Browsing by Author "Fernandoy, Francisco"

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    Antarctic Lichens under Long-Term Passive Warming: Species-Specific Photochemical Responses to Desiccation and Heat Shock Treatments
    (2022) Marin, Catalina; Bartak, Milos; Palfner, Gotz; Vergara-Barros, Pablo; Fernandoy, Francisco; Hajek, Josef; Casanova-Katny, Angelica
    Climate warming in the Antarctic tundra will affect locally dominant cryptogams. Being adapted to low temperatures and freezing, little is known about the response of the polar lichens' primary photochemistry to warming and desiccation. Since 2008, we have monitored the ecophysiological responses of lichens to the future warming scenario during a long-term warming experiment through open top chambers (OTCs) on Fildes Peninsula. We studied the primary photochemical response (potential Fv/Fm and effective efficiency of photosystem II YPSII) of different lichen taxa and morphotypes under desiccation kinetics and heat shock experiments. As lichens grow slowly, to observe changes during warming we methodologically focused on carbon and nitrogen content as well as on the stable isotope ratios. Endemic Himantormia lugubris showed the strongest effect of long-term warming on primary photochemistry, where PSII activity occurred at a lower %RWC inside the OTCs, in addition to higher Fv/Fm values at 30 degrees C in the heat shock kinetic treatment. In contrast, Usnea aurantiaco-atra did not show any effect of long-term warming but was active at a thallus RWC lower than 10%. Both Cladonia species were most affected by water stress, with Cladonia aff. gracilis showing no significant differences in primary photochemical responses between the warming and the control but a high sensibility to water deficiency, where, at 60% thallus RWC, the photochemical parameters began to decrease. We detected species-specific responses not only to long-term warming, but also to desiccation. On the other hand, the carbon content did not vary significantly among the species or because of the passive warming treatment. Similarly, the nitrogen content showed non-significant variation; however, the C/N ratio was affected, with the strongest C/N decrease in Cladonia borealis. Our results suggest that Antarctic lichens can tolerate warming and high temperature better than desiccation and that climate change may affect these species if it is associated with a decrease in water availability.
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    Black carbon and other light-absorbing impurities in snow in the Chilean Andes
    (2019) Rowe, Penny M.; Cordero, Raúl R.; Warren, Stephen G.; Stewart, Emily; Doherty, Sarah J.; Pankow, Alec; Schrempf, Michael; Casassa, Gino; Carrasco, Jorge; Lambert, Fabrice; Pizarro, Jaime; MacDonell, Shelley; Damiani, Alessandro; Rondanelli, Roberto; Huneeus, Nicolás; Fernandoy, Francisco; Neshyba, Steven
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    Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern Andes
    (NATURE RESEARCH, 2021) Pizarro, Jaime; Vergara, Pablo M.; Cerda, Sergio; Cordero, Raul R.; Castillo, Ximena; Rowe, Penny M.; Casassa, Gino; Carrasco, Jorge; Damiani, Alessandro; Llanillo, Pedro J.; Lambert, Fabrice; Rondanelli, Roberto; Huneeus, Nicolas; Fernandoy, Francisco; Alfonso, Juan; Neshyba, Steven
    The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 mu m and 10 mu m particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.
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    Elemental and mineralogical composition of the western andean snow (18°S–41°S)
    (2019) Alfonso, Juan A.; Cordero, Raul R.; Rowe, Penny M.; Neshyba, Steven; Casassa, Gino; Carrasco, Jorge; MacDonell, Shelley; Lambert, Fabrice; Pizarro, Jaime; Fernandoy, Francisco; Feron, Sarah; Damiani, Alessandro; Llanillo, Pedro; Sepulveda, Edgardo; Jorquera, Jose; Garcia, Belkis; Carrera, Juan M.; Oyola, Pedro; Kang, Choong-Min
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    Improving the underground structural characterization and hydrological functioning of an Andean peatland using geoelectrics and water stable isotopes in semi-arid Chile
    (2021) Valois, Remi; Araya Vargas, Jaime; MacDonell, Shelley; Guzman Pinones, Camilo; Fernandoy, Francisco; Yanez Carrizo, Gonzalo; Cuevas, Jaime G.; Sproles, Eric A.; Maldonado, Antonio
    High altitude, Andean wetlands, or bofedales as they are locally known, are important regulators of the local water balance and also play a key role in sustaining biodiversity. Nevertheless, there is almost no information regarding their hydrogeological structure and functioning. This paper aims to characterize the thickness of the alluvial filling of one peat-accumulating wetland in North-Central Chile using Electrical Resistivity Tomography (ERT) to assess its role as a water reservoir. To develop a quasi-3D understanding of the peatland's structure, four ERT profiles were conducted. Results highlight a conductive basin shape of the peatland, with a thicker interface downstream than upstream between alluvial materials and the underlying bedrock or rock screes. Those results allow the estimate of the water column (1000-3400 mm) within the peatland alluvial filling. The second objective is to better understand the water exchanges between the peatland and the streamflow using discharge measurements and water stable isotopes. Water and isotopes budgets highlight a streamflow loss towards the peatland groundwater reservoir at the end of spring season. In addition, ten delta O-18 and delta H-2 surveys were used to characterize the distinct wetland water sources and their temporal variations. A peatland conceptual model is proposed to connect groundwater, rock glaciers, snowmelt, and hillslope flows. Andean peatlands provide a pivotal control on water delivery downstream, and therefore, understanding their structure and function is important, because they are unique structures providing ecological services at high elevations.
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    Metal concentrations and source identification in Chilean public children's playgrounds
    (2018) Rodriguez-Oroz, Delia; Vidal, Rodrigo; Fernandoy, Francisco; Lambert, Fabrice; Quiero, Felipe