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Frugone-Alvarez, M. et. al., We present a 7-ka environmental reconstruction based on sedimentological and geochemical data from Lago Vichuquén, a coastal eutrophic lake in central Chile (34°48'S, 72°03' W, 4m a.s.l.). A relatively shallow and restricted marine environment with low productivity, high detrital input and dominant anoxic conditions in the Vichuquén Basin occurred from 7.0 to 6.5cal ka BP. Rapid onset of a Holocene marine transgression at 6.5cal ka BP favoured deeper and more biologically productive environments that existed until 2.8 cal ka BP. Bioproductivity changes during the mid-Holocene (6.5-4.2cal ka BP) were related to upwelling dynamics controlled by the intensity of the South-east Pacific Anticyclone (SPA). Periods with lower organic productivity and dominant anoxic conditions reflect an increased intensity of SPA (increased upwelling) and decreased precipitation. A shift at ∼4.0cal ka BP reflects the onset of modern Southern Westerly Winds and El Niño-Southern Oscillation patterns. Tectonic uplifting and geormorphological activity (dune advancement) are possible reasons behind the Vichuquén Basin closure at ∼1.2cal ka BP, leading to a low bioproductivity lacustrine environment which has developed until the present. © 2017 John Wiley & Sons, Ltd., This is a contribution of the HOLOCHILL project (CGL2012-32501). Additional funding was provided by the Laboratorio Internacional de Cambio Global (LINCGlobal PUC-CSIC). We thank R. Lopez, E. Royo, C. Alcaino, Escutia C. and A. Salabarnada for help with sample analysis; H. Orellana, Fernando, P. Tarrats and A. L Herrera for their help and logistical support in the field. C.L. acknowledges support from the IEB (grants ICM P05-002 and PFB23) and grants FONDECYT 1150763 and ICM NC120066. A.M. acknowledges support from grant FONDECYT 1140837. J.P-M.was funded by a BasqueGovernment postdoctoral fellowship (No. Ref. POS_2015_1_0006).

[EN] High resolution multiproxy data (pollen, sedimentology, geochemistry, chironomids and charcoal) from the Basa de la Mora (BSM) lake sequence (42°32' N, 0°19' E, 1914m a.s.l.) show marked climate variability in the central southern Pyrenees throughout the Holocene. A robust age model based on 15 AMS radiocarbon dates underpins the first precise reconstruction of rapid climate changes during the Holocene from this area. During the Early Holocene, increased winter snowpack and high snowmelt during summer, as a consequence of high seasonality, led to higher lake levels, a chironomid community dominated by non-lacustrine taxa (Orthocladiinae) related to higher inlet streams, and a forested landscape with intense run-off processes in the watershed. From 9.8 to 8.1calkaBP, climate instability is inferred from rapid and intense forest shifts and high fluctuation in surface run-off. Shifts among conifers and mesophytes reveal at least four short-lived dry events at 9.7, 9.3, 8.8 and 8.3calkaBP. Between 8.1 and 5.7calkaBP a stable climate with higher precipitation favoured highest lake levels and forest expansion, with spread of mesophytes, withdrawal of conifers and intensification of fires, coinciding with the Holocene Climate Optimum. At 5.7calkaBP a major change leading to drier conditions contributed to a regional decline in mesophytes, expansion of pines and junipers, and a significant lake level drop. Despite drier conditions, fire activity dropped as consequence of biomass reduction. Two arid intervals occurred between 2.9 and 2.4calkaBP and at 1.2-0.7calkaBP (800-1300 AD). The latter coincides with the Medieval Climate Anomaly and is one of the most arid phases of the Holocene in BSM sequence. Anthropogenic disturbances were small until 700 AD, when human pressure over landscape intensified, with Olea cultivation in the lowlands and significant deforestation in highlands. Colder and unfavourable weather conditions during the second part of the Little Ice Age caused a temporary cease of high-land management. The most intense anthropogenic disturbances occurred during the second half of 19th century. Last decades are characterized by recovery of the vegetation cover as a result of land abandonment, and lowered lake levels, probably due to higher temperatures. © 2013 Elsevier Ltd., Financial support for research was provided by the former Spanish Inter-Ministry Commission of Science and Technology (CICIYT) through the projects DINAMO (CGL2009-07992), DINAMO2 (CGL2012-33063), GRACCIE-CONSOLIDER (CSD2007-00067) and HORDA (83/2008), from Parques Nacionales. Additional funding support has been provided by the Aragon Government through the project PM073/2007 and by Geoparque del Sobrarbe through the project “High resolution chronological control of Basa de la Mora”. Ana Pérez-Sanz has been supported by a PhD Fellowship provided by the Aragon Government. Ana Moreno, Graciela Gil-Romera and Mario Morellón hold post-doctoral contracts funded by the “Ramón y Cajal”, “Juan de la Cierva” and “JAE-DOC CSIC” programs, respectively. We thank to Santiago Giralt, Alberto Sáez, Armand Hernández, Carlos Martí, Mayte Rico, Juan Pablo Corella and Antonio Vallejo for coring assistance in 2008. We also thank Beatriz Bueno and Aída Adsuar for their help in lab procedures. We are indebted to Prof. Sandy Harrison for her assistance with the English review that has led to a noticeable improvement of the manuscript.

Easter Island is a paradigmatic example of human impact on ecosystems. The role of climate changes in recent vegetation shifts has commonly been rejected without proper assessment. A palynological study of a long sediment core from Raraku Lake documents the vegetation dynamics for the last 34 ka and investigates their driving forces, particularly the effects of climate variability on vegetation changes. Significant relationships between pollen assemblage changes and sedimentary and geochemical proxies demonstrate the rapid response of vegetation to lake crater basin hydrology and climatic changes. The lake surroundings were occupied by an open mixed palm grove during the Last Glacial period. Poaceae and Sophora increased at the expense of palms and Triumfetta, and Coprosma practically disappeared, in response to slightly wetter and/or colder climate during the Last Glacial Maximum. Palms and Triumfetta thrived in a warmer and/or drier climate during the deglaciation. Minor vegetation changes (a slight increase in Sophora and a drop in Asteraceae and Poaceae) occurred between 13.2 and 11.8 cal. ka BP and can be related to rapid changes in the Younger Dryas chronozone. The increase in herbaceous taxa indicates a gradual shallowing of the lake and development of a mire during the Holocene, caused by sediment infilling and warmer and drier climate. Relatively rapid vegetation changes in the Holocene were caused by climate and by plant succession on the expanding mire. The rates of vegetation change observed in the mire were similar to those at the initial stages of human impact identified in a previous study. These results reveal significant vegetation changes prior to human presence, due to the interplay of climate variations (temperature and moisture), changes in lake basin form by infilling and intrinsic dynamics of plant succession. Hence, the potential contribution of these factors in vegetation shifts during the period of human presence should not be neglected., This research was funded by the Spanish Ministry of Science and Education through the projects LAVOLTER (CGL2004-00683/BTE), GEOBILA (CGL2007-60932/BTE), CONSOLIDER GRACCIE (CSD2007-00067) and RapidNAO (CGL2014-40608R) and an undergraduate grant (BES-2008-002938 to N. Cañellas-Boltà).

García M.B. et al.- 12 páginas.- Ilustraciones.- Artículo publicado en Open Access bajo los términos de Creative Commons attribution Non Comercial License 3.0., [EN] The Ordesa and Monte Perdido National Park and the Pyrenean Institute of Ecology (CSIC) recently joined the Spanish LTER network. As part of our strategy to understand recent changes in this protected area, we are carrying out a number of projects to evaluate changes at different spatio-temporal scales, using a variety of methods and approaches. We highlight here some of the most consolidated ones: long-term reconstructions from sedimentary lake records and cave speleothemes, the dynamics of one of the few active Iberian glaciers, the physico-chemical components of alpine streams, springs and lakes, the fingerprint of climatic change from ancient trees, changes in the composition and structure of biodiversity of alpine communities, natural and man-made grasslands at different altitudes, and the treeline, and population dynamics of endangered species or habitat indicators. The ecological monitoring shows that changes in both climate and land use, are having a strong influence in the physiognomy and structure of some of the most iconic and abundant habitats in the National Park. However, we found an important spatial variability in some processes, and also that others do not fit the established paradigms. The integration of partial results obtained from different methodologies and approaches diminishes the importance of each perception separately, helps to evaluate current changes in a long-term framework (geological scale), and will serve to validate the forecasts when modeling future environmental scenarios., [ES] Los espacios protegidos, por el hecho de albergar una gran geo-biodiversidad y asegurar una baja intervención humana, constituyen lugares muy adecuados para el seguimiento de organismos y procesos a escala ecológica, así como para la obtención de series temporales largas a escala geológica. En el marco de la red LTER-España, el Parque Nacional de Ordesa y Monte Perdido (PNOMP) y el Instituto Pirenaico de Ecología-CSIC están impulsando estudios para la detección de cambios a distintas escalas mediante variados métodos y aproximaciones. Destacamos aquí los más consolidados, entre los que se encuentran los análisis de registros de sedimentos en lagos, espeleotemas en cuevas, la dinámica de uno de los pocos glaciares activos de la Península ibérica, el análisis físico-químico de aguas corrientes e ibones de alta montaña, el registro del cambio climático actual en árboles longevos, la afección que éste ejerce sobre masas actuales de pinos en el límite superior del bosque y de abetales en zonas húmedas, la matorralización de algunos pastos y los procesos mecanicistas que subyacen, la reorganización de la diversidad florística en pastos tras el abandono paulatino o drástico de la ganadería, la biodiversidad de las comunidades alpinas y la dinámica poblacional de especies amenazadas o indicadoras de hábitats o de motores de cambio global. Los seguimientos ecológicos actuales muestran que tanto el cambio climático como el de usos del suelo están teniendo una considerable trascendencia en la fisionomía y la estructura de algunos de los ambientes más icónicos y frecuentes del parque (deterioro del glaciar, termofilización de la flora en cumbres alpinas, densificación del bosque en su límite superior, pérdida de productividad en algunos pastos supraforestales, etc.). También sugieren una importante variabilidad espacial en los procesos (por ej. en el PNOMP conviven pastos matorralizados y pastos muy estables), y evidencian que los cambios observados no siempre siguen los paradigmas establecidos (por ej., las especies amenazadas mantienen dinámicas poblacionales estables). La integración de resultados parciales proporcionados por cada aproximación relativiza la importancia de las percepciones que cada estudio destaca por separado, y permite medir los cambios actuales en el marco de referencia de los cambios a escala geológica.Predecir la resistencia y resiliencia de los ecosistemas o las poblaciones de seres vivos para enfrentarse a los futuros cambios ambientales es complicado, no sólo por la falta de conocimientos disponibles sino también porque las respuestas que observamos no siempre son tan rápidas o lineales como se espera. La modelización constituye una herramienta cada vez más utilizada, pero requiere de evidencias reales para validar sus pronósticos, por lo que la observación de los procesos que actúan en el PNOMP ha de incluir un esfuerzo continuado de monitorización multiescalar y multidisciplinar de los distintos componentes de la geo, hidro-, crio- y biosfera, sin olvidar el componente humano. Entender la complejidad supone conectar las interacciones que existen entre todos los sistemas y ponderar sus efectos según las escalas de trabajo., Los resultados presentados proceden de proyectos subvencionados por el Organismo Autónomo de Parques Nacionales: 125/2010 (C.L. Alados), 387/2011 (J.J. Camarero), 430/211 (M.B. García), 258/2011 (A. Moreno), 533S/2012 (P. Mata y M.I. Rieradeval), 623/2012 (M.I. Rieradeval), 083/2009 (B. Valero), 844/2013 (J.I. López-Moreno).

4 páginas, [EN] The sedimentary and geochemical analyses performed in La Parra karstic lake sediment cores (Iberian Range, Cuenca) illustrate the onset of lacustrine sedimentation about 1.600 years ago and a depositional evolution mostly controlled by fluctuations in detrital input to the lake. A total of 11 sedimentary facies were recognized, grouped in 3 lithostratigraphic units, and mainly composed by banded and massive clastic carbonates and a few fine laminated layers. Presence of coarser littoral facies during the Low Middle Age and finely laminated during the Modern Ages suggest lower lake levels during the Medieval Climate Anomaly and higher during the Little Ice Age., [ES] El análisis sedimentario y geoquímico llevado a cabo en los sondeos del lago kárstico de La Parra (Cordillera Ibérica, Cuenca) ilustra el comienzo de la sedimentación en la cuenca hace 1.600 años y su evolución sedimentaria, que principalmente está controlada por variaciones en la descarga detrítica hacia el lago. Un total de 11 facies sedimentarias han sido descritas, agrupadas en 3 unidades litoestratigráficas, compuestas en su mayor parte por carbonatos bandeados y masivos de origen clástico y algunas capas con laminaciones. La presencia de facies litorales más gruesas durante la Baja Edad Media y facies finamente laminadas durante la Era Moderna sugieren unos niveles del lago más bajos durante la Anomalía Climática Medieval y más altos durante la Pequeña Edad del Hielo., Este trabajo se ha financiado con los proyectos GLOBALKARST (CGL2009-08415) y GRACCIE CONSOLIDER-INGENIO (CSD2007-00067), concedidos por la Comisión Interministerial de Ciencia y Tecnología (CICYT). Los autores quieren agradecer la colaboración de las personas que participaron en los muestreos y al servicio de laboratorio del IPE-CSIC.

18 Pag., 7 Fig., [ES] Se resumen los datos disponibles y previamente publicados de sondeos sedimentarios recuperados en tres lagos kársticos españoles: Taravilla en el Sistema Ibérico (provincia de Guadalajara), Estanya en el Prepirineo aragonés (provincia de Huesca) y Zoñar en el valle del Guadalquivir (provincia de Córdoba). El intervalo temporal que abarcan estas secuencias sedimentarias varía desde el último máximo glacial (desde hace 21000 años en Estanya) hasta el Holoceno tardío (desde hace 4000 en Zoñary 2000 años en Taravilla). Los resultados muestran la gran variabilidad de ambientes de depósito que se desarrollaron en estos sistemas lacustres, principalmente ligados a fluctuaciones en el nivel de los lagos, la química de las aguas y cambios en las cuencas de drenaje. Los cambios climáticos han sido los principales responsables de esta gran variabilidad sedimentológica e hidrológica. El impacto de las actividades humanas en las cuencas de recepción ha sido perceptible desde época ibero-romana, pero especialmente a partir de la Edad Media, con un claro aumento de las tasas de sedimentación en los lagos. Las secuencias lacustres representan archivos detallados de cambio global en el pasado que son imprescindibles para conocer tanto la variabilidad climática regional como la dinámica de estos sistemas y así implementar políticas de conservación y gestión de estos espacios naturales y de los recursos hidrológicos y ecológicos que sustentan y estrategias de adaptación al cambio climático., [EN] A paleolimnological perspective of three Spanish karstic lakes (Taravilla, Zoñar and Estanya): sedimentological and hydrological evolution, clima te and human impact and implications for management and restoration policies. We synthesize the available, published paleolimnological information based on sediment core analyses from three Spanish karstic lakes: Taravilla in the Iberian Range (Guadalajara province), Estanya in the Pre-Prepirinean Range (Huesca pro vince) and Zoñar in the Guadalquivir Basin (Córdoba province). The time span ranges from the last 21000 years in Estanya, about 4000 years in Zoñar and 2000 years in Taravilla. The multidisciplinary study shows large depositional chan ges in the lakes mostly related to water level and hydrochemical fluctuations and chan ges in the watershed. Climate change has been the main forcing to explain the hydrological chan ges in the lakes. Human impact in the watershed and the lakes has been documented since Iberian-Roman times and it has increased since the Medieval Ages with a much higher sediment delivery to the lakes. Lake sediment sequences contain detailed archives of global changes in the past, needed to understand the natural climate variability and the dynamics of the lacustrine systems. These data will help to implement conservation and restoration policies of aquatic ecosystems and also strategies for adaptation to future climate changes., Esta investigación se ha financiado con los proyectos LIMNOCAL (CGL2006-13327-C04-01) y GRACCIE (CSD2007-00067); concedidos por la Comisión Interministerial de Ciencia y Tecnología (CICYT); y a través del proyecto multidisciplinar PM073/2007, concedido por la Diputación General de Aragón (DGA).

4 páginas, 3 figuras., The different sedimentological, geochemical and geophysical analysis performed in the Montcortés lake sedimentary record (Pre-Pyrenees, Lleida) helps to interpret the sedimentary evolution of this karstic lake during the last 6.000 years. The deposition of lacustrine varves is continuous during, at least, the last 3.500 Cal. yr BP. This fine lamination is punctuated by massive clastic facies corresponding to turbidite events. A total of 9 litostratigraphic units were recognized corresponding to three different depositional environments that alternate throughout the record; i) a shallow, meromictic lake with very high bioproductivity (unit VI: 6.000- 3.500 Cal. yr BP), ii) a deep, meromictic lake with high bioproductivity (units V, III and I; 3.500-1.250, 500-180 Cal. yr BP and last decades) and iii) deep, meromictic lake with higher clastic inputs (units IV and II; 1.250-500 and 180 Cal. yr BP- last decades). Several slumps deposits have been recognized within the sequence (units A, B and C)., Este trabajo se ha financiado por la Comisión Interministerial de Ciencia y Tecnología (CICYT) a través del proyecto CALIBRE (CGL2006-13327-C04/CLI), y por la acción integrada (UCA-GFZ): «High resolution sedimentary analysis of Spanish karstic lakes: paleoenvironmental and geochronological implications». (HA2007-007) La CAJA DE AHORROS DE LA INMACULADA proporcionó financiación adicional a través del programa Europa para el desarrollo del estudio de microfacies. Juan Pablo Corella tiene una beca DGA de doctorado concedida por la Diputación General de Aragón (CONAI+D). Por último, un especial agradecimiento al Dr. Carlos de Santisteban, por la revisión detallada y minuciosa de este manuscrito.

4 páginas, 2 figuras, 1 tabla.-- Paleoclimatología.-- Trabajo presentado a la 46ª Sesión Científica de la Sociedad Geológica de España celebrada en Madrid en 2009., The sedimentary and geochemical evolution of Lake Estanya (NE Spain) documents arid conditions, reflected by shallow water levels, high salinity and low organic productivity during lateglacial times, with intensified aridity during the so-called Mystery Interval (17,500 – 14,500 cal. years BP), the Younger Dryas (13,300 – 11,600 cal. years BP) and prior to the Holocene (11,600 – 9,400 cal. years BP). Higher water availability characterized the last 9,400 years, as recorded by most Iberian marine and continental records. The Estanya records demonstrate a high impact of suborbital global climate fluctuations in lake hydrology. Increase in lake level and detrital sediment delivery during the last millenium also indicate changes in land uses in the watershed since Medieval times., Esta investigación se ha financiado con los proyectos LIMNOCAL (CGL2006- 13327-C04-01) y GRACCIE (CSD2007- 00067), concedidos por la Comisión Interministerial de Ciencia y Tecnología (CICYT), y a través del proyecto multidisciplinar PM073/2007, concedido por la Diputación General de Aragón (DGA).

2 páginas, 2 figuras.-- Trabajo presentado a la XII Reunión Nacional de Cuaternario, Avila (2007)., The sedimentary evolution of Sanabria Lake (Zamora province, NW Spain) is reconstructed based on 4 kullenberg cores and 3 short cores. The longest core (9 m long) in the deepest (51 m) eastern subbasin reached the laminated and banded clastic proglacial lacustrine sediments deposited when the watershed was still glaciated. Basal 14C AMS dating (ca. 26 ka BP) indicates that the terminal morraine complex deposited prior to the global LGM. A high resolution study including magnetic susceptibility and XRF core-scanner geochemistry show millennial and century scale cycles in Lateglacial and Holocene organic-rich sediments. Calibration studies including 20 year long series of limnological data, short sediment cores, meteorological and land-use changes data are in progress., Este estudio está financiado por los proyectos de la CICYT LIMNOCLIBER (REN2003-09130- C02-02/CLI) y CALIBRE (CGL2006-13327-C04/CLI) y por la Acción Complementaria IBERLIMNO (CGL2004-20236- E).

Paleohydrological reconstructions based on sedimentological, geochemical, and isotopic records from a lake transect in the central-southern Altiplano (18degrees-26degreesS) indicate abrupt moisture fluctuations during the last 500 years. A change to modem conditions occurred in the late 19th century in all the records, from northern Chile (Lago Chungara, 18degrees15'S) and the Atacama (Laguna Miscanti, 23degrees45'S) to the southern tip of the Altiplano (Laguna El Peinado, NW Argentina, 26degrees30'S). A previous drier period shows different patterns of timing, duration, and intensity. In Chungara, the and period was shorter and occurred during the late 19th and early 20th centuries, while in Miscanti, it occurred earlier and ended at the beginning of the 20th century. In El Peinado, conditions were wetter during the 17-19th centuries and the and period occurred prior to the 17th century. Other records from the region show abrupt paleohydrological and paleoclimatic changes synchronous with the termination of the Little Ice Age. Despite local differences and dating uncertainties, the Little Ice Age stands out as a significant though complex climatic event in the Andean Altiplano. The discrepancies between the northern and southern Altiplano records during the last few centuries may reflect contrasting responses to external forcing in two areas with different climatic regimes. (C) 2003 Elsevier Science B.V. All rights reserved., The research work in Laguna Miscanti and Chungará was part of the Swiss National Science Foundation Project ‘Global Change in the Arid Andes’ (SNF-20-36382.92) led by the University of Bern, Switzerland. The Universidad Nacional de Catamarca (Argentina) and the Departamento de Relaciones Internacionales, CSIC (Spain) financially supported the fieldwork in Argentina.

The paleohydrological evolution of several high altitude, saline lakes located in the southernmost Altiplano (El Peinado and San Francisco basins, Catamarca province, NW Argentina) was reconstructed applying sedimentological, geochemical and isotopic techniques. Several playa lakes from the San Francisco basin (26 °56' S; 68°08' W, 3800-3900 m a.s.l.) show evidence of a recent raise in the watertable that led to modern deposition of carbonate and diatomaceous muds. A 2 m- long core from El Peinado Lake (26°29' 59'' S, 68°05' 32'' W, 3820 m a.s.1.) consists of calcitic crusts (unit 3), overlaid by an alternation of macrophyte-rich and travertine clast-rich, laminated muds (unit 2), and topped by travertine facies (unit 1). This sedimentary sequence illustrates a paleohydrological evolution from a subaerial exposure (unit 3) to a high lake stand (unit 2), and a subsequent smaller decrease in lake record also reflects the lake transgression between units 3 and 2. Although there is level (unit 1). The δ13 C(organic matter) a general positive correlation between δ18O(carbonate) and salinity proxies (Na, Li and B content), the large data dispersion indicates that other factors besides evaporation effects control chemical and isotopic composition of lakewater. Consequently, the oxygen isotopic composition cannot be interpreted exclusively as an indicator of salinity or evaporation ratio. The degassing of CO2 during groundwater discharge can explain the enriched δ13C values for primary carbonates precipitated. The carbon budget in these high altitude, saline lakes seems to be controlled by physical rather than biological processes. The Altiplano saline lakes contain records of environmental and climatic change, although accurate 14C dating of these lacustrine sediments is hindered by the scarcity of terrestrial organic material, and the large reservoir effects. Sedimentologic evidence, a 210Pb-based chronology, and a preliminary U/Th chronology indicate a very large reservoir effect in El Peinado, likely as a result of old groundwaters and large contributions of volcanic and geothermal 210C-free CO210 to the lake system. Alternative chronologies are needed to place these paleorecords in a reliable chronological framework. A period of increased water balance in the San Francisco basin ended at about 1660 ± 82 yr B.P. (calendar yr U/Th age), and would correlates with the humid phase between 3000 and 1800 yr B.P detected in other sites of the southern Altiplano. Both, 210Pb and preliminary U/Th dating favor a younger age for the paleohydrological changes in El Peinado. The arid period reflected by subaerial exposure and low lake levels in unit 3 would have ended with a large increase in effective moisture during the late 17th century. The increased lake level during deposition of unit 2 would represent the period between A.D. 1650-1900, synchronous to the Little Ice Age. This chronological framework is coherent with other regional records that show an abrupt transition from more arid to more humid conditions in the early 17th century, and a change to modern conditions in the late 19th century. Although there are local differences, the Little Ice Age stands as a significant climatic event in the Andean Altiplano., Financial support for field work was provided by the Universidad Nacional de Catamarca, Argentina, and by the Departamento de Relaciones Internacionales, CSIC, Spain.

The St. Maurici Lake (1.004818 E, 42.580801 N, 1924 m a.s.l.) is located in the eastern area of >Parc Nacional d’Aigüestortes i Estany de Sant Maurici>, Central Pyrenees, Catalonia. The lake occupies an overexcavated basin behind a terminal moraine. This paper aims to reconstruct the evolution of depositional environments and their relation to climate evolution since deglaciation to the present, based on a 8.7-m long sequence retrieved in the deepest part of the lake and a preliminary chronological model with three 14C AMS dates. After the glacial retreat carbonatic very fine sands and silts without organic matter were deposited in a proglacial environment. Early Holocene sediments are massive fine sands to laminated sandy silts with increasing organic content and some sand layers. A sedimentary hiatus occurred during the mid Holocene and the sedimentation re-started after ca. 4 ka with deposition of organic facies. Changes in clastic content reflect centennial scale run-off variability during the last millennia., El proyecto RECREO del Organismo Autónomo de Parques Nacionales (OPAN-387/2011) ha financiado este estudio.

Coastal back‐barrier perched lakes are freshwater bodies that are elevated over sea‐level and are not directly subjected to the inflow of seawater. This study provides a detailed reconstruction of the Doniños back‐barrier perched lake that developed at the end of a small river valley in the rocky coast of the north‐west Iberian Peninsula during the Holocene transgression. Its sequence stratigraphy was reconstructed based on a core transect across the system, the analyses of its lithofacies and microfossil assemblages, and a high‐resolution radiocarbon‐based chronology. The Doniños perched lake was formed ca 4·5 ka bp. The setting of the perched lake was favoured by Late Holocene sea‐level stabilization and the formation of a barrier and back‐barrier basin, which was contemporaneous with the high systems tract period. This basin developed over marine and lagoonal sediments deposited between 10·2 ka bp and 8·0 ka bp, during rapidly rising sea‐level characteristic of the transgressive systems track period. At 1·1 ka bp, the barrier was breached and the perched lake was partially emptied, causing the erosion of the back‐barrier basin sediments and a significant sedimentary hiatus. Both enhanced storminess and human intervention were likely to be responsible for this event. After 1 ka bp, the barrier reclosed and the present‐day lake was reformed, with the water level reaching as high as 5 m above mean sea‐level. The depositional evolution of the Doniños system serves as a model of coastal back‐barrier perched lakes in coastal clastic systems that have developed over gently seaward‐dipping rugged substrates at small distances from the shoreline and under conditions of rising sea‐level and high sediment supply. A review of estuaries, back‐barrier lagoons, pocket beaches and back‐barrier perched lakes in the rocky coast of north‐west Spain shows that the elevation of the bedrock is the main factor controlling the origin and evolution of these systems., This study was funded by the Spanish Ministry of Economy and Competitiveness through the projects CONSOLIDER‐ Ingenio 2010 GRACCIE (CSD2007‐00067), RapidNAO (CGL2013‐40608‐R) and PaleoMODES (CGL2016‐75281‐C2‐1‐R). AH and ML were supported by the Portuguese Science Foundation (FCT) through post‐doctoral SFRH/BPD/79923/2011 and SFRH/BPD/82103/2011, respectively. RC is grateful for a PhD fellowship from the Xunta de Galicia (Plan I2C) co‐financed by the European Social 94 Fund.

Modern precipitation anomalies in the Altiplano, South America, are closely linked to the strength of the South American summer monsoon (SASM), which is influenced by large-scale climate features sourced in the tropics such as the Intertropical Convergence Zone (ITCZ) and El Niño-Southern Oscillation (ENSO). However, the timing, direction, and spatial extent of precipitation changes prior to the instrumental period are still largely unknown, preventing a better understanding of the long-term drivers of the SASM and their effects over the Altiplano. Here we present a detailed pollen reconstruction from a sedimentary sequence covering the period between 4500 and 1000 cal yr BP in Lago Chungará (18ĝ S; 4570 m a.s.l.), a high-elevation lake on the southwestern margin of the Altiplano where precipitation is delivered almost exclusively during the mature phase of the SASM over the austral summer. We distinguish three well-defined centennial-scale anomalies, with dry conditions between 4100-3300 and 1600-1000 cal yr BP and a conspicuous humid interval between 2400 and 1600 cal yr BP, which resulted from the weakening and strengthening of the SASM, respectively. Comparisons with other climate reconstructions from the Altiplano, the Atacama Desert, the tropical Andes, and the southwestern Atlantic coast reveal that - unlike modern climatological controls - past precipitation anomalies at Lago Chungará were largely decoupled from north-south shifts in the ITCZ and ENSO. A regionally coherent pattern of centennial-scale SASM variations and a significant latitudinal gradient in precipitation responses suggest the contribution of an extratropical moisture source for the SASM, with significant effects on precipitation variability in the southern Altiplano. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License., This investigation was funded by Fondecyt grant 1181829 and International Cooperation Grant PI20150081. The Spanish Ministry of Science and Innovation funded this research through the projects ANDESTER (BTE2001-3225), Complementary Action (BTE2001-5257-E), LAVOLTER (CGL2004- 00683/BTE), GEOBILA (CGL2007-60932/BTE), and CONSOLIDER Ingenio 2010 GRACCIE (CSD2007-00067). In addition, we acknowledge funding from the Spanish government through the MEDLANT project. BV-G is grateful for the support of project CGL2016-76215-R/BTE. IAJ was supported by Fondecyt postdoctoral grant no. 3190181. AH was supported by a Beatriu de Pinós–Marie Curie COFUND contract within the framework of the FLOODES2k (2016 BP 00023) project. This research has been supported by the Gobierno Español (MEDLANT Project).