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Austral Yungas cloud forest (Southern Bolivia and NW Argentina) is known for its high diversity, steep landscape and low accessibility. Anacroneuria Klapálek (Plecoptera: Perlidae) species in this ecoregion have been seldom studied. We aim to know its species diversity (based on adult characters) and explore larval characters important for their recognition. We have reared dozens of larvae from different localities and collected adults with light traps. Reared adults and associated larval exuviae were studied, photographed and drawn. We have identified 13 species (based on male aedeagus) and successfully associated larval and adult stages for seven species. In the present paper we describe seven new species: Anacroneuria tafi sp. nov., A. flavinigra sp. nov., A. saican sp. nov., A. triplex sp. nov., A. calilegua sp. nov., A. lutea sp. nov., and A. tupacamaru sp. nov. For six species previously described we present new data and stage descriptions: A. arrazayalensis Orce, A. handlirschi Klapálek, A. reedi (Navás), A. tucuman Stark, A. saltensis Froehlich, and A. chimborazo Stark. Genetic divergence for some of these species was studied using the barcode region of the mitochondrial gene COI. A key to the male adults of all the species of Anacroneuria from Northwestern Argentina is presented. [ABSTRACT FROM AUTHOR]

In mountain environments, both temperature and food availability vary strongly with altitude, leading to a major challenge to the thermo‐energetic balance of organisms. In this sense, the behavioral repertoire is crucial for animals' adequacy because it implies a short‐term response in the face of environmental changes. In this paper, we explored the behavioral versatility of Phyllotis vaccarum and Abrothrix andina (Rodentia: Cricetidae), two of the mammal species with the highest altitudinal distribution worldwide. By radiotelemetry, we analyzed the activity pattern, home range, and microhabitat selection in populations of both species inhabiting at 2300 and 3100 m altitude in the Central Andes of Argentina. We found that A. andina was diurnal at 3100 m and cathemeral at 2300 m a.s.l., while P. vaccarum was nocturnal at both elevations. Moreover, home range size was larger in A. andina males at 3100 m in contrast to females at identical altitude and males at 2300 m; while, in P. vaccarum, there were no differences according to altitude or sex. Furthermore, we recorded a complex and species‐specific microhabitat selection pattern at different altitudes. Finally, the magnitude of behavioral variability was higher in A. andina than in P. vaccarum for all the traits analyzed. These results are discussed with emphasis on the impact of behavioral traits and their plasticity for species adequacy in high‐altitude environments. [ABSTRACT FROM AUTHOR]

Some of the most intense thunderstorms in the world take place in central and northern Argentina, and their start and development is strongly influenced by the orography of the Andes and sierras de Coórdoba. These thunderstorms are associated with the occurrence of severe weather phenomena that generate important material damages and economic loss in rural and urban areas. The aim of this paper was to do the observational study of the spatial and temporal distribution of different severe weather phenomena, in particular, hail, intense rain and strong winds with gusts. Most of these events took place between the evening and midnight, and also between late Spring and early Summer. At the same time, while studying the occurrence of hail, it was found that its density of accumulation decreased as its diameter increased. [ABSTRACT FROM AUTHOR]

With ongoing climate change, there is a pressing need to better understand how much water is stored as ground ice in areas with extensive permafrost occurrence, as well as how the regional water balance may alter in response to the potential generation of meltwater from permafrost degradation. However, field-based data on permafrost in remote and mountainous areas such as the South American Andes are scarce. Most current ground ice estimates are based on broadly generalized assumptions such as volume–area scaling and mean ground ice content estimates of rock glaciers. In addition, ground ice contents in permafrost areas outside of rock glaciers are usually not considered, resulting in a significant uncertainty regarding the volume of ground ice in the Andes and its hydrological role. In Part 1 of this contribution, present an extensive geophysical data set based on electrical resistivity tomography and refraction seismic tomography surveys to detect and quantify ground ice of different landforms and surface types in several study regions in the semi-arid Andes of Chile and Argentina with the aim to contribute to the reduction of this data scarcity. In Part 2 we focus on the development of a strategy for the upscaling of geophysics-based ground ice quantification to an entire catchment to estimate the total ground ice volume (and its approximate water equivalent) in the study areas. In addition to the geophysical data, the upscaling approach is based on a permafrost distribution model and classifications of surface and landform types. In this paper, we introduce our upscaling strategy, and we demonstrate that the estimation of large-scale ground ice volumes can be improved by including (i) non-rock-glacier permafrost occurrences and (ii) field evidence through a large number of geophysical surveys and ground truthing information. The results of our study indicate that (i) conventional ground ice estimates for rock-glacier-dominated catchments without in situ data may significantly overestimate ground ice contents and (ii) substantial volumes of ground ice may also be present in catchments where rock glaciers are lacking. [ABSTRACT FROM AUTHOR]

In this paper we review the growing evidence of anthropogenic landscapespresent in the semi-deciduous neotropical forest biomes of eastern NW Argentina,which have remained relatively neglected in favour of arid to semi-arid western Andean regions. The evidence gathered in de El Alto-Ancasti provides animportant case study where multidisciplinary methodologies have beenapplied to sites that document the emergence and variability in food productionstrategies across the eastern Andean forests and grasslands of NWArgentina. We discuss evidence offarming structures from archaeological surveys, plant management from phy-tolith analysis, and the tempo and nature of settlement from archaeological excavations undertaken at a variety of sites in the El Alto Ancasti mountainrange. We suggest that the communities that inhabited this region during thefirst millennium AD (ca. 1500–1000 BP) established a strategy of 'overlappingpatchworks' of food production that were able to contend with considerableseasonal variability. We argue that, through the use of cross-channelling, low river areas, erosion control techniques and the establishment of mesothermal crops,including maize, legumes, and tubers, throughout the region, these societies adopted flexible strategies to adapt to life in a region prone to climatic change [ABSTRACT FROM AUTHOR]

Drylines have been identified as relevant synoptic-scale phenomena that frequently occur in several regions around the world. Despite previous works and the experience of local forecasters that recognizes the occurrence of drylines in Argentina and suggests its possible association with convection initiation, knowledge about the mechanisms leading to the genesis of these features is poor. This paper presents the first synoptic climatology of these drylines as well as a first approach to the understanding of the processes leading to their formation. The climatology is based on an automated algorithm for dryline identification applied to reanalysis data. We found that drylines are more frequent between the northern Patagonia plateau and the central Argentinean plains. A composite analysis is performed to analyze the processes leading to the formation of synoptic-scale drylines within this region. It was found that these drylines form in the confluence between a warm and moist air mass driven by a northwesterly flow and drier air flowing east over the northern Patagonia plateau. The dry air originates on top of the Pacific maritime boundary layer and experiences lee subsidence after crossing the Andes range creating an area of dry and warm air that is advected to the east by the westerly synoptic-scale flow, and transported downward during the day due to strong boundary layer turbulence. At the same time, surface heating over the plateau leads to substantial warming of the originally colder dry air behind the dryline, thus reversing the horizontal temperature gradient across the dryline. [ABSTRACT FROM AUTHOR]

Objective/context: This paper once again brings the iconographies of Tiwanaku (Titicaca high plateau, Bolivia) and La Aguada (Northwest of Argentina) into discussion, more than 40 years after the works of Rex González and Ponce Sanginés. It does so in an entirely different context with a decolonial emphasis. Objects, images, ethnographic information and archaeologists from both sides of a border between "nations" are assembled with the clear intention of questioning very deep underlying assumptions of archaeology. Methodology: Beginning with the paths posed by images and colors, these knots also bind humans and things, shamanic experiences and meteorological phenomena. Conclusions: After bringing La Aguada and Tiwanaku into dialogue, based on our research trajectories, the discussion leads to a reflection on the present consequences of naturalizing segmented and functionalist gazes of the animal and plant worlds in the past, which originate in the ontological underpinnings of our own modernity. Originality: The text aims to approach decolonial criticism from the study of concrete cases and to contribute to these debates on the basis of archaeological materiality. [ABSTRACT FROM AUTHOR]

Steppes and grasslands of semiarid environments in the Central Andes are poorly understood in fossil records due to the lack of modern pollen–vegetation studies. This paper is focused on a systematic analysis of the modern pollen–vegetation relationship in three protected areas of the Puna in Jujuy, northwestern Argentina. Vegetation assemblages were described on the basis of their floristic composition in 32 plots. Different multivariate methods, indices of association and simple linear regression models were applied in order to investigate the degree to which the different vegetation assemblages can be distinguished by their pollen spectra. Five plant assemblages were described, which were partially represented by their pollen spectra: mixed and shrubby steppes, scrubland, grassland with shrubs and high Andean grassland. The pollen spectra reflected both altitudinal variations and environmental conditions. In the Puna belt, at 3600 m, shrubs were present in great abundance and their highest pollen percentages were recorded. Both the abundance of Poaceae herbs and their pollen type increased with increasing altitude up to 4220 m, indicating the transition towards the Altoandean belt. Pollen assemblages evidenced the following environmental conditions: (1) the temperature decrease is characterized by taxa adapted to either cold air (<7 °C) or cold soil (Aridisols-Cryids/Inceptisols-Ustepts type) including Poaceae, Frankenia triandra, Apiaceae, Hoffmansegia glauca, Ephedra, Caryophyllaceae; (2) moisture availability in the soil can be discernible by assemblages indicating dry soil (Aridisols-Durids type), such as Baccharis, Fabiana densa, Maihuniopsis boliviana, Fabaceae, Tetraglochin cristatum and Nassauvia axilaris, from those indicating humid soil (Entisols-Psaments type), such as Parastrephia, Astragalus garbancillo and Gentianaceae. Four taxa exhibited both a good association and a significant correlation and could be considered indicative of the steppe (Baccharis and M. boliviana), scrublands (Parastrephia) and grassland (Poaceae) in a fossil record. This work has important implications for interpreting the dynamics of vegetation during the Holocene in the Puna. [ABSTRACT FROM AUTHOR]

A large (>0.1 km 2 ) and complex mass movement in the Central Andes of Argentina (final portion of Cordillera de Olivares, Frontal Cordillera), was studied to identify the triggering factors and understand their relationship with geomorphic, cryogenic and climatic dynamics. This debris-rockslide is composed of clast supported blocks of Permian–Triassic volcanic breccias. In order to characterize this feature, high resolution satellite imagery interpretation was carried out, together with the study of the landslide detachment zones and landslide bodies. These debris-rockslide events could have originated as a consequence of the combination of internal slow deformation and fragmentation under periglacial conditions, followed by a sudden collapse of the rock mass. Pre- and post-slide digital elevation models (DEMs) were created from topographical data with the help of a Geographic Information System (GIS) tool. Approximately 14.89 M m 3 of rock and debris travelled nearly 2 km from an elevation of 5023 m–4325 m asl. Although usually the origin of such catastrophic movements is related to seismically active areas with earthquakes whose magnitude frequently exceed Ms 6, our hypothesis is that this debris-rockslide event has a climatic origin caused by large snow accumulations during winters and subsequent fast meltdown processes during spring, which would have facilitated the sliding. The paper outlines the important role that snowmelt can play in the genesis and evolution of rock displacements and the importance of meteorological data, seismic catalogues, historical aerial photography and satellite images in geomorphological back-analysis. [ABSTRACT FROM AUTHOR]

Marine sedimentary rocks of the lower Miocene Monte León Formation of southeastern Patagonia (Austral Basin), Argentina are important geological archives for better understanding regional tectonics, paleoenvironments, oceanography, and climate. In this paper, we describe assemblages of invertebrates, palynomorphs, foraminifera, ostracods and calcareous nannofossils in a stratigraphical and sedimentological framework, which suggest deposition during a transgressive-regressive cycle. From base to top, the lowermost outcropping deposits of the Punta Entrada Member represent an inner shelf environment, formed during a transgressive phase. The zone of maximum flooding is marked by a high diversity of protoperidiniaceans (heterotrophic) and offshore dinoflagellate cysts, an increase in the percentage and size of planktonic foraminifera, and a decrease in shallow water benthic foraminifera. Regressive deposits in the upper part of the Punta Entrada Member exhibit a progradational stratal stacking pattern and are characterized by an upward decrease in bioturbation and in the content of marine invertebrates; the dinoflagellate cyst assemblages point toward shallower and more restricted marine conditions than in underlying deposits. The cycle ends with the Monte Observación Member, which contains an impoverished and mostly reworked fauna of invertebrates. The presence of monospecific reefs of Crassostrea orbignyi , the decrease in dinoflagellate cysts and calcareous microfossils diversity, and the increase of continental palynomorphs suggest progressively shallower conditions and increasing influence of freshwater discharge. Although eustatic controls could have contributed to the sedimentary evolution of the Monte León Formation, the upward regressive trend is interpreted as the result of tectonism linked to the Andean orogeny, which led to the uplift, exhumation, and erosion of the highlands in the west. This is supported by the abundance of pyroclastic material, together with reworked specimens of Upper Cretaceous forams and Upper Cretaceous and middle Eocene dinoflagellate cysts in the upper part of the Punta Entrada Member and in the Monte Observación Member. • Multiproxy data indicate that study rocks represent a transgressive-regressive cycle. • A maximum flooding and/or higher organic flux zone was identified at the coastal cliffs. • The regressive trend was the result of tectonics, sediment supply dynamics, and volcanism. • Cretaceous/Eocene forams and dinocysts evidence exhumation and reworking from the Andes. [ABSTRACT FROM AUTHOR]

This paper presents a detailed geological map at the 1:20,000 scale of the Tocomar basin in the Central Puna (north-western Argentina), which extends over an area of about 80 km2 and displays the spatial distribution of the Quaternary deposits and the structures that cover the Ordovician basement and the Tertiary sedimentary and volcanic units. The new dataset includes litho-facies descriptions, stratigraphic and structural data and new 234U/230Th ages for travertine rocks. The new reconstructed stratigraphic framework, along with the structural analysis, has revealed the complex evolution of a small extensional basin including a period of prolonged volcanic activity with different eruptive centres and styles. The geological map improves the knowledge of the geology of the Tocomar basin and the local interplay between orogen-parallel thrusts and orogen-oblique fault systems. This contribution represents a fundamental support for in depth research and also for encouraging geothermal exploration and exploitation in the Puna Plateau region. [ABSTRACT FROM AUTHOR]