77 research outputs found

    Heathlands, fire and grazing. A paleoenvironmental view of las Hurdes (Caceres, Spain) history during the last 1200 years

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    Objetivo del estudio: Se hace un estudio diacrónico del cambio de vegetación a través del análisis palinológico de depósitos sedimentarios. Ésta es una herramienta esencial tanto para diseñar estrategias de sonido en la gestión del paisaje como para comprender su carácter dinámico y antropogénico. Área de estudio: La Meseguera (Ladrillar, Cáceres, España) está situada en la región de Hurdes, en la parte occidental de Sistema Ibérico y comenzó a desarrollarse a principios del período islámico (aproximadamente 770 d C), en una zona ampliamente dominado por el breza. Material y métodos: Polen, palinomorfos no polínicos y la tasa de acumulación de carbón (CHAR) combinada con los datos históricos son indicadores útiles para evaluar el papel creciente de la influencia humana sobre la vegetación. Principales resultados: El uso del fuego y la ganadería representa los principales impulsores del cambio del paisaje en el curso de la historia. El establecimiento de planes de reforestación en bosques, a partir de mediados del siglo XX, cambió sustancialmente en las características regionales. La presencia esporádica de pólenes de haya es detectada hasta el siglo XVI, lo que implica su presencia más occidental en el Sistema Ibérico Central. Aspectos destacados de la investigación: La integración del análisis del polen y los datos históricos es una herramienta esencial a los cambios en la vegetación del Holoceno. Estos cambios se han debido principalmente a perturbaciones antropogénicas, específicamente al fuego y a la ganadería.Aim of study: The diachronic study of vegetation change through palynological analysis of sedimentary deposits is an essential tool both to design sound strategies on landscape management and to understand its anthropogenic dynamics. Area of study: La Meseguera mire (Ladrillar, Cáceres, Spain) is located in the Hurdes region in the western part of Iberian Central System and started to develop at the beginning of the Islamic period (ca. 770 cal AD), in an area widely dominated by heathland. Material and methods: Pollen, non-pollen palynomorphs and charcoal accumulation rate (CHAR) combined with historical data are useful indicators to assess the increasing role of human influence on vegetation. Main results: The use of fire and livestock husbandry represents the main drivers of landscape change in the course of the history. The establishment of forest afforestation plans, from the middle of 20th century, changed substantially the regional features. The sporadic presence of beech pollen is detected until 16th century, which implies the most western location in the Iberian Central Mountain System. Research highlights: The integration of pollen analysis and historical data is an essential tool when studying the changes in Holocene vegetation. These changes have been mainly driven by anthropogenic disturbances, more specifically by fire and livestock husbandry.peerReviewe

    Testing the Effect of Relative Pollen Productivity on the REVEALS Model: A Validated Reconstruction of Europe-Wide Holocene Vegetation

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    The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/land12050986/s1. File S1 Glossary of abbreviations used in the paper.This research was funded by the TERRANOVA Project, H2020 Marie Sklodowska-Curie grant agreement no. 813904.Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1° × 1°) over the Holocene (last 11.7 ka BP) using the ‘Regional Estimates of VEgetation Abundance from Large Sites’ (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity.H2020 Marie Sklodowska-Curie TERRANOVA Project 813904Swiss National Science FoundationSwiss Academy of SciencesU.S. National Science FoundationChinese Academy of ScienceLinnaeus University’sMERGE PRG323ETF PRG32

    Vegetation history in the Toledo Mountains (Central-Iberia): human impact during the last 1300 years

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    ABSTRACT: Mid-mountain ecosystems provide a broad diversity of resources, heterogeneous relief, and a mild climate, which are all very useful for human necessities. These features enable different strategies such as the terracing of the slopes as well as wide crop diversification. Their relations lead to a parallel co-evolution between the environment and human societies, where fire and grazing become the most effective landscape management tools. This paper presents the results obtained from a multi-proxy study of the Bermú paleoenvironmental record, which is a minerotrophic mire located in the Quintos de Mora National Hunting Reserve (Toledo Mountains, central Spain). The bottom of this core has been dated in the Islamic period (ca. 711-1100 cal AD), and the study shows how the landscape that was built over time in the Toledo Mountains up to the present day is narrowly linked to human development. This study shows the increasing human pressure on the landscape, as well as the subsequent strategies followed by the plant and human communities as they faced diverse environmental changes. Thus, it is possible to attest the main role played by the humans in the Toledo Mountains, not only as a simple user, but also as a builder of their own reflexion in the environment.Funding: This research was funded the project REDISCO-HAR2017-88035-P (Plan Nacional I+D+I, Spanish Ministry of Economy and Competitiveness). Reyes Luelmo is funded by a FPU grant (Spanish Ministry of Education, Culture and Sports)

    Pollen study of an endorheic lagoon in Almenara de Adaja (Valladolid, Northern Meseta): environmental changes and human activity during the last 2800 years

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    El análisis de microfósiles polínicos y no polínicos de una secuencia obtenida en una laguna endorreica en Almenara de Adaja (Valladolid, Meseta Norte) muestra este registro como sensible tanto a cambios de naturaleza climática como antrópica durante los últimos 2800 años. Se han detectado los momentos de variabilidad climática que se han descrito para esta cronología como el período frío del final de la Edad del Hierro (850-75 cal BC), el Período Cálido Romano (ca. 75 cal BC-300 cal AD), el Período Frío Altomedieval (ca. 300-800 cal AD), el Período Cálido Bajomedieval (ca. 800-1450 cal AD) y la Pequeña Edad del Hielo (ca. 1450-1800 cal AD). Además, se han observado distintos grados de antropización en el paisaje en relación con las pautas de asentamiento en la zona. Aunque es desde la época romana cuando se establecieron las transformaciones del paisaje que han conformado el paisaje actual, que está caracterizado por ser un espacio muy agrícola y ganadero.Este trabajo ha sido financiado por el Programa Consolider TCP-CSD2007-00058 (Programa de investigación en tecnologías para la valoración y conservación del Patrimonio Cultural)Peer Reviewe

    Late glacial-postglacial North African landscape and forestmanagement : Palynological and anthracological studies in the caves of Kaf Taht el-Ghar and El Khil (Tingitana Peninsula, Morocco)

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    This work presents the anthracological and archeopalynological results obtained within the project AGRIWESTMED (ERC AdG 230561), which has involved a comprehensive retrieval of archeobiological remains based on a systematic sampling strategy, beyond the recovery of the usual archeological materials. These surveys were conducted on three sites located in the North ofMorocco: the cave of Kaf Taht-el-Ghar, 8 kmsoutheast from Tetuan, and two caveswithin the El Khil complex, close to Tanger. Both plant micro- and macro-remains (charred wood) were studied through palynological and anthracological analyses, respectively. Our goal was to assess the vegetation composition of the area as well as the impact of human activities on the landscape. In Kaf Taht-el-Ghar the dynamics of vegetation and land use is recorded over the Paleolithic, Epipaleolithic, Neolithic and Historic times. Clear changes such as the demise of ancient Paleolithic pine and juniper woods during the Epipaleolithic and the subsequent spread of grasslands are shown. Other conifers like Abies pinsapo, Cedrus atlantica and Taxus baccata also disappeared from the pollen and charred wood records. In the palynological study, cereal and broad beans (Vicia faba) are already detected in the Early Neolithic, as well as a lowering of grazing pressure. Both cereal and broad beans, along with the development of grazing activities are also documented around El Khil caves since the Early Neolithic. Throughout the whole pollen and anthracological sequences a progressive retreat of the tree cover and an extensive spread of grasslands could be set as the main features of the vegetation dynamics in this area

    Dinámicas naturales y antrópicas en los paisajes vegetales de los valles internos de Cantabria occidental (Norte de España)

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    La construcción de los paisajes vegetales en la montaña media cantábrica es una historia larga y compleja que puede ser interpretada como una herencia de la distinta intensidad con la que han actuado a lo largo del tiempo las dinámicas naturales (climáticas y/o geomorfológicas) y las inducidas por la acción del hombre (uso ganadero, agrícola, y especialmente forestal derivado de las demandas de la Marina, de las ferrerías, o de las comunidades campesinas). Las fluctuaciones en la intensidad de los factores puede interpretarse a través del análisis conjunto de los hechos geomorfológicos, de las comunidades vegetales y de estudios palinológicos a alta resolución.Este trabajo se ha realizado dentro del Plan Nacional de I+D+i 2008-2011 con el Proyecto CSO2009-14116-C03-02 (Subprograma GEOG) y del Programa Consolider de Investigación en tecnologías para la valoración y conservación del Patrimonio Cultural-TCP-CSD2007-00058

    Persistence of tree relicts in the Spanish Central System through the Holocene

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    Persistence of relict tree species in Mediterranean environments is becoming increasingly unlikely in view of ongoing and future global change. The variability in the Holocene climate and more recent anthropogenic impacts have driven many populations to fragmentation and isolation, and even to extinction. However, some have persisted to the present day. The understanding of their evolution requires long-term studies, in which pollen analysis is a key approach both for formulating hypotheses and supporting results from other disciplines. Mountain ranges have played and still play an essential role as both glacial and interglacial refugia during the Quaternary. The Spanish Central System harbors an exceptional diversity due to its geographical location and complex topography. Some cold-adapted species have survived here with significant proportions of their southernmost populations, often displaying striking adaptations to their changing environments. This work contains a comprehensive review of the palynological investigations conducted in the Spanish Central System, and reveals the distribution of genera such as Taxus, Betula, Fagus, Carpinus and Tilia throughout the Holocene. We also highlight the scarcity of well-dated and high-resolution works, which may contribute to a better understanding of their recent and future evolution.This paper is part of the research carried our within the project "Dinámicas socio-ecológicas, resiliencia y vulnerabilidad en un paisaje de montaña: el Sistema Central (9000 cal. BC-1850 cal. AD) " (R&D National Plan of the Spanish Government, HAR2013-43701-P)

    Datos sobre la neolitización del Valle Amblés a la luz de la excavación del yacimiento de La Atalaya (Muñopepe, Ávila)

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    The evidence for Neolithic settlement sites in the province of Ávila (Spain) is still very scanty and consists mainly of certain archaeological items (pottery with fluted or impressed decorations of the Early Neolithic ceramic tradition, flint microliths and a few polished stone tools), which have been found during the excavation of sites of a later date. These excavations have therefore produced inconclusive dating evidence for those findings. Archaeological investigations at La Atalaya, in Muñopepe, revealed a long and complex history of occupation going from the Early Neolithic to the Copper Age, located around granite outcrops some of which are decorated with prehistoric rock paintings. In this paper, we present the cultural sequence of La Atalaya, based on stratigraphic information, chronological data and a techno-typological analysis of the pottery and lithic collections. Environmental and economic information is also provided. Finally, some hypotheses about the Neolithization process in the south-western area of the Spanish Northern Meseta are suggested.El Neolítico es un momento no muy bien caracterizado en la provincia de Ávila. A día de hoy son todavía pocos los asentamientos documentados, los cuales se muestran a través de cerámicas acanaladas o impresas con motivos propios del Neolítico Interior, microlitos en sílex o algún pulimentado. Estos materiales carecen de contexto, al haberse hallado bien en el transcurso de prospecciones superficiales o durante la excavación de niveles prehistóricos más modernos, lo que ha motivado que no se cuente con información precisa sobre el marco cronológico en el que ubicar esas piezas. Los trabajos arqueológicos llevados a cabo en el yacimiento de La Atalaya, en Muñopepe, han revelado una compleja y dilatada secuencia de ocupación desde el Neolítico Antiguo a la Edad del Cobre, la cual se desarrolló en torno a bolos graníticos decorados con pinturas rupestres. Estudiamos aquí la trayectoria cultural de La Atalaya, conjugando la información estratigráfica, los resultados de las dataciones absolutas y el análisis tecno-tipológico de las colecciones cerámicas y líticas, sin olvidarnos de cuestiones paleoambientales y paleoeconómicas. Todo ello nos brinda la oportunidad de debatir los mecanismos del proceso de neolitización en el sector sudoccidental de la Submeseta Norte española
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