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In the last decade, the identification of bone fragments by peptide mass fingerprinting or zooarchaeology by mass spectrometry is developing as a powerful tool in Quaternary palaeontology. The sequence of amino acids that make up the bone collagen molecule shows slight variations between taxa, which can be studied by mass spectrometry for taxonomic purposes. This requires reference databases that allow peptide identification. Although the cave bear (Ursus spelaeus Rosenmüller, 1794) is a common component in many European Pleistocene cave sites, no peptide fingerprint taxonomic study has paid special attention to this species up to now. For peptide markers in Ursidae, the most recent proposal is based on collagen obtained from a modern brown bear sample. In this work we attempt to cover this gap by studying bone collagen of cave and brown bear samples from different origins and different chronology, applying matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF). We also performed an in-silico study of ursid bone collagen sequences published in databases. In our results we detected some discrepancies between the peptides obtained from both in silico and MALDI TOF analysis of fossil collagen and those published in the literature, in which we conclude that there are some misidentified peptides. The identification of skeletal remains by means of their peptide fingerprint is proving to be a powerful tool in palaeontology, which will bear greater fruit once the limitations of a technique that is in its initial stages have been overcome.

Se presentan algunos resultados publicados de campañas de datación por racemización de aminoácidos (AAR) del Laboratorio de Estratigrafía Biomolecular (LEB) de la Escuela de Minas y Energía de la Universidad Politécnica de Madrid, en localidades de la Península Ibérica, que se han seleccionado para mostrar la aplicabilidad del método a muestras de origen biológico muy diverso, foraminíferos, moluscos, crustáceos y mamíferos de diferentes medios geológicos: largos registros de cuenca, terrazas marinas y fluviales, depósitos eólicos y yacimientos en cuevas. Obviamente, no se citan dataciones singulares en muchas localidades. Cerca de veinte mil análisis validan el uso de este método. El método cubre un amplio rango temporal: desde subactual hasta 1.3 Ma; junto con la pequeña cantidad de muestra precisa para los análisis, permite replicar los mismos incluso sobre muestras valiosas de museos u otras instituciones. Asimismo, se puede emplear en determinaciones forenses. Cabe destacar que la pequeña cantidad de muestra necesaria para la realización de un análisis permite emplear un número representativo de muestras de cada nivel objeto de estudio, obteniendo información suficiente para que, mediante un análisis estadístico elemental, se puedan desechar valores anómalos.

The coastal zone in which the lagoons of La Mata and Torrevieja (Eastern Spain) developed can be described as a compilation of geo-hazards typical of the Mediterranean realm. This study has focused mainly on those linked to recent tectonics. Extensive use of the amino acid racemization dating method allowed us to establish the evolution of all the geomorphological units differentiated in the area, the most striking manifestation being at the La Mata Lagoon Bar, where MIS 5 deposits settled on MIS 7 sediments along a marked erosive unconformity, thereby attesting coastal uplift between these two stages. In addition, recent uplift processes were reflected on stepped abrasion platforms and, in some cases, enormous boulders were transported over these platforms by extreme surge waves. Furthermore, we obtained feasible evidence that, during the end of MIS 5, an earthquake with an offshore epicenter linked to Torrevieja Fault, Bajo Segura Fault or the set of faults linked to the former, was responsible for tsunami surge deposits represented in accumulations of randomly arranged and well preserved Glycymeris and Acanthocardia shells. Recent catastrophic effects linked to the earthquakes were also detected. In this regard, comparison of the paleontological and taphonomic analyses allowed us to discern between wave and tsunami surge deposits. Therefore, evidence of these hazards undoubtedly points to important future (and present) erosive and/or catastrophic processes, which are enhanced by the presence of tourist resorts and salt-mining industry. Thus, these sites are also threatened by future increases in sea level in the context of warmer episodes, attested by raised marine fossil deposits. At the north of Cervera Cape, beaches will be eroded, without any possibility of sediment input from the starved Segura River delta. South of this cape, waves (and tsunamis) will erode the soft rocks that built up the cliff, creating deep basal notches and causing rockfall and the collapse of the overlying buildings.

Water is the main limiting factor for groundwater-dependent ecosystems (GDEs) in drylands. Predicted climate change (precipitation reductions and temperature increases) and anthropogenic activities such as groundwater drawdown jeopardise the functioning of these ecosystems, presenting new challenges for their management. We developed a trait-based analysis to examine the spatiotemporal variability in the ecophysiology of Ziziphus lotus, a long-lived phreatophyte that dominates one of the few terrestrial GDEs of semiarid regions in Europe. We assessed morpho-functional traits and stem water potential along a naturally occurring gradient of depth-to-groundwater (DTGW, 2–25 m) in a coastal aquifer, and throughout the species-growing season. Increasing DTGW and salinity negatively affected photosynthetic and transpiration rates, increasing plant water stress (lower predawn and midday water potential), and positively affected Huber value (sapwood cross-sectional area per leaf area), reducing leaf area and likely, plant hydraulic demand. However, the species showed greater salt-tolerance at shallow depths. Despite groundwater characteristics, higher atmospheric evaporative demand in the study area, which occurred in summer, fostered higher transpiration rates and water stress, and promoted carbon assimilation and water loss more intensively at shallow water tables. This multiple-trait analysis allowed us to identify plant ecophysiological thresholds related to the increase in salinity, but mostly in DTGW (13 m), and in the evaporative demand during the growing season. These findings highlight the existence of tipping points in the functioning of a long-lived phreatophyte in drylands and can contribute to the sustainable management of GDEs in southern Europe, paving the way for further studies on phreatophytic species. Supplementary Information The online version contains supplementary material available at 10.1007/s00442-021-04993-w.

We reconstructed the palaeoenvironmental conditions of Cartagena Bay during the Holocene after a multidisciplinary study to identify natural variations and the anthropic processes of this coastal area. A total of 119 samples were recovered for amino acid racemization dating, 3 for radiocarbon dating (14C), and four sets of 80 samples for sedimentological and palaeontological determination, mineralogical content, biomarker and trace elements quantification. Two natural scenarios were identified from the variations of n-alkane indices and palaeobiological content. The first period (6650-5750 yr cal BP) was marked by the development of euhaline marine conditions with strong inputs from aquatic macrophytes and high biodiversity. After a hiatus, the area underwent a profound change, becoming a paucispecific brackish marsh environment with increasing inputs from land plants, with possible episodes of emersion with a greater presence from terrestrial gastropods (3600-300 cal yr BP). By combining trace element abundance and stanol distributions, our study also provides a novel approach to identify the predominant influence of anthropogenic factors in the last three millennia in the coastal record of Cartagena Bay. Findings confirmed that Pb mining and metallurgy began during the Bronze Age, with considerable inputs of this heavy metal into the atmosphere during Phoenician, Punic and particularly Roman times compared to the Middle Ages. Pollution by Cu and Zn was also observed during Punic and Roman times, and was first documented in the Middle Ages. In addition, faecal stanols, such as coprostanol, derived mainly from humans, and 24-ethylcoprostanol from herbivores were present, thereby indicating for the first time a continuous presence of human populations and significant pollution input since 3600 yr cal BP, this being greater in the late Bronze Age and Phoenician, Punic and Roman times than during Late Antiquity and the Middle Ages, when the city was in decline., This paper was made possible by Grant HAR2017-85726-C2-2-P (Cambios ambientales y ocupación humana en el sector central del sureste ibérico) funded by MCIN/AEI/10.13039/501100011033 and by Grant HAR2017-85726-C2-1-P (Carthago Nova desde su entorno litoral: Paleotopografía y evolución medioambiental del Sector central del Sureste Ibérico. Dinámica poblacional y productiva) funded by MCIN/AEI/10.13039/501100011033. XRF core scanner equipment was co-financed by the European Regional Development Fund via the Spanish National Plan for Scientific and Technical Research and Innovation 2013–2016 (IGME13-4E-2576).

Water is the main limiting factor for groundwater-dependent ecosystems (GDEs) in drylands. Predicted climate change (precipitation reductions and temperature increases) and anthropogenic activities such as groundwater drawdown jeopardize the structure and functioning of these ecosystems, presenting new challenges for their management. We developed a trait-based analysis to examine the spatiotemporal variability in the ecophysiology of Ziziphus lotus, a phreatophyte that dominates one of the few terrestrial GDEs of semiarid regions in Europe. We assessed morpho-functional and hydraulic traits along a naturally occurring gradient of depth-to-groundwater (DTGW, 2–25 m) in a coastal aquifer, and throughout the growing season of the species. Increasing DTGW and salinity negatively affected photosynthetic and transpiration rates, increasing plant water stress (lower predawn and midday water potential), and positively affected Huber value (sapwood cross-sectional area per leaf area), reducing leaf area and likely, plant hydraulic demand. However, higher atmospheric evaporative demand fostered higher transpiration rates and water stress. Differences in climatic conditions throughout the growing season drove temporal variability in Z. lotus responses along the DTGW gradient, with warmer and drier conditions promoting carbon assimilation and water loss more intensively at shallow water tables. This multiple-trait analysis allowed us to identify plant ecophysiological thresholds related to the increase in DTGW and evaporative demand during the growing season. These findings highlight the existence of tipping points in the ecophysiological functioning of phreatophytic plants in drylands, which contribute to disentangle the functional responses of the related GDEs under groundwater detriment because of climate change effects.

Premise: Water is the most limiting factor in dryland ecosystems, and plants are adapted to cope with this constraint. Particularly vulnerable are phreatophytic plants from groundwater-dependent ecosystems (GDEs) in regions that have to face water regime alterations due to the impacts of climate and land-use changes. Methods: We investigated two aspects related to the water-use strategy of a keystone species that dominates one of the few terrestrial GDEs in European drylands (Ziziphus lotus): where it obtains water and how it regulates its use. We (1) evaluated plants’ water sources and use patterns using a multiple-isotope approach (δH, δO, and ΔC); (2) assessed the regulation of plant water potential by characterizing the species on an isohydric–anisohydric continuum; and (3) evaluated plants’ response to increasing water stress along a depth-to-groundwater (DTGW) gradient by measuring foliar gas exchange and nutrient concentrations. Results: Ziziphus lotus behaves as a facultative or partial phreatophyte with extreme anisohydric stomatal regulation. However, as DTGW increased, Z. lotus (1) reduced the use of groundwater, (2) reduced total water uptake, and (3) limited transpiration water loss while increasing water-use efficiency. We also found a physiological threshold at 14 m depth to groundwater, which could indicate maximum rooting length beyond which optimal plant function could not be sustained. Conclusions: Species such as Z. lotus survive by squandering water in drylands because of a substantial groundwater uptake. However, the identification of DTGW thresholds indicates that drawdowns in groundwater level would jeopardize the functioning of the GDE., This research was done in the framework of the LTSER Platform “The Arid Iberian South East LTSER Platform - Spain (LTER_EU_ES_027)” and supported by the European project LIFE Adaptamed (LIFE14349 CCA/ES/000612), the Spanish Ecological Transition Ministry (through Biodiversity Foundation) project CO-ADAPTA. (CA_CC_2016), and the RTI2018-102030-B-I00 project of the University of Almería (PPUENTE2020/001). F.G. was financially supported by the “HIPATIA” research program of the University of Almeria, and the Spanish government supported M.T.T. with a FPU predoctoral fellowship (16/02214)

Lopez-Rodriguez, M.D., Salinas-Bonillo, M.J., Torres, M.T., Pacheco-Romero, M., Guirado, E., Castro, H., Cabello, J. 2019. Launching collective science-policy-society strategies to conserve the Ziziphus lotus habitat (Priority Habitat 5220). Ecosistemas 29(1):1890. https://doi.org/10.7818/ECOS.1890 The priority habitat 5220 is dominated by the Ziziphus lotus which has experienced a major setback in recent decades, its area of distribution has seriously deteriorated in its functioning within Spain. Despite the knowledge generated by researchers for its valuation, management and conservation, such knowledge hardly permeates to policy and society. The aim of this study was to develop and evaluate a transdisciplinary process as a means to provide collective knowledge about this habitat and to promote a culture of shared responsibility that contributes to its conservation. To do this, we 1st) conducted a literature review of the existing knowledge of this specie, and 2nd) developed a transdisciplinary process within a community of practice integrated by researchers, decision-makers and social agents. The study allowed us to (1) identify gaps in scientific knowledge and research opportunities around Ziziphus lotus and its habitat, (2) define and promote the implementation of 13 collaborative science-policy-society strategies to contribute to its conservation. Throughout the study, we identified several operational factors that facilitated the transdisciplinary process. These factors included (i) the generation of a trusting environment between members of the community of practice; (ii) the use of a knowledge exchange approach between actor groups by researchers with transdisciplinary skills, and (iii) the creation of co-learning and knowledge co-production work schemes oriented towards practical outcomes. In addition, we introduced and evaluated a graphical tool that acted as a boundary object catalysing collective action for the conservation of this specie. This study provides useful guidance for developing future transdisciplinary processes in other contexts.

In this paper, we conduct a palynological analysis of a high-resolution Holocene record from Cartagena Bay, southeast of the Iberian Peninsula, to establish paleoenvironmental variability of coastal areas in the western Mediterranean region at a centennial-scale over the last 7300 years. Statistical analysis of four palynozones allows reconstruction of paleotemperature and paleohumidity conditions. Pinus, steppic, xerophilous, and Mediterranean taxa persisted continuously through the record, and only during periods of increased humidity did deciduous and Mediterranean taxa expand (Zones II, subzone IIIb). Cooler and dry conditions favored the development of Cupressaceae and scrubs between 7300 and 7000 yr cal BP. The mid-Holocene (Northgrippian) mesophytic optimum took place between 6800 and 4000 yr cal BP during which time a Mediterranean climate was present and open forest developed, predominantly consisting of Mediterranean taxa and deciduous trees. The gradual rise in aridity in the Meghalayan (4000–1700 yr cal BP) led to Mediterranean forest being replaced by steppic and xerophilous vegetation, a change related mostly to a decrease in summer insolation, with superimposed centennial-scale variability in humidity. In parallel with forest degradation caused by increasing aridity, the record shows marked evidence of human influence since 4000 yr cal BP, which accelerated the progression of open landscapes from the Chalcolithic onwards, this change being especially marked during the Roman period. Significant denudation of the landscape can be attributed to the use of fire, as well as due to agriculture and grazing, with a major contributor being intense metallurgical and mining activity in the area. The Cartagena Bay record reported herein shows centennial-scale oscillations in humidity and temperature that correlate with well-known climatic events during the late Holocene in the western Mediterranean region, synchronous with variability in solar and atmospheric dynamics. The alternation of persistent North Atlantic Oscillation modes is likely to have played a key role in regulating humid–arid periods., This paper was made possible by Grant HAR2017-85726-C2-2-P (Cambios ambientales y ocupación humana en el sector central del sureste ibérico) funded by MCIN/AEI/10.13039/501100011033 and by Grant HAR2017-85726-C2-1-P (Carthago Nova desde su entorno litoral: Paleotopografía y evolución medioambiental del Sector central del Sureste Ibérico. Dinámica poblacional y productiva) funded by MCIN/AEI/10.13039/501100011033

We performed detailed geological and geomorphological analyses on a well-exposed series of marine terrace deposits located along a coastal area from the city of Taranto to the Bradano River in the northern Gulf of Taranto (southern Italy). Absolute dating was performed by applying amino acid racemisation (AAR) to ostracod shells and isoleucine epimerisation (D-aIle/L-Ile) to Glycymeris sp. shells. The combination of field geological surveys, remote sensing, digital terrain model analysis, and absolute dating allowed us to study a large number of stratigraphic sections as well as recognise and map three terrace deposits in the Apulian sector of the Gulf of Taranto that date to MIS 7.3, MIS 7.1 and MIS 5. A peculiar feature of the MIS 7.1 terrace deposit is the presence of biohermal and biostromal limestones rich in Cladocora caespitosa, calcareous algae and bryozoans; this feature contrasts with general context of the prevailing siliciclastic deposits. Based on currently available data, we propose two hypotheses regarding the MIS 5 terrace deposit: 1) the MIS 5 terrace formed entirely during MIS 5.5; and 2) the MIS 5 terrace is a set of terraces that correlates to MIS 5.5, 5.3 and 5.1, in which the scarps and abrasion platforms have been partially masked by the superimposition of the so-called givoni, ridges that are elongated sub-parallel to the coastline. Our data, combined with an extensive critical review of age dates in the literature, allow us to exclude the presence of an emerged marine terrace deposit of MIS 3. We calculate the uplift rates of the MIS 7.3, 7.1, 5.5 and 5.3 palaeoshorelines. In the west sector, the mean uplift rates calculated for the recognised inner edges are MIS 7.3 = 0.65 mm/a, MIS 5.5 = 0.39 mm/a, MIS 5.3 = 0.31 mm/a; in the central sector the rates are MIS 7.3 = 0.485 mm/a, MIS 7.1 = 0.37 mm/a, MIS 5.5 = 0.35 mm/a, MIS 5.3 = 0.26 mm/a; in the east sector the rates are MIS 7.3 = 0.39 mm/a, MIS 5.5 = 0.25 mm/a, MIS 5.3 = 0.21 mm/a. These uplift rates show a uniform decreasing trend in time and space, proceeding from the western to the eastern sector, which allows us to hypothesise a slowing of the uplift phase characterising the foredeep, which began in the middle Pleistocene.

Fuente TESIUNAM

Los restos cuyo estudio nos ocupa, han sido extraídos en la denominada «Sima de los Huesos» en la Cueva Mayor, situada en la Sierra de Atapuerca, en las cercanías del pueblo de Ibeas de Juarros, a 14 km. de Burgos, en la margen derecha del río Arlanzón. La Sierra de Atapuerca puede definirse geológicamente como un anticlinal de calizas y margas del cretácico superior, rodeado por terrenos neógenos que se apoyan con una fuerte discordancia angular.

Water availability controls the functioning of dryland ecosystems, driving a patchy vegetation distribution, unequal nutrient availability, soil respiration in pulses, and limited productivity. Groundwater-dependent ecosystems (GDEs) are acknowledged to be decoupled from precipitation, since their vegetation relies on groundwater sources. Despite their relevance to enhance productivity in drylands, our understanding of how different components of GDEs interconnect (i.e., soil, vegetation, water) remains limited. We studied the GDE dominated by the deep-rooted phreatophyte Ziziphus lotus, a winter-deciduous shrub adapted to arid conditions along the Mediterranean basin. We aimed to disentangle whether the groundwater connection established by Z. lotus will foster soil biological activity and therefore soil fertility in drylands. We assessed (1) soil and vegetation dynamics over seasons (soil CO2 efflux and plant activity), (2) the effect of the patchy distribution on soil quality (properties and nutrient availability), and soil biological activity (microbial biomass and mineralization rates) as essential elements of biogeochemical cycles, and (3) the implications for preserving GDEs and their biogeochemical processes under climate change effects. We found that soil and vegetation dynamics respond to water availability. Whereas soil biological activity promptly responded to precipitation events, vegetation functioning relies on less superficial water and responded on different time scales. Soil quality was higher under the vegetation patches, as was soil biological activity. Our findings highlight the importance of groundwater connections and phreatophytic vegetation to increase litter inputs and organic matter into the soils, which in turn enhances soil quality and decomposition processes in drylands. However, biogeochemical processes are jeopardized in GDEs by climate change effects and land degradation due to the dependence of soil activity on: (1) precipitation for activation, and (2) phreatophytic vegetation for substrate accumulation. Therefore, desertification might modify biogeochemical cycles by disrupting key ecosystem processes such as soil microbial activity, organic matter mineralization, and plant productivity. This research was developed in the framework of the LTSER Platform “The Arid Iberian South East LTSER Platform — Spain (LTER_ EU_ES_027)” and supported by the European project LIFE Adaptamed (LIFE14349610 CCA/ES/000612). MTT and BRL were financially supported by a FPU Predoctoral Fellowship of the Spanish Government (16/02214 and 17/01886). EG was supported by the European Research Council (ERC Grant agreement 647038 [BIODESERT]).