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Implications of farmers’ seed exchanges for on-farm conservation of quinoa, as revealed by its genetic diversity in Chile.

Autores:

Fuentes, F., Bazile, D., Bhargava, A., & Martínez, E.

Resumen:

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.

Autores:

Ballester, B., Jackson, D., Carré, M., Maldonado, A., Méndez, C., & Seguel, R.

Resumen:

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.

Autores:

Vera-Escalona, I., D'Elía, G., Gouin, N., Fontanella, F., Muñoz-Mendoza, C., Sites, J., & Victoriano, P.

Resumen:

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.

Autores:

Atala, C., Muñoz-Capponi, E., Pereira, G., Navarrete, E., Oses, R., & Molina-Montenegro, M.

Resumen:

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

Autores:

Macdonell, S. & Fitzsimons, S.

Resumen:

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.

Morphological variability of intertidal Eisenia arborea (Laminariales, Ochrophyta) at Punta Eugenia, Baja California Sur

Autores:

Parada, G., Riosmena-Rodriguez, R., Martinez, E., & Hernandez-Carmona, G.

Resumen:

Water motion is one of the main drivers in morphological variability in species within de order Laminariales, and most of our current knowledge is based on subtidal populations. is a dominant kelp species in the North Pacific, widely distributed along the Baja California Peninsula from mid intertidal down to subtidal areas. This species presents great variability in the intertidal zone but it has not been yet evaluated such variability according to wave exposure. The present work also identifies the spatial / temporal variation, particularly respect to the presence of stipes without medulla (hollow stipes) a feature common among other brown seaweeds. We evaluated the effects of wave action in morphological variation of intertidal (Laminariales, Ochrophyta) at Punta Eugenia. The spatial and temporal variation sampling was surveyed between February, May, July, and August 2004 in the intertidal of Punta Eugenia, Baja California Sur. Our results have shown that exposed sites correlate with increased length and width of stipes as compared to more protected sites. Hollow stipes frequency changed more in association with temporal variation than with spatial heterogeneity suggesting nutrient limitation for thalli development. Our results suggest that compensate by morphological modifications the stress of living in the intertidal zone by showing larger stipes. Hollow stipes might be are also a mechanical adaptation to increase survival in high energy environments.

Año: 2012

Palabras claves: Eisenia arborea;intertidal;Laminariales;morphological variability

Referencia APA: Parada, G., Riosmena-Rodriguez, R., Martinez, E., & Hernandez-Carmona, G. (2012). Morphological variability of intertidal Eisenia arborea (Laminariales, Ochrophyta) at Punta Eugenia, Baja California Sur. ALGAE, 27(2), 109-114.

Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr.

Autores:

Gayo, E., Latorre, C., Santoro, C., Maldonado, A., & De Pol-Holz, R.

Resumen:

Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exceptionally well-preserved plant macrofossils and associated archaeological remains from a hyperarid drainage (Quebrada Maní, ∼21° S, 1000 m a.s.l.) in the Atacama Desert. During the late Holocene, riparian ecosystems and farming social groups flourished in the hyperarid Atacama core as surface water availability increased throughout this presently sterile landscape. Twenty-six radiocarbon dates indicate that these events occurred between 1050–680, 1615–1350 and 2500–2040 cal yr BP. Regional comparisons with rodent middens and other records suggest that these events were synchronous with pluvial stages detected at higher-elevations in the central Andes over the last 2500 yr. These hydroclimate changes also coincide with periods of pronounced SST gradients in the Tropical Pacific (La Niña-like mode), conditions that are conducive to significantly increased rainfall in the central Andean highlands and flood events in the low-elevation watersheds at inter-annual timescales. Our findings indicate that the positive anomalies in the hyperarid Atacama over the past 2500 yr represent a regional response of the central Andean climate system to changes in the global hydrological cycle at centennial timescales. Furthermore, our results provide support for the role of tropical Pacific sea surface temperature gradient changes as the primary mechanism responsible for climate fluctuations in the central Andes. Finally, our results constitute independent evidence for comprehending the major trends in cultural evolution of prehistoric peoples that inhabited the region.

Año: 2012

Palabras claves:

Referencia APA: Gayo, E., Latorre, C., Santoro, C., Maldonado, A., & De Pol-Holz, R. (2012). Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr. Climate Of The Past, 8(1), 287-306. http://dx.doi.org/10.5194/cp-8-287-2012

Inter-annual variability of southerly winds in a coastal area of the Atacama Desert: implications for the export of aeolian sediments to the adjacent marine environment.

Autores:

Flores-Aqueveque, V., Alfaro, S., Caquineau, S., Foret, G., Vargas, G., & Rutllant, J.

Resumen:

The analysis of the aeolian content of marine cores collected off the coast of the Atacama Desert (Mejillones Bay, Chile) suggests that marine sediments can record inter-annual to inter-decadal variations in the regional southerly winds responsible for particle entrainment at the surface of the nearby desert. However, the establishment of a simple and direct correlation between the sediment and wind records is complicated by the difference of time scales between the erosion and accumulation processes. The aim of this work is to: (i) assess the inter-annual variability of the surface winds responsible for the sand movements; and (ii) determine whether the integration over periods of several months completely smoothes the rapid changes in characteristics of the transported and deposited aeolian material. To accomplish this aim, 14 years of 10 m hourly wind speed, measured at the Cerro Moreno (Antofagasta) Airport between 1991 and 2003 and at the Orica Station between 2000 and 2004, were analyzed. For each year, the wind speed statistical distribution can be represented by a combination of two to three Weibull functions. Winds of the lowest Weibull mode are too weak to move the sand grains at the surface of the pampa; this is not the case for the intermediate mode and especially for the highest speed mode which are able to erode the arid surface and transport particles to the bay. In each individual year of the period of study, the highest speed mode only accounted for a limited number of strong erosion events. Quantitative analysis of the distribution of the friction velocities and of their impact on erosion using a saltation model suggests that, although all wind speeds above threshold produce erosion events, values around 0·45 m sec−1 contribute less to the erosion flux. This gap allows separation of the erosion events into low and high saltation modes. The correlation (r = 0·997) between the importance of the third Weibull mode and the extent of higher rate saltation indicates that the inter-annual variability of the erosion at the surface of the pampa, as well as the transport of coarse particles (>100 μm), are directly related to inter-annual variations in the prevalence of the strongest winds. Finally, a transport and deposition model is used to assess the possible impact of the wind inter-annual variability on the deposition flux of mineral particles in the bay. The results suggest that inter-annual differences in the wind speed distributions have a quantifiable effect on the intensity and size-distribution of this deposition flux. This observation suggests that a detailed analysis of the sediment cores collected from the bay could be used for reconstructing the inter-annual variability of past winds.

Año: 2012

Palabras claves: Atacama Desert; dust transport and deposition; wind erosion; wind variability.

Referencia APA: Flores-Aqueveque, V., Alfaro, S., Caquineau, S., Foret, G., Vargas, G., & Rutllant, J. (2012). Inter-annual variability of southerly winds in a coastal area of the Atacama Desert: implications for the export of aeolian sediments to the adjacent marine environment. Sedimentology, 59(3), 990-1000.

What do we know about high-altitude precipitation in the semi-arid Andes of Chile?

Autores:

Bourgin P, Andreassian V, Gascoin S, Valery A.

Resumen:

Mapping precipitations on a regular grid is often required for hydrological and ecological modelling. The spatial interpolation methods are generally used to estimate such a distribution from ground-based measurements. In the case of mountainous areas, the estimation of precipitation amounts is still a challenging task and the results of spatial interpolation should be verified as much as possible. Here we describe a three-steps method for the validation of a precipitation map. This is used in the context of a mountainous semi-arid region, the Norte Chico in Chile (26°S-32°S). The implementation of this validation method showed the benefits of an interpolation method developed by Valéry [2010] for mountainous areas. The hydrological balance of the high-altitude watersheds is now more realistic.

Año: 2012

Palabras claves: Precipitation, spatial interpolation method, extrapolation, altitude, altitudinal corrections, validation, water equivalent, water balance.

Referencia APA: Bourgin P, Andreassian V, Gascoin S, Valery A. (2012). Que sait-on des précipitations en altitude dans les Andes semi-arides du Chili?. La Houille Blanche. 2012;(2):12-17.