54 resultados para NORTHWEST SPAIN


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Over the last forty years, applying dendrogeomorphology to palaeoflood analysis has improved estimates of the frequency and magnitude of past floods worldwide. This paper reviews the main results obtained by applying dendrogeomorphology to flood research in several case studies in Central Spain. These dendrogeomorphological studies focused on the following topics: (1) anatomical analysis to understand the physiological response of trees to flood damage and improve sampling efficiency; (2) compiling robust flood chronologies in ungauged mountain streams, (3) determining flow depth and estimating flood discharge using two-dimensional hydraulic modelling, and comparing them with other palaeostage indicators; (4) calibrating hydraulic model parameters (i.e. Manning roughness); and (5) implementing stochastic-based, cost–benefit analysis to select optimal mitigation measures. The progress made in these areas is presented with suggestions for further research to improve the applicability of dendrogeochronology to palaeoflood studies. Further developments will include new methods for better identification of the causes of specific types of flood damage to trees (e.g. tilted trees) or stable isotope analysis of tree rings to identify the climatic conditions associated with periods of increasing flood magnitude or frequency.

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Growing evidence suggests environmental change to be most severe across the semi-arid subtropics, with past, present and projected drying of the Mediterranean Basin posing a key multidisciplinary challenge. Consideration of a single climatic factor, however, often fails to explain spatiotemporal growth dynamics of drought-prone ecosystems. Here, we present annually resolved and absolutely dated ring width measurements of 871 Scots pines (Pinus sylvestris) from 18 individual plot sites in the Central Spanish Pinar Grande forest reserve. Although comprising tree ages from 6 to 175 years, this network correlates surprisingly well with the inverse May–July diurnal temperature range (r = 0.84; p < 0.00011956–2011). Ring width extremes were triggered by pressure anomalies of the North Atlantic Oscillation, and the long-term growth decline coincided with Iberian-wide drying since the mid-1970s. Climate model simulations not only confirm this negative trend over the last decades but also project drought to continuously increase over the 21st century. Associated ecological effects and socio-economic consequences should be considered to improve adaptation strategies of agricultural and forest management, as well as biodiversity conservation and ecosystem service.

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Hilarión Eslava war der einflussreichste Musikpädagoge und Musikhistoriker der Mitte des 19. Jhs. in Spanien. Die Musikhistoriographie hat seine Leistung jedoch nicht gebührend zur Kenntnis genommen, da sie auf ideologische und historiographische Grundlagen fusst, des späten 20. Jhs. nicht kompatibel war.

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To assess if tree age may modulate the main climatic drivers of radial growth, two relict Pinus nigra subsp. salzmannii populations (Maria, most xeric site; Magina, least xeric site) were sampled in southern Spain near the limits of the species range. Tree-ring width residual chronologies for two age groups (mature trees, age <= 100 years (minimum 40 years); old trees, age > 100 years) were built to evaluate their responses to climate by relating them to monthly precipitation and temperature and a drought index (DRI) using correlation and response functions. We found that drought is the main driver of growth of relict P. nigra populations, but differences between sites and age classes were also observed. First, growth in the most xeric site depends on the drought severity during the previous autumn and the spring of the year of tree-ring formation, whereas in the relatively more mesic site growth is mainly enhanced by warm and wet conditions in spring. Second, growth of mature trees responded more to drought severity than that of old trees. Our findings indicate that drought severity will mainly affect growth of relict P. nigra populations dominated by mature trees in xeric sites. This conclusion may also apply to similar mountain Mediterranean conifer relicts.

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Human diphyllobothriasis is sporadically detected in Spain. Diphyllobothrium latum and Diplogonoporus balaenopterae have been identified. In the study, four cases of presumably imported diphyllobothriasis in Spanish patients were appraised. Molecular diagnosis allowed us to identify 'exotic' fish tapeworms such as Diplogonoporus balaenopterae in one patient and Diphyllobothrium pacificum in the others.

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Detecting and quantifying threats and researching and implementing management actions are key to improving the conservation status of endangered species. Bibliometric analysis can constitute a useful tool for the evaluation of such questions from a long-term perspective. Taking as a case study the Cinereous Vulture Aegypius monachus in Spain, we tested relationships between population dynamics, research efforts, existing threats and conservation milestones. The population growth of the species (from 206 pairs in 1976 to 2,068 in 2011) was parallelled by the increase in the total number of publications, the number of articles in SCI journals and the number of published works dealing with aspects of conservation, threats and management. These results are discussed in terms of cause-effect relationships taking into account that the influence of other non-mutually exclusive factors could also probably explain such associations. Similarly, we analysed the trend of the Cinereous Vulture breeding population with respect to different threats and indices of food availability, obtaining a positive correlation with the increase in big-game hunting bags in Spain. With respect to conservation milestones, we concluded that the current situation is positive in terms of the protection of the species and its habitat, with the situation in relation to food availability being unclear. Finally, we reviewed the main conservation actions that have been taken for the species in Spain and how these have been progressively modified based on new scientific and technical evidence, as an example of adaptive management applied to conservation.

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This study describes and discusses initiatives taken by public (water) agencies in the state of Brandenburg in Germany, the state of California in the USA and the Ebro River Basin in Spain in response to the challenges which climate change poses for the agricultural water sector. The drivers and actors and the process of changing agricultural water governance are its particular focus. The assumptions discussed are: (i) the degree of planned and anticipatory top-down implementation processes decreases if actions are more decentralized and are introduced at the regional and local level; (ii) the degree of autonomous and responsive adaptation approaches seems to grow with actions at a lower administrative level. Looking at processes of institutional change, a variety of drivers and actors are at work such as changing perceptions of predicted climate impacts; international obligations which force politicians to take action; socio-economic concerns such as the cost of not taking action; the economic interests of the private sector. Drivers are manifold and often interact and, in many cases, reforms in the sector are driven by and associated with larger reform agendas. The results of the study may serve as a starting point in assisting water agencies in developing countries with the elaboration of coping strategies for tackling climate change-induced risks related to agricultural water management.

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Banyoles is the largest and deepest lake of karstic-tectonic origin in the Iberian Peninsula. The lake comprises several circular sub-basins characteri- zed by different oxygenation conditions at their hypolimnions. The multiproxy analysis of a > 5 m long sediment core combined with high resolution seis- mic stratigraphy (3.5 kHz pinger and multi-frequency Chirp surveys), allow a precise reconstruction of the evolution of a karstic depression (named B3) until present times. Local meromictic conditions in this sub-basin have been conducive to deposition and preservation of ca. 85 cm of varved sediments since the late 19th century. The onset of these conditions is likely related to lake waters eutrophication caused by increasing farming activities in the wa- tershed. Increasing clastic input and organic productivity during the second half of the 20th century have also been recorded within the laminated sedi- ments, revealing an intensification of human impact and warmer water tem- peratures.

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Since the mid-1980s, migrants from North African and sub-Saharan countries have irregularly crossed the Strait of Gibraltar, in the hope of a better future for themselves and their families. Travelling in small, poorly equipped boats without experienced captains has cost the lives of myriad border crossers. Many of these bodies will never be recovered and the bereaved will never know whether their relatives and friends are alive or not. The bereaved are thus condemned to a state of not knowing and uncertainty. Exploring the junction of death and belonging, I firstly open a discussion about the enigmatic relation between a dead body and a dead person and argue for the importance of the physical presence of the body for mourning. Secondly, I show how the anonymity of dead border crossers and their uncertain belongings are generated, concealed, or rewritten. Following the story of an undertaker, I thirdly examine post-mortem border crossings. Depicting the power relations within identification processes, I outline the ambiguity of the term belonging by emphasising the constitutive significance of personal belongings such as clothes to restore a person’s identity. Reflecting on the ethical relationships which different actors (including the researcher) undertake with the deceased, I aim at gaining a better understanding of the multiple belonging of dead border crossers found on Spanish shores.

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Lake sediments from arcto-boreal regions commonly contain abundant Betula pollen. However, palaeoenvironmental interpretations of Betula pollen are often ambiguous because of the lack of reliable morphological features to distinguish among ecologically distinct Betula species in western North America. We measured the grain diameters and pore depths of pollen from three tree-birch species (B. papyrifera, B. kenaica and B. neoalaskana) and two shrub-birch species (B. glandulosa and B. nana), and calculated the ratio of grain diameter to pore depth (D/P ratio). No statistical difference exists in all three parameters between the shrub-birch species or between two of the tree-birch species (B. kenaica and B. papyrifera), and B. neoalaskana is intermediate between the shrub-birch and the other two tree-birch species. However, mean pore depth is significantly larger for the tree species than for the shrub species. In contrast, mean grain diameter cannot distinguish tree and shrub species. Mean D/P ratio separates tree and shrub species less clearly than pore depth, but this ratio can be used for verification. The threshold for distinguishing pollen of tree versus shrub birch lies at 2.55 μm and 8.30 for pore depth and D/P ratio, respectively. We'applied these thresholds to the analysis of Betula pollen in an Alaskan lake-sediment core spanning the past 800 years. Results show that shrub birch increased markedly at the expense of tree birch during the‘Little Ice Age’; this patten is not discernible in the profile of total birch pollen.