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Los pinsapares de Abies pinsapo son una de las formaciones boscosas más originales de la península ibérica. A pesar de la singularidad de estos ecosistemas, hasta el momento ningún análisis de microfósiles polínicos había sido emprendido en aquellos territorios donde esta especie, en peligro de extinción, aún pervive. Con este trabajo se presentan los primeros resultados en los que, haciendo uso del registro fósil, han podido ser identificados los impactos climáticos pasados y los cambios de uso de suelo histórico en la evolución de las poblaciones del sur de la península ibérica para el Holoceno final (1180 AD hasta el presente). Los resultados son comparados con las fluctuaciones climáticas y cambios en el manejo forestal documentados en los últimos ocho siglos. La secuencia de polen muestra una fase de estabilidad estructural y estado de conservación óptimo del pinsapar durante el Período Musulmán (~1180-1400 AD), etapa que se desarrolla en la Anomalía Climática Medieval (ACM). A continuación, se inicia un proceso de degradación de estos bosques en el Período Cristiano concurrente con la Pequeña Edad de Hielo, PEH (ca. 1400-1530 AD). El Período Moderno (1530-1800 AD; PEH) está vinculado a la gestión forestal intensiva, relacionada con la industria naval. Posteriormente, se registra una reducción y declive progresivo de estas formaciones que tiene como punto de partida la Edad Contemporánea (Período Industrial; PI) y que culmina con un paisaje profusamente deforestado en el Calentamiento Reciente (CR).

Precipitation is a key climate parameter of vegetation and ecosystems in the Iberian Peninsula. Here, we use a regional pollen–climate calibration model and fossil pollen data from eight sites from the Atlantic coast to southern Spain to provide quantitative reconstructions of annual precipitation trends and excursions and their regional patterns for the last 11 700 years. The Early Holocene (11 700 to 11 000 cal. a BP) was characterized by high precipitation values followed by a slowly declining trend until about 9000 cal. a BP in the south and about 8000 cal. a BP in the north. From 8000 to 6000 cal. a BP the reconstructed precipitation values are the highest in most records, especially in those located in the Mediterranean climatic region in the southern part of the peninsula, with maximum values nearly 100% higher than the modern reconstructed values. The results suggest a declining precipitation during the Late Holocene in the south, with a positive excursion at around 2500 cal. a BP, while in the north precipitation remained high until 500 cal. a BP. However, the Late Holocene climate reconstructions in the Iberian Peninsula are biased by intensifying human impact on vegetation. The statistical time series analyses using SiZer technique do not indicate any statistically significant high-frequency drought events in the region. In general, our results suggest regional differences in the precipitation patterns between the northern and southern parts of the peninsula, with a more distinct Middle Holocene period of high humidity in the south.

A set of 30 modern pollen samples collected in pine communities of the Gúdar Range (southeastern Iberian System) has been investigated to determine the relationships between pollen percentages and vegetation composition along a ~ 1000 m elevation transect. Pollen representation was estimated by comparing the presence of plant taxa from a recent vegetation survey with pollen spectra. Classification and ordination of modern pollen samples indicated the existence of eight vegetation units, which can be assigned to the six studied pine forest communities. Lowland forests are clearly discriminated from high-altitude ones. These analyses also allow separating Pinus nigra and P. pinaster communities according to their tree cover, and even those of P. sylvestris according to the bioclimatic belt they inhabit. We show that it is possible to obtain distinct pollen markers for Mediterranean pine forest communities. These results will also improve the reconstruction of pine forests from fossil pollen diagrams, as far as modern pollen rain studies are carried out in specific regions, an approach which can be extrapolated to other plant formations regardless the involved territory.

A new record from a long sediment core (S3) in Navamuño (1505 m asl, western Iberian Central System) provides the reconstruction of the vegetation history and environmental changes in the region between 15.6 and 10.6 ka cal BP, namely during the Late Glacial and the early Holocene, using a multiproxy analysis (pollen-based vegetation and climate reconstruction, sedimentary macrocharcoals, loss-on-ignition, magnetic susceptibility and X-ray fluorescence (XRF) measurements). The results are then compared with other sequences from the Iberian Central System and the whole Iberian Peninsula in order to better understand the past dynamics of the main forest constituents. The pollen record shows a shift from open pine forests ∼15.6–14.7 ka cal BP (Oldest Dryas) to mixed open pine-birch woodlands ∼14.7–14.0 ka cal BP (Bølling). Woodlands were succeeded by a steppe-like landscape until ∼13.4 ka cal BP (Older Dryas), which was replaced again by high-mountain pine forests and riparian woodlands ∼13.4–12.6 ka cal BP (Allerød). A great development of cold steppe grasslands linked to the decline of birch woodlands is documented ∼12.6–11.7 ka cal BP (Younger Dryas). The early Holocene (11.7–10.6 ka cal BP) was characterized by a progressive reforestation of the study area by pine and birch forests in the highlands and oak woods in the lowlands. Temperate tree taxa (Carpinus betulus, Castanea sativa, Corylus avellana, Fraxinus, Juglans, Tilia, and Ulmus) were also common but likely at lower elevations. Pollen of Fagus sylvatica was already recorded during the Late Glacial and the early Holocene. The marked increasing local fire activity during the warmer and wetter Allerød oscillation could be related to a rise in tree cover, supporting the climatically driven character of these fires. Nevertheless, the strong increase in fire activity during the Younger Dryas would probably be related to growing tree and shrub mortality, as well as to the wet/dry biphasic structure of this stadial

La diversidad vegetal de Sierra Nevada es resultado de múltiples procesos que han determinado que se haya producido la sucesión continuada de contingentes florísticos y comunidades vegetales de diverso origen a lo largo de su historia geológica. Gran parte de la flora actual de Sierra Nevada proviene de latitudes septentrionales de Europa ( elementos arctoterciarios), cuando aún los materiales que dieron lugar al macizo nevadense estaban unidos al este de la placa ibérica en el Oligoceno, lejos de su emplazamiento final al sur de Iberia. A finales de este período, y durante todo el Mioceno, el clima inicia una tendencia hacia la aridez y enfriamiento global que provoca la extinción de parte de la flora paleotropical de Iberia, y su progresiva sustitución por la flora arctoterciaria. Es cuando la vegetación del sureste peninsular se enriquece en elementos sabanoides, quedando relegados los bosques siempreverdes y semideciduos a las zonas de mayor disponibilidad hídrica. La alta montaña nevadense es ocupada por cinturones de coníferas, mientras que por la franja costera y lagunas salobres se distribuyen los manglares. La desecación parcial del Mediterráneo durante la crisis del Messiniense promueve la creación de puentes que constituyen importantes rutas migratorias para especies irano-turánicas y saharo-síndicas. Tras la apertura del Estrecho de Gibraltar en el Plioceno, se consolida la estacionalidad propia del clima mediterráneo, que dio lugar a una vegetación muy similar en estructura a la actual. Finalmente, el Cuaternario supone la culminación del lento proceso de enfriamiento iniciado en el Terciario, durante el cual la alternancia de períodos glaciales e interglaciales proporciona refugio a táxones arctoterciarios e induce la extinción de los últimos elementos paleotropicales. La reciente recuperación climática del Holoceno supuso la expansión de bosques de frondosas del género Quercus.

Current knowledge of climate change effects on forest ecology and species conservation should be linked to understanding of the past-time. Abies pinsapo forests constitute a model of an endangered ecosystem, highly vulnerable to ongoing warming, whose populations have been declining for centuries, while the drivers of this local depletion trend remain poorly understood. We hypothesized that long-term disturbances, both human- and natural-induced, have shaped A. pinsapo forests, contributing to these decline processes. Until today, studies using fossil pollen record to identify past climate impacts and land-use changes on A. pinsapo populations have not been done. Here, we investigate forests’ dynamics since the late Holocene (1180 cal. AD to present) in Southern Iberian Peninsula from a fossil pollen record by comparing the results obtained with climate fluctuations and land-uses changes. The pollen sequence shows a phase of stability during the Islamic Period (~1180–1400 cal. AD; ‘Medieval Climate Anomaly’), followed by increasing degradation at Christian Period concurrent with ‘Little Ice Age’ (LIA) (ca. 1487–1530 cal. AD). The Modern Period (1530–1800 cal. AD; LIA) is linked to intensive forest management, related to the naval industry. Afterwards, a progressive reduction is recorded during the Contemporary Age period (‘Industrial Period’) until ‘Recent Warming’. In short, historical severe forest management coupled with increasing aridity since LIA appear to influence A. pinsapo forest current species composition and poor structural diversity. These disturbances might be limiting the resilience of A. pinsapo forests under a climate change scenario. A selected forest management could promote a more complex forest structure.

The Iberian Central System (ICS) is a clue region to reveal Mediterranean/Atlantic inferences over Iberia. We present a multidisciplinary study from western Spain conducted in the Navamuño depression (ND), covering the last 16.8 ka (cal BP). A reconstruction of the palaeotemperature from the resulting geochemical data highlights four cold and dry intervals, namely, the Oldest Dryas, Older Dryas, Intra-Allerød Cold Period (IACP), and the Younger Dryas, along with warmer intervals: the Bølling (14.7–14 ka) and the Allerød (12.9–12.6 ka); however, the Greenland Interstadial GI-1c (13.4–13.1 ka) is barely distinguishable in the ND. Despite the shortage of biomass to sustain fire, the earliest charcoals are from ~14.4–13.8 ka. Evidence of ash/dust events overprinting the geochemical background starts at ~13.8–12.8 ka. Significant fire activity in the Early Holocene at ~11.7–10.6 ka affected the ND, matching the westernmost ICS data. This period includes short oceanic spells inferred from Cl peaks at ~10.9–10.2 ka and three cold intervals at 11.4, 9.3, and 8.2 ka disrupted the progressive temperature increase. The Mid-Holocene showed a continuously increasing trend towards an arid climate, peaking at 4.2 ka under a pervasive dust influx from North Africa, which has prevailed since almost ~7.9 ka. A prominent volcanic event at ~6.8–5.8 ka is in Navamuño and Roñanzas (Asturias, N Spain; Gallego et al., 2013) identified from heavy metal-rich layer, synchronous with the last known eruption of the Calatrava volcanic field (South-Central Spain; Poblete-Piedrabuena et al., 2019). This volcanic eruption could affect many other regions half north of Iberia. The pervasive presence of oceanic aerosols in the last three millennia (2.8 ka ~ ) allowed the formation of a Cl-rich peat layer during the Ibero-Roman humid period ~2.1 ka, before a changing around ~0.4 ka toward colder and drier conditions at the Little Ice Age (LIA) period., Ministerio de Ciencia, Innovación y Universidades, Andalusian Office of Economy and Knowledge, Spanish Ministry of Education, Culture, and Sports, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

Human impact on western Mediterranean mountains is gaining more attention, as they harbour a rich plant diversity threatened by global change. This paper presents an analysis of two pollen records from both sides of Sierra Nevada, the prime plant-diversity centre of the Mediterranean, spanning the last 5400 years. The analysis sought to answer the following key questions: When did natural systems transform to cultural landscapes? What was the intensity and extent of alterations driven by the diverse civilizations? A compilation of archaeological and paleaeoclimatic data supported this analysis, as well as a multi-proxy palaeoecological study using pollen, non-pollen palynomorphs and microcharcoal, searching for the imprint that diverse societies left on these mountains. Results suggest that human influences started earlier than expected, with a strong impact on forest cover, oriented more towards crops on the southern face and towards livestock on the northern one, whereas mining and metallurgy were initial key drivers of population dynamics. Irrigation has supported farming since at least the Islamic period. More recent anthropogenic control and land-use management have allowed a further spread of the tree cover. Proper conservation strategies need long-term perspectives, including palaeoecological studies. The preservation of traditional human activities like grazing, high-elevation cropping or irrigation systems become essential to maintain current biodiversity., Ministerio de Ciencia e Innovación (MICINN), Ministerio de Economía y Competitividad (MINECO)/Gobierno de Andalucia/Fondo Regional de Desarrollo Económico(FEDER), Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI 2020)//Fondo Europeo de Desarrollo Regional(FEDER), Depto. de Biodiversidad, Ecología y Evolución, Fac. de Ciencias Biológicas, TRUE, pub

Human impact on western Mediterranean mountains is gaining more attention, as they harbour a rich plant diversity threatened by global change. This paper presents an analysis of two pollen records from both sides of Sierra Nevada, the prime plant-diversity centre of the Mediterranean, spanning the last 5400 years. The analysis sought to answer the following key questions: When did natural systems transform to cultural landscapes? What was the intensity and extent of alterations driven by the diverse civilizations? A compilation of archaeological and paleaeoclimatic data supported this analysis, as well as a multi-proxy palaeoecological study using pollen, non-pollen palynomorphs and microcharcoal, searching for the imprint that diverse societies left on these mountains. Results suggest that human influences started earlier than expected, with a strong impact on forest cover, oriented more towards crops on the southern face and towards livestock on the northern one, whereas mining and metallurgy were initial key drivers of population dynamics. Irrigation has supported farming since at least the Islamic period. More recent anthropogenic control and land-use management have allowed a further spread of the tree cover. Proper conservation strategies need long-term perspectives, including palaeoecological studies. The preservation of traditional human activities like grazing, high-elevation cropping or irrigation systems become essential to maintain current biodiversity.

Human impact on western Mediterranean mountains is gaining more attention, as they harbour a rich plant diversity threatened by global change. This paper presents an analysis of two pollen records from both sides of Sierra Nevada, the prime plant-diversity centre of the Mediterranean, spanning the last 5400 years. The analysis sought to answer the following key questions: When did natural systems transform to cultural landscapes? What was the intensity and extent of alterations driven by the diverse civilizations? A compilation of archaeological and paleaeoclimatic data supported this analysis, as well as a multi-proxy palaeoecological study using pollen, non-pollen palynomorphs and microcharcoal, searching for the imprint that diverse societies left on these mountains. Results suggest that human influences started earlier than expected, with a strong impact on forest cover, oriented more towards crops on the southern face and towards livestock on the northern one, whereas mining and metallurgy were initial key drivers of population dynamics. Irrigation has supported farming since at least the Islamic period. More recent anthropogenic control and land-use management have allowed a further spread of the tree cover. Proper conservation strategies need long-term perspectives, including palaeoecological studies. The preservation of traditional human activities like grazing, high-elevation cropping or irrigation systems become essential to maintain current biodiversity.

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 of Morocco: the cave of Kaf Taht-el-Ghar, 8 km southeast from Tetuan, and two caves within 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.

Pollen analyses supported byfifteen AMS14C dates from Fuente de la Leche (1382 m) and Fuente del PinoBlanco (1343 m) peat sequences, in the Gredos range (central Spain), are used to reconstruct the lateHolocene vegetation history in this mountain region. These results are compared with other sequencesfrom the Spanish Central System in order to better understand the past dynamics of the main forestconstituents and to provide a critical view of the dialectic between conifers and deciduous forests. Thevegetation record at Fuente de la Leche starts at 3000 cal yr BP, with the occurrence of rather closedforests composed ofPinus sylvestrisandBetula.Pinus sylvestriswas the dominant pollen taxa for almostthe entire period. However, during the last 850 years,Pinus sylvestrisforests were progressively replacedbyQuercus pyrenaicawoodlands and grasslands, as a result of a high pastoral pressure, until formingmixed woodlands ~400 years ago. The interpretation of Fuente del Pino Blanco record is that dramaticchanges started about 265 years ago. Prior to this date, an open canopy woodland included species (Alnusglutinosa,Quercus pyrenaica) whose distributions no longer exist in the studied area. We suggest that theincrease in agricultural (rye and other cereals) and livestock activities forced a change in the role offire inthe supramediterranean belt of the Gredos range, thus Pyrenean oak canopy was consumed byfires,providing openings forPinus pinasterand broom communities better adapted tofire.

BACKGROUND: High-mountain pine forests and broom communities in central Spain today have led to contrasting interpretations of their natural or human-induced origin. AIMS: We evaluated the vulnerability and resilience of high-mountainPinus sylvestris/P. nigra forests and derivedCytisusbroom scrub communities to climate and anthropogenic disturbances. METHODS: We assessed historical transitions from forest to scrub and their relation to climate and human influences, using a multi-proxy paleoenvironmental study (pollen, non-pollen palynomorphs, charcoal, magnetic susceptibility) in three mires in the Gredos Range, western Iberian Central System. RESULTS: High percentages of Pinus sylvestris/nigrapollen and the identification of their macro remains demonstrated that high-mountain pine forests have been present in the oromediterranean bioclimatic belt of the Gredos Range since the mid-Holocene. After that, a major human-induced decline, enhanced by climate conditions, has led to their gradual replacement by broom communities. CONCLUSIONS: Broom communities are derived from ancient pine forests that were intensively transformed by human activities after 700 cal year BP, and largely disappeared byca. 500 cal yr BP. Today’s landscape, dominated by broom scrub and grasslands with scattered stands of pines, shows high resilience and provides suitable refugia for a rich mountain biodiversity which deserves a further protection.

The use offire and, consequently, its severity and incidence on the environment have grown steadily during the last millennia throughout theMediterranean. This issue can be assessed in several mountain ranges of central Iberia where changes in the management policy on anthropicactivities and exploitation of high-mountain environments have promoted a remarkable increase onfire frequency. Our research focuses onfire dynamics throughout the last 3,000 years from three peat bog charcoal records of the Gredos range (central Iberia). Our aim is toreconstruct pastfire regimes according to forest vegetation typology (Castanea sativa,Pinus pinaster, andPinus sylvestris). Charcoal influxshows low values between 3,140 and 1,800 cal. yearBPwhen forests were relatively dense in both high and mid-mountain areas. Fireappeared synchronous between 1,800 and 1,700 cal. yearBPfor Lanzahíta and Serranillos and around 1,400–1,240 cal. yearBPfor the threesites, suggesting anthropogenicfire control between the Late Roman and Visigothic periods that can be related to the cultivation of olive treesin the valleys and a greater human impact in high-mountain areas. By contrast, during the Muslim period (1,240–850 cal. yearBP),firedynamics becomes asynchronous. Later,fires turn again coeval in the Gredos range during the Christian period (850–500 cal. yearBP)and can be also correlated with drought phases during the Late Medieval Warm Episode. In short, our study demonstrates thatfire activityhas been enormously variable during the late Holocene in response to both short-term and long-term regional and global climate, vegetationdynamics, and land use changes.

Quantifying and reconstructing past vegetation changes is an important step to fully understand human-environment interactions in the past. In this study we present a reconstruction of arboreal cover of six studysites in the Gredos Range (central Spain) over the last 3000 yr based on multivariate statistical analysis (clusteranalysis and non-metric multidimensional scaling, NMDS) of 186 modern pollen samples, modern vegetationdata and six detailed fossil pollen records. The integrated approach allows distinguishing eight modern vegeta-tion communities and linking the fossil pollen records with these vegetation communities as modern analogues.The information of the arboreal cover of the modern pollen sites was used to estimate the past arboreal cover ofthe fossil pollen sites in the Gredos Range. This estimated arboreal cover shows a higher level of landscape open-ness than suggested by the original pollen percentages data. Our results show that the evolution of the arborealcover through time differs along an altitudinal gradient, with a decrease in arboreal cover during the Roman andVisigoth periods (2000–1240 cal BP) at low altitudes and only during the Christian/Feudal period (850–500 calBP) at high altitudes. The applied methodology, integrating fossil pollen data with modern pollen and vegetationdata in one NMDS, allows reconstructing past arboreal cover in a quantitative way.

Cedrus atlantica (Atlas cedar) is a relict and endemic endangered species from northwestern African mountains, whose distribution range has undergone a dramatic reduction over recent decades. Long-term studies are needed for a better understanding of the development of its range as well as for assisting in the implementation of sustainable conservation measures. The multi-proxy analysis of a high-resolution fossil record of 180 cm depth allowed us to depict the final demise of an Atlas cedar population from the western Rif Mountains (Jbel Khesana), despite its high resilience during the last ~4000 years. Currently, Atlas cedar trees are not observed in Jbel Khesana but they still occur in the nearby area as scattered populations on a few mountain tops at altitudes higher than 1400 m a.s.l. Our data show an initial relatively stable period (~4000¿2400 cal. yr BP) followed by a phase where both climatic and human-induced disturbances cause an alternate dominance of oaks and Atlas cedars (2400~1550 cal. yr BP). Then, the increasing aridity and human activities favoured the depletion of Atlas cedar forests (~1550¿800 cal. yr BP). Our record shows that Atlas cedar forests have recovered after each deforestation event, which reveals a high resilience of the species until the mid-20th century, when they became extinct in the study area. The main driver of their local extinction may be attributed to the strong human pressure. Management measures of Atlas cedar in the Rif Mountains should aim at limiting intensive loggings and protecting the existing populations for their local regeneration.

[EN] The Mediterranean species included in the genus Abies, and Cedrus atlantica show very limited distribution ranges at present. In this work, we outline the origin and migratory routes followed by Abies pinsapo, A. marocana, A. tazaotana and Cedrus atlantica, from the beginning of the Tertiary to the present, as well as the likely causes which have led their populations to their current state of isolation and danger of extinction. Abies and Cedrus would have reached the Western Mediterranean along with other elements of the arctotertiary flora between the Middle Eocene (45 Ma) and the Oligocene (30 Ma). They subsequently underwent speciation processes until relatively recent times, among which the opening of the Strait of Gibraltar (5.33 Ma) would have played an essential role. Mediterranean firs and cedars would have stayed in Southeastern Iberian and North African mountainous refugia during Quaternary glaciations-deglaciations. Despite a noticeable expansion and altitudinal migration in the Mid-Holocene thermal optimum, these species have experienced a further remarkable decline, as a result of the increasing aridity and pressure of human activities. The development of the most appropriate conservation strategies requires the best information on the response of these species to diverse disturbances, thus the knowledge on their temporal evolution becomes essential. The fossil record, both macrorests and pollen, contributes, along with diverse genetic studies, to assessing their resilience and vulnerability., [ES] Las especies mediterráneas incluidas en el género Abies, y Cedrus atlantica presentan en la actualidad unas áreas de distribución muy limitadas. En este trabajo, se describen el origen y las rutas migratorias seguidas por Abies pinsapo, A. marocana, A. tazaotana y Cedrus atlantica, desde los inicios del Terciario hasta la actualidad, así como las posibles causas que han llevado a sus poblaciones a su estado actual de aislamiento y peligro de extinción. Abies y Cedrus habrían alcanzado el Mediterráneo Occidental junto con otros elementos de la flora arctoterciaria entre el Eoceno Medio (45 Ma) y el Oligoceno (30 Ma). Posteriormente, experimentaron procesos de especiación hasta fechas relativamente recientes, en los que la apertura del estrecho de Gibraltar (5.33 Ma) habría jugado un papel esencial. A lo largo de las glaciaciones-deglaciaciones del Cuaternario, abetos y cedros mediterráneos habrían permanecido en refugios montañosos del sur de la península ibérica y del norte de África. A pesar de presentar cierta expansión y migración altitudinal coincidiendo con el óptimo térmico del Holoceno Medio, estas especies han sufrido un notable declive posterior de sus poblaciones, como consecuencia del incremento de la aridez y del impacto de las actividades humanas. El desarrollo de las estrategias de conservación más adecuadas requiere una mejor información sobre la respuesta de estas especies a las distintas perturbaciones, para lo cual resulta indispensable conocer su evolución a lo largo del tiempo. El registro fósil, tanto de macrorrestos como de polen, junto a diversos estudios genéticos contribuyen a evaluar su resiliencia y vulnerabilidad

[EN] Studying community assembly drivers and its past dynamics incorporating phylogenetic and functional data to the fossil record. The fossil record provides information on species relative abundances at specific times, which in turns can inform about community dynamics over long time periods, being the Pleistocene and the Holocene the best represented. However, palaeoecological data are rarely incorporated in hypothesis and models recently developed to explain community composition. The role of abiotic variables (i.e., climate) to drive community assembly is well documented both in contemporary ecology and the fossil record. Although the role of biotic interactions in community assembly remains controversial, phylogenetic and functional traits information are contributing to clarify its importance on contemporary communities. The growing popularity of ecoinformatic modelling tools along with an increasing availability of palaeoecological data in online databases facilitates the integration of palaeoecological data to inform theory and models of community ecology. However, such integration remains largely unexplored. Aiming to boost such sort of studies, we review here advances in palaeoecological studies to inform community ecology, we also provide a guide on common uncertainties associated with fossil records to ensure a rigorous use of them, and propose further working lines in such integration., [ES] Estudiando los determinantes de la composición de comunidades y sus dinámicas en el pasado incorporando información filogenética y funcional al registro fósil. El registro fósil contiene información sobre la composición relativa de especies en un momento concreto, aportando información de la dinámica de comunidades a lo largo de intervalos temporales extensos, siendo el Pleistoceno y el Holoceno los periodos mejor representados. Sin embargo, estos datos son rara vez considerados en las hipótesis y modelos que se han desarrollado recientemente para explicar la composición de comunidades. El papel de las variables abióticas (i.e., climáticas) en el ensamblaje de comunidades está bien documentado tanto en el registro fósil como por datos ecológicos actuales. Sin embargo, el papel de las interacciones bióticas es más controvertido, aunque el uso de información filogenética y de rasgos funcionales está ayudando a comprender su papel relativo en las comunidades actuales. La creciente popularidad de herramientas ecoinformáticas de modelización junto con un mayor volumen de datos paleoecológicos disponibles online facilita su integración con la teoría y los modelos de ecología de comunidades. Sin embargo, su uso en el estudio de las interacciones bióticas es todavía escaso y su integración con datos funcionales y filogenéticos es prácticamente inexistente. Con el objetivo de fomentar nuevos estudios, revisamos los avances en la integración de paleoecología con la teoría y modelos de la ecología de comunidades, analizamos las principales incertidumbres asociadas a los datos fósiles, para asegurar un análisis serio y riguroso y finalmente sugerimos futuras líneas de trabajo

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.

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).

This paper describes the patterns and processes of vegetation change and fire history in the Late Holocene (c. 3,140 cal BP) palaeoecological sequence of El Tiemblo, in a mountainous area in central Spain (Gredos range, Spanish Central System), and provides the first Iberian pollen sequence undertaken within a Castanea sativadominated woodland. These new data reassess not only the autochthonous nature of the species in the region and in the Iberian Peninsula, but also the naturalness of well-developed sweet chestnut forests. The study focuses on anthropogenic dynamics linked both to the effects of livestock husbandry and the use of fire for forest clearance. With this aim, non-pollen palynomorphs (coprophilous fungi ascospores) and charcoal accumulation rate are useful indicators for assessing the increasing role of human influence on vegetation

Los humedales y turberas de la cuenca de El Padul (provincia de Granada) constituyen un enclave natural singular y único, uno de los más importantes de Andalucía y la única zona húmeda de origen endorreico en Granada. En estos sistemas palustres encuentran cobijo una gran variedad de especies de flora y fauna, algunas de ellas amenazadas o en riesgo de extinción. En esta depresión, los sedimentos llegan a alcanzar un espesor de más de 100 metros y hasta 1 millón de años de antigüedad, lo que permite considerar el registro paleoambiental de el Padul como uno de los más importantes de Europa occidental y de todo el Mediterráneo. Su valor paleontológico es excepcional, al haberse encontrado restos de mamut intercalos entre niveles de turba, los cuales representan la población más occidental y meridional de restos de estos proboscídeos

[EN] Palynological analyses were carried out on layers from the site of La Vereda in Burguillos (Sevilla), in southern Spain. The layers dated to the 3rd century AD, around the time of the abandonment of the present excavated area. Data from pollen and non-pollen palynomorphs contributed to add details on the function of the site and their structures. During Roman times, cereals, flax and olive were cultivated, and human activities highly influenced the landscape, [ES] Análisis arqueopalinológicos se llevaron a cabo en contextos del yacimiento de La Vereda (Burguillos, Sevilla), en el sur de España, ubicados cronológicamente en el siglo III d.C. en el momento de abandono hasta la actualidad del área excavada. Los datos aportados por el estudio de pólenes y microfósiles no polínicos contribuyen notablemente a detallar la función de determinadas estructuras documentadas en el sitio. En época romana se cultivaron cereales, lino y olivos, en un paisaje muy alterado por las actividades antrópicas

[EN] Salt exploitation in the Villafáfila lagoon complex (Tierra de Campos, Zamora) is one of the most important events since Prehistory in the northern plateau of the Iberian Peninsula. Salt production is documented from the Bell Beaker (ca. 2450 cal BC). In 2013, a core drilling was performed in the salty swamp of the Laguna de las Salinas. The analysis of pollen and non-pollen palynomorphs of this record suggests the origin of the lagoon eight thousand years ago linked to the 8,2 ky cal BP climatic event, a very anthropized environment from the beginning of the Chalcolithic period ca. 3300 cal BC and the subsequent exploitation of salt, the gradual and definitive degradation of the holm oak forest from the Bronze Age onwards, and, in general, a wide climatic variability, with alternate humid and arid phases throughout the palaeoenvironmental sequence, [ES] La explotación de la sal en el complejo lagunar de Villafáfila (Tierra de Campos, Zamora) es uno de los eventos más importantes de la meseta norte de la península ibérica desde la Prehistoria. La producción de sal se documenta a partir del periodo Campaniforme (ca. 2450 cal BC). En 2013, se efectuó un sondeo mecánico en los pastizales húmedos anexos a la Laguna de las Salinas. El análisis de polen y microfósiles no polínicos de este registro sugiere el origen de la laguna hace al menos ocho mil años vinculado al evento climático 8,2 ka cal BP, un ambiente muy antropizado desde los inicios del Calcolítico ca. 3300 cal BC y la posterior explotación de la sal, la degradación paulatina y definitiva del bosque de encinas a partir de la Edad del Bronce, y, en general, una amplia variabilidad climática alternando fases húmedas y áridas a lo largo de toda la secuencia paleoambiental.

[EN] We present the palynological study of Pozo de la Nieve peat bog, located in a very valuable socio-cultural placement within the Iruelas Valley Natural Park (Gredos range, Iberian Central System). We have focused in relating landscape changes to natural resources management and climatic events. Firstly, we carried out seven radiocarbon dates suggesting the origin of this record ca. 240 cal BC. The palynological data show the existence of dense high-mountain pine woodlands dominated by Pinus sylvestris/nigra from the Late Iron Age to the Muslim period. Later, from the Christian period, anthropogenic activities have intensified, especially livestock grazing in the Contemporary Age. Its consequences are the progressive disappearance of highmountain pine forests and the extension of grasslands by means of fire, which has shaped current landscape dominated by broom communities, [ES] En este trabajo se presenta el análisis palinológico de la turbera de Pozo de la Nieve, localizada en el Parque Natural del Valle de Iruelas (Ávila), un área de alto valor sociocultural dentro de la Sierra de Gredos (Sistema Central). Con el objetivo de relacionar los cambios en el paisaje con la explotación de los recursos naturales y eventos climáticos, en primer lugar se han realizado 7 dataciones radiocarbónicas que sitúan el inicio del registro sedimentario ca. 240 cal BC. Los datos polínicos indican la existencia de un denso pinar altimontano dominado por Pinus sylvestris/nigra desde la Segunda Edad de Hierro hasta el periodo islámico. A partir del periodo cristiano las actividades antrópicas se intensifican, especialmente la ganadería en la Edad Contemporánea, lo cual conlleva la progresiva desaparición del pinar de alta montaña y el desarrollo de pastizales mediante el manejo del fuego, situación que culmina con el desarrollo del paisaje actual dominado porpiornales pirófilos.

A multi-proxy palaeoenvironmental study (pollen, non-pollen palynomorphs, charcoal particles) of a mire, located in the western Spanish Central System (Gredos range), was undertaken to trace historic human activities related to woodland clearance and past land-uses at high altitudes during the last three millennia. The results of this study constrained by 4 AMS radiocarbon measurements are combined with archaeological data and compared with similar research carried out at the same altitude in mountains of central Iberia. The pollen data indicate that high-mountain areas were dominated by birch and pine woodlands until c. 2350 years. From this date on a strong forest decline is recorded during the Late Iron Age and a deeper one c. 1500 years ago in the Visigothic period, which may be related to increasing grazing activities and/or the occurrence of anthropogenic fires. Cereals and faba beans were cultivated in the surrounding valley since c. 2900 cal BP, while chestnut, walnut and olive tree are documented mainly from the Roman period onwards.