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The aim of this research is to improve our current understanding of the deglaciation stages in the southeastern Pyrenees and integrate it into reconstructions of the long-term deglaciation in the Iberian mountains since the Last Glaciation. First, we examine the existing chronological data for deglaciation in Iberian mountain ranges, mainly focusing on the Pyrenees and the results derived from cosmic ray exposure dating methods. Then, we recalculate the age of 17 samples from four different areas in the SE Pyrenees (Arànser, La Llosa and Duran valleys and Malniu-Guils complex) based on the 36Cl isotope and applying a new age calculator. In addition, we date eight new samples from the Malniu-Guils complex to provide a more accurate chronology for this site. The results do not clarify the timing of the maximum glacier extent, but support an extensive glacial advance followed by multiple small advances and retreats during the Last Glacial Maximum (LGM). Geomorphological and chronological data show evidence of massive deglaciation at the end of the LGM around 18 ka, and deglaciation was practically complete during the Bølling-Allerød interstadial. There is no geomorphological evidence of glacial advances in the cirques during the Younger Dryas. Instead, cirque walls were covered with rock glaciers during the Bølling-Allerød interstadial. The fronts of these rock glaciers stabilized at the end of this period, while their roots remained active until well into the Holocene., Spanish Ministry of Economy and Competitiveness. Grant Number: CGL2015-65813-R, High Mountain Physical Geography Research Group (Complutense University of Madrid), Ramón y Cajal Program of the Spanish Ministry of Economy and Competitiveness, Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

An accurate review of the literature on surface exposure dating methods shows evidence of the difficulty in applying cosmogenic dating methods to old moraines because of the intensity of late Quaternary erosion processes. Moreover, as in some previous cases, we also found special difficulties in applying these methods to LIA moraines, caused by the intensity of current paraglacial processes. The objective of this study is to apply cosmogenic dating methods to very old and very young moraines, which in both cases have been or are being affected intensively by erosion. With this purpose, we collected samples of boulders from moraines corresponding to (i) the penultimate glaciation and (ii) the Little Ice Age (LIA), both from Sierra Nevada in the south of the Iberian Peninsula. The sampling strategy was based on a preliminary accurate analysis of the geomorphological settings of two valley sites that resulted in the collection of only four boulder samples from an old moraine and three more from a very recent moraine. Using in situ-produced cosmogenic 10Be to date these boulders, the old samples yielded an age of ca. 130–135 ka for moraine stabilization. The younger samples indicate that the LIA moraine accretion probably occurred between the fourteenth and seventeenth centuries, with a subsequent stage of accumulation during the nineteenth century as suggested by historical documents. Dating a glaciation that occurred prior to the last Pleistocene glacial cycle and dating LIA glacial stages are novel in the context of Iberian glaciations and agree with other palaeoenvironmental studies in Iberian and in other European mountains. The limited number of boulders adequate for cosmic-ray exposure dating prevents statistical methods to be applied, and therefore highlights the need to improve geomorphological criteria in sample selection., Ministerio de Economía y Competitividad, Programa de investigación Ramón y Cajal, Grupo de investigación ANTALP, Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

The COVID-19 pandemic is having an enormous negative impact on human health, with more than 4.44 million deaths worldwide; on the economy, with an unprecedented deep and abrupt crisis; and on society, with millions of people facing unemployment and dependent, in the best-case scenario, on public welfare or social aid systems. Home confinement, measures to limit non-essential economic activity and travel restrictions in many countries during the spring of 2020 led to rapid air quality improvements in cities. A detailed analysis of Barcelona’s daily immissions of seven pollutants (CO, SO2, NO, NO2, NOx, PM10 and O3) shows a clear decrease from mid-March to June, with the peak in April and the nitrogen oxides. For these pollutants the reduction of traffic density is very likely the main cause of their immissions decrease. On another note, the global reduction of CO2 emissions derived from the use of fossil fuels was estimated at approximately 8 % in 2020, which, despite constituting an unprecedented drop, will have little impact on concentrations of CO2 and other greenhouse gases in the atmosphere. The current situation must be seen as an opportunity to push, without delay, for a drastic change in the energy and economy models towards a socio-environmental paradigm based on sustainability, economic efficiency and solidarity between peoples., La pandemia de la COVID-19 está teniendo un enorme impacto negativo en la salud humana, con más de 4,44 millones de muertos en todo el mundo; en la economía, con una profunda y abrupta crisis sin precedentes; y en la sociedad, con millones de personas en situación de desempleo y dependientes, en el mejor de los casos, de los sistemas de asistencia social o de bienestar público. El confinamiento domiciliario, las medidas para limitar la actividad económica no esencial y las restricciones de los viajes en muchos países durante la primavera de 2020 llevaron a mejoras rápidas en la calidad del aire de las ciudades. Un análisis detallado de las inmisiones diarias de Barcelona de siete contaminantes (CO, SO2, NO, NO2, NOx, PM10 y O3) muestra una clara disminución desde mediados de marzo hasta junio, con el pico en abril y en los óxidos de nitrógeno. Para estos contaminantes, la reducción de la densidad del tráfico es muy probablemente la principal causa de la disminución de sus inmisiones. Por otro lado, la reducción global de las emisiones de CO2 derivadas del uso de combustibles fósiles se estimó en aproximadamente un 8 % en 2020, lo que, a pesar de constituir una caída sin precedentes, tendrá poco impacto en las concentraciones de CO2 y de otros gases de efecto invernadero en la atmósfera. La situación actual debe ser vista como una oportunidad para impulsar, sin demora, un cambio drástico en los modelos energético y económico hacia un paradigma socioambiental basado en la sostenibilidad, la eficiencia económica y la solidaridad entre los pueblos.

The hypothesis that the study of plant functional traits can complement phytodiversity studies, and in what way the information can be obtained in a short time with few funding scenarios, for plant community management and other purposes, is tested. This study is based on the nominal soft plant traits from our own botanical surveys drawn up from Doñana and el Hierro. Plants traits influence the survival of the taxa present in different plant communities. These dry woodlands are high micro hot-spots of biodiversity (97 taxa have been located as a result of our own studies in Doñana, and 131 taxa of vascular plants in el Hierro). The presence of a higher number of phanerophytes in Doñana than in El Hierro, and a comparable number of chamaephytes in both places, are at variance with the theory of ¿empty niche¿. The higher presence of hemicriptofphytes in Doñana than in El Hierro could be the result of a greater herbivory pressure in the National Park. The greatest abundance of annuals in el Hierro is explained by the episodes of severe drought in this oceanic island. It is essential to combine phytodiversity studies in order to reach conservation targets and to get a more detailed understanding of how plant biodiversity works in dry juniper woodland.

Juniperus turbinata subsp. canariensis is an endemism located in the Canary and Madeira Archipelagos. The biggest populations of this endemic juniper are located in the island of El Hierro. Some physical factors (air temperature, air humidity, altitude, type of soil) and their relationship with plant biodiversity are studied since 2012. Soils are generally classified as being shallow, stony and well-drained. Woodlands are associated with soils having medium to low fertility and episodic availability of water near the soil surface. Exhaustive relevés were drawn up to identify all the plants present in the plots studied, located in the same places where the data loggers were installed. The dry woodlands cover 1/10 of the island’s surface, where 1/5 of the amount of vascular flora present on El Hierro island is found. Juniper woodlands occur on soils that have developed from recent volcanic parent material and belong to one of three soil orders (Aridisols, Entisols, and Inceptisols). The most significant differences are in summer/winter soil temperature, and winter soil moisture. Differences are detected also in relative humidity data between the north (to windward) and south (to leeward) faces of the island. These differences are reflected in the biodiversity with the presence of hygrophilous plants on the windward and thermophilous plants on the leeward. These results highlight the relationship of climatic conditions with the biodiversity of the dry juniper woodlands. This kind of dry woodlands located on an oceanic island is sensitive to climatic change and should be conserved for its hot-spots of biodiversity.

The aim of this research is to improve our current understanding of the deglaciation stages in the southeastern Pyrenees and integrate it into reconstructions of the long-term deglaciation in the Iberian mountains since the Last Glaciation. First, we examine the existing chronological data for deglaciation in Iberian mountain ranges, mainly focusing on the Pyrenees and the results derived from cosmic ray exposure dating methods. Then, we recalculate the age of 17 samples from four different areas in the SE Pyrenees (Arànser, La Llosa and Duran valleys and Malniu-Guils complex) based on the 36Cl isotope and applying a new age calculator. In addition, we date eight new samples from the Malniu-Guils complex to provide a more accurate chronology for this site. The results do not clarify the timing of the maximum glacier extent, but support an extensive glacial advance followed by multiple small advances and retreats during the Last Glacial Maximum (LGM). Geomorphological and chronological data show evidence of massive deglaciation at the end of the LGM around 18 ka, and deglaciation was practically complete during the Bølling-Allerød interstadial. There is no geomorphological evidence of glacial advances in the cirques during the Younger Dryas. Instead, cirque walls were covered with rock glaciers during the Bølling-Allerød interstadial. The fronts of these rock glaciers stabilized at the end of this period, while their roots remained active until well into the Holocene., Ministerio de Economía y Competitividad (España), Universidad Complutense de Madrid, Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

An accurate review of the literature on surface exposure dating methods shows evidence of the difficulty in applying cosmogenic dating methods to old moraines because of the intensity of late Quaternary erosion processes. Moreover, as in some previous cases, we also found special difficulties in applying these methods to LIA moraines, caused by the intensity of current paraglacial processes. The objective of this study is to apply cosmogenic dating methods to very old and very young moraines, which in both cases have been or are being affected intensively by erosion. With this purpose, we collected samples of boulders from moraines corresponding to (i) the penultimate glaciation and (ii) the Little Ice Age (LIA), both from Sierra Nevada in the south of the Iberian Peninsula. The sampling strategy was based on a preliminary accurate analysis of the geomorphological settings of two valley sites that resulted in the collection of only four boulder samples from an old moraine and three more from a very recent moraine. Using in situ-produced cosmogenic 10Be to date these boulders, the old samples yielded an age of ca. 130–135 ka for moraine stabilization. The younger samples indicate that the LIA moraine accretion probably occurred between the fourteenth and seventeenth centuries, with a subsequent stage of accumulation during the nineteenth century as suggested by historical documents. Dating a glaciation that occurred prior to the last Pleistocene glacial cycle and dating LIA glacial stages are novel in the context of Iberian glaciations and agree with other palaeoenvironmental studies in Iberian and in other European mountains. The limited number of boulders adequate for cosmic-ray exposure dating prevents statistical methods to be applied, and therefore highlights the need to improve geomorphological criteria in sample selection., Ministerio de Economía y Competitividad (España), Universitat de Barcelona, Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

Historical documents have shown their potential to infer the origin and evolution of the glacier existing in the Veleta cirque, in the massif of Sierra Nevada (Spain). This information encompasses written sources spanning from the 17th to the mid-20th centuries, and provides valuable knowledge about the Little Ice Age. These new data complement the already existing geomorphological knowledge about the natural system and landscape evolution in Sierra Nevada, particularly with regards to glacial geomorphic events in the summit areas. From a transdisciplinary methodological approach, the results show that the Veleta glacier was a singular geomorphic event that owed its existence to the particular environmental conditions of the high lands of Sierra Nevada, besides the favourable morpho-topographical setting, altitude, aspect as well as microclimate conditions prevailing in this area., La documentación histórica analizada ha ratificado su utilidad en el estudio del origen y evolución del foco glaciar del Corral del Veleta, instalado en el macizo de Sierra Nevada (España). La información obtenida, que abarca escritos desde el siglo XVII hasta mediados del siglo XX, ha ampliado conocimientos auxiliares valiosos de la Pequeña Edad del Hielo. Los nuevos datos aportados han permitido explicar mejor saberes parciales que desde la Geomorfología ya poseíamos de los sistemas naturales y paisajes de la Sierra, en particular de los acontecimientos geomórficos glaciares de sus cumbres. Los resultados obtenidos, desde un enfoque metodológico transdisciplinar, han demostrado que el foco glaciar del Corral del Veleta resultó ser un acontecimiento geomorfológico singular debido a las particulares condiciones ambientales del nivel de cumbres de Sierra Nevada, así como a la favorable configuración morfotopográfica del relieve, altitud, orientación y condiciones climáticas locales del reducto geográfico que cobijó al foco glaciar. De no ser así, difícilmente éste podría haberse desarrollado.

El Hierro es la isla más occidental del archipiélago canario y se halla en latitudes subtropicales (27,5ºN). El clima subtopical/tropical canario de la isla se caracteriza por tener gran diversidad de microclimas debido a la importante influencia de algunos factores geográficos. El objetivo principal de este trabajo es analizar los datos de temperatura y humedad relativa del aire, registrados a resolución horaria por sensores instalados en sabinares de El Hierro, a lo largo de tres ciclos anuales (de septiembre de 2012 a agosto de 2015) y estudiar episodios extremos de termohigrométricos. Los datos provienen de dos enclaves con orientación y altitud contrastadas: El Júlan (996 m, en la vertiente sur y en el interior) y Sabinosa (258 m, en la cara norte y cerca de la línea de costa). Los resultados obtenidos muestran ciclos termohigrométricos muy similares entre ambas áreas de estudio, pero presentan grandes diferencias en el rango de sus valores a pesar de hallarse a menos de 4 km de distancia horizontal. Los contrastes extremos de temperatura acontecen en julio y agosto cuando El Júlan registra hasta 21ºC más que Sabinosa a la misma hora. Son situaciones sinópticas en que los alisios soplan fuerte y dejan Sabinosa bajo el mar de nubes. Los contrastes extremos de humedad tienen lugar también en verano, sobre todo en agosto, bajo advecciones del este de origen sahariano, donde los valores de El Júlan pueden caer por debajo del 5% y los de Sabinosa mantenerse por encima del 90%., El Hierro is the westernmost island of Canary Isles and it is located in the north subtropic (27.5ºN). The subtropical-tropical Canary climate is featured by multiple microclimates due to geographical factors. The main objective of the present study is to analyse air temperature and relative humidity data of Juniperus turbinata forests and study extreme events of thermohygrometric differences. Sensors in the branches of Juniperus turbinata trees hourly recorded these data along three annual cycles (from September 2012 to August 2015). Data come from two locations with different aspect and altitude: El Júlan (996 masl, in the south face and inland) and Sabinosa (258 masl, in the north face and next to the sea). The results show similar thermohygrometric cycles in both locations. Despite these two points are very close (horizontally separated by 4 km), a large difference is found between their respective ranges of values. The largest temperature differences take place in July and August. El Júlan can record 21ºC more than Sabinosa at the same time in summer. Trade winds contribute to this large temperature difference because they form orographic clouds over the north face of the island (Sabinosa is to windward). The largest differences of relative humidity take place in summer too, above all, in August. Easterly winds from Sahara Desert reduce humidity in El Júlan below 5%, whereas humidity in Sabinosa can keep over 90%.

A partir de los datos diarios de precipitación, permanencia y espesor de nieve, se han calculado los valores más significativos de nivosidad e innivación en La Molina (1.703 m, extremo oriental del Pirineo), durante 38 temporadas nivales (de noviembre a mayo, de 1956/57 a 1995/96). Su rasgo más destacado es la acusada irregularidad de todas las variables nivoclimáticas estudiadas, tanto las relacionadas con la cuantía y frecuencia de la precipitación nivosa, como las relacionadas con la permanencia y espesor del manto de nieve., Daily snow data in La Molina (1.703 m asl, eastern Pyrenees) is analysed during 38 nival seasons (November to May; 1956/57 to 1995/96), from which the most significant values of snowfall and snow cover are calculated. It should be pointed the accused irregularity of all climatic characteristics studied: the amount and frequency of snow precipitation, as well as the persistence and thickness of the mantle of snow.

The large number of studies of Sierra Nevada’s environmental history since the Last Pleistocene glacial period makes it one of the most intensively analysed massifs in the Iberian Peninsula. The early geomorphological descriptions have been complemented in recent decades with absolute dating techniques that have allocated in time the sequence of environmental events occurred in Sierra Nevada during the last millennia. The maximum expansion of the glaciers during the Last Glaciation took place around 30-32 ka, with a subsequent re-advance by 19-20 ka. The process of deglaciation was very fast, and around 14-15 ka the ice had almost completely retreated from the massif. Since then, with greater or less intensity and extent, periglacial processes have driven the environmental change in the massif. The coldest and wettest phases during the Holocene have favoured the development of small glaciers in the highest northern cirques. The last of these phases was the Little Ice Age, where abundant historical sources and sedimentary records exist. During the mid XX century the last glaciers melted, resulting in the complete deglaciation of the massif., Sierra Nevada es uno de los macizos ibéricos con mayor información de su último periodo glaciar pleistoceno. El análisis geomorfológico de campo se ha ido completando durante las últimas décadas con técnicas de datación absolutas que han permitido localizar en el tiempo los acontecimientos ambientales acontecidos en Sierra Nevada durante los últimos milenios. La máxima expansión de los hielos durante la Última Glaciación tuvo lugar en torno a 30-32 ka, con un reavance posterior en torno a 19-20 ka. La deglaciación, entonces, fue rápida y en torno a 14-15 ka el macizo estaba ya prácticamente deglaciado. Desde entonces, con mayor o menor intensidad y extensión, los procesos periglaciares controlan los cambios ambientales en el macizo. En la actualidad éstos fijan su límite inferior en torno a los 2500 m. Durante el Holoceno las fases más frías y húmedas han conllevado la aparición de pequeños focos glaciares en los circos septentrionales de mayor altura. De ellas, la Pequeña Edad de Hielo ha sido la última y de la que mayor información se dispone, ya sea a través de fuentes históricas como de registros sedimentológicos. A mediados del siglo XX desaparecen los últimos vestigios glaciares, conllevando la deglaciación completa de Sierra Nevada.