César Borja Barrera

This paper presents an application of a methodology to map the subaerial areas of the Iberian Peninsula's continental shelf during the last glacial cycle. By integrating a bathymetric digital elevation model with a sea level curve that accounts for the complex and dynamic nature of sea level change during the period from 115 ka BP to 6 ka BP, the time of emergence for each grid cell is identified. This method differs from previous studies that have used fixed isobaths of -120 or -130 meters to identify the subaerially exposed areas, providing a more accurate assessment of the extent of the subaerial exposed lands. The obtained results show that the largest subaerial areas during the last glacial cycle were located in the Bay of Cadiz and the Gulf of Valencia. In contrast, the coastal areas of the Cantabrian Sea and the Andalusian Mediterranean experienced minor changes during this period. These findings provide valuable information for geologists and oceanographers studying past sea level fluctuations and their impact on the coastline.

Coastal marshes play a crucial role in global carbon (C) cycles as net C sinks, making them valuable for offsetting anthropogenic greenhouse gas emissions through C stock preservation or wetland restoration. However, the capacity of restored marshes to sequester organic C often falls below expectations, even decades post-restoration. This discrepancy highlights gaps in our understanding of biogeochemical processes that influence soil organic matter (SOM) dynamics and C sequestration potential. Specifically, the quality and molecular composition of SOM and its interaction with microbial communities remain underexplored. This study investigates the chemical composition of SOM and its relationship with biogeochemical processes and biome composition in marshes within the Doñana National Park, a globally significant biodiversity hotspot in Andalusia, Spain. The park has historically undergone significant human-driven transformations, necessitating large-scale restoration efforts.Our research focuses on three representative sites within the Doñana. The first site, “Marisma Gallega” (MG), is a high marsh that remains in its natural state, having never been cultivated. The second site, the “Finca de Caracoles” (FC), is undergoing active restoration and includes two distinct zones: a northern zone (FCN) with a lower degree of restoration due to a shorter time since cultivation ceased, and a southern zone (FCS) that has been uncultivated for a longer period. The third site is a fully transformed paddy soil (PS) currently used for rice cultivation. Soil samples were collected from each site at three depths (0–10; 10–20; and 20–30 cm) to analyze soil organic carbon (SOC), soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), and other key nutrients. Microbial activity was assessed through soil respiration (MicroResp technique), whereas microbial diversity and abundance were evaluated using phospholipid fatty acid (PLFA) analysis and metagenomic shotgun sequencing of 16S rRNA genes. Bioinformatic analyses provided insights into microbial richness, alpha diversity indices, and the relative abundance of different microbial communities.Our results indicate that MG and both FC zones exhibited higher SOC, SOM, TN, and TP contents compared to PS, suggesting higher C accumulation and improved SOM quality in the restoration sites, with values not significantly differing from MG. However, MG and both FC zones displayed lower concentrations of available P and NO₃⁻ relative to PS. These findings can be attributed to the conditions in degraded wetlands like PS, which disrupt N and P storage and cycling, promoting the mineralization of organic nutrients, such as organic N, and its transformation to NO₃⁻. Microbiological analyses revealed higher microbial respiration rates and greater fungal and bacterial biomass in MG and FC compared to PS, along with shifts in microbial community composition. These variations were influenced by the degree of naturalization and restoration. Accumulated organic C, combined with aerobic conditions, likely supports microbial growth, thereby accelerating microbial respiration.By characterizing SOM properties and linking them to microbial and biogeochemical processes, this study provides insights into how restoration and land-use change impact C storage and ecosystem services in marshes. The findings will inform future restoration strategies and improve the monitoring of these ecosystems’ health and functionality.

This research addresses the geomorphological connectivity existing amid the piedmont’s karstic fillings (Sierra de Esparteros) and the Guadaíra and Guadalquivir Rivers’ alluvial terraces (SW of Spain), spotted with vestiges of human activities (Middle Palaeolithic). This study includes the analysis of 20 geoarchaeological sites and 28 lithic assemblages, with a total of 13,233 lithic pieces. Techno-typological and use–wear (SEM) analyses were conducted on these artifacts. Depending on the raw materials and the provenance of these lithic industries, two groups of assemblages were identified: one made of quartzite from the north, and another made of flint from the south. Two main geochronological periods were established (OSL and U/Th): (1) a short duration (MIS6/MIS5) and (2) a long duration (MIS5/MIS3). Techno-typological analysis showed three sorts of activities: (a) the provision and distribution of raw materials, (b) knapping, and (c) other activities that imply the use of a lithic workshop (LW), along with the settlement characteristics of habitual or recurrent (HS), temporary (TS), and indeterminate (IN). This geoarchaeological connectivity is called the “hominid alluvial corridor” (HAC). The underlined features are the geomorphological units, the continuum alluvial series, the raw material of the lithic industries as an indicator of provenance and transportation throughout the alluvial system, and the use–wear analysis of the tool-kit to interpret the functionality of the pieces.

Human societies face challenges in transitioning towards low‐carbon economies and sustainable management of land use and natural resources. Documenting and learning from past transitions helps policy‐makers cope with such challenges. The agricultural revolution in Cantabrian Spain (ca. 7000 cal a bp) was one major adaptation of hunter‐gatherers to a changing environment that started with the Last Glacial Maximum (ca. 24 000 cal a bp) and lasted until the Mid‐Holocene (ca. 5300 cal a bp). Classic approaches to documenting prehistoric cultural timelines are based on manufacturing and technology, thus limited in their ability to describe the sustainability of past societies. Energy regimes, a functional societal approach independent from time, investigate and consider patterns of resource and energy use in various cohabiting and cooperating cultural phases. To examine past energy regimes, a database of archaeological remains was compiled to document four indicators: mobility, economy, overexploitation and societal complexity. Statistical analyses were conducted to elucidate trends, changes and continuity in subsistence strategies by hunter‐gatherers and sedentary societies. Results show that energy regimes act as a complement to cultural phases, adding novel functional analyses of past societies to cultural stratigraphy units common in archaeology, shedding light on the sustainability of past societal transitions.

Geomorphological studies are crucial for understanding the evolution of relief, and when associated with cartography, they enhance the interpretation and knowledge of environmental dynamics. Hence, historical cartography is essential for the documental rescue of landscapes, which, based on the mapped geoforms, enhances post-discovery studies for the state of Ceará, Brazil. Historically, this state was intermittently mapped in the sixteenth and seventeenth centuries but gained greater attention from Portugal in the eighteenth and nineteenth centuries after its separation from Pernambuco. Despite this, cartographic studies on coastal geoforms are not typical for the Ceará coast over a given period, highlighting the importance of this investigation. Therefore, this article aimed to study the environmental history of the coastal geoforms mapped on the extreme west coast of Ceará in the seventeenth and eighteenth centuries. This research had a qualitative and exploratory basis, with cartographic documental surveys online and in loco, covering the municipalities of Jijoca de Jericoacoara, Camocim, and Barroquinha. Fifty maps of different origins were collected, three of which were used: a French sketch and two Portuguese maps. In the French material of 1615, geoforms in the Cape de la Tortue indicated the presence of a rocky island separated from the mainland. From the Portuguese map of 1629, a well-cut coastline was noted, identifying Buraco das Tartarugas, where there were two islands of different sizes. In the 1794 map, an island in the cove called Geri qua Coá was noted, differing in landscape from the previous ones, as it did not have tombolos connected to the continent. The cartographies presented particularities for revealing a possible advance in the local sea level. Thus, it is possible to motivate future research in the area of historical cartography as a tool for the analysis of the paleogeographic evolution of the coastal zones of Ceará.

The Holocene is defined by the impact of agricultural societies on their natural environments and resources, a paradigmatic shift triggered by the Agricultural Revolution. In Cantabrian Spain, the adoption of a sedentary economy (ca. 7000 cal yr BP) remains misunderstood, with contemporary Mesolithic and Neolithic sites apparently random dispersed. Energy Regimes, a time-independent and functional analysis of past societies, considers two cultures that cohabit and/or cooperate, based on their differential pattern of use of energy and resources, as well as on the variation in land-use strategies. We test and implement the framework of Energy Regimes through a targeted review, to examine the hunter-gatherer subsistence strategies in Cantabrian Spain. Archeological proxies such as demography, mobility, complexity of society, economy, and overexploitation of resources identified in 95 articles and books, allow us to apply Energy Regimes to reexamine transitions in hunter-gatherer societies. Neolithization in Cantabrian Spain is the result of a long process that started with the Solutrean cultural phase ca. 24,000 cal yr BP, during the Last Glacial Maximum. Hunter-gatherers developed onward novel subsistence strategies with subtle changes in energy use until the transition toward a sedentary economy. Energy Regimes provide new insights for other regional contexts where time-bounded analyses conceal the complexity of energy transition processes in Europe and beyond.

Human-triggered climate change is widely acknowledged as a salient challenge to societal sustainability and welfare. Yet, our understanding of how human social systems may react to future change scenarios remains largely incomplete. However, human societies are the result of a long history of changes and adaptations to changing climates and environments. Understanding how individuals and their cultures have reacted and adapted to environmental changes over history and what effects these changes have had on landscapes could help us to more effectively design transition strategies towards low carbon societies. Hunter-gatherer societies in Cantabrian Spain between the Last Glacial Maximum (ca. 20,000 BP) and the Agricultural Revolution during the Mid Holocene (ca. 6,000 BP) evolved within a context of strong climate and environmental changes, as well as through societal changes via the adoption of a sedentary economy. Energy Regimes is a time-independent and functional theoretical and analytical tool of past societies, useful to identify and document past transitions. Statistical tests and analyses were used on archaeological data to document proxies such as demography, mobility, societal complexity, economy and overexploitation. The results were interpreted in the framework of Energy Regimes to better understand the changes and adaptation of human societies leading to the Agricultural Revolution and beyond in the context of changing environment and climate. Finally, quantification of energy use was extrapolated from the data and compared to the framework of social-metabolism, a quantitative approach similar to Energy Regimes. This work is part of the TERRANOVA programme. TERRANOVA is a Marie Skłodowska-Curie Innovative Training Networks (H2020-MSCA-ITN) project between Humanities and Science, which aims to map past environments and energy regimes, and to rethink human-environment interaction and designing land management tools for policy.

Se analizan tecno-tipológicamente las industrias líticas, mayoritariamente elaborada sobre cuarcitas, del yacimiento paleolítico al aire libre de Tarazona III (2.479 piezas líticas), formando parte de la Secuencia Paleolítica del Guadalquivir, que abarca el final del Pleistoceno Medio e inicios del Pleistoceno Superior (129 ka y <104 ka). Se identifican las cadenas operativas del yacimiento, desde la selección de materias primas hasta la fabricación de los útiles con percutor duro. Son cadenas dirigidas especialmente a la obtención de pequeñas lascas (<5 cm), lo que refuerza la selección del tamaño del canto rodado, con patrones de reducción de núcleos elementales, buena representación de los centrípetos y baja presencia del levallois. La serie de N3 es muy equilibrada y completa; y relativamente completas las de N1 y N2 lo que sugiere, o bien la preconfiguración de las cadenas operativa en otros lugares cercanos y el transporte de los productos de talla al yacimiento; o, en N1, el desplazamiento hidro-geomorfológico de las piezas de dimensiones más reducidas. La proporción útiles lasca/lasca es del 24% (N2) y 34,7% (N3), esto es, en los niveles posteriores a 104 ka BP. Esta proporción junto a la baja variabilidad de los tipos sobre lasca, la exigua o nula presencia de macroútiles, define la industria de Tarazona III, como uno de los yacimientos representativos del Paleolítico Medio Antiguo (PMA) del Valle del Guadalquivir.