http://hdl.handle.net/10498/19458 2026-11-05T21:20:47Z 2026-11-05T21:20:47Z Fantuzzi, Leandro Hassini, Hicham Bernal Casasola, Darío Kbiri Alaoui, Mohammed Díaz Rodríguez, José Juan Cau‑Ontiveros, Miguel Ángel http://hdl.handle.net/10498/40550 2026-11-05T05:01:52Z 2026-01-19T00:00:00Z

Lixus and the petrographic characterization of its amphorae: first results from the 2018 and 2021 excavations in the Southern Sector Fantuzzi, Leandro; Hassini, Hicham; Bernal Casasola, Darío; Kbiri Alaoui, Mohammed; Díaz Rodríguez, José Juan; Cau‑Ontiveros, Miguel Ángel Las excavaciones realizadas en años recientes en el Sector Sur de Lixus (Larache, Marruecos) han permitido recuperar, entre otros materiales, un importante conjunto de ánforas de diversas cronologías, desde las fases finales de la época mauritana de la ciudad hasta la época tardorromana, incluyendo numerosos envases salsarios/salazoneros de tipologías propias de la región del Estrecho de Gibraltar. Teniendo en cuenta la importancia de la industria haliéutica en Lixus y la ausencia, hasta la fecha, de evidencias directas de alfares en el entorno del yacimiento (cuya existencia sería esperable, debido a la necesidad de suministrar envases a las factorías locales), el estudio de este extenso conjunto anfórico resultaba de gran interés para examinar la posibilidad de identificar envases locales y/o regionales, buscando obtener nuevos indicios para una mejor comprensión de las dinámicas de producción y comercio en este importante enclave tingitano. Para ello, se realizó un estudio petrográfico, mediante microscopía óptica por lámina delgada, de una selección de veintiséis ánforas de los contextos excavados de épocas mauritana a tardorromana, englobando una amplia variedad de tipologías. El estudio permitió identificar una gran variedad de fábricas petrográficas, en su mayor parte incompatibles con la hipótesis de un origen local y, en cambio, relacionables varias de ellas con una proveniencia del sur de Hispania. Esta preeminencia de ánforas regionales en los contextos lixitanos es significativa y, si bien no excluye la posible existencia de una producción anfórica local, ofrece, en cambio, interesantes novedades sobre las dinámicas comerciales de Lixus y, en un sentido más amplio, sobre la complejidad de los circuitos de producción y distribución de envases anfóricos en la Antigüedad en la región del Estrecho.; Excavations conducted in recent years in the Southern Sector of Lixus (Larache, Morocco) uncovered, among others, an important assemblage of amphorae of various chronologies, from the final phases of the Mauretanian period to the Late Roman period, including numerous amphorae for fish preserves/sauces ascribed to types that are characteristic of the Strait of Gibraltar region. Bearing in mind the importance of the halieutic industry in Lixus and the absence, to date, of direct evidence for pottery workshops in the vicinity of the site (whose existence would be expected, given the need to supply the local fish factories with amphorae), the study of this large amphora assemblage was of great interest as it allowed for investigating the possible presence of local and/ or regional containers in the Lixitan contexts, with the aim of gaining new insights into the production and trade dynamics of this important city of the Tingitan peninsula. For this reason, a mineralogical and petrographic analysis, by means of thinsection optical microscopy, was carried out on a sample of 26 amphorae from the excavated contexts, encompassing various amphora types from the Mauretanian to the Late Roman periods. The study allowed for the identification of a wide variety of petrographic fabrics, in most cases incompatible with a local provenance and, in fact, many of them related to an origin in southern Hispania. This prevalence of regional amphorae in the Lixitan contexts is significant, and, while not excluding the possible existence of a local amphora production, it does, however, provide new interesting data on the commercial dynamics of Lixus and, in a broader sense, on the complexity of the circuits of production and distribution of transport amphorae in the Strait of Gibraltar region in Antiquity.

2026-01-19T00:00:00Z González Olalla, Juan Manuel Cabrerizo, M.J. Medina-Sánchez, J.M. Villar-Argaiz, M. Carrillo, P. http://hdl.handle.net/10498/40539 2026-11-05T05:00:59Z 2026-01-01T00:00:00Z

Lessons from 30 years of multiple-stressor experiments on microbial plankton in a Spanish high-mountain lake González Olalla, Juan Manuel; Cabrerizo, M.J.; Medina-Sánchez, J.M.; Villar-Argaiz, M.; Carrillo, P. The impact of multiple environmental stressors on freshwater ecosystems has been linked to the study of global change and its effects on biotic communities since the last quarter of the 20th century. In the high mountain lakes of Sierra Nevada National Park (Spain), these studies emerged in the early 1990s, initially aiming to determine whether the most influent environmental stressors in the region (ultra-oligotrophy and high UV radiation) could explain the unique properties of the microbial communities in these systems (a simple, phytoplankton-dominated structure). Later, the focus shifted toward understanding how environmental stressors associated with global change could shape their trophic structure and functioning. In this review, we analyze the 35 experimental studies carried out in the Lakes of Sierra Nevada, with the aim of synthesizing the existing information on the combined effects of different stressors in these ecosystems. The findings highlight a predominant interest in studying the effects of nutrients and UV radiation on phytoplankton and bacterial communities. Interestingly, we report an increase in positive effects on variables such as chlorophyll-a, primary production, and bacterial production as the number of interacting stressors increases. The combination of stressors leads to a higher proportion of non-additive effects (-90%) over additive ones (-10%), with antagonistic effects predominantly affecting autotrophic variables and synergistic effects affecting heterotrophic ones. Taken together, the evidence indicates that while the microbial network structure in Sierra Nevada lakes shows a certain resistance to multiple stressors, their chronic effects may reveal an incipient shift toward a greater prominence of the bacterial compartment, ultimately transforming the microbial food web dynamics in these ecosystems.

2026-01-01T00:00:00Z Picó Jordá, Sergio Almaraz, P. Godoy del Olmo, Oscar http://hdl.handle.net/10498/40538 2026-11-05T05:01:54Z 2026-01-01T00:00:00Z

Species Accumulation Stabilizes the Synchronous Responses to the Environment of Vertebrate Communities Worldwide Picó Jordá, Sergio; Almaraz, P.; Godoy del Olmo, Oscar Multiple drivers contribute to community stability measured as the temporal invariability of total abundance, density, or biomass. However, the direct and indirect effects of these drivers, such as number of species, synchrony between species, species' life strategies, and environmental conditions in communities of terrestrial vertebrates remain unclear. To address this gap, we compiled a worldwide dataset of time series corresponding to 124 natural communities of terrestrial vertebrates including mammals, birds, and reptiles. We found that communities tend to be more synchronous than expected under the theoretical scenario of weak covariance between species because, at the interannual level, shared responses to the environment predominate over compensatory dynamics. Furthermore, piecewise structural equation models reveal that the number of species had a consistent positive effect on stability (either directly or indirectly via synchrony), but the sign and magnitude of the paths involving synchrony changed depending on the metric used and whether detrending was applied or not. Interestingly, we did not find the expected decreasing latitudinal gradient in community stability towards the poles. Our results demonstrate that the synchrony metrics used are not interchangeable and thus, whenever we use multivariate methods to understand the relation between richness, synchrony, and stability, our results may depend on how we define synchrony and how we measure it. Put together, our results also reinforce the idea of the predominance of environmental forcing over compensatory dynamics and the key role of the accumulation of species (statistical averaging) for the temporal stability of ecological communities.

2026-01-01T00:00:00Z Cuervo Novas, Senia Mendiguchía Martínez, Carolina Moreno Aguilar, Carlos http://hdl.handle.net/10498/40523 2026-10-31T05:04:17Z 2026-01-01T00:00:00Z

A dual solid and liquid solvent bar microextraction coupled with portable X-ray fluorescence for lead determination in seawater Cuervo Novas, Senia; Mendiguchía Martínez, Carolina; Moreno Aguilar, Carlos Trace metals play a crucial role in many biogeochemical processes in water. Due to their low concentrations and the complexity of the matrix, analysing these metals in seawater is a complex task that usually requires a previous preconcentration step. We present a simple two-step method for determining lead concentration in seawater. In the first step, we use a two-phase solvent bar microextraction system (2-SBME), previously prepared with a polypropylene hollow fiber. The extracted metal is then measured directly within the solid fiber using a portable X-ray fluorescence spectrometer. The 2-SBME contains two different extraction reagents: one liquid (Cyanex 272) and one solid (carbon nanotubes functionalized with carboxylic groups (CNT-COOH)). Two different microextraction processes are then carried out simultaneously: a LPME and a SPME, achieving a synergistic effect in the separation process. Efficiency was evaluated in terms of the percentage of lead extracted, with optimum conditions obtained at 0.06 mol L−1 of Cyanex 272, 10 mg mL−1 of CNT-COOH, a stirring rate of 50 rpm and an extraction time of 90 min. The influence of X-ray exposure time was also studied. Under optimal conditions, the LOD and LOQ were 0.061 mg L−1 and 0.203 mg L−1, respectively. Finally, the greenness of the new method was evaluated using the AGREEprep and SPMS methods. The method was successfully used to determine the lead concentration in fortified real seawater samples from three different locations, thus demonstrating its applicability. Using portable X-ray fluorescence equipment avoids the re-extraction step, and opens the possibility of in situ analysis.

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