News Article | November 18, 2015
Results from the seven-year study show the first evidence of eradicating the chytrid pathogen Batrachochytrium dendrobatidis (Bd) affecting amphibians in situ. Published today (18 November) in Biology Letters, the paper details the outcome of a project led by scientists from the Zoological Society of London (ZSL), the National Museum of Natural History in Spain (MNCN-CSIC), and Imperial College London. The study combined antifungal treatment of Mallorcan midwife toad (Alytes muletensis) tadpoles with environmental disinfection. By using an antifungal to treat tadpoles and a common laboratory decontaminant to sterilise the environment, researchers were able to clear infection from populations of the toad over the research period. Co-author Dr Trenton Garner, Reader within ZSL's Institute of Zoology, said: "This study represents a major breakthrough in the fight against this highly-destructive pathogen; for the first time we have managed to rid wild individuals of infection for a continued period. "Amphibian-associated chytrid fungi are a critical conservation issue that requires simple, straightforward and transferrable solutions. Our study is a significant step towards providing these." Dr Jaime Bosch, Senior Researcher at MNCN-CSIC, added: "This is the first time that chytrid has ever been successfully eliminated from a wild population - a real positive which we can take forward into further research to tackle this deadly disease. Chytrid is a global issue which affects amphibian populations worldwide, and I am proud to be part of a team of leading institutions at the forefront of this pioneering research working towards a solution." Chytrid fungal infections causing amphibian mass mortality were first identified at the end of the 20th century by a consortium of scientists, including ZSL researchers. More information: Bosch J, Sanchez-Tome E, Fernandez-Loras A, Oliver JA, Fisher MC, Garner TWJ. (2015). Successful elimination of a lethal wildlife infectious disease in nature. Biol. Lett. 20150874. dx.doi.org/10.1098/rsbl.2015.0874
Ruiz-De-Castaneda R.,MNCN |
Vela A.I.,Complutense University of Madrid |
Gonzalez-Braojos S.,MNCN |
Briones V.,Complutense University of Madrid |
Behavioural Processes | Year: 2011
Early incubation has been suggested as a defensive adaptation against potentially pathogenic bacteria colonizing avian eggshells in the wild. The inhibitory mechanisms underlying this adaptation are poorly understood and only recent experimental evidence demonstrates that keeping eggs dry is a proximate mechanism for the antimicrobial effects of avian incubation. We estimated partial incubation (the bouts of incubation that some birds perform during the egg-laying period, days of lay 3-5 in our population) intensity of female pied flycatchers breeding in nest-boxes using data loggers that allowed a precise measurement of temperature just between the eggs in the nest-cup. We also measured relative humidity within the nest-boxes and related it to incubation intensity, showing that more intense incubation during laying contributes to drying the air near the eggs. We analyzed separately the effects of incubation and of relative humidity on loads of three types of culturable bacteria known to be present on eggshells, heterotrophic bacteria, Gram-negative enterics and pseudomonads. Our results show an association of early incubation with an inhibition of bacterial proliferation through a drying effect on eggshells, as we found that incubation intensity was negatively and relative humidity positively associated with eggshell bacterial loads for heterotrophic bacteria, Gram-negative bacteria and pseudomonads, although the significance of these associations varied between bacterial groups. These results point to microclimatically driven effects of incubation on bacterial proliferation on eggshells during laying in a temperate cavity nesting passerine. © 2011 Elsevier B.V.
Pastor J.,MNCN |
Hernandez A.J.,University of Alcalá
Journal of Environmental Management | Year: 2012
This study was designed to determine the state of polluted soils in the main landfills of the Community of Madrid (central Spain), as part of a continuous assessment of the impacts of urban solid waste (USW) landfills that were capped with a layer of soil 20 years ago. Our analysis of this problem has been highly conditioned by the constant re-use of many of the USW landfills, since they have never been the target of any specific restoration plan. Our periodical analysis of cover soils and soils from discharge areas of the landfills indicates soil pollution has worsened over the years. Here, we examined heavy metal, salts, and organic compounds in soil and surface water samples taken from 15 landfills in the Madrid region. Impacts of the landfill soil covers on nematode and plant diversity were also evaluated. These analyses continue to reveal the presence of heavy metals (Zn, Cu, Cr, Ni, Pb, Cd) in soils, and salts (sulphates, chlorides and nitrates) in soils and surface waters. In addition, non-agricultural organic compounds, mainly aromatic and aliphatic hydrocarbons, often appeared in very high concentrations, and high levels of insecticides such as gamma-HCH (lindane) were also detected in soils. Around 50% of the water samples collected showed chemical demand of oxygen (CDO) values in excess of 150mg/l. Traces of phenolic compounds were detected in some landfills, some of which exhibited high levels of 2-chlorophenol and pentachlorophenol. All these factors are conditioning both the revegetation of the landfill systems and the remediation of their slopes and terrestrial ecosystems arising in their discharge areas.This work updates the current situation and discusses risks for the health of the ecosystems, humans, domestic animals and wildlife living close to these landfills. © 2011 Elsevier Ltd.
Gutierrez-Gines M.J.,University of Alcalá |
Pastor J.,MNCN |
Hernandez A.J.,University of Alcalá
Ecotoxicology | Year: 2012
This study addresses the effects of soil polluted with more than one heavy metal in a grass species. A 16-week bioassay with Avena sativa L. was conducted in microcosms using soils from two abandoned mines in central Spain that contained levels above World Health Organization (WHO) reference limits for soils of more than three heavy metals. Pollution effects were examined at cell, tissue, organ, plant and population levels. For this purpose, dry weight, maximum height and number of leaves were determined; leaf tissues were observed by low temperature scanning electron microscopy; the metal contents of roots and shoots were determined by plasma emission spectroscopy and their distribution in different tissues was analyzed by X-ray microanalysis using an environmental scanning electron microscope. The results explain the accumulation and translocation of soil metals by this plant species; their effects in cells, tissues and growth of plants; and allow inference on population effects. The discussion of the methodological approach leads us to propose a valid protocol to assess the effects of a set of heavy metals present in the topsoil of polluted sites on a plant population. We recommend its use for an ecotoxicological diagnosis and risk analysis of similarly polluted sites. © Springer Science+Business Media, LLC 2012.
Gutierrez-Gines M.J.,Science Building |
Pastor J.,MNCN |
Hernandez A.J.,Science Building
Environmental Sciences: Processes and Impacts | Year: 2013
In soil pollution studies, large numbers of soil samples collected at random need to be processed and analyzed to determine their heavy metal contents. This study was designed to assess the use of a field portable X-ray fluorescence (FPXRF) spectrometry system for the in situ determination of heavy metal levels in both soil and plant samples. First, we optimised the method using 84 reference soil standards and soil samples from known polluted sites. The optimised method was then used to determine heavy metals at three abandoned mine sites and two sealed landfills in central Spain. Given that knowledge of heavy metal levels in plants is important for the ecotoxicological study of these sites, the FPXRF device was also used to determine heavy metals in plants. Our results indicate the acceptable to high quality of the data provided by the system especially for soil samples. The cost-benefits and sustainability of this instrument in relation to other techniques were also examined. The use of the FPXRF system for the study of potentially polluted sites was found to save on costs, time and materials. Results indicate its suitable use for the preliminary screening of heavy-metal polluted sites. © 2013 The Royal Society of Chemistry.
News Article | January 12, 2016
Rombophryne ornata received its name owing to its colour and decorative features. It can be told apart from other frogs of the same genus by the reddish colour it presents. Credit: Miguel Vences The Tsaratanana Massif –the highest mountain on Madagascar and one of the island's most remote regions– is home to several indigenous species. Yet, the majority of these species remain unknown to science due to the fact that this woodland area is difficult to reach. Thanks to a European expedition to this area, however, a group of scientists has discovered, among other species, two new species of very elusive frogs that live on the forest floor. The rainforests located in the northern part of the island of Madagascar are rich in biodiversity, yet only a small number of species here are known to science. Discovering new native species is a difficult task since access to this remote zone in the Tsaratanana Massif –the highest mountain– is complicated. Here, the massif's rainforests are fragmented and threaten the species that live therein. In spite of this, a team of scientists from Germany and Spain –financed by the previous Ministry for Science and Innovation– ventured into these remote rainforests in 2010. "Those mountains are home to a high level of native species and are very rarely visited by researchers seeing as there are no roads ‑and barely any paths‑ that lead to the base," explains David Vieites to SINC, one of the authors of this study and a scientist at the National Museum of Natural Sciences in Madrid (MNCN-CSIC). As a result of the expedition the biologists found a number of species, many of which are new to science based on taxonomy criteria such as genetics, morphology and even the sounds they make. Among these new species, the study, published in the journal Herpetelogica, emphasises the discovery of two new species of frogs: Rombophryne ornata and Rombophryne tany. "Both species live on the forest floor –among the fallen leaves– and are difficult to spot," notes Vieites. Rombophryne ornata, which received its name owing to its colour and decorative features, can be told apart from other frogs of the same genus by the reddish colour it presents. It has a black mark between each eye as well as on its back, and it also presents spines located over its eye sockets. The scientists carried out a more thorough molecular analysis on Rombophryne tany since this species does not have any features that distinguish it from other species belonging to the same genus. In fact, its name tany, which means 'land' or 'ground' in the local language, not only references the frog's brownish colour, but also its tendency to spend time on the ground. This species also presents spines over each eye. Discovering this species "is another example of the great diversity of animals in tropical areas that have yet to be described before many of these areas disappear as a result of the deforestation suffered by tropical regions, especially Madagascar," says the researcher regretfully. Luckily for these two species, however, the area where they were discovered is a national park that is very difficult to access. "We hope that this area will remain pristine for a long time," concludes the expert. Explore further: A new species of nocturnal gecko from northern Madagascar More information: Mark D. Scherz et al. Two New Microhylid Frogs of the Genus Rhombophryne with Superciliary Spines from the Tsaratanana Massif in Northern Madagascar, Herpetologica (2015). DOI: 10.1655/HERPETOLOGICA-D-14-00048
Martinez-De La Puente J.,M.N.C.N. |
Merino S.,M.N.C.N. |
Tomas G.,M.N.C.N. |
Tomas G.,CSIC - Estación Experimental De Zonas Áridas |
And 6 more authors.
Biology Letters | Year: 2010
While avian chronic haemoparasite infections induce reproductive costs, infection has not previously been shown to affect survival. Here, we experimentally reduced, through medication, the intensity of infection by Haemoproteus parasites in wild-breeding female blue tits Cyanistes caeruleus. However, this treatment did not reduce the intensity of infection in males or the intensity of infection by Leucocytozoon. Medicated females, but not males, showed increased local survival until the next breeding season compared with control birds. To our knowledge, this is the first empirical evidence showing long-term direct survival costs of chronic Haemoproteus infections in wild birds. © 2010 The Royal Society.
Dorado J.,CSIC - Institute of Agricultural Sciences |
Almendros G.,MNCN |
Gonzalez-Vila F.J.,Institute Recursos Naturales y Agrobiologia IRNAS
Journal of Analytical and Applied Pyrolysis | Year: 2016
The effects on the structural features of humic acids (HA) from dryland farming soils under long term management practices have been approached by analytical pyrolysis (Curie-point pyrolysis-gas chromatography/mass spectrometry, Py-GC/MS). The field experiments (started in 1987) include conventional, minimum and no-tillage plots, as well as non cultivated plots. The HAs isolated from the various plots showed significant differences in their pyrolytic behavior, in particular regarding the total abundances of alkyl pyrolysis compounds (fatty acids, alkenes and alkanes). The occurrence of very short-chain fatty acids (C5-C11) in uncultivated plots could be indicative of constitutional alkyl structures in the relictual HA from undisturbed soil. The effect of soil tillage managements substantially increased total abundances of fatty acids in plots under conservation practices (mainly no-tillage). The HAs from uncultivated soils showed the greatest percentages of alkanes and alkenes. This was associated to the increased proportions of even C-numbered alkene homologues from C12 to C18, possibly related to the incorporation of microbial compounds during the humification process. High percentage of alkylbenzenes and catechols were also characteristic of the uncultivated plots. The increased proportions of methoxyphenols, in special of the syringyl (dimethoxyphenyl) type, in HAs from plots subjected to conventional tillage pointed out to humification processes based on progressive alteration of plant lignins. From the viewpoint of soil quality, the results suggest comparatively advanced transformation stages of the HA from uncultivated plots, which means that conservation tillage practices seems to lead to increasing soil C levels, at expenses of the accumulation of comparatively recent organic matter derived either from altered lignins and/or microbial biomass. © 2015 Elsevier B.V. All rights reserved.
Fernandez-Getino A.P.,INIA |
Hernandez Z.,MNCN |
Piedra Buena A.,MNCN |
European Journal of Soil Science | Year: 2013
Semi-quantitative data of peak intensities in infrared (IR) spectra of humic acids (HAs) from semiarid soils under contrasting environmental conditions (vegetation type, geological substrate and local climate) were analysed by multivariate data treatments. Resolution-enhanced IR spectra (applying a second derivative-based subtractive operator) showed a typical lignin pattern, which was coded to obtain an index used to classify the degree of diagenetic alteration of the lignin moiety in the HA fraction. Partial least squares regression (PLS) was used in the exploratory screening for supervised data reduction previous to other multivariate data treatments as well as to identify IR peaks responsive to soil dependent variables. Regression models and multi-dimensional scaling (MDS) were applied in order to classify individual IR peaks or sets of peaks associated with the degree of diagenetic alteration of organic matter, or inform on soils' potential for carbon (C) accumulation. Soil properties co-varying with the intensities of these peaks were mainly related to soil texture and consequently to water holding capacity at different pressures. Principal component analysis (PCA) based on the IR peaks selected in the previous PLS treatments maximized differentiation in terms of the impact of environmental factors on HA characteristics: (i) vegetation type (angiosperms or gymnosperms), (ii) the effect of the geological substrate (granite or limestone) on soil organic matter dynamics and (iii) soil taxonomical differences reflected by independent clusters. The successful forecasting of several factors related to soil C sequestration indicated the validity of the semi-quantitative information extracted from the IR spectra of the HAs and the potential of the multivariate data treatments used to identify biogeochemical proxies of the soil organic matter stabilization processes. © 2013 The Authors. Journal compilation © 2013 British Society of Soil Science.
de Blas E.,University of Vigo |
Almendros G.,MNCN |
Sanz J.,Institute Quimica Organica General
Geoderma | Year: 2013
There is little information available about the molecular composition of organic fractions with a possible bearing in soil water repellency. Extremely water-repellent forest soils developed on granites or schists, under vegetation of pine or eucalyptus, were used for sequential isolation of two lipid fractions: free lipid extracted with petroleum ether and 'bound' lipid obtained with the same solvent after 2M H3PO4 pre-treatment. Soil water repellency tests were carried out, and lipids were analyzed by gas chromatography/mass spectrometry (GC-MS). Free lipids in soils under eucalyptus consisted mainly of sesquiterpenes (globulol, aromadendrene, eudesmol and ledene) whereas soils under pine included diterpene resin acids (mainly dehydroabietic, pimaric and seco-dehydroabietic) and phenol. Free alkanes (C15 to C37) displayed homologous series typical in epicuticular waxes, whereas free fatty acids series showed bimodal distribution.'Bound' lipids consisted almost exclusively of fatty acids (mainly C16 and C18 acids), and alkanes (maximum at C27 or C28 and no even-to-odd C-number preference). Major compounds related to soil water repellency are typically found in higher plants and are not synthesized by microorganisms. After removing free lipids, soil water repellency decreased slightly but remained extreme. After extraction of bound lipids, the repellency considerably decreased, but did not disappear completely. As regards the effect of the lipid fractions in soil water repellency, it was clear the dominant role of the vegetation type in the case of free lipid, whereas for bound lipid, repellency mainly represents an emergent property arising from strong interaction between organic matter and the geological material. The results suggest that soil lipids only explain a part of the soil water repellency, which also depends on surface properties of the soil matrix, i.e., not only depends on hydrophobic coatings but probably of diffusion of hydrophobic cements into micellar associations self-organized into zonal structures in humus-clay matrix. © 2013 Elsevier B.V.