CEAZA
Major hydrological regime change along the semiarid western coast of South America during the early Holocene.
Ortega, C., Vargas, G., Rutllant, J., Jackson, D., & Méndez, C.
Water availability in the semiarid western coast of Chile (30–32°S) is conditioned by high interannual precipitation variability, reflecting the transition between arid subtropical and moist mid-latitude climates in the Southeastern Pacific Ocean. A paleoclimate reconstruction based on the latest Pleistocene–Holocene geological record from the Quebrada Santa Julia archeological site in Chile (31°50′S) and on modern meteorological mechanisms producing alluvial episodes in this region indicates a major change in the rainfall regime shortly after 8600 cal yr BP. This, together with other paleoclimate proxies along the west coast of South America (34°–14°S), suggests La Niña-like conditions 13,000–8600 cal yr BP. Based on sedimentological and geomorphologic evidence, we hypothesized that the absence of heavy rainfall events in northern Chile and the new hydrological regime that prevailed ca. 8600–5700 cal yr BP in north-central Chile resulted from an increase in the large-scale westerly flow over central Chile, as expected in near-neutral ENSO conditions. This atmospheric circulation anomaly is compatible with an equatorward shift of the influence of the Southeast Pacific Subtropical Anticyclone relative to the early Holocene, prior to the onset of modern ENSO variability.
Año: 2012
Palabras claves: Paleoclimate; Early Holocene; Alluvial flow; Heavy rainfall; Coastal fog; El Niño Southern Oscillation (ENSO); Western South America; Paleohydrology; Pacific Ocean.
Referencia APA: Ortega, C., Vargas, G., Rutllant, J., Jackson, D., & Méndez, C. (2012). Major hydrological regime change along the semiarid western coast of South America during the early Holocene. Quaternary Research, 78(3), 513-527.
Abandoned tailings deposits, acid drainage and alluvial sediments geochemistry, in the arid Elqui River Basin, North-Central Chile. Journal of Geochemical Exploration
Oyarzún J, Castillo D, Maturana H, Kretschmer N, Soto G, Amezagad JM, Röttingd TS, Youngere PL, Oyarzún R
Two major pollutant sources related to hydrothermal ore deposits and mining operations exist in the Elqui river basin, Chile: (a) acid drainage from Andean epithermal El Indio Au–Ag–Cu–As district and nearby hydrothermal alteration zones, and (b) diffuse sediment dispersion from abandoned tailings deposits in usually dry creeks in the western belt of the basin. This work analyses the contribution of both sources to the current metal contents of the fine grained sediments of the rivers and creeks of the Elqui basin, including a group of chemical elements and data analysis techniques not considered in previous works carried out in the area. Analysis of “active sediments” (i.e., sediments in permanent contact with surface water) in the main channel and tributaries of the Elqui river reveals that both pollutant sources contribute to their exceptionally high Cu contents (between 0.1 and 0.2% in the minus 60 mesh fraction). However, As pollution (0.03%) is mainly derived from the El Indio district. Potentially toxic heavy metals (notably Cd, Pb, Hg and Mo) are present in low concentrations and do not represent major threats to ecology or human health. Nevertheless, ongoing erosion of abandoned tailings deposits may result in soil contamination and thus be detrimental to the export-oriented agriculture of the Elqui basin. Consequently, remediation of that source should be prioritized.
Año: 2012
Palabras claves: Acid drainage; Active sediments; Hydrothermal alteration; Tailings; CAMINAR
Referencia APA: Oyarzún J, Castillo D, Maturana H et al. (2012). Abandoned tailings deposits, acid drainage and alluvial sediments geochemistry, in the arid Elqui River Basin, North-Central Chile. Journal of Geochemical Exploration. 2012;115:47-58.
Characterization of genetic markers linked to sex determination in the haploid-diploid red alga gracilaria chilensis1.
Guillemin, M., Huanel, O., & Martínez, E.
Bulk segregant analysis, random amplified polymorphic DNA (RAPD), and sequence characterized amplified region (SCAR) methods were used to identify sex-linked molecular markers in the haploid-diploid rhodophyte Gracilaria chilensis C. J. Bird, McLachlan et E. C. Oliveira. One hundred and eighty 10 bp primers were tested on three bulks of DNA: haploid males, haploid females, and diploid tetrasporophytes. Three RAPD primers (OPD15, OPG16, and OPN20) produced male-specific bands; and one RAPD primer (OPD12), a female-specific band. The sequences of the cloned putative sex-specific PCR fragments were used to design specific primers for the female marker SCAR-D12-386 and the male marker SCAR-G16-486. Both SCAR markers gave unequivocal band patterns that allowed sex and phase to be determined in G. chilensis. Thus, all the females presented only the female band, and all the males only the male band, while all the tetrasporophytes amplified both male and female bands. Despite this sex-specific association, we were able to amplify SCAR-D12-386 and SCAR-G16-486 in both sexes at low melting temperature. The differences between male and female sequences were of 8%–9% nucleotide divergence for SCAR-D12-386 and SCAR-G16-486, respectively. SCAR-D12-386 and SCAR-G16-486 could represent degenerated or diverged sequences located in the nonrecombining region of incipient sex chromosomes or heteromorphic sex chromosomes with sequence differences at the DNA level such that PCR primers amplify only one allele and not the other in highly specific PCR conditions. Seven gametic progenies composed of 19 males, 19 females, and the seven parental tetrasporophytes were analyzed. In all of them, the two SCAR markers segregated perfectly with sexual phenotypes.
Año: 2012
Palabras claves: cultivated red alga; Gracilaria chilensis; random amplified polymorphic DNA; sequence characterized amplified region; sex-linked markers
Referencia APA: Guillemin, M., Huanel, O., & Martínez, E. (2012). Characterization of genetic markers linked to sex determination in the haploid-diploid red alga gracilaria chilensis1. Journal Of Phycology, 48(2), 365-372
Mid-Holocene mean climate in the south eastern Pacific and its influence on South America.
Carré, M., Azzoug, M., Bentaleb, I., Chase, B., Fontugne, M., & Jackson, D., Ledru, M.P., Maldonado, A., et al
The eastern tropical Pacific plays a key role in the tropical atmospheric circulation and in the global carbon cycle, and assessing the sensitivity of this region to global climate changes is a major challenge facing climatologists. Provided here is a synthesis of proxy records of the mean climate of the mid-Holocene (5–8 ka) along the south eastern Pacific margin and four regions of South America. These regions were selected for the strength and stability of ENSO teleconnections, and located outside the direct influence of the intertropical convergence zone or the southern westerlies in order to avoid the overprinting signal of their insolation-related variations and focus on the relationship between the eastern tropical Pacific and South America. This study is based on a review of published multiproxy data as well as new isotopic data from the Peruvian and Chilean coast. The available evidence indicates that sea-surface temperatures were ∼1–4 °C cooler from the Galapagos to the southern Peruvian coast as a result of increased coastal upwelling forced by changes in longshore windfields. The mean La Niña-like conditions in the eastern South Pacific were associated to aridity in southern Brazil and along the whole South American Pacific coast from central Chile to the Galapagos, and to wetter conditions on the western central Andes. This regional synthesis provides a coherent picture of the South American mean climate that is very similar to the modern precipitation pattern observed during La Niña conditions, suggesting that atmospheric teleconnections linking the South Eastern Pacific to these continental areas were similar in the middle Holocene.
Año: 2012
Palabras claves:
Referencia APA: Carré, M., Azzoug, M., Bentaleb, I., Chase, B., Fontugne, M., & Jackson, D., Ledru, M.P., Maldonado, A et al. (2012). Mid-Holocene mean climate in the south eastern Pacific and its influence on South America. Quaternary International, 253, 55-66.
Genetic diversity and comparison of physicochemical and nutritional characteristics of six quinoa (Chenopodium quinoa willd.) genotypes cultivated in Chile.
Miranda, M., Vega-Gálvez, A., Martinez, E., López, J., Rodríguez, M., Henríquez, K., & Fuentes, F.
The present study was focused on the analysis of agronomical, nutritional, physicochemical, and antioxidant properties of six genetically different quinoa (Chenopodium quinoa Willd) genotypes cultivated in three distinctive geographical zones of Chile. Ancovinto and Cancosa genotypes from the northern Altiplano (19 ºS), Cáhuil and Faro from the central region (34 ºS), and Regalona and Villarica from the southern region (39 ºS) are representative of high genetic differentiation among the pooled samples, in particular between Altiplano and the central-southern groups. A Common-Garden Assay at 30 ºS showed significant differences among seed origins in all morphometric parameters and also in yields. Altiplano genotypes had larger panicule length but no seed production. A significant influence of the different quinoa genotypes on chemical composition and functional properties was also observed. Protein concentration ranged from 11.13 to 16.18 g.100 g–1 d.m., while total dietary fiber content ranged from 8.07-12.08 g.100 g–1 d.m., and both were the highest in Villarrica ecotype. An adequate balance of essential amino acids was also observed. Sucrose was the predominant sugar in all genotypes. Antioxidant activity was high in all genotypes, and it was highest in Faro genotype (79.58% inhibition).
Año: 2012
Palabras claves: quinoa; antioxidant activity; amino acids; functional properties.
Referencia APA: Miranda, M., Vega-Gálvez, A., Martinez, E., López, J., Rodríguez, M., Henríquez, K., & Fuentes, F. (2012). Genetic diversity and comparison of physicochemical and nutritional characteristics of six quinoa (Chenopodium quinoa willd.) genotypes cultivated in Chile. Food Science And Technology (Campinas), 32(4), 835-843.
Species replacement along a linear coastal habitat: phylogeography and speciation in the red alga Mazzaella laminarioides along the south east pacific.
Montecinos, A., Broitman, B., Faugeron, S., Haye, P., Tellier, F., & Guillemin, M.
The Chilean shoreline, a nearly strait line of coast expanding across 35 latitudinal degrees, represents an interesting region to assess historical processes using phylogeographic analyses. Stretching along the temperate section of the East Pacific margin, the region is characterized by intense geologic activity and has experienced drastic geomorphological transformations linked to eustatic and isostatic changes during the Quaternary. In this study, we used two molecular markers to evaluate the existence of phylogeographic discontinuities and detect the genetic footprints of Pleistocene glaciations among Patagonian populations of Mazzaella laminarioides, a low-dispersal benthic intertidal red seaweed that inhabits along ~3,700 km of the Chilean coastal rocky shore.
Año: 2012
Palabras claves: Phylogeography, South East Pacific coast, COI, rbcL, Red seaweed, Parapatric distribution, Sister-species, complex, Pleistocene glaciations
Referencia APA: Montecinos, A., Broitman, B., Faugeron, S., Haye, P., Tellier, F., & Guillemin, M. (2012). Species replacement along a linear coastal habitat: phylogeography and speciation in the red alga Mazzaella laminarioides along the south east pacific. BMC Evol Biol, 12(1), 97.
Application of the Watershed Sustainability Index to the Elqui river basin, North-Central Chile
Cortés, A., Oyarzún, R., Kretschmer, N., Chaves, H., Soto, G., & Soto, M. et al.
El índice WSI, desarrollado para estimar la sustentabilidad de una cuenca en forma integrada con énfasis en la gestión de recursos hídricos, fue determinado en la Cuenca del Río Elqui considerando un período de 5 años (2001-2005). La cuenca del Río Elqui se ubica en una región semiárida de Chile, y ha sido incorporada a la red de cuencas hidrográficas del programa HELP de la UNESCO. El resultado fue un valor global de 0.61 para el indicador WSI (en el rango de 0 a 1), calificando el nivel de sustentabilidad como "intermedio". Las mayores fortalezas de la cuenca se relacionaron con los indicadores de Ambiente y de Políticas. Por otro lado, las mayores debilidades observadas en la cuenca se relacionaron con el indicador de Hidrología, debido principalmente a la situación de escasez hídrica. La identificación de estas limitantes representan una oportunidad para mejorar la actual situación en la cuenca, lo que obliga a una coordinación más eficiente entre las diferentes instituciones involucradas en la gestión de los recursos naturales. La aplicación del WSI a la Cuenca de Elqui demostró su utilidad como instrumento analítico asi como herramienta de gestión para autoridades relacionadas con el agua, usuarios y grupos de interés. Sin embargo, la actualización de la información local es necesaria para la planificación a mediano y largo plazo y la formulación de estrategias de desarrollo para esta cuenca y otras.
Año: 2012
Palabras claves: gestión integrada de cuencas, hidrología, ambiente, calidad de vida, políticas
Referencia APA: Cortés, A., Oyarzún, R., Kretschmer, N., Chaves, H., Soto, G., & Soto, M. et al. (2012). Application of the Watershed Sustainability Index to the Elqui river basin, North-Central Chile. Obras Y Proyectos, (12), 57-69.
Implications of farmers’ seed exchanges for on-farm conservation of quinoa, as revealed by its genetic diversity in Chile.
Fuentes, F., Bazile, D., Bhargava, A., & Martínez, E.
Quinoa cultivation in Chile presents an ancient and active complex of geographic, climatic, social and cultural interactions that has determined its current biodiversity in the three main growing zones (north, central and south). Importantly, these interactions involve the participation of farmers, whose activities are at the base of seed exchange networks due to their knowledge and in situ conservation of genetic diversity. The present study reports how a better understanding of farmers’ seed exchanges and local production practices could impact the genetic structure and diversity of quinoa at national scale in Chile. Using field interviews and characterization of 20 microsatellite genetic markers in a multi-origin set of 34 quinoa accessions representative of Chile and the South American region, the phenetic analysis of germplasm was consistent with the current classification of quinoa ecotypes present in Chile and Andean zone. This allowed the identification of five populations, which were represented by quinoa of Salares (northern Chile), Coastal/Lowlands (central and southern Chile), Highlands (Peru, Bolivia and Argentina) and Inter-Andean Valleys (Ecuador and Colombia). The highly informative quality of the markers used revealed a wide genetic diversity among main growing areas in Chile, which correlated well with natural geographical–edaphic–climatic and social–linguistic context to the expansion of quinoa biodiversity. Additionally, in addition to ancient seed exchanges, this process is still governed by the diverse agricultural practices of Andean farmers. Genetic erosion is considered an imminent risk due to small-scale farming, where the influence of increased migration of people to urban systems and export-driven changes to the agro-ecosystems may further reduce the diversity of quinoa plants in cultivation.
Año: 2012
Palabras claves:
Referencia APA: Fuentes, F., Bazile, D., Bhargava, A., & Martínez, E. (2012). Implications of farmers’ seed exchanges for on-farm conservation of quinoa, as revealed by its genetic diversity in Chile. J. Agric. Sci., 150(06), 702-716.
An Early Holocene task camp (~8.5 ka cal BP) on the coast of the semi-arid north of Chile.
Ballester, B., Jackson, D., Carré, M., Maldonado, A., Méndez, C., & Seguel, R.
According to current thinking, the peopling of South America involved a coastal as well as an inland exploitation. Here the authors describe a camp that may denote a transition between the two. As indicated by bifacial tools, the investigation shows that people began to move inland and hunt mammals around 8500 cal BP, perhaps in association with a change in the climate.
Año: 2012
Palabras claves: Chile, peopling of South America, coastal, inland, shell, midden, bifacies
Referencia APA: Ballester, B., Jackson, D., Carré, M., Maldonado, A., Méndez, C., & Seguel, R. (2012). An Early Holocene task camp (~8.5 ka cal BP) on the coast of the semi-arid north of Chile. Antiquity, 86(331), 88-98.
Lizards on Ice: Evidence for Multiple Refugia in Liolaemus pictus (Liolaemidae) during the Last Glacial Maximum in the Southern Andean Beech Forests.
Vera-Escalona, I., D'Elía, G., Gouin, N., Fontanella, F., Muñoz-Mendoza, C., Sites, J., & Victoriano, P.
Historical climate changes and orogenesis are two important factors that have shaped intraspecific biodiversity patterns worldwide. Although southern South America has experienced such complex events, there is a paucity of studies examining the effects on intraspecific diversification in this part of the world. Liolaemus pictus is the southernmost distributed lizard in the Chilean temperate forest, whose genetic structure has likely been influenced by Pleistocene glaciations. We conducted a phylogeographic study of L. pictus in Chile and Argentina based on one mitochondrial and two nuclear genes recovering two strongly divergent groups, Northern and Southern clades. The first group is distributed from the northernmost limit of the species to the Araucanía region while the second group is distributed throughout the Andes and the Chiloé archipelago in Southern Chile. Our results suggest that L. pictus originated 751 Kya, with divergence between the two clades occurring in the late Pleistocene. Demographic reconstructions for the Northern and Southern clades indicate a decrease in effective population sizes likely associated with Pleistocene glaciations. Surprisingly, patterns of genetic variation, clades age and historical gene flow in populations distributed within the limits of the Last Glacial Maximum (LGM) are not explained by recent colonization. We propose an “intra-Andean multiple refuge” hypothesis, along with the classical refuge hypothesis previously proposed for the biota of the Chilean Coastal range and Eastern Andean Cordillera. Our hypothesis is supported by niche modelling analysis suggesting the persistence of fragments of suitable habitat for the species within the limits of the LGM ice shield. This type of refuge hypothesis is proposed for the first time for an ectothermic species.
Año: 2012
Palabras claves: Haplotypes, Phylogeography, Gene flow, Chile (country), Phylogenetic analysis, Population genetics, Mitochondrial DNA, Mitochondria.
Referencia APA: Vera-Escalona, I., D'Elía, G., Gouin, N., Fontanella, F., Muñoz-Mendoza, C., Sites, J., & Victoriano, P. (2012). Lizards on Ice: Evidence for Multiple Refugia in Liolaemus pictus (Liolaemidae) during the Last Glacial Maximum in the Southern Andean Beech Forests. Plos ONE, 7(11), e48358.
Impact of mycorrhizae and irrigation in the survival of seedlings of Pinus radiata D. Don subject to drought.
Atala, C., Muñoz-Capponi, E., Pereira, G., Navarrete, E., Oses, R., & Molina-Montenegro, M.
In drought condition, plants increase survival chance by adjusting their functional traits and by biological associations. Mycorrhizae association and artificial watering have been shown to increase plant survival under drought, especially at early developmental stages when plants are more susceptible. In Chile, Pinus radiata is the most important forest species. It is grown mainly in Central Chile, where precipitations are predicted to drop in 40% and change in frequency in the future due to climate change. Rhizopogon luteolus is an ectomycorrhizae usually associated with Pinus species and has been found to increase drought tolerance. We addressed the effect of R. luteolus inoculation on survival and functional traits of P. radiata seedlings exposed to two watering treatments. These treatments simulated control (50 ml) and 40% reduced precipitations (20 ml). We also evaluated the combined effect of watering quantity (20 and 50 ml) and frequency (every 5, 10 and 30 days) on the same variables. R. luteolus inoculation increased seedling survival, but reduced plant size. Watering quantity affected plant survival only at intermediate watering frequencies, but not at the high and low frequencies. The lowest frequency, normal for the summer of Central Chile, resulted in -80% seedling mortality. Most of the functional traits measured were not affected neither by watering frequency nor quantity, but they were affected by mycorrhization. Mycorrhizae inoculation, together with some sort of artificial watering could be a possible strategy to cope with prolonged drought events.
Año: 2012
Palabras claves: Pinus radiata, Rhizopogon luteolus, climate change, ectomycorrhizae, drought tolerance.
Referencia APA: Atala, C., Muñoz-Capponi, E., Pereira, G., Navarrete, E., Oses, R., & Molina-Montenegro, M. (2012). Impact of mycorrhizae and irrigation in the survival of seedlings of Pinus radiata D. Don subject to drought. Gayana Bot., 69(2), 296-304.
Observations of cryoconite hole system processes on an Antarctic glacier
Macdonell, S. & Fitzsimons, S.
Los "cryoconite holes" son cavidades que contienen agua, formadas en las superficies de glaciares, donde la desigual distribución de sedimentos causa diferencias espaciales en el derretimiento. Los "cryoconite holes" son importantes componentes de los sistemas glaciares fríos, debido a que incrementan el derretimiento del hielo, permiten el desarrollo de complejos sistemas de drenajes y facilitan el crecimiento de comunidades microbianas en la superficie del glaciar. Este estudio describe el desarrollo de una red hidrológica de "cryoconite holes" en un glaciar de la Antártica y explora las implicancias para la reserva y entrega de nutrientes dentro del sistema del glaciar. Las mediciones de terreno incluyen dimensiones internas y mapeo de "cryoconite holes" a lo largo de la superficie del glaciar. El trabajo de laboratorio incluye análisis de cationes y aniones de hielo limpio y de los "cryoconite holes". Los resultados mostraron que la distribución de los "cryoconite holes" estaba determinada por la topografía y las tasas de erosión locales. Las superficies planas se caracterizaron por una alta densidad de "cryoconite holes". Los "cryoconite holes" fueron poco comunes dentro de canales sobre la superficie del glaciar y en superficies con altas tasas de erosión. La correlación negativa encontrada entre la densidad de "cryoconite holes" y la tasa de erosión sugiere que la superficie del glaciar necesita estar relativamente estable para el desarrollo y persistencia de los "cryoconite holes". Además, los "cryoconite holes" posiblemente contribuyan en 1/3 a la generación del derretimiento en superficies planas. Sin embargo, no toda esta agua es retenida en las cavidades. El agua puede ser drenada por canales, grietas o drenajes intergranulares, no obstante, la importancia relativa de cada uno no es conocida aún. Debido a que los "cryoconite holes" son relativamente ricos en nutrientes, comparados con el hielo limpio del glaciar, sería importante conocer la naturaleza de sus conexiones, a fin de determinar la entrega de nutrientes a lo largo del glaciar y a la región proglacial.
Año: 2012
Palabras claves: Agua de fusión, biogeoquímica, hidrología de glaciares, sistema de drenaje, sustancia disuelta.
Referencia APA: Macdonell, S. & Fitzsimons, S. (2012). Observations of cryoconite hole system processes on an Antarctic glacier. Rev. Chil. Hist. Nat., 85(4), 393-407.