The endemic halophyte Sarcocornia carinata Fuente, Rufo & Sánchez-Mata (Chenopodiaceae) in relation to environmental variables: elemental composition and biominerals.

Aims We propose a thorough study of the succulent halophyte Sarcocornia carinata endemic to the saline lagoons of the center of the Iberian Peninsula. We describe its elemental composition and possible seasonal variation in relation to edaphic and climatic variables, identify biominerals and analyze the distribution of salt ions and biominerals in tissue. Methods Plants and edaphic samples were collected in the four seasons of 1 year. Soils were analyzed for their pH, EC, color, and bioavailable concentration of Na+, K+, Mg2+, Ca2+, Cl−, SO42−. Soils and plants were analyzed for their total elemental and mineralogical composition. The distribution of elements and minerals in tissues was studied by scanning electron microscopy. Results Despite the variations observed in the edaphic and climatic variables, the variables studied in the plants varied slightly throughout the year. In the plants, Mg was the element that reflected climatic changes the most, while the K and Ca concentrations did not vary. Salty precipitates and crystallizations were distributed mainly in the epidermis, water storage parenchyma, cortex, and vascular vessels. Several crystals observed were compatible with halite, gypsum, glushinskite and weddellite. Conclusions The study corroborates that inland S. carinata behaves in the same way as other littoral succulent euhalophytes and reinforces the hypothesis that the concentration of elements and quantitative abundance pattern depend largely on the main adaptation mechanisms of halophytes.pre-print374 K

Arthrocaulon meridionalis (Chenopodiaceae), a new species of Mediterranean flora.

A new species of Arthrocaulon Piirainen & G. Kadereit, A. meridionalis is described. This diploid taxon is known from the islands of Sicily and Sardinia and from circum-Mediterranean territories (from North Africa to the Anatolian Peninsula in Turkey and as far as the Persian Gulf on the Asian continent). The distinctive macro-, micromorphological and chorological features of this taxon are given.post-print1.31 M

Screening risk assessment tools for assessing the environmental impact in an abandoned pyritic mine in Spain

This is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Science of the Total Environment 409.4 (2011): 692-703 http://dx.doi.org/10.1016/j.scitotenv.2010.10.056This paper describes a new methodology for assessing site-specific environmental impact of contaminants. The proposed method integrates traditional risk assessment approaches with real and variable environmental characteristics at a local scale. Environmental impact on selected receptors was classified for each environmental compartment into 5 categories derived from the whole (chronic and acute) risk assessment using 8 risk levels. Risk levels were established according to three hazard quotients (HQs) which represented the ratio of exposure to acute and chronic toxicity values. This tool allowed integrating in only one impact category all the elements involved in the standard risk assessment. The methodology was applied to an abandoned metal mine in Spain, where high levels of As, Cd, Zn and Cu were detected. Risk affecting potential receptors such as aquatic and soil organisms and terrestrial vertebrates were assessed. Whole results showed that impact to the ecosystem is likely high and further investigation or remedial actions are necessary. Some proposals to refine the risk assessment for a more realistic diagnostic are included.This work has been financed by Madrid Community through EIADES Project S-505/AMB/0296, and by Spanish MinistryfEducation and Science, project CTM-2007-66401-CO2/TECN

Caracterización de las fitocenosis del Río Tinto: biodiversidad y aplicaciones biotecnológicas

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 02-04-200

Iron absorption, localization, and biomineralization of Cynodon dactylon, a perennial grass from the Río Tinto basin (SW Iberian Peninsula)

Cynodon dactylon (L.) Pers. is a perennial rhizomatous grass (Poaceae), grown for cattle nutrition on the riverbanks of Río Tinto (Southwest Iberian Peninsula, Spain), a highly acidic area with high concentrations of iron (Fe) and other metals. This study focuses on the absorption, distribution, and accumulation of Fe in the root, rhizome, and leaves of C. dactylon under controlled conditions. Plants collected from Río Tinto were grown in a Hoagland solution containing 500 mgkg-1 of ferrous Fe. Samples were collected up to 2 months after exposure and analyzed for total Fe concentration using inductively coupled plasma-mass spectrometry (ICP-MS) and for Fe distribution and bioformations by scanning electron microscopy (SEM) with an energy-dispersive x-ray analyzer (EDX). The results show high concentrations of Fe in all plant organs, with fast Fe translocation from roots to leaves. Iron bioformations composed mainly of Fe, S, and K were detected in all plant organs and were especially apparent in roots and leaves. These results differ from those reported for another species of Poaceae, Imperata cylindrica, which grows under the same environmental conditions, suggesting the existence of different resistance strategies between species of the same family. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Spanish Ministerio de Educacióny Ciencia ( CGL2009-11059); Spanish Ministerio de Ciencia e Innovación (CTM2007-63795)Peer Reviewe

Surface geochemistry of soils associated to the Tinto River (Huelva, Spain)

5 pages, 2 figures, 1 table.The Tinto River (Iberian Pyritic Belt) is a unique ecosystem characterized by extreme acidity and abnormally high concentrations of heavy metals in water, sediments and alluvium, with high microbial diversity and low plant diversity. The low pH value, a direct consequence of the high amount of Fe and S derived from the bedrock, promotes the dispersion of heavy metals. Less mobile elements (Fe, As, Pb, Ag and Ti) show the highest concentrations in the mid stretches of the river while easily mobile metals (Cu, Zn and Cd) accumulate in the estuarine sediments. Tinto River soils show a scarcity of nutrients (Ca, K, P, Mg and Na) due to the lack of lithologic sources and to loss by acid washing. Sea water and phospho-gypsum deposits near Huelva contribute to increase the Na, Mg and P concentrations in the estuarine soils. As a whole these features represent an extreme habitat to which plants must adapt.Grant CGL2006-02534/BOS from the Spanish Ministerio de Educación y Ciencia is acknowledged. L.R. is a fellow from the Comunidad Autónoma De Madrid.Peer reviewe

Heavy metal content in Erica andevalensis: An endemic plant from the extreme acidic environment of Tinto river and its soils

15 pages.-- ISI Article Identifier: 000243170400004.The Tinto River (Huelva, Spain) constitutes a complex and singular system characterized by extreme acidity and high concentrations of iron and other metals (Cu, Co, Mn, Zn, Pb, As) of its soils and waters. Traditional mining activity and the resulting intensive deforestation have eliminated its natural vegetation. Communities of the endemic Erica andevalensis colonize the fluvial terraces of the mining areas of the Tinto River, from drier to more humid soils, reaching its optimum in the proximity of rivers and streams. Concentrations of 22 (S, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Pb, Sr, Cr, Na, Mg, Al, Sc, Ti, Rb, Cd, Ba, Hg) elements have been determined for soils and E. andevalensis specimens at several points near the origin of the river. Erica andevalensis shows a remarkable capacity to survive with meager quantities of nutrients and an extraordinary tolerance to high concentrations of heavy metals. However, this heath does not show a lack of nutrients (Ca: 2012-5942 ppm; K: 223-3771 ppm; Mg: 883-2566 ppm) nor an excess of metals in its tissues (Fe: 73-514 ppm; Cu: 9-16 ppm; Co: ND-2 ppm). These abilities make E. andevalensis an ideal candidate for revegetation of mining areas and phytostabilization of heavy metal contaminated soils. These characteristics together with the exclusive extreme habitat on which E. andevalensis grows, make it possible to classify it as a metal bioindicator, e.g., for Cu.Peer reviewe

Streptanthus purpureus spec. nova (Cruciferae), an endemic nickel hyperaccumulator from Sierra Nevada (California, USA)

The genus Streptanthus Nutt. is one of the most important indicators of ultramafic floras in western North America. This genus contains taxa that are endemic or tolerant of ultramafic soils. Streptanthus polygaloides is an annual nickel hyperaccumulator strictly confined to ultramafic soils throughout the Californian Sierra Nevada foothills. Nickel concentration in S. polygaloides populations was evaluated by elemental microanalysis using inductively coupled plasma mass spectrometry (ICP-MS). Representative samples of S. polygaloides roots, stems, leaves, flowers, and fruits were studied by scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray probe (SEM-EDX). Results show Ni accumulation values between 0.09 and 1.18 %, and a distribution pattern similar to that observed in other Ni hyperaccumulator taxa, with the leaf epidermis accumulating the largest concentrations.Ministry of Education and Science (Spanish Government), Centro de Biología Molecular Severo Ochoa (CBMSO); Centro de Astrobiología; Complutense University in Madrid (UCM); University of California (UC)Peer Reviewe

An Improved Semiquantitative Method for Elemental Analysis of Plants Using Inductive Coupled Plasma Mass Spectrometry

A semiquantitative ICP-MS method suitable for evaluating metal content in plants exposed to high metal concentrations is described. The methodology which has been tested using different plant reference material is able, in only a few minutes, to obtain qualitative and quantitative information from the sample. Recoveries close to 100% were obtained for more than half of the referenced elements with an RSD <10%, thus avoiding the generation of a calibration line for each of the elements to be analyzed. The use of multi-standards improves the results obtained with conventional standards by a factor of two. In these conditions the semiquantitative multi-elemental analysis is a valid alternative for most of the analyzed elements with the exception of Si, Al, and P which requires the use of a quantitative ICP-MS analysis for its determination. Two different digestion protocols were tested, with and without the addition of HF to the HNO3 + H2O2 extraction mixture. Similar results were obtained for poplar and bush reference materials using the HNO3 + H2O2 mixture. The addition of HF did not improve the recovery of different elements, in general, but is critical for the quantitative measurements of Al and Si as its presence allows results to be obtained with an RDS <5%.Peer reviewe