23 results on '"Otero, X. L."'
Search Results
2. Characterizing Humic Substances from Estuarine Soils and Sediments by Excitation-Emission Matrix Spectroscopy and Parallel Factor Analysis
- Author
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Santín, C., Yamashita, Y., Otero, X. L., Álvarez, M. Á., and Jaffé, R.
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- 2009
- Full Text
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3. Phosphorus geochemistry in a Brazilian semiarid mangrove soil affected by shrimp farm effluents
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Nóbrega, G. N., Otero, X. L., Macías, F., and Ferreira, T. O.
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- 2014
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4. Sand as a relevant fraction in geochemical studies in intertidal environments
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Otero, X. L., Huerta-Díaz, M. A., De La Peña, S., and Ferreira, T. O.
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- 2013
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5. Cover loss in a seagrass Posidonia oceanica meadow accelerates soil organic matter turnover and alters soil prokaryotic communities
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Piñeiro-Juncal, N., Kaal, J., Moreira, J. C.F., Martínez Cortizas, A., Lambais, M. R., Otero, X. L., Mateo, Miguel A., Piñeiro-Juncal, N., Kaal, J., Moreira, J. C.F., Martínez Cortizas, A., Lambais, M. R., Otero, X. L., and Mateo, Miguel A.
- Abstract
© 2020 Elsevier Ltd Carbon stocks in coastal vegetated ecosystems account for half of the carbon in marine sediments and soils. Disturbance in these ecosystems can release vast amounts of carbon through mineralization, depending on poorly understood factors, such as soil organic matter (SOM) quality and environmental factors. The meadows of the seagrass Posidonia oceanica, which is the species with the larger carbon stocks, are currently under threat. The aim of this study was to determine the impact of cover loss on the SOM and microbial community composition in a P. oceanica meadow. For this purpose, soil cores were taken in dead, degraded and healthy areas in the same meadow. Cores were analyzed for total, inorganic and organic carbon and nitrogen contents, as well as for molecular SOM composition by analytical pyrolysis (fraction). Bacteria and archaea communities were assessed by 16S rRNA gene metabarcoding. The results showed the mineralization of polysaccharides and guaiacyl and syringyl lignin and a selective preservation of p-hydroxybenzoic acid moieties and methylene chain compounds. Soil depth and plant cover showed significant effects on microbial richness and diversity. Spatial variations in SOM inputs and microbial community composition between cores highlighted the importance of intra-meadow variability. Cover loss resulted in a release of soil organic carbon (1.8 fold decrease) and the boost of archaeal communities in the rhizosphere, whereas no effect was found in deeper layers. Our study demonstrates that seagrass cover loss enhances SOM mineralization and highlights the importance of soil stabilization against erosion to avoid the release of millenary SOM stocks.
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- 2021
6. Iron and sulfur geochemistry in semi-arid mangrove soils (Ceará, Brazil) in relation to seasonal changes and shrimp farming effluents
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Nóbrega, G. N., Ferreira, T. O., Romero, R. E., Marques, A. G. B., and Otero, X. L.
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- 2013
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7. Relationships between Vegetation and Environmental Characteristics in a Salt-Marsh System on the Coast of Northwest Spain
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Sánchez, J. M., Otero, X. L., and Izco, J.
- Published
- 1998
8. Natural and Anthropogenic Variations in the Large Shifting Dune in the Corrubedo Natural Park, NW Iberian Peninsula (1956–2017)
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Pérez-Alberti, Augusto, primary, Gómez-Pazo, Alejandro, additional, and Otero, X. L., additional
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- 2020
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9. Contribution of GIS and Geochemical Proxies to Improving Habitat Identification and Delimitation for the Natura 2000 Network: The Case of Coastal Lagoons in Galicia (NW Iberian Peninsula)
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Gómez-Pazo, Alejandro, primary, Pérez-Alberti, Augusto, additional, Fraga-Santiago, Pedro, additional, Souto-Souto, Martin, additional, and Otero, X. L., additional
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- 2020
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10. Natural and Anthropogenic Variations in the Large Shifting Dune in the Corrubedo Natural Park, NW Iberian Peninsula (1956–2017).
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Pérez-Alberti, Augusto, Gómez-Pazo, Alejandro, and Otero, X. L.
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OPTICAL radar ,LIDAR ,SAND dunes ,NATURAL numbers ,COASTAL zone management ,ENVIRONMENTAL management - Abstract
This work analyzes the evolution of the large shifting dune included in the Corrubedo Natural Park from 1956 until the present day. The analysis was carried out using aerial images, orthophotographs, topographic surveys and LiDAR (Light Detection and Ranging) data. Variations were analyzed in terms of four different aspects: evolution of pathways in each period, changes in the position of the mobile dune front and the degree of vegetation cover, all between 1956 and 2017; and variations in elevation and volume of the dune system between 2001 and 2015. To analyze these aspects, geospatial and geostatistical techniques were employed, which revealed that the dune front had undergone two different phases: one until the 1980s, with a mean seaward advance of 32 m and another one between the 1980 s and 2017, when the front prograded to the continent, with an approximate mean advance of 82 m. Loss of volume, related to the expansion of the mobile dune towards the north, was confirmed in this sector. It is evident that these changes are closely linked to anthropic influence, due to sand extraction until the early 1990s and, more recently, due to an increase in the number of visitors to the Natural Park. The results obtained highlight the need to carry out detailed studies to understand the evolution of this system and to prevent further damage in the future. Moreover, based on these analyses, a strategy to improve coastal and environmental management in the Corrubedo Natural Park could be designed. [ABSTRACT FROM AUTHOR]
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- 2021
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11. Edaphic factors controlling summer (rainy season) greenhouse gas emissions (CO2 and CH4) from semiarid mangrove soils (NE-Brazil)
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NOBREGA, G. N., FERREIRA, T. O., SIQUEIRA NETO, M., QUEIROZ, H. M., ARTUR, A. G., MENDONÇA, E. deS., SILVA, E. de O., OTERO, X. L., Gabriel N. Nóbrega, Escola Superior de Agricultura Luiz de Queiroz - Departamento de Ciência do Solo, Tiago O. Ferreira, Escola Superior de Agricultura Luiz de Queiroz - Departamento de Ciência do Solo, M. Siqueira Neto, Centro de Energia Nuclear na Agricultura - Laboratório de Biogeoquímica Ambiental, Hermano M. Queiroz, Universidade Federal do Ceará - Departamento de Ciência do Solo, Adriana G. Artur, Universidade Federal do Ceará - Departamento de Ciência do Solo, Eduardo De S. Mendonça, Universidade Federal do Espírito Santo - Departamento de Produção Vegetal, EBENEZER DE OLIVEIRA SILVA, CNPAT, and Xosé L. Otero, Universidade de Santiago de Compostela - Departamento Edafoloxía e Química Agrícola.
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BLUE CARBON ,methane ,carbon dioxide ,Coastal wetland soils ,soil organic matter - Published
- 2015
12. Selective geochemistry of iron in mangrove soils in a semiarid tropical climate: effects of the burrowing activity of the crabs Ucides cordatus and Uca maracoani
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Araújo Júnior, J. M. C., Otero, X. L., Marques, A. G. B., Nóbrega, G. N., Silva, J. R. F., and Ferreira, T. O.
- Abstract
Bioturbation by crabs may affect processes associated with organic matter decomposition in mangrove soils. This study examines how two crabs (Uca maracoani and Ucides cordatus), which are of substantial ecological and economic importance in semiarid coastal areas of Brazil, affect biogeochemical processes in mangrove soils. For this purpose, the physicochemical and geochemical parameters of the soils at different sites were analyzed. The redox potential was always positive at bioturbated sites (+12 to +218 mV), indicating more oxidizing conditions conducive to the oxidation of pyrite and precipitation of oxyhydroxides. In contrast, anoxic conditions prevailed at the control site (Eh
- Published
- 2012
13. 11 Millones de años de ciclos de biostaxia-resistaxia en la cuenca oligoceno-miocénica de As Pontes en Galicia
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Macías-García, I., Pérez Alberti, A., Martínez Cortizas, A., Nieto, C., Pérez Otero, X. L., Monterroso, M. C., García González, M. T., Valle, R., FELIPE MACIAS, and Fundación Endesa
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Lignito ,Paleosoles ,Oligoceno ,Siderite ,Mioceno ,Oligocene ,Gleisols ,Miocene ,Paleosols ,Plinthosols ,Siderita ,Gleisoles ,Plinthosoles ,Histosols ,Lignite ,Histosoles - Abstract
[ES] La apertura de la mina de lignitos de As Pontes, prácticamente hasta su base, ha permitido estudiar con detalle la naturaleza y procesos de formación de un yacimiento Oligoceno-Miocénico con hasta 500 m de depósitos sedimentarios producidos durante unos 10-11 millones de años. El yacimiento está caracterizado por la alternancia de capas de carbón (lignitos, fundamentalmente lignito pardo) separadas por capas de sedimentos detríticos de textura variada. Dentro de esta secuencia se ha podido comprobar que la formación del carbón se ha producido mayoritariamente en un ambiente pantanoso, con vegetación dominada por géneros como Thypha y Juncus, que se desarrollaron en suelos hidromorfos, fundamentalmente Gleisoles e Histosoles. En condiciones de pH próximas a la neutralidad y ambiente anóxico-subóxico en el que el Fe se reduce al estado ferroso, dando origen a la formación de nódulos y concreciones de siderita y sulfuros biogénicos. La siderita, aparece claramente asociada a la rizosfera de macrófi tos acuáticos dentro de antiguos horizontes gleicos, con segregación y movilización de Fe (Bg y Cg o Cr) teniendo la respiración de las raíces una clara relación con la formación del mineral. Estos suelos tenían horizontes superfi ciales muy ricos en materia orgánica (H Hísticos o A móllicos o úmbricos) que, posteriormente fueron fosilizados por aportes torrenciales ricos en materiales caoliníticos derivados de suelos bien drenados (probablemente suelos ferralíticos) del entorno de la cuenca. La fosilización y posterior subsidencia de los suelos hidromorfos dio origen a la conversión de los horizontes superfi ciales en las capas de carbón y a la compactación de los materiales. Posteriormente, el material torrencial de cobertura fue edafi zado de nuevo con mayor o menor intensidad y duración. En los sistemas laterales de los depósitos aluvio-torrenciales se han identifi cado Plinthosoles, suelos rojos fermonosialíticos muy evolucionados y corazas lateríticas, lo que pone de manifi esto la variedad de condiciones de evolución edáfi ca y climática que tuvieron lugar. La alternancia de condiciones de biostaxia (formación de suelos en condiciones hidromorfas en la cuenca y de buen drenaje en los taludes laterales) y de resistaxia (erosión, aportes aluvio-torrenciales y fosilización de los suelos) debió responder a cambios climáticos (probablemente oscilaciones de períodos húmedos a otros con mayor aridez o con estación seca muy contrastada). Se han identifi cado claramente dos grandes fases evolutivas. Una, inicial, de muy probable infl uencia marina, y con posibles suelos de manglar o marisma, con neoformación de arcillas esmectíticas, y, otra, claramente continental, con arcillas caoliníticas y suelos de tipo Histosol, Gleisol y suelos gleicos incipientes, que fueron fosilizados sucesivamente. Más de 30 ciclos de edafogénesis y fosilización se han sucedido en los 10-11 millones de años de evolución de la cuenca durante la formación de los lignitos terciarios, explicándose esta enorme variabilidad por las condiciones de la cuenca con fallas activas alpinas, creación del relieve por efectos de levantamientos y hundimientos y los cambios climáticos del Oligoceno-Mioceno, especialmente en la distribución de las precipitaciones. La repetición de esta alternancia ha originado una secuencia de paleosuelos oligocénicos y miocénicos superpuestos, claramente identifi cables por los rasgos edáfi cos, la mineralogía de sus componentes y la presencia de rizosferas carbonizadas y piritizadas. Los efectos tectónicos, la subsidencia de la cuenca y las consecuencias del proceso de explotación minera, con su modifi cación de las condiciones hídricas y del estado redox, han incrementado la complejidad de la secuencia evolutiva y la difi cultad para interpretar los procesos edáfi cos y geoquímicos que se sucedieron., [EN] The excavation of the lignite mine of As Pontes, almost to its base, allowed to sample and study in detail the nature and process of formation of an Oligocene-Miocene lignite deposit with up to 500 m of sedimentary material, produced in a time span of 10-11 million years. The site is characterized by alternating layers of coal (lignite) and detrital sediments of varied texture. Within the sequence the process of coal formation seems to have occurred mostly in a swampy environment, with vegetation dominated by Juncus and Thypha, that developed on hydromorphic soils, mainly Gleysols and Histosols. At a pH close to neutrality and under anoxic-suboxic conditions, Fe was reduced to ferrous state, leading to the formation of nodules and concretions of siderite and biogenic sulfi des. Siderite, is clearly associated to the rhizosphere of aquatic plants in gleyic soil horizons, with segregation and mobilization of Fe, being root respiration clearly related to the formation of the mineral. These soils had surface horizons rich in organic matter (H o A) which were later fossilized by fl uvial-torrential sediments derived from soils and saprolites of kaolinitic soils formed in well-drained conditions (probably lateritic soils) at the margins of the basin. Fossilization and subsequent subsidence of the hydromorphic soils led to the transformation of surface horizons into lignite and the compaction of the materials. Afterthat, the new sediments underwent pedogenesis with varying intensity and duration. In the systems at the margins of basin Plinthosols, fermonosialithic red soils highly evolved and lateritic crusts were found, which highlights the variety of soil conditions and climate evolution that occurred. Alternating conditions of biostaxy (formation of hydromorphic soils in the watershed and well drained, kaolinitic soils in the slopes) and rhesistaxy (erosion, alluvium-torrential sedimentation and fossilization of soils) may be responded to climatic change (probably between wet periods and others more arid or with intense seasonality). Two evolutionary phases have been clear identifi ed. A initial one, most likely with marine infl uence, and potential mangrove soils or marsh with an abundance of neoformation of smectite clays, and a later one, clearly continental, with kaolinitic clays and Histosols and gleyic soils in the basin and kaolinitic soils in the well drained areas of the margin of the basin. More than 30 cycles of pedogenesis and fossilization have occurred in the 10-11 million years of evolution of the basin during the formation of tertiary lignites, pointing to a huge variability in the soil forming conditions. The repetition of this alternation led to a sequence of Oligocene and Miocene paleosols, clearly identifi able by soil characteristics, mineralogy of its components and the presence of charred and pyritized rhizospheres. Tectonic movements, the subsidence of the basin and the consequences of the mining operations and its modifi cations of the hydric and redox conditions have increased the complexity and the interpretation of the pedogenetical and geochemical evolution of the basin soils., Los autores quieren mostrar su agradecimiento a la empresa ENDESA por su financiación de numerosos proyectos ambientales, prácticamente ininterrumpidos desde 1980 hasta la actualidad, sobre la recuperación de la escombrera, los impactos de la central térmica sobre la cuenca del Eume y los suelos de Galicia, las Cargas críticas de acidez y metales pesados, la modelización geoquímica de las aguas de llenado del hueco final y la recuperación de la información científica de la cuenca y de su información edafológica y geoquímica, entre otros proyectos. Asimismo agradecemos a Francisco Arechaga, Director de la mina, y a Aníbal Gil, Jefe del Servicio de Restauración, su autorización, conocimientos, amistad y ayuda, en todos los sentidos y durante muchos años, sin la cual ni éste ni los sucesivos trabajos derivados habrían sido posibles
- Published
- 2007
14. Soil genesis on hypersaline tidal flats (apicum ecosystem) in a tropical semi-arid estuary (Ceará, Brazil)
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Albuquerque, A. G. B. M., primary, Ferreira, T. O., additional, Nóbrega, G. N., additional, Romero, R. E., additional, Júnior, V. S. Souza, additional, Meireles, A. J. A., additional, and Otero, X. L., additional
- Published
- 2014
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15. Soil genesis on hypersaline tidal flats (apicumecosystem) in a tropical semi-arid estuary (Ceará, Brazil)
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Albuquerque, A. G. B. M., Ferreira, T. O., Nóbrega, G. N., Romero, R. E., Júnior, V. S. Souza, Meireles, A. J. A., and Otero, X. L.
- Abstract
Wetland soils, especially those under a semi-arid climate, are among the least studied soils in the tropics. The hypersaline tidal flats on the north-eastern Brazilian coast, locally named apicum, are coastal wetland ecosystems in the peripheral portions of semi-arid estuaries. Despite their great ecological importance, they have been highly impacted by anthropogenic activities. Morphological and analytical data of six soil profiles, representative of the different coastal compartments (mangroves, apicum and coastal tablelands) of the north-eastern Brazilian coast, were examined to better understand the pedogenesis of apicum soils. The hypersaline tidal flat soils were classified as Typic Fluvaquents and Typic Sulfaquents with the following main characteristics: predominance of sand fraction (62–77%); presence of high-activity clays (>24cmolckg-1 clay); clay fraction comprising kaolinite, illite, smectite and an interstratified smectite/illite; exchangeable complex dominated by Na+ (ESP ≥15%); elevated levels of salinity (electrical conductivity, EC 25–44dSm-1); alkaline pH values (7.5–9.5). The sandy texture and quartz-dominated composition of the hypersaline, tidal flat soils indicate a pedogenesis associated with the superficial addition of mineral material. This upbuilding process would have lowered the watertable (relatively to the ground level) and decreased the flooding frequency by the tides, favouring salinisation and solonisation processes at the hypersaline tidal flats. Furthermore, the still-existing hydromorphism would have promoted the maintenance of gleisation and sulfidisation. The presence of pyrite on the hyper-saline tidal flat soils further corroborates the formation of apicum soils from/over buried mangroves.
- Published
- 2014
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16. Cover loss in a seagrass Posidonia oceanica meadow accelerates soil organic matter turnover and alters soil prokaryotic communities
- Author
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<p>SUMILEN Conselho Nacional de Desenvolvimmento Científico e Tecnológico São Paulo Research Foundation</p>, Piñeiro-Juncal, N., Kaal, J., Moreira, J. C.F., Martínez Cortizas, A., Lambais, M. R., Otero, X. L., Mateo, Miguel A., <p>SUMILEN Conselho Nacional de Desenvolvimmento Científico e Tecnológico São Paulo Research Foundation</p>, Piñeiro-Juncal, N., Kaal, J., Moreira, J. C.F., Martínez Cortizas, A., Lambais, M. R., Otero, X. L., and Mateo, Miguel A.
- Abstract
Piñeiro-Juncal, N., Kaal, J., Moreira, J. C. F., Cortizas, A. M., Lambais, M. R., Otero, X. L., & Mateo, M. A. (2021). Cover loss in a seagrass Posidonia oceanica meadow accelerates soil organic matter turnover and alters soil prokaryotic communities. Organic Geochemistry, 151, article 104140. https://doi.org/10.1016/j.orggeochem.2020.104140
17. Heavy metal geochemistry of saltmarsh soils from the Ria of Ortigueira (mafic and ultramafic areas, NW Iberian Peninsula
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Macias, F., Otero, X. L., and Huerta-Diaz, M. A.
- Subjects
GEOCHEMISTRY ,HEAVY metals ,POLLUTION - Abstract
Concentrations of Fe, Mn, Ni, Cu, Cr and Zn in their total, silicate, organic, reactive and pyrite fractions were determined in soils collected from the Ortigueira saltmarshes (Esteiro, Ladrido and Mera, NWIberian Peninsula), from sediments of the Landoi and Esteiro Rivers,and from sludge generated by a nearby dunite mine. The Esteiro saltmarsh presented clear enrichments of the four metals studied (first 10cm), especially of Ni and Cr, whose concentrations were among the highest. It is proposed that the elevated Cr and Ni levels found in theEsteiro saltmarsh were derived from recent contributions of the mine, which are partially discharged into the Landoi River. Total Cu and Zn concentrations were lower than the corresponding ones for Cr and Ni. Under suboxic conditions, Ni, Cr, Cu and Zn were mainly associatedwith the reactive fraction. Under anoxic conditions, Cu and Ni were associated mainly with the pyrite phase. Pyritic Zn and Cr concentrations were relatively low and similar in all three saltmarshes; however, where anoxic/sulfidic conditions prevailed these two metals were mainly associated with the reactive and organic fractions. [ABSTRACT FROM AUTHOR]
- Published
- 2000
18. Chemical characteristics of wildfire ash across the globe and their environmental and socio-economic implications.
- Author
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Sánchez-García C, Santín C, Neris J, Sigmund G, Otero XL, Manley J, González-Rodríguez G, Belcher CM, Cerdà A, Marcotte AL, Murphy SF, Rhoades CC, Sheridan G, Strydom T, Robichaud PR, and Doerr SH
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- Humans, Ecosystem, Water analysis, Magnesium analysis, Carbon analysis, Nitrogen, Socioeconomic Factors, Wildfires
- Abstract
The mobilisation of potentially harmful chemical constituents in wildfire ash can be a major consequence of wildfires, posing widespread societal risks. Knowledge of wildfire ash chemical composition is crucial to anticipate and mitigate these risks. Here we present a comprehensive dataset on the chemical characteristics of a wide range of wildfire ashes (42 types and a total of 148 samples) from wildfires across the globe and examine their potential societal and environmental implications. An extensive review of studies analysing chemical composition in ash was also performed to complement and compare our ash dataset. Most ashes in our dataset had an alkaline reaction (mean pH 8.8, ranging between 6 and 11.2). Important constituents of wildfire ash were organic carbon (mean: 204 g kg
-1 ), calcium, aluminium, and iron (mean: 47.9, 17.9 and 17.1 g kg-1 ). Mean nitrogen and phosphorus ranged between 1 and 25 g kg-1 , and between 0.2 and 9.9 g kg-1 , respectively. The largest concentrations of metals of concern for human and ecosystem health were observed for manganese (mean: 1488 mg kg-1 ; three ecosystems > 1000 mg kg-1 ), zinc (mean: 181 mg kg-1 ; two ecosystems > 500 mg kg-1 ) and lead (mean: 66.9 mg kg-1 ; two ecosystems > 200 mg kg-1 ). Burn severity and sampling timing were key factors influencing ash chemical characteristics like pH, carbon and nitrogen concentrations. The highest readily dissolvable fractions (as a % of ash dry weight) in water were observed for sodium (18 %) and magnesium (11.4 %). Although concentrations of elements of concern were very close to, or exceeded international contamination standards in some ashes, the actual effect of ash will depend on factors like ash loads and the dilution into environmental matrices such as water, soil and sediment. Our approach can serve as an initial methodological standardisation of wildfire ash sampling and chemical analysis protocols., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2023
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19. Seabird colonies as the main source of nutrients for the coastal ecosystems in the Atlantic Islands of Galicia National Park (NW Spain).
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De La Peña-Lastra S, Pérez-Alberti A, and Otero XL
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- Animals, Atlantic Islands, Islands, Nutrients, Parks, Recreational, Spain, Charadriiformes, Ecosystem
- Abstract
Seabirds form large colonies during the reproductive period, producing substantial changes in coastal ecosystems. The present study quantifies the amount of N and P deposited in colonies of yellow-legged gull (Larus michahellis) in the Atlantic Islands of Galicia National Park (AINP). Based on the composition of droppings, the amount of total N (TN), total P (TP) and bioavailable P (Pbio) deposited directly on the area occupied by the colony was determined. In addition, the amount of NH
3 released into the atmosphere was also estimated by applying a bioenergetic model. The results indicated that 5.35 t total N, 3.35 t total P and 1.24 t bioavailable P are deposited in the colony annually. The archipelagos that received the greatest amount of nutrients were the Cíes Islands (2.37 t TN y-1 , 1.48 t TP y-1 , 0.55 t Pbio y-1 ), Sálvora (1.94 t TN y-1 , 1.22 t TP y-1 , 0.55 t Pbio y-1 ) and Ons (1.04 t TN y-1 , 0.65 TP y-1 , 0.24 t Pbio y-1 ). Rainwater from the colonies showed higher values of nutrients than in the control plot, possibly also due to gull influence. Therefore, the yellow-legged gull colony seems to be the most important source of nutrients at a local level, exerting a clear influence on the N and P cycles in this National Park. Another aspect worth taking into consideration is that increased N and P bioavailability may have a negative effect on the conservation of rare or threatened habitats and species by promoting the expansion of non-native ruderal species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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20. The potential of a Technosol and tropical native trees for reclamation of copper-polluted soils.
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Asensio V, Flórido FG, Ruiz F, Perlatti F, Otero XL, Oliveira DP, and Ferreira TO
- Abstract
Technosols created to reclaim degraded soils is a promising solution that needs further research. The objectives of the study were: i) to create a Technosol with a very high capacity to immobilize copper from mining, ii) to assess the capacity of the Technosol to immobilize copper after planting two tropical native tree species, and iii) to analyse the capacity of the native trees for extracting copper from polluted soils. Myracrodruon urundeuva (aroeira) and Cedrela fissilis (pink cedar) were planted in pots with Technosol spiked with copper at concentrations of 125, 1525 and 3050 mg Cu kg
-1 . Height and stem diameter were measured over 90 days. Biomass and Cu concentration in leaves, stem and roots were determined. Copper was analysed in soils by sequential extraction, as well as in leached water. The Technosol showed a very high capacity to immobilize copper, since 60-80% of the added copper was strongly retained in the soil, mainly by bentonite and carbonates. The Technosol with trees showed the same capacity to immobilize copper as the control, since concentration in shoots was higher than 300 mg Cu kg-1 and concentration in roots was even higher. These results show that Technosol and both species are useful tools to immobilize copper in polluted soils. Further studies are necessary to determine the total capacity of these trees to immobilize and/or extract copper in the long term and under field conditions., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
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21. Trace elements in biodeposits and sediments from mussel culture in the Ria de Arousa (Galicia, NW Spain).
- Author
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Otero XL, Vidal-Torrado P, Calvo de Anta RM, and Macías F
- Subjects
- Animals, Arsenic analysis, Chromium analysis, Copper analysis, Industrial Waste, Iron analysis, Manganese analysis, Mercury analysis, Oxidation-Reduction, Rivers, Spain, Spectrophotometry, Ultraviolet, Tanning, Zinc analysis, Bivalvia chemistry, Environmental Monitoring methods, Geologic Sediments chemistry, Trace Elements analysis, Water Pollutants, Chemical analysis
- Abstract
The trace elements present at highest concentrations were Cr and Zn, which probably originated from the dumping of effluent from a tanning factory. High proportions of these two elements were associated with the residual fraction. Biodeposits and sediments showed high concentrations of Cd and Pb in the reactive fraction, with a high proportion of the concentration in the reactive fraction being associated with carbonates. Nickel showed a higher degree of pyritization than the previous elements, although most of the Ni was associated with the residual and reactive fractions. Arsenic, Hg and Cu showed high degrees of pyritization, particularly below a depth of 5 cm. The results demonstrate that those elements with a high degree of pyritization may be released into the water through oxidation of the metal sulphides that they form when in suspension in oxic sea water, with the subsequent risk of increased bioavailability to benthic fauna.
- Published
- 2005
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22. Heavy metal geochemistry of saltmarsh soils from the Ría of Ortigueira (mafic and ultramafic areas, NW Iberian Peninsula).
- Author
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Otero XL, Huerta-Diaz MA, and Macías F
- Abstract
Concentrations of Fe, Mn, Ni, Cu, Cr and Zn in their total, silicate, organic, reactive and pyrite fractions were determined in soils collected from the Ortigueira saltmarshes (Esteiro, Ladrido and Mera, NW Iberian Peninsula), from sediments of the Landoi and Esteiro Rivers, and from sludge generated by a nearby dunite mine. The Esteiro saltmarsh presented clear enrichments of the four metals studied (first 10 cm), especially of Ni and Cr, whose concentrations were among the highest. It is proposed that the elevated Cr and Ni levels found in the Esteiro saltmarsh were derived from recent contributions of the mine, which are partially discharged into the Landoi River. Total Cu and Zn concentrations were lower than the corresponding ones for Cr and Ni. Under suboxic conditions, Ni, Cr, Cu and Zn were mainly associated with the reactive fraction. Under anoxic conditions, Cu and Ni were associated mainly with the pyrite phase. Pyritic Zn and Cr concentrations were relatively low and similar in all three saltmarshes; however, where anoxic-sulfidic conditions prevailed these two metals were mainly associated with the reactive and organic fractions.
- Published
- 2000
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23. [Influence of incubation time in the in vitro antifungal activity of terbinafine against Trichophyton rubrum.].
- Author
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Fernández-Torres B, Pereiro M Jr, Llovo J, Otero XL, and Toribio J
- Abstract
Antifungal susceptibility tests are influenced by a number of technical variables, including inoculum size, temperature, medium formulation and duration of incubation. In this study, we have compared the in vitro susceptibility of 20 strains de Trichophyton rubrum against clotrimazole and terbinafine, and studied the influence of incubation time on MICs of both drugs. The assay was performed by agar dilution, the medium used was Saboraud glucose agar without an antibiotic. The MIC was evaluated at 15, 30 and 45 days' incubation. The MICs ranges of terbinafine were 0.002 to 0.0975 microg/ml, 0.0975 to 0.39 microg/ml and 0.195 to 0.39 microg/ml at 15, 30 and 45 days' incubation, respectively. The MICs ranges of clotrimazole at 15, 30 and 45 days' incubation were 3.125 to 50 microg/ml. T. rubrum was markedly more susceptible to terbinafine than to clotrimazole (p<0.001). In addition, we observed that an increase of incubation time causing an increase in the MIC value of terbinafine (p<0.001), but MIC values for clotrimazole remained constant with time (p=0.464). In conclusion, the MIC is dependent on reading time and the antifungal compound.
- Published
- 1998
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