Southwestern Iberian Peninsula Research Articles

Four new species of Typhlocharis (baetica group) (Coleoptera: Carabidae: Anillini) from southwestern Iberian Peninsula with notes on their biogeographical and morphological implications

Four new species of Typhlocharis (Carabidae: Anillini) are described from the southwest of the Iberian Peninsula, assigned to the baetica species group. T. primasp.n., T. secundasp.n. and T. tertiasp.n. (from La Palma del Condado, Huelva, Spain) are syntopic, and T. quartasp.n. (from Barrancos, Beja, Portugal) is the first species of the group with umbilicate series 4 + 4. They represent, respectively, the southernmost and westernmost distribution data for the group. The baetica group remains well defined and includes ten species. The diagnosis is simplified, with the confirmation that many morphological features characteristic of this group are widespread within the genus. The defining character is the presence of denticles in apical margin of elytra, not associated to the seventh stria or to the elytral suture. The new species provide morphological data that suggest the baetica and silvanoides groups are closely related. Distribution of both groups in the south of the Iberian Peninsula and the presence of morphological characters that are considered plesiomorphic are coherent with the hypothesis of betic‐riffain origin of the genus. They also support the hypothesis of easy alteration of the umbilicate pattern between closely related species and the independent origin of apical denticles in the group compared with those present in other species of the genus. The presence of three well‐differentiated size ranges in syntopic populations suggest ecological diversification to avoid interspecific competition.

The application of the Liocourt model to uneven-aged cork oak stands

The purpose of this study is to determine the applicability of the Liocourt model to cork oak (Quercus suber L.) stands in the south-western Iberian Peninsula, and to review the general applicability of the Liocourt method. Seven uneven-aged stands in a densely structured cork oak forest (basal area ≥ 10 m2/ ha) were selected and analysed. The results indicate that the Liocourt expression suffers from theoretical limitations which make it difficult to obtain through regression analysis. Additionally, the paper concludes that the Liocourt model is inapplicable to cork oak stands in conditions similar to those of the study.

A mesoscale simulation of coastal circulation in the Guadalquivir valley (southwestern Iberian Peninsula) using the WRF-ARW model

Located in the southwest of the Iberian Peninsula, the Guadalquivir valley is a site of frequent problems related to air pollution. The atmospheric dynamics of this region is poorly characterised but is fundamental to understanding the chemical and photochemical processes that contribute to the pollution problems. In this work, the atmospheric mesoscale Weather Research and Forecasting (WRF-ARW) model was used to study the horizontal and vertical development of the two sea–land breeze patterns (pure and non-pure) that are identified in the coastal area as being responsible for many of the air pollution events. In addition, data from five meteorological stations within the valley were used to validate and compare the model results.The FNL archives were used to define the initial and boundary conditions of the model. Four domains with a grid resolution of 81, 27, 9 and 3km and 40 sigma pressure levels in each domain were defined. The Medium Range and Forecast (MRF) parameterisation scheme was used with new values for both the bulk critical Richardson number and the coefficient of proportionality. This new configuration was obtained from the sensitivity exercises.Several periods were modelled for both breeze patterns, focusing on the wind, the potential temperatures and the specific humidity fields. For the pure breeze, the horizontal movement along the valley was conditioned by the arrival of a Mediterranean flow in the Guadalquivir valley that limits the horizontal extension of the breeze to 20–40km inland. In contrast, the non-pure pattern was only identified in the coastal area; although motivated by the entrance of southwestern flows, a marine air mass transport along the valley was detected and reached inland areas located approximately 200km from the coast line.In both cases, the model results indicated the formation of a thermal internal boundary layer with a vertical development of less than 500m for the pure sea breeze while for the non-pure breeze can reach a vertical extension of 1km. In the case of the non-pure pattern, the model forecast for the Atmospheric Boundary Layer (ABL) height distribution along the valley revealed a homogeneous pattern related to the entrance of the southwestern flows, in contrast with the clear division of the valley observed for the pure pattern motivated by the arrival of Mediterranean flows.

Diet of the introduced pikeperch Sander lucioperca (L.) (Osteichthyes, Percidae) in a recent colonised reservoir in south-western Iberian Peninsula

The present study examines the diet of pikeperch (Sander lucioperca) in Iberian freshwaters. Food habits of Sander lucioperca were studied based on stomach content analyses of 376 specimens (12.22–52.52 cm total length) collected in 2009 on a south-western Iberian reservoir. A total of 265 stomachs (79.52%) contained food, and fifteen taxonomic levels of prey were identified. The most important prey was fish according to the Relative Importance Index (IRI). Trophic level analysis revealed that S. lucioperca is a top predator throughout its life history. There were no differences between sexes (p = 0.573, ANOSIM) and seasons (p = 0.266) in the diet composition, but minor dietary shifts with ontogeny were found. The Levins' standardized index indicated wider niche breadth for small pikeperch, whereas larger pikeperch specimens showed a narrow niche breadth with a specialization in congeners. The graphical analysis (Amundsen method) of the diet confirmed that pikeperch feed mainly on congeners in Alcántara reservoir; however some native species were also consumed.

The Performance of Different Boundary-Layer Parameterisations in Meteorological Modelling in a Southwestern Coastal Area of the Iberian Peninsula

The performance of four atmospheric boundary layer (ABL) schemes in reproducing the diurnal cycles of surface meteorological parameters as well as the ABL structure and depth over a coastal area of southwestern Iberia was assessed using the mesoscale meteorological Weather Research and Forecasting (WRF) model. The standard configuration of the medium-range forecast (MRF) and the Yonsei University (YSU) ABL schemes were employed. Modified versions of each, in which the values of the bulk critical Richardson number () and the coefficient of proportionality () were varied, were also used. The results were compared to meteorological measurements representative of SW-NW and NE synoptic flows. The WRF model in its basic configuration was found to yield satisfactory forecasting results for nearly all near-surface atmospheric variables. Modifications in and did not influence the simulation of surface meteorological parameters. Both parameterisations appeared to be optimal predictors of ABL structure, and all four ABL schemes tended to produce a cold ABL during both periods, although this ABL was drier in the SW-NW flow season and wetter in the NE flow season. Considering all the parameters analysed, the MRF ABL parameterisation with the lowest values of and coefficients tested (0.25 and 0.0, resp.) tends to show a realistic simulation.

Vertical behaviour and meteorological properties of air masses in the southwest of the Iberian Peninsula (1997–2007)

Air masses are characterized by physical (temperature, humidity) and chemical (transported gases and aerosols) properties, being associated their arrival to different meteorological scenarios. The knowledge of the air masses over a region is fundamental as complementary information in several atmospheric studies, being the calculation of back-trajectory the most widely used tool whenever air masses are analyzed. A study of air masses has been carried out in southwestern Iberian Peninsula using 5-day kinematic back trajectories computed by the HYSPLIT model at three heights (500, 1,500 and 3,000 m) from 1997 to 2007. The main aims have been to characterize their vertical behaviour and their thermal and humidity properties. Thirteen trajectory clusters have been defined, showing the northerly and westerly clusters a high coupling degree. Seasonal daily variation of potential temperature and specific humidity has been analyzed, obtaining higher differences among clusters in the cold season.

Retrieval and variability analysis of optically thin cloud optical depths from a Cimel sun-photometer

In this work we propose a technique to retrieve optical depths for optically thin clouds. This method complements the current performance of AERONET for optically thick cloud measurements using data eliminated by the cloud-screening algorithm that are not useful to derive aerosol properties, therefore inexpensively increasing the capabilities of the sun-photometers. The proposed method is based on the computation of the apparent cloud optical depths and on a forward scattering correction method that exploits state-of-the-art ice cloud scattering models. This complementary procedure is applied to Cimel sun-photometer measurements performed at the Évora Geophysics Centre (Portugal, 38.6°N, 7.9°W, 293m asl) included in the AERONET network in order to obtain a climatology of optical depths for optically thin clouds over middle-latitude continental regions of the southwestern Iberian Peninsula. Main features regarding annual and seasonal variability and the relative changes in the infrared radiative forcing from 2007 to 2010 are also reported and analyzed.

A tale of two seas: Upper Paleolithic ecology in Vale Boi, southwestern Algarve (Portugal) and the arrival of the first modern humans to Southwestern Iberia

A tale of two seas: Upper Paleolithic ecology in Vale Boi, southwestern Algarve (Portugal) and the arrival of the first modern humans to Southwestern Iberia

Mollusc communities along upstream–downstream gradients in small coastal basins of the south-western Iberian Peninsula

Freshwater mollusc communities readily respond to various human-induced stressors, and thus are appropriate models for studying the effects of such stressors on the structure and dynamics of stream macroinvertebrate communities. This paper examined the distribution of freshwater molluscs in 35 stream reaches of 18 small coastal basins in the south-western Iberian Peninsula. Using several multivariate techniques, I showed that mollusc distribution mainly responded to gradients in drainage area, water availability, pollution and salinity. Upstream and downstream communities were clearly differentiated, with the former dominated by freshwater species (Bithynia tentaculata, Galba truncatula, Radix balthica, Ancylus fluviatilis and Planorbarius metidjensis) and the latter by species typical of brackish waters (Peringia ulvae and Myosotellamyosotis). There was a clear decrease in species richness from upper to lower reaches. The conservation of mollusc communities of these small basins requires a deeper understanding of their ecological requirements, effective control of urban discharges and an analysis of their interaction with invasive species.

Meteorological factors influencing the 7Be and 210Pb concentrations in surface air from the southwestern Iberian Peninsula

During a seven-year period (April 2004–July 2011), the 210Pb and 7Be activity concentrations in surface air were determined at El Arenosillo, located on the coastline of the southwestern Iberian Peninsula. The 210Pb and 7Be activity concentrations have been classified in four ranges according to the values of percentiles, 0–P10 (lowest concentrations), P10–P50 (intermediate concentrations), P50–P90 (high concentrations), and P90–Maximum (peaks of concentrations).The computation of both backward trajectories and cluster techniques has been used for identifying the types of air masses that arrive at the sampling station for each range of 210Pb and 7Be activity concentrations. Meteorological parameters, such as the wind roses and daily cycles of specific and relative humidity, and the potential temperature have been calculated (or measured) for each one of the sampling periods and grouped according to the ranges of 210Pb and 7Be activity concentrations.The results indicate that different synoptic patterns are associated with different 210Pb and 7Be activities in this area, which indicates the differences between the arrival of maritime and continental air masses based on the 210Pb and 7Be activities. In addition, the study on the evolution of air masses from the lowest and highest ranges of 7Be/210Pb confirms that both radionuclides can be used as two independent atmospheric transport markers.

Environmental determinants of freshwater mollusc biodiversity and identification of priority areas for conservation in Mediterranean water courses

This study evaluates which environmental factors influence the biodiversity, distribution and conservation of freshwater mollusc communities in a Mediterranean Biosphere Reserve in the south-western Iberian Peninsula. Habitat features and two biodiversity indices (native species richness and diversity) were evaluated at 109 locations. Environmental gradients were assessed using principal component analysis, which orders the habitat variables along two gradients: headwater characteristics and water availability. According to a canonical correspondence analysis, the main environmental factors related to the distribution of species and community structure were, also, climate and headwater habitat features (precipitation, order, channel width, slope and pH), and heterogeneity and trophic features (IHF index and instream macrophytes cover). Relationships between biodiversity indices and environmental variables were best explained by a regression model incorporating, basically, aridity index and precipitation as the variables that accounted for most of the variance. This study demonstrates that distribution of freshwater molluscs along a highly stressed by drought Mediterranean region mostly depends on the local pool of species and their adaptive patterns to water availability.

Bronze production in Southwestern Iberian Peninsula: the Late Bronze Age metallurgical workshop from Entre Águas 5 (Portugal)

Archaeological works at Entre Águas 5 (Portugal) uncovered a seasonal LBA settlement with significant metallurgical remains (crucibles, moulds, prills and a tuyere) related to bronze production. Radiocarbon dating ascribes an occupation period (10th–9th century BC) previous to Phoenician establishment in Southwestern Iberia. In spite of the proliferation of metal artefacts during LBA, the production of bronze alloys is still poorly understood. An integrated analytical approach (EDXRF, optical microscopy, SEM–EDS, micro-EDXRF and Vickers microhardness) was used to characterise this metallurgy. Crucibles show immature slags with copious copper nodules, displaying variable tin content (c. 0–26 wt.%), low iron amount (<0.05 wt.%) and different cooling rates. Certain evidences point to direct reduction of oxide copper ores with cassiterite. Scorched moulds with residues of copper and tin indicate local casting of artefacts. Finished artefacts also recovered at the site have an analogous composition (bronze with ∼10 wt.% Sn and low amounts of Pb, As and Fe) typical of coeval metallurgy in SW Iberia. Some artefacts reveal a relationship between typology and composition or manufacture: a higher tin content for a golden coloured ring or absence of the final hammering for a bracelet. An uncommon gilded nail (gold foil c. 140 μm thick; 11.6 wt.% Ag; ∼1 wt.% Cu) attests the existence of evolved prestige typologies. This LBA settlement discloses a domestic metallurgy whose main features are typical in Iberian Peninsula. Finally, it should be emphasized that a collection as comprehensive and representative of a single workshop has rarely been studied, enabling a deeper understanding of the various operations involving the bronze production and manufacture of artefacts.

The importance of the surroundings: are bird communities of riparian galleries influenced by agroforestry matrices in SW Iberian Peninsula?

The remaining riparian stretches are often the unique suitable habitats for forest breeding birds in Mediterranean landscapes undergoing long-term changes. Understanding the interactions between riparian zones and their surroundings is critical to establish successful management actions. We assessed the influence of surrounding matrix on riparian bird communities and the use of riparian galleries as surrogate habitats for the forest passerine communities of southwestern Iberia. We used point counts in three simultaneous sampling stations, one in the riparian gallery and two in the adjacent matrix. Three matrix types were selected with a decreasing tree density gradient: dense montado, sparse montado, and open agricultural areas. Data were analysed with redundancy analysis and differences in species’ occurrences were tested with one-way ANOVA. In riparian galleries, we found bird species belong to three ecological guilds: riparian, woodland, and edge guilds. The richness of bird guilds and the occurrence of some species depended on the surrounding matrix type. Riparian bird richness was constant in all surrounding matrices, woodland bird guild was richer in galleries embedded in dense montados, and edge guild in riparian galleries surrounded by sparse montados. Five among 19 assessed species were influenced by matrix type, within particular a few strictly riparian species. Species richness increased close to riparian galleries, due to the increase in habitat heterogeneity and resource availability for birds in densely vegetated riversides. However, the occurrence of some bird species differed according to the type of surrounding matrix. The matrix type explained most of the variance in riparian bird assemblages. Some woodland birds have used riparian galleries as surrogate habitat. Our study suggests that land use in the surrounding matrices must be taking into account for the management and rehabilitation of watercourses and bird conservation actions.

Geographical Distribution of Diploid and Tetraploid Cytotypes of Thymus sect. Mastichina (Lamiaceae) in the Iberian Peninsula, Genome Size and Evolutionary Implications

The occurrence of diploid and tetraploid cytotypes in Thymus section Mastichina (Lamiaceae) was investigated by chromosome counting and flow cytometric measurements of DNA content. To cover the entire native distribution of the section across the Iberian Peninsula, plant material was sampled from 29 populations, representing all three taxa (Thymus albicans, T. mastichina subsp. mastichina and T. mastichina subsp. donyanae). We provide first estimates of genome size for taxa of this section. Analyses revealed the existence of new cytotypes in T. mastichina subsp. mastichina (2n = 2x = 28, 30) and confirmed the existence of previous ones (2n = 4x = 56, 58, 60). We also confirmed the presence of exclusively diploid cytotypes (2n = 2x = 30) in the southwestern Iberian endemics T. albicans and T. mastichina subsp. donyanae. We conclude that the southwestern Iberian Peninsula acted as a Pleistocene glacial refugium that may have permitted speciation processes within this section. Several hypotheses concerning these processes and the origin and distribution of the studied taxa are discussed.

Metal concentration and distribution in plant tissues of Nerium oleander (Apocynaceae, Plantae) from extremely acidic and less extremely acidic water courses in the Río Tinto area (Huelva, Spain)

Nerium oleander L. is a micro–nano phanerophyte common in rivers, streams and temporary pools of water in southwestern Iberian Peninsula. In the mining area of Río Tinto, it grows in both extreme acidic and highly metal concentrated waters and in less extremely acidic water courses. In this work we study metal concentration and distribution in plant tissues of N. oleander by means of ICP-MS, SEM and EDX analysis. We observed differences between leaves and roots in the same plant, being Na, As, Fe and Pb concentrations significantly higher in the root. No differences in metal concentration and distribution between individuals of both environments were found. A deposition of Fe, Si, Al and K all over the root surface and the first cell layer of the epidermis with Pb and As in acidic water plants and Mn in less acidic water plants was observed. Ca druses and prismatic crystals were found in stems cortex and around leaves vascular bundle. Given the nutrient accumulation and the metal exclusion capacities of N. oleander, it could be of great interest in metal enriched soils phytostabilization.

Understanding human movement through spatial technologies. The role of natural areas of transit in the Late Prehistory of South-western Iberia

Archaeological, historical, and ethnographic research has demonstrated how mountainous environments influence the socio-cultural dynamics of the communities that live in them and in their neighbouring areas. The development of these communities tends to occur at the margins, often far away from centres of political power. This marginality is also extended to movement in these regions, where mountain ranges regularly constitute mighty obstacles on account of their natural configuration which plays a central role in strategy, commerce and travelling. In the case of western Sierra Morena in Spain, its constitution shaped both the ways of transit through the mountains during Later Prehistory and the historical routes of communication that traverse Andalucia. Using a GIS methodology developed specifically to identify particular characteristics of the landscape relevant to human movement, such as passageways, crossing points, and natural areas of transit, we examine the role that natural accessibility had for the late prehistoric societies of this region. We conclude that the location of their habitats and symbolic places are strongly related to corridors, possibly due to an increasing importance of herding activities.

Long term black carbon measurements in the southwestern Iberia Peninsula

Black carbon mass concentration (BCPM10) measurements carried out at Évora, Portugal, between 2007 and 2009, were analyzed and interpreted at different timescales. Additional measurements of aerosol mass concentration (MPM10) were included and the black carbon to total mass fraction (BC mass fraction) was derived when measurements of both quantities were coincident. BCPM10 values were found to vary between 0.3 and 5 μg m−3, mainly in the range of 0.5–2 μg m−3. A clear and consistent seasonal behavior was found; an increase by a factor of two in the average BCPM10 values was observed from summer (0.9 μg m−3) to winter (1.8 μg m−3) which is reflected in the BC mass fraction, amplified from about 4 to 10%. Comparison of the average BCPM10 mass concentrations on week days and week ends indicate that local traffic emissions strongly influence the observed average diurnal patterns. Other factors, such as wood burning for heating, lower boundary layer height and more frequent winter-time temperature inversions, also likely influence the observed BCPM10 but were not directly studied here. When different air mass types are considered then black carbon levels show a much lower variation than PM10 mass concentrations, stressing the relevance of local emissions in the BCPM10 levels. BCPM10 values under continental or maritime influence only differ by a factor of approximately 1.4 only, much lower than the factor of 10 reported for a coastal rural site in Portugal.

Assessment of an air pollution event in the southwestern Iberian Peninsula

On 12 and 13 August 2006, an exceptional air pollution event occurred in the southwest of the Iberian Peninsula (western Andalusia). High concentrations of surface ozone, CO and PM10 were registered at several air quality stations, in some cases reaching record values. During the late afternoon and evening of these two dates, the information and alert thresholds of surface ozone at coastal stations were exceeded, with peaks of 270 μg m−3. Concentrations of CO and PM10 reached 1800 μg m−3 and 240 μg m−3. Surface meteorological observations, back trajectories computed with the HYSPLIT model and wind and specific humidity fields from the meso-meteorological WRF-ARW model have all been used to gain an understanding of the origin of this event. The results indicate that this event was caused by the long-range transport of air masses from the wildfires that had occurred in the northwest of the Iberian Peninsula (Galicia and northern Portugal) during the first two weeks of August 2006. Air masses loaded with pollutants were transported approximately 1000 km from north to south, over Portugal and the Atlantic Ocean, to reach the southwestern Iberian Peninsula, with the consequent negative high impact on the air quality of this region.

The Magdalenian in central and southern Portugal: Human ecology at the end of the Pleistocene

During the Magdalenian and early Epipaleolithic between ca. 20,000 and 10,000 cal BP, mild and temperate environmental conditions existed in southwestern Iberia due to the position of the Polar Front, and proximity to the Mediterranean, North Africa and the Atlantic warm currents coming from the tropics. Thus, Portugal was marked by a relatively high diversity of terrestrial and marine animal species that were fully exploited by humans during this period.The differential use of caves, rock-shelters and open-air sites and the stone raw material economy suggests various patterns of land use characterized by inland-coastal movements through river valleys cutting through the limestone massif. Data suggest a logistic mobility pattern for Portuguese Magdalenian hunter-gatherer groups based on both diversification and specialization of natural resources.

A multianalytical approach to study the Phoenician bronze technology in the Iberian Peninsula—A view from Quinta do Almaraz

Abstract Phoenician settlers were responsible for very important changes on the metallurgical practices used in the Iberian Peninsula during the first half of the 1st millennium BC. The study of copper-based artefacts from the Phoenician settlement of Quinta do Almaraz (Portugal) was used to characterise exogenous influences on local metallurgy. Micro-EDXRF analyses on cleaned metal surfaces identified copper, low-tin bronze (2.2 to 8.1 wt.% Sn) and leaded bronze artefacts (4.6 to 5.9 wt.% Pb). Additionally, significant impurities of iron were found (0.15 to 1.3 wt.% Fe) suggesting the smelting of copper ores under a strong reducing atmosphere. SEM-EDS and optical microscopy identified polygonal and nearly equiaxial α-copper grains with annealing twins and slip bands, which indicate comprehensive manufacturing procedures involving hammering and annealing operations. Vickers microhardness testing was utilised to assess the mechanical performance attained by ancient metallurgists. The microstructural features and microhardness values showed that a common approach was to workharden the artefact with a strong final hammering (discernible by high density of slip bands), although some examples also benefited from a highly skilful usage of the forging plus annealing cycles (uniform and very small grain size). Comparison with coeval collections from the southwestern Iberian Peninsula has established that the metals in the settlement of Quinta do Almaraz were produced by a different technology from the indigenous metallurgy.