Geochemistry and mineralogy of a complex sedimentary deposit in the alkaline volcanic Lake Specchio di Venere (Pantelleria Island, south Mediterranean)

Specchio di Venere is a peculiar, ambient temperature, geothermal, alkaline lake, with lake water oversaturated in carbonate phase where siliceous stromatolites actively grow despite the undersaturation of silica phases. The most of the main sedimentary structures of this lake have been investigated in recent years, with the exception of the carbonate bank running along the south-western margin of the lake, which is the object of this study. Here we report on the mineralogical and geochemical characterisation of the carbonate bank, based on the study of two cores taken in the area mostly affected by the circulation of fluids of different origin. The ultimate results of our study suggest that silica gel deposits form inside the carbonate bank, following an Alkali-Silica Reaction. These new findings complete the general overview on the sedimentary processes acting in a Lake Specchio di Venere, whose origin is sometimes chemico-physical and sometimes strongly conditioned by microbial activity

Applying bioacoustic techniques to urban ornithology studies: guidelines and recommendations

Una de las principales maneras de comunicarse de las aves, a través de la emisión de sonidos o vocalizaciones, puede verse afectada por los sonidos derivados de las actividades antrópicas. Estos disturbios (ruidos) interfieren en la comunicación pudiendo afectar la identificación de pares, los procesos reproductivos, la defensa de los territorios e, incluso, la composición y diversidad de las comunidades de aves. Las urbanizaciones son fuente de alta emisión de ruidos antropogénicos y constituyen ambientes sonoros complejos para las aves. La bioacústica, a través del monitoreo acústico pasivo (MAP), es una de las herramientas en auge y con numerosas ventajas que resultan particularmente útiles en estudios de ecología urbana. El MAP es un método no invasivo y eficiente que permite obtener información de forma autónoma, continua, simultánea y en diversas condiciones ambientales. A pesar de esto, resulta una herramienta aún poco explotada en los países del Neotrópico. Realizamos una descripción metodológica mostrando las potencialidades del MAP en investigaciones de aves y, particularmente en aquellas que ocurren en ambientes urbanos y/o peri-urbanos. Para esto realizamos una revisión no sistemática de la bibliografía existente, resumiendo nociones básicas del sonido y su proceso de grabación, opciones de micrófonos y grabadores asociados al MAP, diseños de muestreo, programas de análisis e índices acústicos. También, presentamos ejemplos de estudios nuestros sobre el MAP en ambientes urbanos de la Patagonia. Resaltamos el valor de esta herramienta de estudio para investigaciones a largo plazo, en sitios complejos de estudiar, para programas de monitoreo y proyectos de conservación.One of the main ways birds communicate, through the emission of sounds or vocalizations, can be affected by sounds produced by human activities in urban areas. These noises or disturbances interfere with bird communication, affecting mate identification, reproductive processes, territory defense, and even bird community richness and diversity. In this way, urban areas constitute complex sound environments for birds. Bioacoustics, through passive acoustic monitoring (PAM), is a growing tool with numerous advantages especially useful for urban ecology studies. PAM is a non-invasive and effective method for obtaining information autono-mously, continuously, simultaneously and under various environmental conditions. Despite this, it is still an un-der-exploited tool in Neotropical countries. We here provide a methodological description showing the potential of PAM in bird research, particularly for birds living in urban and/or peri-urban environments. To this end, we conducted a non-systematic review of the existing literature presenting basic notions of sound and its recording process, options of microphone and recorders associated with the PAM, sampling designs, analyzes programs, and acoustic indexes. We also present examples of our research on monitoring urban environments in Patagonia. We highlight the value of this study tool for long-term research, complex study sites, monitoring programs and conservation projects.Fil: Bahia, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede Junín de Los Andes-inibioma-centro de Ecología Aplicada del Neuquén (cean) | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede Junín de Los Andes-inibioma-centro de Ecología Aplicada del Neuquén (cean).; Argentin

Carbonatites from the southern brazilian platform. A review. II. Isotopic evidences

Early and Late Cretaceous alkaline and alkaline– carbonatitic complexes from southern Brazil are located along the main tectonic lineaments of the South America Platform. Calcium-, magnesium-, and ferrocarbonatites are well represented and frequently associated even in the same complex. Primary carbonates present significant variations in C–O isotopic compositions, which are mainly due to isotope exchange with H2O–CO2-rich hydrothermal fluids, whereas fractional crystallization or liquid immiscibility probably affects the δ18O and δ13C values by no more than 2δ‰. Our isotope exchange model implies that the most significant isotopic variations took place in a hydrothermal environment, e.g., in the range 400–80°C, involving fluids with the CO2/H2O ratio ranging from 0.8 to 1. Sr–Nd–Pb isotope systematics highlight heterogeneous mixtures between HIMU and EMI mantle components, similar to the associated alkaline rocks and the flood tholeiites from southern Brazil. In spite of the strong variation shown by C–O isotopes, Sr-Nd–Pb–Os isotopic systematics could be related to an isotopically enriched source where the chemical heterogeneities reflect a depleted mantle “metasomatized” by small-volume melts and fluids rich in incompatible elements. These fluids are expected to have promoted crystallization of K-rich phases in the mantle, which produced a veined network variously enriched in LILE and LREE. The newly formed veins (enriched component) and peridotite matrix (depleted component) underwent a different isotopic evolution with time as reflected by the carbonatites. These conclusions may be extended to the whole Paraná–Etendeka system, where isotopically distinct parent magmas were generated following two main enrichment events of the subcontinental lithospheric mantle at 2.0–1.4 and 1.0–0.5 Ga, respectively, as also supported by Re–Os systematics. The mantle sources preserved the isotopic heterogeneities over a long time, suggesting a non convective lithospheric mantle beneath different cratons or intercratonic regions. Overall, the data indicate that the alkaline–carbonatitic magmatism originated from a locally heterogeneous subcontinental mantle

Carbonatites from the Southern Brazilian platform: I

We present a comprehensive overview of the geochemical characteristics and evolution of the carbo- natites from the southern Brazilian Platform (Paraná Basin). The carbonatites from dierent complexes dis- play large compositional variability in terms of abun- dances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous litho- spheric sources, as conrmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the Brazilian carbonatites, which can be summarized as following: exsolution of the primary Ca- or Mg-carbona- titic liquids systematically takes place at the phonolite- peralkaline phonolite stage of magma dierentiation; this is followed by progressive Fe-enrichment and by nal emplacement of uorocarbonatites associated with hydrothermal uids

Physiological dormancy broken by endozoochory: Austral parakeets (Enicognathus ferrugineus) as legitimate dispersers of calafate (Berberis microphylla) in the Patagonian Andes

Aims: Seed dispersal by endozoochory is an important process in plant regeneration and the establishment of new populations. Seeds with dormancy may especially benefit after disperser gut passage. However, the ways in which gut passage affect the germination of plant species with physiological dormancy remain unclear. Here, we experimentally assessed the mutualistic interaction between the Austral parakeet (Enicognathus ferrugineus) as a disperser of calafate (Berberis microphylla), a thorny bush inhabiting the understory of the Austral temperate forests of South America with seeds that are characterized by deep physiological dormancy. Methods: Germination success and viability of calafate seeds obtained from faeces and from intact fruits were tested under four treatments: (i) digested seeds, (ii) digested seeds with faecal extract, (iii) intact seeds from fruit and (iv) intact seeds from fruit with pulp. Important Findings: About 65% of the Austral parakeet droppings contained calafate seeds. Viability of seeds did not differ between treatments. However, germination was significantly higher in digested seeds than in intact seeds from fruits, while no difference was found between faecal and pulp extracts. Neither faecal matter nor fruit pulp provided seeds with any ecological advantages derived from enhancing germinability, but did confer some disadvantage in germination time. Faecal matter is expected to be completely lacking around seeds after several months under snow before germinating in the following spring, given intense washing due to persistent rain and the spring thaw in the Patagonian Andes. The higher germinability along with faster germination of digested seeds supports the hypothesis of a legitimate mutualistic interaction between Austral parakeets and calafate. We hypothesized that the passage through the disperser digestive tract might break physiological dormancy as differences in germinability between ingested and non-ingested seeds. Our results highlight the relevant role of endozoochory in plant species with physiological dormancy living in highly seasonal environments.种子由动物内携传播是植物再生和新种群建立的重要过程。具有休眠的种子经过传播者肠道传代作用后可能特别受益。然而，肠道 传代作用如何影响具有生理休眠植物的萌发尚不清楚。在本研究中，我们实验性地评估了南鹦哥(Enicognathus ferrugineus)作为小檗属植 物(Berberis microphylla)传播者的互惠共生。Berberis microphylla是一种多刺的灌木，栖息在南美洲温带森林的下层，其种子具有深度生 理休眠的特性。本研究通过四种处理：(1)种子消化处理，(2)粪便提取物消化处理，(3)果实种子完整处理和(4)包含果肉果实种子完整 处理，测定了从粪便和完整果实中提取的B. microphylla种子的发芽成功率和活力。研究结果表明，大约65%的南鹦哥的粪便中含有B. microphylla种子。不同处理的种子存活率无显著差异。然而，消化后的种子萌发率显著高于完整果实种子，而粪便和果肉提取物处理之间没有差异。粪便和果肉都没有为种子提供任何提高发芽能力的生态优势，但在萌发时间上确实造成了一些劣势。由于持续降雨和巴塔哥尼亚安第斯山脉春季融雪带来的严重冲刷，种子附近的粪便在雪下几个月后就会完全缺失。消化种子较高的发芽能力和较快的发芽速度验证了南鹦哥和B. microphylla之间具有合理互惠共生的假设。因为消化和非消化种子发芽能力的差异，我们假设通过传播者的肠道传代作用可能打破种子的生理休眠。我们的研究结果强调了在具有高度季节性的环境下，具有生理休眠的植物物种中与动物内携传播的相关作用。Fil: Bravo, Carolina. Consejo Superior de Investigaciones Científicas; España. Museo Nacional de Ciencias Naturales; EspañaFil: Chamorro, Daniel. Consejo Superior de Investigaciones Científicas; España. Universidad de Castilla-La Mancha; EspañaFil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas; España. Estación Biológica de Doñana; EspañaFil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Tella, José L.. Estación Biológica de Doñana; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Blanco, Guillermo. Consejo Superior de Investigaciones Científicas; España. Museo Nacional de Ciencias Naturales; Españ

Uncoupled evolution of male and female cone sizes in an ancient conifer lineage

Sexual functions in gymnosperms are mostly performed by separate reproductive structures, which largely reduces sexual interference and sets the scene for morphological and functional sexual specialization. The evolutionary trajectories followed by traits related to the male and female functions are therefore expected to be uncoupled. Studies on the fossil record of the conifer family Araucariaceae revealed important morphological changes occurring in reproductive cones. Here, we explored the pattern of evolution of male and female cone sizes in Araucariaceae, with a special focus on Araucaria-the most variable and widespread genus in the family. We gathered data on male and female cone sizes from fossils and extant Araucariaceae species. Focusing on Araucaria, we analyzed whether cone sizes are phylogenetically structured. Furthermore, we compared the evolutionary trajectories of male and female cone sizes by evaluating the goodness of fit of different evolutionary models. Finally, we evaluated whether different selective regimes across the phylogeny could have shaped cone morphology. Size changes in Araucariaceae occurred in both male and female cones, with the largest cones appearing in extant Araucaria. In this genus, different evolutionary models best described cone size changes, with male cone evolution best described by a model not influenced by phylogeny and female cone evolution by a stabilizing selection model with two optima. This resulted in contrasting phylogenetic signals, with female cone size being more phylogenetically structured than male cone size. Changes in cone size in Araucariaceae occurred in both male and female cones. The largest male and female cones appeared in Araucaria through uncoupled evolutionary pathways, both involving a natural selection component as a driver of evolutionary change. A contrasting pattern of phylogenetic signal in male and female cone size reflected the uncoupled evolutionary trajectories followed by these sexual structures.Fil: Gleiser, Gabriela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Tella Escobedo, José Luis. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentin

An overlooked plant–parakeet mutualism counteracts human overharvesting on an endangered tree

The exponential growth of the human population often causes the overexploitation of resources and disruption of ecological interactions. Here, we propose that the antagonist effect of humans on exploited species might be alleviated with the advent of a second predator species. We focused on the complex interactions between an endangered conifer (Araucaria araucana) and two seed exploiters: the Austral parakeet (Enicognathus ferrugineus) and human seed collectors. We tested the importance of partial seed consumption by parakeets as an escape from human seed harvesting. Although parakeets frequently ate whole seeds, a substantial proportion of the seeds found under trees were only partially eaten and avoided by human seed collectors. These seeds germinated at a similar proportion but faster than intact seeds under laboratory conditions. Our results revealed an overlooked mutualism between parakeets and an endangered tree. Incomplete seed eating by parakeets, plus selection against these eaten seeds by humans, may enhance regeneration possibilities for this conifer species subject to human seed collection, turning the scale of the antagonism–mutualism continuum to the mutualistic side. In this context, parakeets might be providing an important service in those forests subject to human harvesting by allowing a fraction of seeds to escape human predation.Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Gleiser, Gabriela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Tella Escobedo, José Luis. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Aizen, Marcelo Adrian. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

State of knowledge on the ecology and conservation of rocky outcrops in Argentina: A review

Los roquedales proveen recursos que aprovechan diferentes especies, lo cual los convierte en sitios relevantes para conservar la biodiversidad. Sin embargo, estos sistemas permanecen poco estudiados a nivel global, y la Argentina no es la excepción. Por este motivo, realizamos una revisión bibliográfica para aportar información sobre el estado del conocimiento en relación con el rol ecológico de los roquedales y sobre su importancia como elementos clave de diferentes ecosistemas argentinos. Encontramos 85 artículos que pusieron en evidencia el uso de los roquedales por diferentes especies. De ellos, sólo un tercio se enfocó en el análisis específico de estos sistemas y evaluó, principalmente, su función como hábitat para las especies, seguido por su rol como refugios y, finalmente, como sitios de interacción entre individuos. La literatura científica sugiere que en la Argentina son escasos los trabajos que evalúan de forma apropiada la importancia de los roquedales para la conservación de la biodiversidad, su contribución hacia las personas, el posible impacto antrópico sobre ellos y las acciones que se podrían tomar para favorecer su conservación y el mantenimiento de los servicios que brindan. Esta información es necesaria para diagramar estrategias de manejo adecuadas que incluyan a estos sitios. La falta de dichas estrategias se podría asociar al bajo interés que generan los roquedales como sistemas de estudio, ya que por lo general se los considera como inertes o poco relevantes. Sugerimos incentivar el estudio ecológico de estos ambientes que pueden contener organismos e interacciones novedosas. Además, proponemos acciones específicas para preservar los procesos naturales que allí suceden, y para evaluar y reducir el impacto antrópico con la finalidad de mantener sus funciones.Rocky outcrops provide resources that are used by different species and make them extremely important sites for biodiversity conservation. However, these systems remain poorly studied at a global level, and Argentina is not an exception. For this reason, we reviewed the available literature to provide the state of knowledge about the ecological role of rocky outcrops, and their importance as key landscape elements of Argentine ecosystems. Our review showed 85 articles that evidenced the use of rocky outcrops by different species. Of these, only one third focused on the specific study of these systems, evaluating mainly their function as habitat for species, followed by their role as shelters and, finally, as sites of interaction between individuals. The articles found suggest there are few studies in Argentina which properly evaluate the importance of rocky outcrops for biodiversity conservation, their contribution to people, the possible anthropic impact on them, and the actions that could be taken to favor their conservation and the maintenance of the services they provide. This information is essential for the design of adequate management policies that include these sites. The lack of these policies could be associated to a low interest aroused by those habitats as study systems, generally considered as inert or not very relevant. We suggest encouraging the ecological studies of these environments, which may contain novel organisms and interactions. In addition, we suggest specific actions for the preservation of the natural processes that take place there, and to evaluate and reduce the anthropic impact on them in order to maintain their functions.Fil: Gómez Carella, Dulce Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentin

Effect of pressure on the crystal structure of ettringite

X-ray diffraction and infrared data have been collected froma sample of ettringite from ambient pressure to 6.4 GPa. The sample wasfound to reversibly transform to an amorphous phase at 3 GPa. Theisothermal bulk modulus of ettringite was found to be 27(7) GPa and theincompressibilities of the lattice parameters were found to be 71(30) GPaalong a and 108(36) GPa along c