Patagonia Research Papers - Academia.edu (original) (raw)

We quantified the diet of the Chilean Hawk (Accipiter chilensis) by analyzing 495 prey remains collected during two breeding seasons (2001-2002 and 2002-2003) in an Andean Nothofagus forest of Nevados de Chillán, northern Patagonia. The... more

We quantified the diet of the Chilean Hawk (Accipiter chilensis) by analyzing 495 prey remains collected during two breeding seasons (2001-2002 and 2002-2003) in an Andean Nothofagus forest of Nevados de Chillán, northern Patagonia. The diet was almost exclusively birds (97.8% of all prey remains), with relatively few rodents (1.6%) and insects (0.6%). At least 19 vertebrate species composed the prey remains (1 small mammal and 18 bird species), with Austral Thrush (Turdus falcklandii), White-crested Elaenia (Elaenia albiceps), Black-chinned Siskin (Carduelis barbata), Fire-eyed Diucon (Xolmis pyrope), and Thorn-tailed Rayadito (Aphrastura spinicauda) being the most common. All identified vertebrate prey are known to use forest habitats; 47% (n ϭ 9) are forest specialists. Prey that inhabit both forest and shrublands accounted for 82% of the remains, and 18% of prey remains were of forest specialists. Our results indicate that during the breeding season, Chilean Hawks in Nevados de Chillán are pre-eminent, bird-eating predators that feed primarily on forest-dwelling birds.

Este libro es testimonio del oficio de los hombres de mar de la Región de Magallanes y Antártica Chilena; una pincelada dentro de las miles de historias que componen el pasado, el presente y el devenir de la pesca artesanal en la región... more

Este libro es testimonio del oficio de los hombres de mar de la Región de Magallanes y Antártica Chilena; una pincelada dentro de las miles de historias que componen el pasado, el presente y el devenir de la pesca artesanal en la región más austral del mundo. Busca contribuir al conocimiento de las personas y experiencias que dan vida a la actividad pesquera, tanto en el mar como en el borde costero. Son historias que arrojan luces sobre dimensiones poco tratadas en los estudios marítimo-costeros de la región magallánica.

El presente articulo presenta la guia del contenido y organizacion del material historico que se encuentra en custodia del Archivo Salesiano Patagonico con sede en Bahia Blanca. El material documental, fotografico y audiovisual (cartas,... more

El presente articulo presenta la guia del contenido y organizacion del material historico que se encuentra en custodia del Archivo Salesiano Patagonico con sede en Bahia Blanca. El material documental, fotografico y audiovisual (cartas, cronicas, diarios personales, cuadernos de viaje, mapas, fotografias de distintos soportes, periodicos impresos, libros de estudio, etc.) testifica la presencia de los salesianos desde 1875 hasta el presente en el territorio que va desde la ciudad de Buenos Aires hasta las Islas Malvinas y desde la costa Atlantica hasta la cordillera. Cada documento recibe un tratamiento especifico en funcion de las propiedades de su soporte y su importancia historica. La organizacion en fondos y colecciones y la accesibilidad de los investigadores al mismo responden a la capacidad del personal profesional y voluntario del archivo de organizarlo para que este disponible a la consulta e investigacion. Palabras claves : Archivo; Salesiano; Patagonia. ABSTRACT This arti...

Summary In this last decade, the Patagonia Region was affected for fires that burned thousand of hectares of native forests and natural grasslands. The climate conditions, characterized by a winter with a scarce snowy and a spring with... more

Summary In this last decade, the Patagonia Region was affected for fires that burned thousand of hectares of native forests and natural grasslands. The climate conditions, characterized by a winter with a scarce snowy and a spring with insufficient precipitations, have increased blazes with greater frequency and intensity. The objective of the present work was to apply detection and monitoring

Hydatidosis is endemic in Neuquén, Patagonia, Argentina, even though sanitary authorities have been performing a control programme since 1970. At present, the programme is in consolidation phase, and dogs have being evaluated by arecoline... more

Hydatidosis is endemic in Neuquén, Patagonia, Argentina, even though sanitary authorities have been performing a control programme since 1970. At present, the programme is in consolidation phase, and dogs have being evaluated by arecoline purgation. The aims of this study were to evaluate diagnostic performance of a coproantigen (CAg) ELISA test developed "in house" and to assess CAg detection in prepatent period. We examined 8 dogs experimentally infected with Echinococcus granulosus and 403 rural dogs in an endemic area in Neuquén using CAg ELISA test and arecoline purgation. Within the experimental dog group, sensitivity and specificity of the test were 93.6% and 88.5% respectively. In rural dogs group, the overall prevalence of canine echinococcosis was 3.7% using arecoline purgation and 12.4% by the CAg test; sensitivity and specificity of the test using arecoline purge as standard were 73.3% and 89.9% respectively. Possible cross reactions in CAg test were evaluated in rural dogs: CAg was undetectable in 96.4% of the dogs infected only with taeniids nonE. granulosus, and in 90.1% of dogs infected with non-taeniid helminths. The CAg test could detect infections within prepatent period and produced negative results after worm expulsion. Our test showed adequate diagnostic performance with experimentally and naturally infected dogs, in the epidemiological situation of Neuquén. Employment of this sensitive and practical method for surveillance in the control programme in Neuquén would improve screening of canine echinococcosis by detecting infected dogs even with low burdens or within prepatent period.

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This... more

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

The brown hare, a Leporid widespread in the world, is now dispersed across Argentina after its introduction at the end of the 19th century. Studies on hare feeding ecology are important to evaluate a potential competition with domestic... more

The brown hare, a Leporid widespread in the world, is now dispersed across Argentina after its introduction at the end of the 19th century. Studies on hare feeding ecology are important to evaluate a potential competition with domestic and native wild herbivores. This study analyses the brown hare diet in relation to food availability, and dietary overlaps with several herbivores in northern Patagonia. Food availability was estimated by point-quadrat transects, and hare diet by microhistological analysis of faeces, carried out in five habitats in five seasonal samplings. Significant differences were detected by Kruskall-Wallis ANOVA with multiple comparisons by Tukey test. Feeding selection was detected by w 2 test, and dietary preferences by the confidence interval of Bailey. Grasses and chamaephytes were the most available plant categories, with Stipa, Panicum and Acantholippia as main species. Grasses and phanerophytes were the main dietary categories, including Poa, Panicum, Bromus, Adesmia and Prosopidastrum. The phanerophytes Prosopidastrum and Ephedra were more eaten in winter, when the main food item (Poa) presented lower availability. A higher dietary proportion of the chamaephyte Acantholippia occurred in rocky habitats, where the coarse dominant grasses were always avoided. Hares shared most food items with several wild and domestic herbivores in northern Patagonia. The lack of preference for forbs differentiates brown hares from other herbivores. However, hares exhibited important dietary similarities with plain and mountain vizcachas, goats and horses, and an interspecific competition for food is highly probable.

The aim of this study was to determine the dioecious or monoecious condition of Fitzroya cupressoides and Pilgerodendron uviferum. The study area lies west of the Nahuel Huapi National Park in northern Patagonia (Argentina), where these... more

The aim of this study was to determine the dioecious or monoecious condition of Fitzroya cupressoides and Pilgerodendron uviferum. The study area lies west of the Nahuel Huapi National Park in northern Patagonia (Argentina), where these species form mixed stands. One hundred individuals of each species were studied over three successive years. The nature and position in the crown of their reproductive organs were recorded. Results showed that both species are dioecious. This feature has been confirmed on trees of these species growing in other sites within their natural distribution area in Argentina and Chile.

Comau Fjord is a stratified Chilean Patagonian Fjord characterized by a shallow brackish surface layer and a >400 m layer of aragonite-depleted subsurface waters. Despite the energetic burden of low aragonite saturation levels to... more

Comau Fjord is a stratified Chilean Patagonian Fjord characterized by a shallow brackish surface layer and a >400 m layer of aragonite-depleted subsurface waters. Despite the energetic burden of low aragonite saturation levels to calcification, Comau Fjord harbours dense populations of cold-water corals (CWC). While this paradox has been attributed to a rich supply of zooplankton, supporting abundance and biomass data are so far lacking. In this study, we investigated the seasonal and diel changes
of the zooplankton community over the entire water column. We used a Nansen net (100 mm mesh) to take stratified vertical hauls between the surface and the bottom (0-50-100-200-300-400-450 m). Samples were scanned with a ZooScan, and abundance, biovolume and biomass were determined for 41 taxa identified on the web-based platform EcoTaxa 2.0. Zooplankton biomass was the highest in summer (209 g dry massm􀀀2) and the lowest in winter (61 g dry massm􀀀2). Abundance, however, peaked in spring, suggesting a close correspondence between reproduction and phytoplankton spring blooms (Chl a max. 50.86 mgm􀀀3, 3mdepth). Overall, copepods were the most important group of the total zooplankton community, both in abundance (6481%) and biovolume (2070%) followed by mysids and chaetognaths (in terms of biovolume
and biomass), and nauplii and Appendicularia (in terms of abundance). Throughout the year, diel changes in the vertical distribution of biomass were found with a daytime maximum in the 100200 m depth layer and a nighttime maximum in surface waters (050 m), associated with the diel vertical migration of the calanoid copepod family Metridinidae. Diel differences in integrated zooplankton abundance, biovolume and
biomass were probably due to a high zooplankton patchiness driven by biological processes (e.g., diel vertical migration or predation avoidance), and oceanographic processes (estuarine circulation, tidal mixing or water column stratification). Those factors are considered to be the main drivers of the zooplankton vertical distribution in Comau Fjord.

La informalidad es una de las características constitutivas de los procesos de urbanización en América Latina. Como consecuencia, los Estados han generado diversas respuestas de política habitacional para combatirla. En la Argentina, el... more

La informalidad es una de las características constitutivas de los procesos de urbanización en América Latina. Como consecuencia, los Estados han generado diversas respuestas de política habitacional para combatirla. En la Argentina, el Programa de Mejoramiento de Barrios (PROMEBA) es una política pública habitacional de naturaleza integral y escala nacional que busca consolidar asentamientos informales a partir de intervenciones urbanas, ambientales y sociales focalizadas en población con necesidades básicas insatisfechas. En este artículo, se realiza un abordaje contextual y exploratorio que, a partir de documentos oficiales, estadísticas disponibles, material bibliográfico y entrevistas a informantes clave, revisa los objetivos, componentes y funcionamiento del PROMEBA. Se busca analizar cómo se ejecutaron sus intervenciones en la austral provincia de Chubut, para finalmente considerar sus consecuencias sobre la ciudad de crecimiento demográfico relativo más acelerado de los últi...

Summary 1 Wildfires are predicted to increase in many ecosystems in relation to globally increasing temperatures but future patterns of post-fire vegetation change are largely unknown, particularly when there are synergistic effects from... more

Summary 1 Wildfires are predicted to increase in many ecosystems in relation to globally increasing temperatures but future patterns of post-fire vegetation change are largely unknown, particularly when there are synergistic effects from introduced biota. In the late 1990s northern Patagonia, Argentina, experienced extreme droughts which led to severe wildfires affecting a range of Andean ecosystems.

The main objective of this work is the estimation of the speed ice flow on the Upsala Glacier using radar images. The Upsala Glacier is one of the temperate glaciers of high scientific interest in the Southern Patagonian Ice Field that... more

La Lupa Colección Fueguina de divulgación científica. Comité Editorial: Franch Bach, Anna Marina, Tomás. Ignacio. Lasa, Adriana. Bartoli, Valeria Roulier, Catherine. Kaminsky, Julieta. Balza, Ulises. Granitto, María. Pal, Nélida. García,... more

La Lupa Colección Fueguina de divulgación científica.
Comité Editorial:
Franch Bach, Anna
Marina, Tomás. Ignacio.
Lasa, Adriana.
Bartoli, Valeria
Roulier, Catherine.
Kaminsky, Julieta.
Balza, Ulises.
Granitto, María.
Pal, Nélida.
García, Victoria. Julieta.

This article analyzes the situation of energy in the Chilean region of Aysén, in recent years. The singularities generated by its late full incorporation into the national territory, its composition and the tensions in the area, which... more

Este trabajo propone analizar la producción agropecuaria en la provincia de Tierra del Fuego en las últimas dos décadas. Para ello se explora la distribución y formas de tenencia de la tierra y se identifican los cambios de las... more

Este trabajo propone analizar la producción agropecuaria en la provincia
de Tierra del Fuego en las últimas dos décadas. Para ello se explora la
distribución y formas de tenencia de la tierra y se identifican los cambios de las principales actividades productivas.
El análisis se basa en datos preliminares del Censo nacional Agropecuario 2018 y su comparación con los anteriores (1988 y 2002), a los efectos de evidenciar las transformaciones históricas acontecidas. Complementariamente se utilizó información provista por el Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA), el Consejo Federal de Inversiones (CFI), el Instituto Nacional de Tecnología
Agropecuaria (INTA) y estudios realizados por otros investigadores en la
provincia.

The Quaternary is synonymous with extensive glaciation of Earth's mid-and high-latitudes. Although there were local precursors, significant glaciation began in the latest Eocene (ca 35 Ma) in eastern Antarctica. It was followed by... more

The Quaternary is synonymous with extensive glaciation of Earth's mid-and high-latitudes. Although there were local precursors, significant glaciation began in the latest Eocene (ca 35 Ma) in eastern Antarctica. It was followed by glaciation in mountain areas through the Miocene (in Alaska, Greenland, Iceland and Patagonia), later in the Pliocene (e.g. in the Bolivian Andes and possibly in Tasmania) and in the earliest Pleistocene (e.g. in the Alps, New Zealand, Iceland and Greenland). Today, evidence from both the land and the ocean floors demonstrates that the major continental glaciations, outside the polar regions, rather than occurring throughout the 2.6 Ma of the Quaternary, were markedly restricted to the last 1 Ma-800 ka or less. Marine Isotope Stage (MIS) 22 (ca 870-880 ka) included the first of the 'major' worldwide events with substantial ice volumes that typify the Later Pleistocene glaciations (i.e. MIS 16, 12, 10, 6, 4-2). r

The European green crab Carcinus maenas is a widely spread invasive species. Studying the most recently introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of... more

The European green crab Carcinus maenas is a widely spread invasive species. Studying the most recently introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of the visceral-cavity detaching from the rest of the exoskeleton after ecdysis) accumulated on the intertidal may be used as a valuable complementary material to analyze the size structure of crabs. However, since growth rate (and consequently size at instar) of crabs differs between males and females, finding a method to distinguish crab sex by observation of carapace morphology was necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes.

Este trabajo refleja lo investigado en el primer año de trabajo del PI 29A/428 “Migraciones internacionales e identidad territorial en la ciudad de Río Gallegos en el siglo XXI, Patagonia Austral Argentina”. El proyecto se basa en que los... more

Este trabajo refleja lo investigado en el primer año de trabajo del PI 29A/428 “Migraciones internacionales e identidad territorial en la ciudad de Río Gallegos en el siglo XXI, Patagonia Austral Argentina”. El proyecto se basa en que los migrantes desarrollan diversas prácticas espaciales de sus tradiciones como consumo y venta de productos de comidas típicas, festejo de fiestas patrias y de la liturgia religiosa. De este modo, se generan procesos de conformación de identidad territorial, a través de grupos migratorios internacionales que arribaron a la ciudad durante las dos primeras décadas del siglo XXI, y que se identifican, según localización, en las distintas áreas internas de la ciudad. El objetivo de este trabajo es exponer los resultados que surgieron de identificar, relevar y espacializar las estrategias culturales generadoras de cohesión territorial —religiosidad popular, fiestas y bailes, recursos culinarios y asociaciones—, traducidos en prácticas socioespaciales y que generan identidad territorial en el Área Central y Tercera Franja Residencial de Rio Gallegos.
Metodológicamente se analizó bibliografía específica, se realizó observación directa e
indirecta, realización de entrevistas a informantes clave, relevamientos de campo y
elaboración de cartografía temática. Los resultados aportan desde lo teórico y metodológico a
la Geografía Cultural sobre las migraciones en la Patagonia Austral Argentina en general y en
particular para Río Gallegos, como para el municipio, como aporte para la gestión territorial.

Pilgerodendron uviferum (Cipres de las Guiatecas, Cupressaceae) is a long-lived conifer, endemic to southern Chile and Argentina, reaching a southern limit in Tierra del Fuego. Remnant populations are generally fragmented and highly... more

Pilgerodendron uviferum (Cipres de las Guiatecas, Cupressaceae) is a long-lived conifer, endemic to southern Chile and Argentina, reaching a southern limit in Tierra del Fuego. Remnant populations are generally fragmented and highly disturbed because of exploitation for timber, grazing and fire. The extent of genetic variation within and between 16 populations of this species, distributed throughout its range, was assessed using random amplified polymorphic DNA (RAPD) markers. Eight 10-mer primers produced a total of 84 scorable markers, 30 of which (35.7%) were polymorphic. AMOVA indicated that 18.6% of the variation recorded was attributable to differences between populations, a relatively high value compared with other conifers from the region. Pair-wise Phi st comparisons between populations were all significant at P <0.05, with one exception, highlighting a high degree of population differentiation. Values of Shannon's diversity index (S) differed significantly among populations (P=0.002, ANOVA), values ranging from 0.337 to 0.716, suggesting that some populations are currently characterised by very low genetic variability. Current patterns of genetic variation were related to biogeographic history and human impact. The high degree of population differentiation recorded here highlights the need for additional conservation measures for this species, both in terms of incorporating further populations into the protected areas, and the restoration of severely degraded populations, to ensure their continued viability. #

Anthropogenic habitat disturbance can have profound effects on multiple components of forest biotas including pollinator assemblages. We assessed the effect of small-scale disturbance on local richness, abundance, diversity and evenness... more

Anthropogenic habitat disturbance can have profound effects on multiple components of forest biotas including pollinator assemblages. We assessed the effect of small-scale disturbance on local richness, abundance, diversity and evenness of insect pollinator fauna; and how habitat disturbance affected species turnover across the landscape and overall diversity along a precipitation gradient in NW Patagonia (Argentina). We evaluated the effect of disturbance on overall pollinator fauna and then separately for bees (i.e. Apoidea) and non-bee pollinators. Locally, disturbed habitats had significantly higher pollinator species richness and abundances than undisturbed habitats for the whole pollinator assemblage, but not for bees or non-bees separately. However, significant differences in species richness between habitats vanished after accounting for differences in abundance between habitat types. At a local scale Shannon-Weaver diversity and evenness did not vary with disturbance. A b diversity index indicated that, across forest types, species turnover was lower between disturbed habitats than between undisturbed habitats. In addition, rarefaction curves showed that disturbed habitats as a whole accumulated fewer species than undisturbed habitats at equivalent sample sizes. We concluded that small patches of disturbed habitat have a negligible effect on local pollinator diversity; however, habitat disturbance reduced b diversity through a homogenization of the pollinator fauna (in particular of bees) across the landscape.

Aquatic invasive species are a major threat to native freshwater ecosystems and cause enormous ecological and economic damage worldwide. Didymosphenia geminata (Lyngbye) M. Schmidt is an emerging invasive aquatic species that is spreading... more

Aquatic invasive species are a major threat to native freshwater ecosystems and cause enormous ecological and economic damage worldwide.
Didymosphenia geminata (Lyngbye) M. Schmidt is an emerging invasive aquatic species that is spreading aggressively in Southern South America.
Using niche analysis and species distribution models (SDMs), we examined niche requirements of D. geminata using climatic, topographic, and
biological variables. We compared the realized niche of the species in the United States (US) with the niche in Chile. Within Chile, we also
examined the environmental conditions (environmental envelopes) of rivers with and without this alga, to assess whether this species has the
potential to colonize more rivers. Finally, we compared the SDMs from the US and Chile projected to Chile. Results showed that the potential
distribution of D. geminata varied significantly between US and Chile. The US-based model predicted a geographic distribution in Chile which
ranged from 32º to 55º S latitude while the Chile-based model predicted suitable habitats only from 36° to 48º S, and not so in the coastal ranges nor
in Southern Patagonia ( ̴ 52–55°S). In Chile, we found no differences in the environmental envelopes of the invaded and uninvaded rivers, thus
suggesting that this species has even more suitable habitats to invade. These results can be used for prioritizing survey sites in Southern Chile for an
early detection and management of D. geminata and for the conservation of native flora and fauna in freshwater ecosystems in Chile.

The diet of the nudibranch mollusc Tritonia odhneri was investigated for the first time based on a detailed anatomical analysis of the gut content of 52 specimens. Digestive tracts of specimens were analysed under stereoscopic microscope... more

The diet of the nudibranch mollusc Tritonia odhneri was investigated for the first time based on a detailed anatomical analysis of the gut content of 52 specimens. Digestive tracts of specimens were analysed under stereoscopic microscope equipped with digital camera. Portions of octocorals containing the calcareous sclerites were removed from the tracts and prepared for scanning electron microscopy (SEM). Sclerite morphology and size were determined at the species and genus level on the basis of a taxonomical revision and compared with fresh octocoral specimens collected from Patagonia (San Jorge Gulf) and with voucher specimens from the collections of Museo Argentino de Ciencias Naturales (MACN-in). Specific predation of T. odhneri on octocoral species present in the southwestern Atlantic Ocean was detected. The nudibranch feeds on the gorgonians Primnoella divaricata, Primnoella scotiae (=P. compressa) and Tripalea clavaria, and the pennatulaceans Renilla octodentata and Stylatula sp. A world checklist of dietary interactions between species of the genus Tritonia and octocorals is presented and discussed.

This paper presents a contingent valuation study concerning landscape impacts generated by the construction of one dam (Baker 1) of the HIDROAYSEN hydropower project located in the Chilean Patagonia. A survey was used to collect... more

This paper presents a contingent valuation study concerning landscape impacts generated by the construction of one dam (Baker 1) of the HIDROAYSEN hydropower project located in the Chilean Patagonia. A survey was used to collect information about citizens’ opinions towards the hydropower project in four major cities in Chile. Specifically, a One-and-One-Half-Bound (OOHB) willingness to pay eliciting format was applied to capture citizens’ WTP. The economic loss, associated to the landscape impacts for people living in urban areas of the country, is found to be approximately US$ 205 million, which is nearly 28% of the total investment. Our results also show that the cities’ distance from the dam affects citizens’ willingness to pay.

The average age at sexual maturity (ASM) is an important parameter for evaluating the reproductive potential or status of a population. South American sea lions, Otaria flavescens in Patagonia (Argentina) were exploited and reduced to... more

The average age at sexual maturity (ASM) is an important parameter for evaluating the reproductive potential or status of a population. South American sea lions, Otaria flavescens in Patagonia (Argentina) were exploited and reduced to less than 10% of pre-exploitation numbers. At present, the population is recovering at a rate of 6%. In this paper, we studied growth and age at sexual maturity of South American sea lions in the south-western south Atlantic by examining 219 individuals (females and males) collected between 1989-2008. Individuals were aged by counting growth layer groups in tooth sections, standard body length was measured and male and female reproductive organs were examined macroscopically and histologically to establish individual sexual maturity. Maximum recorded length for males and females was 264 cm and 200 cm, respectively, and maximum ages 19 and 21 yrs. ASM defined as the age where 50% of females are mature, was estimated at 4.870.5 years old, corresponding to a mean SL of 147 cm, about 81% of their asymptotic length. First observed ovulation occurred during the 4th year, first birth may occur between 4 and 5 years old. Males physiologically mature between 4-6 years, but the size of the testes shows that all males became sexually mature by the age of 9 years when they reach a mean SL of 212 cm, about 86% of their asymptotic body length. The present information on ASM and growth of O. flavescens will improve the development of population dynamics models, to investigate the impact of recovering sea lions populations on its marine environment, as well as its trophic interactions with commercial fisheries.

Pesticide distribution in the soil profile depends on soil and pesticide properties as well as on the composition of irrigation water. Water containing surfactants, acids or solvents, may alter pesticide desorption from soil. The... more

Pesticide distribution in the soil profile depends on soil and pesticide properties as well as on the composition of irrigation water. Water containing surfactants, acids or solvents, may alter pesticide desorption from soil. The distribution of organochlorine pesticides (OCPs) in two Argentinean agricultural areas, Pampa and Patagonia, was evaluated. Furthermore, pesticide desorption from aged and freshly spiked soils was performed by the batch technique, using solutions of sodium oxalate and citrate, dissolved organic carbon (DOC), wastewater and surfactants. Patagonian soil showed the highest OCP levels (46.5-38.1 lg g À1 OC) from 0 to 30 cm depth and the predominance of p,p 0 -DDE residues reflected an extensive and past use of DDT. Pampean soil with lower levels (0.039-0.07 lg g À1 OC) was mainly polluted by the currently used insecticide endosulfan. Sodium citrate and oxalate, at levels usually exuded by plant roots, effectively enhanced desorption of p,p 0 -DDT, p,p 0 -DDE and a-cypermethrin, while no effects were observed for a-endosulfan and endosulfan sulfate. The non-ionic surfactant Tween 80 behaved similarly to the acids, whereas the anionic sodium dodecyl sulfate enhanced desorption of all pesticides. Increased desorption of the hydrophobic pesticides also occurred when DOC from humic acids but not from sewage sludge or wastewater were used. Soil profile distribution of pesticides was in accordance with results from desorption studies. Data suggest pesticide leaching in Pampean and Patagonian soils, with risk of endosulfan to reach groundwater and that some organic components of wastewaters may enhance the solubilisation and leaching of recalcitrant compounds such as p,p 0 -DDT and p,p 0 -DDE. Ó

Servicio Nacional de Geología y Minería Chile Vattuone, María E.; Latorre, Carlos O.; Leal, Pablo R. Mineralogía y paragénesis de dachiardita cálcica en rocas volcánicas cretácicas ceolitizadas, Esquel,

Airborne and satellite remote sensing is the only practical approach for deriving a wide area, regional assessment of glacier mass balance. A number of remote sensing approaches are possible for inferring the mass balance from some sort... more

Airborne and satellite remote sensing is the only practical approach for deriving a wide area, regional assessment of glacier mass balance. A number of remote sensing approaches are possible for inferring the mass balance from some sort of proxy estimate. Here, we review the key methods relevant, in particular to Andean glaciers, discussing their strengths and weaknesses, and data sets that could be more fully exploited. We also consider future satellite missions that will provide advances in our observational capabilities. The methods discussed include observation of elevation changes, estimation of ice flux, repeat measurement of changes in spatial extent, snowline elevation and accumulation-ablation area ratio estimation. The methods are illustrated utilising a comprehensive review of results obtained from a number of studies of South American glaciers, focusing specifically on the Patagonian Icefields. In particular, we present some new results from Glaciar Chico, Southern Patagonian Icefield, Chile, where a variety of different satellite and in-situ data have been combined to estimate mass balance using a geodetic or elevation change approach over about a 25 yr period.

The Magallanes or Austral Basin is shared by Argentina and Chile; both countries developed the knowledge on foraminifera in different timing and ways. These differences delayed the integration of the stratigraphical information from both... more

The Magallanes or Austral Basin is shared by Argentina and Chile; both countries developed the knowledge on foraminifera in different timing and ways. These differences delayed the integration of the stratigraphical information from both parts of the Basin. In Chile, the studies began in the ´40s in the national oil company ENAP and most of its reports remained unpublished until 1974, when a system of stages for correlation was proposed. This system, particularly for the Paleogene, was based on benthonic foraminifera because of the scarcity of planktonic forms. In Argentina, a first study on the Paleogene foraminifera from the Austral Basin is published in the late 60s, and after several years devoted to publish and illustrate the Cretaceous foraminifera, the research has been again focused on the Paleogene since the end of the century.

This investigation of identity construction in twentieth-century Welsh Patagonia breaks new ground by looking at the Welsh community in Chubut not as a quaint anomaly, but in its proper context as an integral part of contemporary... more

This investigation of identity construction in twentieth-century Welsh Patagonia breaks new ground by looking at the Welsh community in Chubut not as a quaint anomaly, but in its proper context as an integral part of contemporary Argentina. Addressing the implications of the settler colonialism of the foundational myth of Chubut and its place in the larger question of settler colonialism throughout Argentina, it draws on the literature of the under-studied period immediately preceding the turn-of-the-twentieth-century revitalization of the Welsh community in Patagonia. Ultimately, it presents a newly broad, much richer panorama of what it means to be Welsh in Argentina, free from old stereotypes and fully part of the contemporary nation.

While the Ensenadan Stage/Age (ca. 2.1 to 0.5 Ma) was characterized by certain mammal associations in the Pampean plains, the Andean ranges of Patagonia and Tierra del Fuego, their piedmont areas and, in some cases, the adjacent lowlands... more

While the Ensenadan Stage/Age (ca. 2.1 to 0.5 Ma) was characterized by certain mammal associations in the Pampean plains, the Andean ranges of Patagonia and Tierra del Fuego, their piedmont areas and, in some cases, the adjacent lowlands were undergoing a well-defined alternating sequence of glacial and interglacial stages driven by the regional climate of Southernmost South America and Antarctica. This paper reviews the available geographical, geological and chronological evidence of glaciation during the Ensenadan stage/age, with perhaps more than 15 distinct glacial events, including the Great Patagonian Glaciation (GPG) and other cold episodes that took place before and after it. Finally, a tentative correlation of Patagonian glacial episodes and the Pampean biostratigraphic stages, based on radiometric dating and paleomagnetic studies, is herein presented.

The up-to-date knowledge of the Magellanic Plover (Pluvianellus socialis), an endemic shorebird of Southern Patagonia: putting together the pieces of the puzzle. -The Magellanic Plover (Pluvianellus socialis) is a species endemic to... more

The up-to-date knowledge of the Magellanic Plover (Pluvianellus socialis), an endemic shorebird of Southern Patagonia: putting together the pieces of the puzzle. -The Magellanic Plover (Pluvianellus socialis) is a species endemic to southern Patagonia, with an estimated population of less than 1500 individuals. We report findings on distribution, migratory movements, abundance, habitat and reproductive biology, in the zone of the highest known densities: south-central Santa Cruz Province, Argentina. Also, in the interest of combining and reporting dispersed information on the species, we surveyed researchers within its geographic range for encounters and observations. We report the largest known group of individuals encountered, almost 15% of the population; the discovery of at least two successful brooding attempts within a breeding season; a high rate of hatching success (12 of 17 nests, ~70%), in the 2006-2007 season), and the extension of their breeding range. Although we present some indications that the global population is higher than previously estimated, an accurate estimate is difficult because it is a rare species with a localized abundance using highly variable reproductive environments annually and inter-annually.

Durante el año 2003, Shultz y colaboradores informaron sobre un esqueleto de ictiosaurio fragmentario que se colectó en el PN Torres del Paine, sur de Chile. El espécimen fósil fue descubierto dentro de un bloque errático, y dado lo... more

Durante el año 2003, Shultz y colaboradores informaron sobre un esqueleto de ictiosaurio fragmentario que se colectó en el PN Torres del Paine, sur de Chile. El espécimen fósil fue descubierto dentro de un bloque errático, y dado lo fragmentario de los restos, no podían ser asignados a una especie, menos datarse con precisión, ni ligar a una formación específica (Shultz et al., 2003). Durante el mismo año, un grupo de glaciólogos magallánicos tomaron las primeras fotos de los huesos in situ en estratos expuestos en la base del Glaciar Tyndall. Estos especímenes descubiertos en Torres del Paine representan los ictiosaurios más meridionales conocidos hasta la fecha y amplían la distribución de este grupo de reptiles marinos unos 1500 - 2000 km al sur del material previamente descrito para la cuenca de Neuquén en Argentina (Gasparini y Fernández, 1997, 2005; Fernández y Aguirre-Urreta, 2005). Desde 2008, un grupo de investigación Chileno-Alemán estudia el ensamble fósil y la geología de este depósito. En un área de menos de 10 km2 se ha detectado sobre numerosos especímenes de ictiosaurios articulados y, a veces prácticamente completos, los que han sido tentativamente asignados a diferentes especies de Ophtalmosauridae. A ello se suman huesos aislados de ictiosaurios y cocodrilos, bien conservados, peces teleósteos ganoídeos, belemnites, amonites, inocerámidos y restos de plantas son también abundantes.