Canaries (Îles)

Les Canaries, ancrées au large de la lisière septentrionale du Sahara adantique, peuvent être considérées comme une extension insulaire, marginale et fortement individualisée, du vaste univers berbère. La présence aux îles de groupes berbérophones du moins dans la phase finale de la préhistoire locale, les temps préhispaniques, semble fermement attestée par plusieurs arguments d’ordre archéologique, ethnohistorique et paléo-linguistique. Mais à l’heure actuelle des difficultés méthodologiques..

Canaries (Îles)

Les Canaries, ancrées au large de la lisière septentrionale du Sahara adantique, peuvent être considérées comme une extension insulaire, marginale et fortement individualisée, du vaste univers berbère. La présence aux îles de groupes berbérophones du moins dans la phase finale de la préhistoire locale, les temps préhispaniques, semble fermement attestée par plusieurs arguments d’ordre archéologique, ethnohistorique et paléo-linguistique. Mais à l’heure actuelle des difficultés méthodologiques..

Canaries (Îles)

Les Canaries, ancrées au large de la lisière septentrionale du Sahara adantique, peuvent être considérées comme une extension insulaire, marginale et fortement individualisée, du vaste univers berbère. La présence aux îles de groupes berbérophones du moins dans la phase finale de la préhistoire locale, les temps préhispaniques, semble fermement attestée par plusieurs arguments d’ordre archéologique, ethnohistorique et paléo-linguistique. Mais à l’heure actuelle des difficultés méthodologiques..

Canaries (Îles)

Les Canaries, ancrées au large de la lisière septentrionale du Sahara adantique, peuvent être considérées comme une extension insulaire, marginale et fortement individualisée, du vaste univers berbère. La présence aux îles de groupes berbérophones du moins dans la phase finale de la préhistoire locale, les temps préhispaniques, semble fermement attestée par plusieurs arguments d’ordre archéologique, ethnohistorique et paléo-linguistique. Mais à l’heure actuelle des difficultés méthodologiques..

Wintering grounds, population size and evolutionary history of a cryptic passerine species from isotopic and genetic data

Cryptic species pose a particular challenge to biologists in the context of life history investigations because of the difficulty in their field discrimination. Additionally, there is normally a lag in their widespread acceptance by the scientific community once they are formally recognised. These two factors might constrain our ability to properly assess the conservation status of the different species conforming a cryptic complex. In this study, we analysed isotopic and genetic data to shed light into the still unclear wintering grounds, population size and evolutionary history of the Iberian chiffchaff Phylloscopus ibericus, a species included within the common chiffchaff Phylloscopus collybita until two decades ago due to their phenotypic similarity. We used molecular methods to identify spring-migrating Phylloscopus species captured in northern Iberia, and by comparing the Hydrogen isotopic ratios of their claw tips (δ2Hc; which would reflect the signatures of their wintering grounds), we detected that δ2Hc values of Iberian chiffchaffs were similar to willow warblers (Phylloscopus trochilus; a renowned trans-Saharan migrant), and higher than common chiffchaffs (mostly a pre-Saharan migrant). These results strongly support the idea that Iberian chiffchaffs winter in tropical Africa. We additionally reconstructed the phylogeny and evolutionary history of the Iberian chiffchaff's clade using mitochondrial and nuclear markers. Our results revealed relatively high values of nucleotide diversity (and, hence, high Ne) for the species that were greater than the values of the common/Iberian most recent common ancestor. This suggests that the Iberian chiffchaff did not experience strong bottlenecks after diverging from the common chiffchaff approximately one million years ago. Ultimately, our study provides another illustrative example of how isotopic and genetic analysis tools can help to enhance our understanding of avian ecology and evolution.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

Variable Shifts in the Autumn Migration Phenology of Soaring Birds in Southern Spain

While alteration of the migratory habits of birds is widely regarded as one of the most evident ecological effects of climate change, studies reporting shifts in migration phenology for long-lived, long-distance migrants have been few. Using time series of count data collected in southern Spain during autumn migration, we examined the magnitude and direction of phenological shifts for six common species of soaring birds. Many current methods for investigating phenological change rely on continuous data sets; however, these data may be unavailable for a variety of reasons. We used a cross-correlation analysis, which allowed us to compare recent data on the timing of migration from 1999–2011 to a historic data set collected during 1976–1977. The direction of phenological shifts for autumn migration was species-specific. White Storks Ciconia ciconia and Black Kites Milvus migrans appeared to have delayed passage, Black Storks Ciconia nigra and European Honey Buzzards Pernis apivorus have advanced their migratory timing, and we found no clear phenological change for Short-toed Eagles Circaetus gallicus or Booted Eagles Hieraaetus pennatus

Growth response to thinning in a mixed pine-oak stand of Pinus pinaster and Quercus pyrenaica.

During the last decades the interest on mixed stands has increased in forestry due to their potential benefits, especially conifer-broadleaves mixtures. However, more knowledge is need about their dynamic and their response to silvicultural treatments. On the other hand, climate change can affect different species in different ways, so it is important to study the effect of climate in mixed stands with different silvicultures. In this work we present preliminary results of a thinning trial in a mixed stands of Pinus pinaster Ait. and Quercus pyrenaica Willd located in ?Montes de Toledo? (Central Spain). The main objectives of the experiment are to study the growth response of each species to thinning and to analyse if there are different climate-growth relationships between species and thinning treatments. The stand is a stratified mixture with a planted pine overstory and a natural regenerated oak lower stratum (understory). The experiment design is a Latin square of order three with the following treatments: heavy thinning from below (40% of basal area is removed), moderate thinning from below (25% of basal area is removed) and control or unthinned. The thinning was applied during the winter 2009-10. The position of all trees larger than 7.5 cm of diameter per plot was recorded. Diameter of all trees and heights of a sample were measured before the thinning. In each plot dendrometer bands were installed in 10 trees per species in order to study the effect of treatments on individual tree growth. Dedrometer bands were read every month to detect possible differences in growth pattern between treatments. These data were complemented with continued records registered with electronic dendrometer installed in one tree per species and treatment. Climatic variables and soil temperature and humidity were recorded with a weather station and soil sensors set up in the study site. Data from the first growing season after the thinning treatment (spring of 2010) will be presented in this work. The possible differences in total growth and in growth pattern between species and treatments will be analysed and discussed

Molecular elucidation of CO2 methanation over a highly active, selective and stable LaNiO3/CeO2-derived catalyst by in situ FTIR and NAP-XPS

The CO2 methanation mechanism over the highly active (TOF=75.1 h−1), selective (>92%) and stable 10% LaNiO3/CeO2-derived catalyst is still unresolved. The surface of the catalyst is monitored under hydrogenation (H2), oxidizing (CO2) and CO2 methanation (H2 +CO2) conditions by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) using synchrotron radiation. Meanwhile, the main reaction intermediates are identified by in situ FTIR analysis. NAP-XPS experiments confirm that LaNiO3 perovskite reduction leads to the ex-solution of Ni0 nanoparticles and Ni2+single bondCeO2−x and Ni2+single bondLa2O3 interfaces conformation, favouring the CO2 adsorption and the H2 dissociation/transfer. In situ FTIR experiments combined with the C1s spectra (NAP-XPS) suggest that the CO2 activation occurs on CeO2−x (oxygen vacancies and OH–) at low temperatures, in the form of bicarbonates; whereas, mono-/bidentate carbonates are formed on different strength La2O3 sites at increasing temperatures. These species are consecutively reduced to formates, as the main reaction intermediate, and methane by the H spilled from Ni0 nanoparticles near to NiOsingle bondCeO2−x and NiOsingle bondLa2O3 interfaces.Support for this study was provided by Projects PID2019–105960RB-C21 and PID2019–105960RB-C22 by MCIN/AEI/10.13039/501100011033, the Basque Government (Project IT1509–2022), Generalitat Valenciana (CIPROM/2021/74) and ALBA synchrotron. One of the authors (JAOC) acknowledges the postdoctoral research grant (DOCREC20/49) provided by the University of the Basque Country (UPV/EHU)