can be especially vulnerable to earthquakes. They were designed only considering gravity loads and some of them are located in earthquake prone areas, such as the southwestern Iberian Peninsula. Besides, there is a high uncertainty in the definition of their constructive parameters and complex geometry. Due to that, it is paramount to develop accurate numerical models to obtain a reliable assessment of their seismic behaviour. Given this, the main objective of this manuscript is to analyse the seismic behaviour of the Giralda tower, located in Seville (Spain). It was declared as a Word Heritage Site of Outstanding Universal Value by the UNESCO in 1987. Seville has a moderate seismic hazard, but it has been shown that the soft alluvial strata amplify the seismic action. The tower has a brick and stone masonry structure, which was constructed in several construction phases. A 3D Finite Element Model of the tower has been developed using OpenSees software, employing a 3D CAD model. Modal analyses and nonlinear static analyses have been applied to calibrate and to assess the tower’s seismic behaviour. The results showed significant differences in function of the load pattern. It should be remarked that the boundary conditions have a notable effect upon getting a good calibration of the model. Regarding the damage, it has been found to match the historic records: the ramps would be ruined and, in the outer wall, it would be concentrated near the openings, especially close to the belfry.

Mafic microgranular enclaves (MMEs) trace the origin of post-collisional magmas

Abstract Mafic microgranular enclaves (MMEs) are a ubiquitous feature of post-collisional magmatism, receiving much attention among earth scientists over the last decades. While recent advances point to the large-scale involvement of the lithospheric mantle in granite petrogenesis, MMEs have received less attention in such discussion. Because MMEs are commonly acknowledged to represent the mafic end member with a mantle affinity that is related to early-stage batholith petrogenesis, they constitute a good proxy for the mantle role in the process. Using MME data from Los Pedroches batholith in southwestern Iberia, we conduct a geochemical comparative study between MMEs and the mafic-intermediate (sanukitoid) suite of post-collisional batholiths. An accurate overlap between the two groups is revealed, implying a potential genetic link between MMEs and the sanukitoid suite. Together with evidence from experimental cotectic liquids, the link between the high-Mg signature of postcollisional magmas and the predominance of amphibole in the studied MME samples is used to account for the composition of post-collisional magmatism. Implications for post-collisional batholith petrogenesis is then discussed in a qualitative manner, suggesting a heterogeneous yet common two-stage origin for all post-collisional magmatism in which the relationship between MMEs, sanukitoid, and the host felsic magmas is a differentiation process, thus representing a major input of juvenile magma into the crust.

Lead isotope fingerprinting techniques help identify and quantify 3000 years of atmospheric lead pollution from Laguna Roya, northwestern Iberia

Legacy pollution research has established that over the past 3000 years, mining and metallurgical activities have resulted in widespread deposition of lead (Pb) pollution. However, there is still a limited understanding of how humans have impacted the long-term cycling of Pb in the environment. We present a 4,000-year lake sediment Pb isotope record from Laguna Roya, northwestern Iberia, that identifies and quantifies the predominant sources of atmospheric Pb pollution. For the first time, Pb isotopic compositions of ancient slag samples dated (∼600 BCE–200 CE) from a mining district in the southwest of the Iberian Peninsula are compared to Pb isotope ratios of Pb pollution deposited contemporaneously in lake sediments. In addition, literature Pb isotope ratios of ores from mining regions throughout Iberia are compared with those of leaded gasoline and coal to identify additional sources of anthropogenic Pb. Deposition of atmospheric Pb pollution begins after 950 BCE, and until 1750 CE, the Pb isotopic composition most resembles the southwestern slag deposits, containing a mixture of Pb ores from southeast Iberia (up to 36%) and southwest Iberia (∼74%). Between 1750 and 1960 CE, Pb pollution is attributed to Pb mining in southcentral Iberia. After 1960 CE, the dominant Pb pollution source (∼85%) is again metal refining in southwestern Iberia, and only ∼15% is from leaded gasoline. Provenance and reconstruction of the temporal and spatial distribution of legacy Pb pollution further our understanding of how humans have affected the biogeochemical cycle of this toxic element in the environment over time.

Another non-anthropic leporid accumulation in Southwestern Iberia? The case of a leporid sample from Morgado superior (Tomar, Portugal)

ABSTRACT The Morgado Superior Rock Shelter is located near the city of Tomar, in Central Portugal. This site presents important funerary contexts that according to published information encompass the Neolithic, Chalcolithic and Bronze Age. Other non-funerary uses have not yet been characterised but were briefly suggested. A faunal sample of the 1988 and 2012 interventions is analysed from a zooarchaeological and taphonomical perspective, focusing on the leporid remains that largely dominate the assemblage. Clear indicators of a human origin are absent, while a configurational approach allows the description of exogenous and intrusive origins. The characteristics of the registered consumption taphonomical indicators are suggestive of scat and non-ingested accumulation by foxes. Furthermore, this study allows us to discuss some aspects of the formation of the stratigraphy of this important cave necropolis, while also serving as an example of the expected results of foxes’ action on leporid remains in an archaeological site.

Quaternary fluvial carbonate deposits of the Almonda River Valley, Central Portugal

This paper discusses the formation and preservation of a fluvial tufa system influenced by Atlantic climate based on stratigraphical, chronological (amino-acid racemization, AAR), sedimentological and stable-isotope analyses. On the southwestern Iberian Peninsula, the tufas and associated deposits of the Almonda River valley occur as isolated terraced bodies and reach 25 m thick. AAR dated most deposits to within the warm Marine Isotope Stage 5 (MIS-5). Two Holocene ages were reset within MIS-5 based on diverse criteria. Widely varied carbonate and minor allochthonous coarse detrital facies occur arranged in four simple vertical associations. The deposit geometry and facies association distribution correspond to a low- to moderate-sloped fluvial valley consisting of several short knickpoints and extensive flat areas between them. The latter are occupied by slow-flowing water facies (carbonate sand, lime mud, phytoclast and oncoid rudstones, and up-growing stem boundstones). Facies that formed in moderate- to high-slope substrates were stromatolite, moss and down-growing stem boundstones. The homogeneous Miocene bedrock lithology and gentle structural deformation propitiated this depositional architecture. Calcite δ13C and δ18O values suggest that the aquifer water provided the outflowing Almonda water with (1) 18O-enriched water, compared with present precipitation and groundwater δ18O values, and (2) 13C-depleted CO2 from bituminous rocks and vegetation cover in the catchment. The proximity to the Atlantic coast favoured the Mesozoic-rock aquifer recharge with 18O-enriched water precipitation, assuring water availability during the formation of the studied tufas. No evidence of frequent intense erosion phases might indicate stable precipitation regimes, which would have allowed the preservation of loose fine-grained and palustrine deposits.

Chalcolithic copper production and use in the western end of the Iberian Peninsula: The testimony of Castro de Chibanes (Portugal)

Recent archaeological excavations identified a prehistoric occupation at Castro de Chibanes (Setúbal Peninsula, Portugal) displaying ceramic crucibles and metal artefacts in stratigraphic levels assigned to 2500–1900 cal BC. Apart from basic tools such as flat axes and awls, the collection includes ceramic crucibles, with emphasis to an uncommon example with a pouring lip and four feet. The studied set was completed with metal prills and artefacts from neighbouring Chalcolithic settlements of Rotura and Pedrão. The studied collection was characterised by chemical and microstructural techniques (p-EDXRF, micro-PIXE, optical microscopy and SEM-EDS). Overall, the results point to a local production of copper with variable arsenic contents, agreeing with the composition of artefacts (Cu with 0.14 to 4.4 wt% As), whose post-casting manufacture included hammering and annealing (recrystallized grains and annealing twins), although with incipient conditions that prevented a full compositional homogenisation. These results were compared with the Chalcolithic metallurgy of southwestern Iberian Peninsula, allowing to integrate the Setúbal Peninsula region into a wider context of metal production and use during the 3rd millennium BC. Finally, a supposed Bell Beaker “tanged dagger” was found to be composed by a leaded bronze alloy with a worked microstructure exhibiting Cu-Fe sulphides with high Se contents. The contradiction between analytical features and ancient chronology led to a revision of the typology and chronology of this bronze, showing the importance of the integration of analytical and archaeological research.

Morphological Correlates of Locomotion in the Aquatic and the Terrestrial Phases of Pleurodeles waltl Newts from Southwestern Iberia

Animals capable of moving in different environments might face conflicting selection on morphology, thus posing trade-offs on the relationships between morphology and locomotor performance in each of these environments. Moreover, given the distinct ecological roles of the sexes, these relationships can be sexually dimorphic. In this article, I studied the relationships between morphological traits and locomotor performance in male and female semiaquatic Pleurodeles waltl newts in their aquatic and their terrestrial stages. Morphology was sexually dimorphic: males have proportionally longer limbs and tails, as well as a better body condition (only in the aquatic phase), whereas females were larger and had greater body mass in both phases. Nonetheless, these morphological differences did not translate into sexual divergence in locomotor performance in either stage. This finding suggests other functions for the morphological traits measured, among which only SVL showed a positive relationship with locomotor performance in both stages, whereas the effect of SMI was negative only in the terrestrial stage, and that of tail length was positive only in the aquatic stage. In any case, the morphological correlates of terrestrial and aquatic locomotion did not conflict, which suggests no trade-off between both locomotory modes in the newts studied.