CEAZA
Climatic trends and impact of climate change on agriculture in an arid Andean valley.
Fiebig-Wittmaack, M., Astudillo, O., Wheaton, E., Wittrock, V., Perez, C., & Ibacache, A.
Little is known about climate change and its impacts for the arid coastal and mountainous regions in northern Chile. The Elqui river basin, part of the Norte Chico of Chile between 27ºS and 33ºS latitude, is located south of the hyper-arid Atacama desert. Despite water scarcity, agricultural development in this region has been enhanced by agronomic practices and the marketing of valuable products. This paper characterizes the actual climate conditions and presents an overview and analyses of past climate variability, and future possible climate trends, emphasizing those relevant to agriculture. Precipitation shows an important decrease during the first decades of the past century. Runoff shows decreasing trends for the first half of the past century and increases for 1960 to 1985. Drought appears to be increasing. Statistical downscaling was accomplished using the Long Ashton Research Station Weather Generator. Both future periods of 2011 to 2030 and 2046–65 showed trends to higher minimum and maximum temperature. The number of hot days (maximum temperature greater than or equal to 30°C) has a strong increasing trend during October to April. Even though the downscaled results for precipitation do not show trends, the continuation of the present trend of low amounts is a concern. We discuss some implications of climatic changes for agriculture and we emphasize the importance of adaptation, especially to deal with water scarcity.
Año: 2012
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Referencia APA: Fiebig-Wittmaack, M., Astudillo, O., Wheaton, E., Wittrock, V., Perez, C., & Ibacache, A. (2012). Climatic trends and impact of climate change on agriculture in an arid Andean valley. Climatic Change, 111(3-4), 819-833
Plant invasions research in Latin America: fast track to a more focused agenda.
Gardener, M., Bustamante, R., Herrera, I., Durigan, G., Pivello, V., & Moro, M., Stoll, A., et al.
While many developed countries have invested heavily in research on plant invasions over the last 50 years, the immense region of Latin America has made little progress. Recognising this, a group of scientists working on plant invasions in Latin America met in Chile in late 2010 to develop a research agenda for the region based on lessons learned elsewhere. Our three main findings are as follows. (1) Globalisation is inevitable, but the resultant plant introductions can be slowed or prevented by effective quarantine and early intervention. Development of spatially explicit inventories, research on the invasion process and weed risk assessments can help prioritise and streamline action. (2) Eradication has limited application for plants and control is expensive and requires strict prioritisation and careful planning and evaluation. (3) Accepting the concept of novel ecosystems, new combinations of native and introduced species that no longer depend on human intervention, may help optimise invasive species management. Our vision of novel ecosystem management is through actions that: (a) maintain as much native biodiversity and ecosystem functionality as possible, (b) minimise management intervention to invasives with known impact, and (c) maximise the area of intervention. We propose the creation of a Latin American Invasive Plants Network to help focus the new research agenda for member countries. The network would coordinate research and training and establish funding priorities, develop and strengthen tools to share knowledge, and raise awareness at the community, governmental and intergovernmental levels about the social, economic and environmental costs of plant invasions.
Año: 2012
Palabras claves: control, eradication, globalisation, inventories, novel ecosystems, plant invasions, quarantine, Weed Risk Assessment,
Referencia APA: Gardener, M., Bustamante, R., Herrera, I., Durigan, G., Pivello, V., & Moro, M., Stoll, A., et al. (2012). Plant invasions research in Latin America: fast track to a more focused agenda. Plant Ecology & Diversity, 5(2), 225-232.
Evaluation of sediment trace metal records as paleoproductivity and paleoxygenation proxies in the upwelling center off Concepción, Chile (36°S)
Muñoz, P., Dezileau, L., Lange, C., Cardenas, L., Sellanes, J., Salamanca, M., & Maldonado, A.
This study analyzes the records of several trace metals sensitive to redox conditions in continental shelf sediments off Concepción, Chile (36°S). The continental margin off Concepción (36°S; 73°W) lies beneath an important upwelling center characterized by high primary production rates and, consequently, high fluxes of organic matter. In spring and summer, this material settles to the seafloor where it decays, producing periods of very low oxygen content in bottom waters (<1 mL L−1). In addition, an oxygen minimum zone develops at ∼100–400 m water depth, where dissolved oxygen levels are <0.5 mL L−1. This situation changes during strong El Niño events, when dissolved oxygen at the bottom increases drastically (>1 mL L−1).
Año: 2012
Palabras claves:
Referencia APA: Muñoz, P., Dezileau, L., Lange, C., Cardenas, L., Sellanes, J., Salamanca, M., & Maldonado, A. (2012). Evaluation of sediment trace metal records as paleoproductivity and paleoxygenation proxies in the upwelling center off Concepción, Chile (36°S). Progress In Oceanography, 92-95, 66-80.
A three-year mark-recapture study in a remnant population of Crocodylus acutus Cuvier in Portete Bay (Guajira, Colombia).
Espinosa, M., Bertin, A., Gómez, J., Mejía, F., Guerra, M., & Baez, L., Gouin, N., Patiño, E.
El Cocodrilo Americano Crocodylus acutus, ha experimentado importantes declines poblacionales a lo amplio de su distribución debido a la persecución humana, la sobreexplotación y la pérdida de hábitat. C. acutus permanece en peligro crítico en algunos países tales como Colombia donde la ausencia de estudios detallados sobre su ecología y distribución constituyen una de las barreras principales para el desarrollo de efectivas estrategias de conservación. Durante tres años desarrollamos un estudio de captura-recaptura para investigar el estatus demográfico de C. acutus e identificar las variables medioambientales más influyentes en su distribución en Bahía Portete (Colombia). Nosotros estimamos que la población de cocodrilos es relativamente pequeña (< 140 animales), incluye muy pocos adultos y demuestra un fuerte déficit de hembras en la clase juvenil. La humedad relativa y la temperatura promedio del aire estuvieron positivamente correlacionadas con el número de avistamientos de cocodrilos. Por el contrario, la salinidad promedio del agua se encontró relacionada con la baja probabilidad de observación, presumiblemente debido a la preferencia de los juveniles por áreas de baja salinidad. Nuestros resultados sugieren que la población de C. acutus en Bahía Portete está en riesgo y puede requerir la intervención humana para asegurar su persistencia.
Año: 2012
Palabras claves: Captura-recaptura, cocodrilo, variables medioambientales, manglar
Referencia APA: Espinosa, M., Bertin, A., Gómez, J., Mejía, F., Guerra, M., & Baez, L., Gouin, N., Patiño, E. (2012). A three-year mark-recapture study in a remnant population of Crocodylus acutus Cuvier in Portete Bay (Guajira, Colombia). Gayana (Concepción), 76(1), 52-58.
Annual brood number and breeding periodicity of squat lobsters (Decapoda: Anomura: Galatheidae) from the continental shelf of the SE Pacific—Implications for fisheries management.
Thiel, M., Espinoza-Fuenzalida, N., Acuña, E., & Rivadeneira, M.
The reproductive potential of a population depends on the number of broods that individuals produce during the annual reproductive season. Determining the annual brood number is especially relevant for species that are actively fished. Herein we combined different approaches to estimate the annual brood number of two commercially exploited species of squat lobsters from the Chilean continental shelf and upper slope, Cervimunida johni and Pleuroncodes monodon. Long-term maintenance in the laboratory revealed that most females (>70%) produced 3 or more broods during the annual reproductive season. Incubation of individual broods required about 40 days, which would allow for 3 subsequent broods during the main reproductive period (June–September). The dynamics of brood release of ovigerous females that were collected from the field at approximately monthly intervals supported the estimate of 3–4 annual broods for adult females. Furthermore, these latter data also indicated a high degree of breeding synchrony among reproductive females. It is suggested that the production of successive broods might be an adaption to the variable oceanographic conditions during the reproductive period, ensuring that at least one larval cohort finds favorable conditions for development and settlement. Based on these results it is recommended that fishing effort is reduced during the main reproductive period of the two squat lobsters.
Año: 2012
Palabras claves: Squat lobsters; Trawl fishery; Fisheries management; Reproduction; Annual brood number; Mating synchrony
Referencia APA: Thiel, M., Espinoza-Fuenzalida, N., Acuña, E., & Rivadeneira, M. (2012). Annual brood number and breeding periodicity of squat lobsters (Decapoda: Anomura: Galatheidae) from the continental shelf of the SE Pacific—Implications for fisheries management. Fisheries Research, 129-130, 28-37.
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.