Humans and environments in the most arid place of the world

The Atacama Desert lies between the Pacific coast and the Andes in northern Chile. It is the largest desert in South America and the driest on Earth. Here, annual precipitation is almost zero. The little water that is available depends on the summer rainfall that falls on the Andean mountains. It reaches the desert by runoff and is found within some canyons or by the emergence of groundwater. The presence of life in this extreme environment may seem unimaginable today; however, fossil and archaeological records reveal that plants, animals, and even humans lived in this region during various periods over the last 18,000 years.Fil: de Porras, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Gayo, Eugenia M.. Centro de Ciencia del Clima y la Resiliencia; ChileFil: Uribe, Mauricio. Universidad de Chile; ChileFil: Maldonado, Antonio. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chil

Synchronization of Energy Consumption By Human Societies Throughout the Holocene

We conduct a global comparison of the consumption of energy by human populations throughout the Holocene and statistically quantify coincident changes in the consumption of energy over space and time—an ecological phenomenon known as synchrony. When populations synchronize, adverse changes in ecosystems and social systems may cascade from society to society. Thus, to develop policies that favor the sustained use of resources, we must understand the processes that cause the synchrony of human populations. To date, it is not clear whether human societies display long-term synchrony or, if they do, the potential causes. Our analysis begins to fill this knowledge gap by quantifying the long-term synchrony of human societies, and we hypothesize that the synchrony of human populations results from (i) the creation of social ties that couple populations over smaller scales and (ii) much larger scale, globally convergent trajectories of cultural evolution toward more energy-consuming political economies with higher carrying capacities. Our results suggest that the process of globalization is a natural consequence of evolutionary trajectories that increase the carrying capacities of human societies

Synchronization of Energy Consumption By Human Societies Throughout the Holocene

We conduct a global comparison of the consumption of energy by human populations throughout the Holocene and statistically quantify coincident changes in the consumption of energy over space and time—an ecological phenomenon known as synchrony. When populations synchronize, adverse changes in ecosystems and social systems may cascade from society to society. Thus, to develop policies that favor the sustained use of resources, we must understand the processes that cause the synchrony of human populations. To date, it is not clear whether human societies display long-term synchrony or, if they do, the potential causes. Our analysis begins to fill this knowledge gap by quantifying the long-term synchrony of human societies, and we hypothesize that the synchrony of human populations results from (i) the creation of social ties that couple populations over smaller scales and (ii) much larger scale, globally convergent trajectories of cultural evolution toward more energy-consuming political economies with higher carrying capacities. Our results suggest that the process of globalization is a natural consequence of evolutionary trajectories that increase the carrying capacities of human societies

Desde el pacífico a la foresta tropical: redes de interacción social en el desierto de atacama durante el pleistoceno final

The social groups that initially inhabited the hyper arid core of the Atacama Desert of northern Chile during the late Pleistocene integrated a wide range of local, regional and supra regional goods and ideas for their social reproduction as suggested by the archaeological evidence contained in several open camps in Pampa del Tamarugal (PdT). Local resources for maintaining their every-day life, included stone raw material, wood, plant and animal fibers, game, and fresh water acquired within a radius of ∼30 km (ca. 1-2 days journey). At a regional scale, some goods were introduced from the Pacific coast (60-80 km to the west, ca. 3-4 days journey), including elongated rounded cobbles used as hammer stones in lithic production, and shells, especially from non-edible species of mollusks. From the Andes (ranging 80-150 km to the east, ca. 5-8 days of journey), they obtained camelid fiber, obsidian and a high-quality chalcedony, in addition to sharing knowledge on projectile point designs (Patapatane and Tuina type forms). Pieces of wood of a tropical forest tree species (Ceiba spp.) from the east Andean lowlands (600 km away, ca. 30 days of journey) were also brought to the PdT. While local goods were procured by the circulation of people within the PdT, the small number of foreign items would have been acquired through some sort of exchange networks that integrated dispersed local communities throughout several ecosystems. These networks may have been a key factor behind the success exhibited by these early huntergatherers in the hyper arid ecosystems of the Atacama Desert at the end of the Pleistocene. Different lines of archaeological evidence including open camps, workshop-quarries, lithic artifacts, archaeofaunal remains, plant and animal fibers and textiles, archaeobotanical remains, and paleoecological data show that people of the PdT managed a wide range of cultural items from the Pacific coast, the Andean highland and the tropical forest, that were integrated with resources gathered locally within the socio-cultural systems established by the end of the Pleistocene. These results are interpreted as material expressions of multi-scalar networking for resource management and other social material and immaterial requirements, which in other words, means that these people were actively connected to regional (coastal and highland), and supra-regional (trans-Andean) exchange networks from and out of the PdT.Los grupos sociales que inicialmente habitaban el núcleo hiperárido del Desierto de Atacama en el norte de Chile durante el Pleistoceno tardío integraron una amplia gama de bienes e ideas, locales, regionales y supra regionales, para su reproducción social, como lo sugieren las evidencias arqueológicas materiales recuperadas en varios campamentos al aire libre en Pampa del Tamarugal (PdT). Los recursos locales para mantener su vida diaria, incluían materias primas líticas, fibras de plantas y animales, presas de caza y agua dulce adquiridos en un radio de ̴30 km (ca. 1-2 días de viaje). A escala regional, se introdujeron algunos elementos desde la costa del Pacífico (60-80 km hacia el oeste, ca. 3 a 4 días de viaje), incluidos rodados redondeados alargados, utilizados como percutores en la producción lítica y conchas, especialmente de especies no comestibles de moluscos. Desde los Andes (80-150 km al este, ca. 5-8 días de viaje), obtuvieron fibra de camélido, obsidiana y una calcedonia de alta calidad, además de compartir conocimientos sobre diseños de puntas de proyectil (tipo Patapatane y Tuina). También se llevaron a la PdT trozos de madera de una especie de árbol de los bosques tropicales (Ceiba spp.) de las tierras bajas al este de los Andes (600 km de distancia, ca. 30 días de viaje). Mientras que los bienes locales fueron adquiridos por la circulación de personas dentro de la PdT, el pequeño número de artículos foráneos se adquirieron a través de redes de intercambio que integraron comunidades locales dispersas en varios ecosistemas; lo que debió ser un factor clave detrás del éxito demostrado por estos primeros cazadores-recolectores en los ecosistemas hiperáridos del Desierto de Atacama hacia el final del Pleistoceno. Diferentes líneas de evidencia arqueológica que incluyen campamentos al aire libre, talleres, canteras, artefactos líticos, restos arqueofaunales, fibras y textiles de plantas y animales, restos arqueobotánicos y datos paleoecológicos, muestran que la gente de la PdT manejaron una amplia gama de elementos culturales desde la costa del Pacífico, el altiplano andino y el bosque tropical, que se integraron a los recursos recolectados localmente dentro de los sistemas socioculturales establecidos al final del Pleistoceno. Estos resultados se interpretan como una expresión material de una red de múltiples escalas para la gestión de recursos y otros requisitos sociales e inmateriales, lo que en otras palabras, significaría que estos grupos sociales estaban conectados activamente con redes de interacción regionales (costa y tierras altas) y supra-regionales (transandinas) desde y hacia la PdT.Fil: Santoro, Calógero M.. Universidad de Tarapaca.; ChileFil: Gayo, Eugenia M.. Centro de Ciencia del Clima y la Resiliencia; Chile. Universidad de Concepción; ChileFil: Capriles Flores, Jose Mariano. State University of Pennsylvania; Estados UnidosFil: Rivadeneira Valenzuela, Marcelo Michel. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chile. Universidad Católica del Norte; Chile. Universidad de La Serena; ChileFil: Herrera, Katherine A.. Universite Paris Ouest Nanterre la Defense; Francia. Universidad de Tarapaca.; ChileFil: Mandakovic, Valentina. No especifíca;Fil: Rallo, Mónica. No especifíca;Fil: Rech, Jason A.. University of Miami; Estados UnidosFil: Cases, Bárbara. Universidad de Tarapaca.; ChileFil: Briones, Luis. Museo Municipalidad de Pica; ChileFil: Olguín, Laura. Universidad Católica del Norte, San Pedro de Atacama; ChileFil: Valenzuela, Daniela. Universidad de Tarapaca.; ChileFil: Borrero, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Ugalde, Paula C.. University of Arizona; Estados Unidos. Universidad de Tarapaca.; ChileFil: Rothhammer, Francisco. Universidad de Tarapaca.; ChileFil: Latorre, Claudio. Pontificia Universidad Católica de Chile; Chile. Instituto de Ecología y Biodiversidad; ChileFil: Szpak, Paul. Trent University; Canad

p3k14c, a synthetic global database of archaeological radiocarbon dates.

Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according to a standardized sample selection criteria. This database increases the reusability of archaeological radiocarbon data and streamlines quality control assessments for various types of paleo-demographic research. As part of an assessment of data quality, we conduct two analyses of sampling bias in the global database at multiple scales. This database is ideal for paleo-demographic research focused on dates-as-data, bayesian modeling, or summed probability distribution methodologies

Assessing changes in global fire regimes

PAGES, Past Global Changes, is funded by the Swiss Academy of Sciences and the Chinese Academy of Sciences and supported in kind by the University of Bern, Switzerland. Financial support was provided by the U.S. National Science Foundation award numbers 1916565, EAR-2011439, and EAR-2012123. Additional support was provided by the Utah Department of Natural Resources Watershed Restoration Initiative. SSS was supported by Brigham Young University Graduate Studies. MS was supported by National Science Centre, Poland (grant no. 2018/31/B/ST10/02498 and 2021/41/B/ST10/00060). JCA was supported by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 101026211. PF contributed within the framework of the FCT-funded project no. UIDB/04033/2020. SGAF acknowledges support from Trond Mohn Stiftelse (TMS) and University of Bergen for the startup grant ‘TMS2022STG03’. JMP participation in this research was supported by the Forest Research Centre, a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UIDB/00239/2020). A.-LD acknowledge PAGES, PICS CNRS 06484 project, CNRS-INSU, Région Nouvelle-Aquitaine, University of Bordeaux DRI and INQUA for workshop support.Background The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Results Respondents indicated some direct human influence on wildfire since at least ~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime change until around 5,000 years BP, for most study regions. Responses suggested a ten-fold increase in the frequency of fire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in frequency, severity, and size in all biomes except grassland ecosystems. Fire regimes showed different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher warming scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, while recognizing that management options are constrained under higher emission scenarios. Conclusion The influence of humans on wildfire regimes has increased over the last two centuries. The perspective gained from past fires should be considered in land and fire management strategies, but novel fire behavior is likely given the unprecedented human disruption of plant communities, climate, and other factors. Future fire regimes are likely to degrade key ecosystem services, unless climate change is aggressively mitigated. Expert assessment complements empirical data and modeling, providing a broader perspective of fire science to inform decision making and future research priorities.Peer reviewe

delta O-18 of Fissurella maxima as a proxy for reconstructing Early Holocene sea surface temperatures in the coastal Atacama desert (25 degrees S)

Fissurella maxima is a keyhole limpet that is abundant and well preserved in archaeological shell midden sites along the coast of Chile, making it an appropriate species to use for reconstructions of past sea surface temperature (SST). In the present study we evaluate the potential of F. maxima shells as a proxy of SST by analysing delta O-18 of modern shells collected alive from the Atacama desert (area of Taltal, 25 degrees S) and archaeological shells from two Early Holocene rockshelter sites: 224A and Paposo Norte 9. Reconstructed SST from modern F. maxima shells were related to SST obtained from in situ thermometers, supporting the use of this mollusc species as a paleotemperature archive. Mean SST reconstructed from Early Holocene archaeological shells (14.13 degrees C) was 2.86 degrees C cooler than mean temperature recorded in modem shells (16.99 degrees C). Mean SST reconstructed from modem shells was 1.04 degrees C wanner than the mean temperature of in situ thermometers (15.95 degrees C). Hence the paleo SST data from archaeological sites 224A and Paposo Norte 9 enrich the Early Holocene nearshore paleoceanographic scenario of the Pacific coast of South America, with mean SST cooler than present-day SST. Our results validate the use of F. maxima shells as a SST proxy and contribute to a better understanding of the latitudinal distribution of the coastal upwelling regime during the Early Holocene, temporal changes in the structure of the Humboldt Current along the Holocene, and its influence on human adaptation through the prehistory of South America

Reconstruction of glaciers in the western boundary of the Altiplano (18.5°-19°S): Singularities and insights on potential drivers of past advances

Today, glaciers in the western Altiplano are very scarce, even on peaks exceeding 6000 m. In this mostly ice-free landscape, however, moraines and other glacial deposits are commonly found attesting to quite different climate conditions that favored the advance of glaciers in the past. Although other areas of the Altiplano have been commonly accounted for regarding paleoclimate reconstructions, western Altiplano has been often overlooked. Here we present a detailed map of glacial landforms and a paleoglacier reconstruction from a test area in the western Altiplano between 18.5° and 19°S. We reconstructed regional equilibrium line altitudes (ELA) for several moraine stages, representing extensive past glacier advances in the region. During a prominent and ubiquitous ‘Principal Moraine (PM)’ stage glaciers from most peaks and all orientations advanced to altitudes of up to 4000 m asl. Reconstructed PM ELAs along 90 valleys range from 4400 to 5000 m asl. ELA distribution reveals a strong aspect-dependency at the western boundary of the Altiplano, with ELAs 300 m lower on west-facing glaciers than east-facing glaciers. The coincidence of such steep gradient with a prominent NW-SE ridge accounts for topographic control on the precipitation and thus in the advance of glaciers along the western boundary of the Altiplano. To the east, ELAs from the peaks towering the Altiplano are comparable to ELAs from east-facing glaciers at the western Altiplano boundary but show little to no aspect-dependency. Since these patterns cannot be solely explained by increased moisture advection from the Amazon basin, we suspect that western-sourced moisture associated with increased frequency of cold fronts and cut-off events played an important role in the glacier dynamics at this latitude. Nevertheless, further investigations are required to evaluate the relative role of both precipitation regimes on the glacier dynamics from the westernmost Altiplano

Arqueometría. Estudios analíticos de materiales arqueológicos.

Capítulo de Isótopos Estables aplicados a Arqueología