Future variability of droughts in three Mediterranean catchments

This study investigates the intensity change in typhoons and storm surges surrounding the Korean Peninsula under global warming conditions as obtained from the MPI_ECHAM5 climate model using the A1B series. The authors use the Cyclostationary Empirical Orthogonal Function to estimate future background fields for typhoon simulations from twenty-first-century prediction results. A series of numerical experiments applies WRF (Weather Research and Forecasting) and POM (Prinston Ocean Model) models to simulate two historical typhoons, Maemi (2003) and Rusa (2002), and associated storm surges under real historical and future warming conditions. Applying numerical experiments to two typhoons, this study found that their central pressure dropped about 19 and 17 hPa, respectively, when considering the future sea surface temperature (a warming of 3.9 °C for 100 years) over the East China Sea (Exp. 1). The associated enhancement of storm surge height ranged from 16 to 67 cm along the southern coast of the Korean Peninsula. However, when the study considered global warming conditions for other atmospheric variables such as sea-level pressure, air temperature, relative humidity, geopotential height, and wind in the typhoon simulations (Exp. 2), the intensities of the two typhoons and their associated surge heights scarcely increased compared to the results of Exp. 1. Analyzing projected atmospheric variables, the authors found that air temperatures at the top of the storm around 200 hPa increased more than those at the surface in tropical and mid-latitudes. The reduced vertical temperature difference provided an unfavorable condition in the typhoon’s development even under conditions of global warming. This suggests that global warming may not always correlate with a large increase in the number of intense cyclones and/or an increase in associated storm surges.     

Nutrients and Abiotic Stress Interact to Control Ergot Plant Disease in a SW Atlantic Salt Marsh

Over the last decades, human activities have strongly affected ecosystems, with pervasive increases in nutrient loadings, abiotic stress, and altered herbivore pressure. The evaluation of how those environmental factors interact to influence plant–pathogen interactions under natural conditions becomes essential to fully understand the ecology of diseases and anticipate the possible effects of global change on natural and agricultural systems. In a SW Atlantic salt marsh, we performed a field factorial experiment to evaluate the effect of herbivory, salinity, and nutrient availability, three main limiting factors for salt marsh plant growth, on the infection of the fungus Claviceps purpurea (ergot) upon the cordgrass Spartina densiflora. Results show that herbivory has no effect but both nutrients and salinity increase fungal infection. The combined effect of salinity and nutrients is not additive but interactive. Salinity stress increases infection at ambient nutrient levels but in combination with fertilizer it buffers the higher infection produced by increased nutrient availability. Since both, nitrogen availability and salinity are factors predicted to globally increase due to human impact on ecosystems, this interaction between environmental factors and ergot infection can have strong effects on natural and productive agricultural systems.     

Lung cancer risk associated with residential proximity to industrial installations: a spatial analysis

Lung cancer is the most common cause of cancer-related death and thus a major public health problem. While lung cancer frequency might be partially attributable to smoking habit and occupational exposure, the role of industrial pollution also needs to be assessed. To ascertain the possible effect of residential proximity to industrial installations on lung cancer risk in Asturias, an industrial region in Spain, taking into account the type of industrial activity and carcinogenic substances released. We conducted a hospital-based case–control study covering 700 lung cancer patients and 700 controls recruited in Asturias, matched individually by ethnicity, hospital, age, and sex. Distances were computed from the respective participants’ residential locations to the 48 industrial facilities governed by the Integrated Pollution Prevention and Control Act 16/2002 and included in the European Pollutant Release and Transfer Register, and located in the study areas. Using logistic regression, odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated and adjusted for sex, age, hospital area, tobacco consumption, family history of cancer, area of residence, and occupation. Excess risk of lung cancer was observed for individuals living near industrial installations (OR = 1.43; 95 % CI = 1.08–1.89), particularly metal industries (OR = 1.40; 95 % CI = 1.05–1.87), cement plants (OR = 4.81; 95 % CI = 1.20–19.19), and shipyards (OR = 1.69; 95 % CI = 1.17–2.43). Residents living close to industrial facilities releasing dioxins displayed a high, though non-statistically significant, excess risk of lung cancer (OR = 1.62; 95 % CI = 0.86–3.07). This study suggests a possible association between lung cancer risk and proximity to industrial installations, specifically metal industries, cement plants, and shipyards.     

Dams in the last large free-flowing rivers of Patagonia,the Santa Cruz River,environmental features,and macroinvertebrate community

Three large rivers have their headwaters in the Patagonian Ice Fields (PIFs) in the Andes Mountains, the largest mid-latitude ice masses on Earth: Santa Cruz, Baker and Pascua. They are the last large free flowing rivers in Patagonia, but plans are advanced for building dams for hydroelectric power generation. The three PIF rivers, with a discharge dominated by ice melt, share a common, unique hydrograph compared to that of the other eight large rivers in the region: a distinct seasonal cycle, and an extremely stable discharge, with much lower variability than other rivers. In this study we present the first extensive survey of habitats and benthic macroinvertebrates in the least studied system, the Santa Cruz River. We assess how much of the natural capital provided and sustained by benthic invertebrates are expected to be lost by flooding and discuss how dams would affect riverine habitat and biota. In the Santa Cruz River, we conducted an intensive field survey during September 2010; a total of 52 sites located at regular 6 km intervals were sampled along the 310 river-km for macroinvertebrates and seventeen habitat variables. Although some habitat structure is apparent at the local scale, the Santa Cruz River could be described as very homogeneous. Macroinvertebrate density and the richness (38 genera) found in the Santa Cruz River resulted to be one of the lowest in comparison with 42 other Patagonian rivers. Albeit weak, the structure of the macroinvertebrates assemblages was successfully described by a reduced set of variables. The reduced flow variation and the lack of bed scouring flows have a direct and negative effect on the heterogeneity of riverbeds and banks. The high turbidity of the Santa Cruz River may also contribute to shorter food webs, by affecting autotrophic production, general trophic structure, and overall macroinvertebrate productivity and diversity. Dams will obliterate 51% of the lotic environment, including the most productive sections of the river according to our macroinvertebrate data. Since Santa Cruz River has a naturally homogeneous flow cycle, dams may provide more variable flows and more diverse habitat. Our data provide critically valuable baseline information to understand the effects of dams on the unique set of glacial driven large rivers of Patagonia.     

Fusion of airborne LiDAR and multispectral sensors reveals synergic capabilities in forest structure characterization

Forest stand structure is an important concept for ecology and planning in sustainable forest management. In this article, we consider that the incorporation of complementary multispectral information from optical sensors to Light Detection and Ranging (LiDAR) may be advantageous, especially through data fusion by back-projecting the LiDAR points onto the multispectral image. A multivariate data set of both LiDAR and multispectral metrics was related with a multivariate data set of stand structural variables measured in a Scots pine forest through canonical correlation analysis (CCA). Four statistically significant pairs of canonical variables were found, which explained 83.0% accumulated variance. The first pair of canonical variables related indicators of stand development, i.e. height and volume, with LiDAR height metrics. CCA also found attributes describing stand density to be related to LiDAR and spectral variables determining canopy coverage. Other canonical variables pertained to Lorenz curve-derived attributes, which are measures of within-stand tree size variability and heterogeneity, able to discriminate even-sized from uneven-sized stands. The most relevant result was to find that metrics derived from the multispectral sensor showed significant explanatory potential for the prediction of these structural attributes. Therefore, we concluded that metrics derived from the optical sensor have potential for complementing the information from the LiDAR sensor in describing structural properties of forest stands. We recommend the use of back-projecting for jointly exploiting the synergies of both sensors using similar types of metrics as they are customary in forestry applications of LiDAR.     

Social-ecological and regional adaptation of agrobiodiversity management across a global set of research regions

To examine management options for biodiversity in agricultural landscapes, eight research regions were classified into social-ecological domains, using a dataset of indicators of livelihood resources, i.e., capital assets. Potential interventions for biodiversity-based agriculture were then compared among landscapes and domains. The approach combined literature review with expert judgment by researchers working in each landscape. Each landscape was described for land use, rural livelihoods and attitudes of social actors toward biodiversity and intensification of agriculture. Principal components analysis of 40 indicators of natural, human, social, financial and physical capital for the eight landscapes showed a loss of biodiversity associated with high-input agricultural intensification. High levels of natural capital (e.g. indicators of wildland biodiversity conservation and agrobiodiversity for human needs) were positively associated with indicators of human capital, including knowledge of the flora and fauna and knowledge sharing among farmers. Three social-ecological domains were identified across the eight landscapes (Tropical Agriculture-Forest Matrix, Tropical Degrading Agroecosystem, and Temperate High-Input Commodity Agriculture) using hierarchical clustering of the indicator values. Each domain shared a set of interventions for biodiversity-based agriculture and ecological intensification that could also increase food security in the impoverished landscapes. Implementation of interventions differed greatly among the landscapes, e.g. financial capital for new farming practices in the Intensive Agriculture domain vs. developing market value chains in the other domains. This exploratory study suggests that indicators of knowledge systems should receive greater emphasis in the monitoring of biodiversity and ecosystem services, and that inventories of assets at the landscape level can inform adaptive management of agrobiodiversity-based interventions.     

A regionalized IO-model to value seasonal recreational ecosystem services in a mountain National Park in Spain

Recreational Ecosystem Services (RES) are among the most frequently evaluated ecosystem services.RES are seen as a major opportunity for sustainable development...     

The volcanic-hosted massive sulphide deposits of the Iberian Pyrite Belt Review and preface to the Thematic Issue

The Iberian Pyrite Belt (IPB) has, over the past decade, been an area of renewed mining activity and scientific research that has resulted in a wealth of new data and new geological and metallogenic concepts that are succinctly presented in this Thematic Issue. The reason for this interest in the IPB, which forms part of the Hercynian orogenic belt, is that its Late Devonian to Middle Carboniferous rocks host a huge quantity of volcanic-hosted massive sulphide (VMS) mineralization (1700 Mt of sulphides, totalling 14.6 Mt Cu, 13.0 Mt Pb, 34.9 Mt Zn, 46100 t Ag and 880 t Au). The mineralization and its environment display a number of typical signatures that can be related to the mineralogy and zoning of the sulphide orebodies, to the lead isotopes of the mineralization, to the geochemical and mineralogical variations in the hydrothermal alteration halos surrounding the orebodies, to the geochemical characteristics of the bimodal volcanics hosting the VMS, to the complex structural evolution during the Hercynian orogeny, to the presence of palaeofaults and synsedimentary structures that acted as channels and discharge traps for the metalliferous fluids, and to the gossans developed over VMS. Discriminant geological criteria have been deduced for each domain which can be helpful in mineral exploration, complementing the more traditional prospecting techniques. Although the question of the IPB's geodynamic setting is still under debate, any interpretation must now take into account some incontrovertible constraints: for example, the geochemical characteristics of a large part of the basic lavas are comparable to those of mantle-derived basalts emplaced in extensional tectonic settings, and the associated acidic rocks were produced by melting of a basic crustal protolith at low- to medium-pressures and a steep geothermal gradient, thus, the sulphide-bearing volcano-sedimentary sequence differs strongly from recent arc-related series. It is considered here that the tectonic setting was extensional and epicontinental and that it developed during the Hercynian plate convergence, that culminated in thin-skinned deformation and accretion of the South Portuguese terrane to the Iberian Paleozoic continental block.

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Resumen (translated by E. Pascual) Durante la década pasada, la Faja Pirítica Ibérica (FPI) ha sido un área de actividad minera e investigación cientifica renovadas, lo que ha conducido a la obtención de nuevos datos y conceptos geológicos y metalogénicos, que se exponen sucintamente en este Número Especial. La razón de este interés en la FPI, que forma parte del cinturón orogénico hercínico, es que sus rocas, cuyas edades abarcan desde el Devónico tardío al Carbonífero Medio, albergan una enorme cantidad de mineralizaciones de sulfuros masivos ligados a vulcanismo (1700 millones de toneladas de sulfuros, que totalizan 14,6 Mt de Cu, 13,0 Mt de Pb, 34,9 Mt de Zn, 46100 toneladas de Ag y 880 toneladas de Au). Las mineralizaciones y su entorno muestran signaturas que se pueden relacionar con la mineralogía y la zonación de las masas de sulfuros, con los isótopos de plomo de la mineralización, con las variaciones en los halos de alteración hidrotermal alrededor de las mineralizaciones, con los caracteres geoquímicos de las rocas volcánicas bimodales que albergan los sulfuros masivos, con la compleja evolución tectónica del conjunto durante la orogenia hercínica, con la existencia de paleofallas y estructuras sinsedimentarias que actuaron como canales y trampas de descarga para los fluidos metalíferos y los gossans que se desarrollaron sobre los sulfuros. Se han deducido criterios geológicos discriminantes para cada área de conocimiento, que pueden ser útiles para la exploración minera, complementando las técnicas más tradicionales de prospección. Aunque la cuestión del entorno geodinámico de la FPI todavía es materia de debate, cualquier interpretación tiene que tener ahora en cuenta algunas restricciones incontrovertibles: por ejemplo, los caracteres geoquímicos de una gran parte de las rocas básicas son comparables a los de basaltos derivados del manto y emplazados en entornos tectónicos extensionales, y las rocas ácidas asociadas se produjeron a partir de un protolito cortical básico, a presiones bajas o intermedias y asociadas a un abrupto gradiente térmico. Por consiguiente, la secuencia vulcanosedimentaria que contiene los sulfuros masivos difiere claramente de las series recientes relacionadas con entornos de arco. Consideramos aquí que el entorno tectónico fue extensional y epicontinental y que tuvo lugar durante la convergencia de placas hercínica, que culminó en deformación “thin-skinned” y acreción del terreno constituído por la Zona Sudportuguesa al bloque continental paleozoico ibérico.

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Received: 4 April 1996 / Accepted: 10 April 1997     

Geology and genesis of the Aznalcóllar massive sulphide deposits, Iberian Pyrite Belt, Spain

The Aznalcóllar mining district is located on the eastern edge of the Iberian Pyrite Belt (IPB) containing complex geologic features that may help to understand the geology and metallogeny of the whole IPB. The district includes several ore deposits with total reserves of up to 130 Mt of massive sulphides. Average grades are approximately 3.6% Zn, 2% Pb, 0.4% Cu and 65?ppm Ag. Mined Cu-rich stockwork mineralizations consist of 30?Mt with an average grade of 0.6% Cu. Outcropping lithologies in the Aznalcóllar district include detrital and volcanic rocks of the three main stratigraphic units identified in the IPB: Phyllite-Quartzite Group (PQ), Volcano-Sedimentary Complex (VSC) and Culm Group. Two sequences can be distinguished within the VSC. The Southern sequence (SS) is mainly detritic and includes unusual features, such as basaltic pillow-lavas and shallow-water limestone levels, the latter located in its uppermost part. In contrast, the Aznalcóllar-Los Frailes sequence (AFS) contains abundant volcanics, related to the two main felsic volcanic episodies in the IPB. These distinct stratigraphic features each show a different palaegeographic evolution during Upper Devonian and Lower Carboniferous. Massive sulphides occur in association with black shales overlying the first felsic volcanic package (V_A1) Palynomorph data obtained from this black shale horizon indicate a Strunian age for massive sulphides, and consequently an Upper Devonian age for the V_A1 cycle. Field and textural relationships of volcanics suggest an evolution from a subaerial pyroclastic environment (V_A1) to hydroclastic subvolcanic conditions for the V_A2. This evolution can be related to compartmentalizing and increasing depth of the sedimentary basin, which may also be inferred from changes in the associated sediments, including black shales and massive sulphides. Despite changes in the character of volcanism, the same dacitic to rhyolitic composition is found in both pyroclastic and subvolcanic igneous series. The main igneous process controlling chemical variation of volcanics is fractional crystallization of plagioclase (+accessories). This process took place in shallow, sub-surface reservoirs giving rise to a compositional range of rocks that covers the total variation range of felsic rocks in the IPB. The Hercynian orogeny produced a complex structural evolution with a major, ductile deformation phase (F₁), and development of folds that evolved to thrusts by short flank lamination. These thrusts caused tectonic repetition of massive and stockwork orebodies. In Aznalcóllar, some of the stockwork mineralization overthrusts massive sulphides. These structures are cut by large brittle overthrusts and by late wrench faults. The original geometric features of massive sulphide deposits correspond to large blankets with very variable thicknesses (10 to 100?m), systematically associated with stockworks. Footwall rock alteration exhibits a zonation, with an inner chloritic zone and a peripheral sericitic zone. Silicification, sulphidization and carbonatization processes also occur. Hydrothermal alteration is considered a multi-stage process, geochemically characterized by Fe, Mg and Co enrichment and intense leaching of alkalies and Ca. REE, Zr, Y and Hf are also mobilized in the inner chloritic zones. Three ore types occur, both in stockworks and massive sulphides, named pyritic, polymetallic and Cu-pyritic. Of these, Cu-pyritic is more common in stockworks, whereas polymetallic is prevalent in massive sulphides. Zoning of sulphide masses roughly sketches a typical VHMS pattern, but many alternating polymetallic and barren pyritic zones are probably related to tectonics. Although the paragenesis is complex, several successive mineral associations can be distinguished, namely: framboidal pyritic, high-temperature pyritic (300?°C), colloform pyritic, polymetallic and a late, Cu-rich high-temperature association (350?°C). Fluid inclusion data suggest that hydrothermal fluids changed continuously in temperature and salinity, both in time and space. Highest Th and salinities correspond to inner stockworks zones and later fluids. Statistic population analysis of fluid inclusion data points to three stages of hydrothermal activity, at low (<200?°C), intermediate (200–300?°C) and high temperatures (300–400?°C). ³⁴S values in massive sulphides are lower than in stockwork mineralization suggesting a moderate bacterial activity, favoured by the euxinoid environment prevailing during black shale deposition. The intimate relation between massive sulphides and black shales points to an origin of massive sulphides by precipitation and replacement within black shale sediments. These would have acted both as physical and chemical barriers during sulphide deposition. Hydrothermal activity started during black shale deposition, triggered by a rise in thermal gradient due to the ascent of basic magmas. We suggest a three-stage genetic model: (1) low temperature, diffuse fluid flow, producing pyrite-bearing lenses and disseminations interbedded with black shales; locally, channelized high-T fluid flow occurs; (2) hydrothermal cyclic activity at a low to intermediate temperature, producing most of the pyritic and polymetallic ores, and (3) a late high-temperature phase, yielding Cu-rich and Bi-bearing mineralization, mainly in the stockwork zone.