Argentine Pampas Research Articles

Activity Budgets, Foraging Behavior, and Diet of White-Tailed Kites (Elanus leucurus) During Breeding and Nonbreeding Seasons In the Argentine Pampas

From 2005 to 2009 we evaluated the activity patterns and food habits of White-tailed Kites (Elanus leucurus) during the breeding and nonbreeding seasons in the Argentine Pampas. According to time-activity budget analyses, perching was the most frequently observed activity during the nonbreeding season (52% of total time), whereas foraging was the most frequent activity during the breeding season (41% of total time). Flight was the least frequent of all kites' activities in both seasons (8% and 9% during the breeding and nonbreeding season, respectively). Even when kites spent a similar percentage of time foraging during both breeding and nonbreeding seasons (41% and 39%, respectively), their hunting technique differed between seasons. During the nonbreeding season, we only observed kites using active searching to forage, but during the breeding season, we observed them using active and passive searching in similar proportions. According to pellet analyses, the diet of kites was mostly composed of rodents (> 96% of total prey). Small rodents (body mass < 35 g) were dominant in numeric terms in the diet in both seasons, but larger rodents represented the bulk of biomass. Our results indicate that in the Argentine Pampas, White-tailed Kites are predominantly mammal-eating, active-search predators, as previously reported for the species in South America and North America and for other Elanus species around the world.

Diffusivity and sorptivity determination at different soil water contents from horizontal infiltration

Determination of soil hydraulic properties under non-saturated conditions is crucial in order to describe soil water dynamics in the field. The objectives of this work were: i- to determine soil water diffusivity (D) as a function of soil moisture with a simple lab set-up, based on Whisler et al. (1968) methodology, from soil moisture profiles obtained using capacitive sensors in three contrasting soils from Argentinean Pampas Region; and ii- to obtain a function that allows to determine sorptivity (S) values in the whole moisture range from diffusivity data. Additionally, horizontal infiltration data was used to obtain hydraulic conductivity function (K (h)) through inverse parameterization using HYDRUS 1-D. Horizontal infiltration was performed in order to determine D and S at different soil water content in 15 repacked columns from three different textured soils (loam, silty loam and sandy loam). The results indicate that the new approach is a suitable methodology for D (θ) and S (θ) determination. D values measured using the proposed laboratory setup ranged between 1 × 10−5 and 1.67 cm2 s−1, showing an exponential dependence with soil water content (r2 > 0.85). S values for different soil water contents ranged between 0.078 and 0.14 cm s−1/2. The highest value of S corresponded to the lowest soil water content, remaining practically constant in a large range of soil water content, and abruptly decreasing near saturation toward zero. The sandy loam soil showed higher values of D at saturation (D0) and total sorptivity (S0), as compared with the loam and silty loam soils. In conclusion, it was possible to determine D (θ) using a simple and robust setup, based on Whisler et al. (1968) method. Additionally, the proposed setup represents a simple way to measure soil S (θ) from horizontal infiltration, and to obtain K(h) functions through inverse parameterization.

Human occupation strategies and related environmental-climate during the middle and late Holocene in central Pampas of Argentina

The main objective of this work is to generate and integrate interpretations of human occupation strategies and inferences of the environmental-climatic conditions in the central Pampas during the middle and late Holocene. We present a novel archeological–geological–paleoecological analysis in the area of the Cabeza de Buey lake, placed in an aeolian landscape. During the middle Holocene, two events of human occupations were recognized at Laguna Cabeza de Buey 2 archeological site. Both events present a small amount of lithic materials, a low diversity of tools and activities developed with them (principally hard material), and the hunting and primary processing of artiodactyls. These evidences suggest a locus of specific activity associated with an ephemeral human settlement under climate conditions drier than present and the presence of small, brackish, and shallow water bodies. For the late late Holocene, the hunter-gatherer occupation has a higher depositional rate of lithic assemblage, stones with diverse origins, presence of pottery fragments, a great lithic tool diversity, knapping techniques, and activities developed with these tools (processing wood, bone, hide, non-woody plant, and soft material). These evidences reveal an occupation with a higher degree of recurrence represented by a locus of multiple activities associated with a more stable landscape, such as an environment of dunes fixed by grass vegetation, and the establishment of a permanent water body. The different environmental characteristics for the middle and late Holocene in this area promoted that human groups develop two different patterns of mobility, settlement and use of space.

Impact of the Elevation Angle on CYGNSS GNSS-R Bistatic Reflectivity as a Function of Effective Surface Roughness over Land Surfaces

The Earth’s surface bistatic reflectivity Γ L H C P , C y G N S S is experimentally characterized using the novel Global Navigation Satellite Systems Reflectometry (GNSS-R) L-band passive multistatic radar technique from the Cyclone Global Navigation Satellite Systems (CyGNSS) eight-microsatellite constellation. The focus of this study is to evaluate the influence of the GNSS satellites’ elevation angle θ e on Γ L H C P , C y G N S S , as a function of soil moisture content (SMC) and effective surface roughness parameter h . As the average response, the change of the scattering regime at a global scale and considering also vegetated surfaces appears at θ e ≈ 55°. This empirical observation is understood as a change on the dominant scattering term, from incoherent to coherent. Then, the correlation of Γ L H C P , C y G N S S and SMC is evaluated as a function of θ e over specific sparsely vegetated target areas. The smoother the surface, the higher the angular variability of the Pearson correlation coefficients. Over croplands (e.g., Argentinian Pampas), an improved correlation coefficient is achieved over angular ranges where the coherent scattering regime becomes the dominant one. As such, this function depends on the surface roughness. The maximum correlation coefficients are found at different θ e for increasing mean roughness levels: r P a m p a s ≈ 0.78 at θ e ≈ [60,70]°, r I n d i a ≈ 0.72 at θ e ≈ [50,60]°, and r S u d a n ≈ 0.74 at θ e ≈ [30,40]°. SMC retrieval algorithms based on GNSS-R multi-angular information could benefit from these findings, so as to improve the accuracy using single-polarized signals.

How Can Soil P Balance Influence Soil Test P? A case study from the Argentinian Pampas

Data from long-term crop rotation study sites were combined to evaluate the effect of long-term application (and omission) of P fertilizers. The impact of maintaining either a negative or positive P balances on soil test P at five distinct sites was described by single response functions despite a range of differences in soil properties.

A linked modelling framework to explore interactions among climate, soil water, and land use decisions in the Argentine Pampas

In flat environments, groundwater is relatively shallow, tightly associated with surface water and climate, and can have either positive and negative impacts on natural and human systems depending on its depth. A linked modelling and analysis framework that seeks to capture linkages across multiple scales at the climate/water/crop nexus in the Argentine Pampas is presented. This region shows a strong coupling between climate, soil water, and land use due to its extremely flat topography and poorly developed drainage networks. The work describes the components of the framework and, subsequently, presents results from simulations performed with the twin goals of (i) validating the framework as a whole and (ii) demonstrating its usefulness to explore interesting contexts such as unexperienced climate scenarios (wet/dry periods), hypothetical policies (e.g., differential grains export taxes), and adoption of non-structural technologies (e.g., cover crops) to manage water table depth.

Early Holocene water well in the Pampas of Argentina: Human responses to water shortage events

Water wells are ethnographically and archaeologically described in Australia and the plains of North America. Recently, a prehistoric water well from the early Holocene was recorded in the Pampas of Argentina. The aim of this paper is to present the main characteristics of the water well, considering its form, dimension, sediment analyses (texture and chemical parameters), and material culture content. This is the first water well recorded in the Pampas of Argentina. Consequently, a discussion about natural or cultural origins of this kind of features is provided. An evaluation of similarities and differences with well-described water wells from the United States and Australia is included in order to highlight the cultural origin of the pit. Also, the meaning of the cultural response to water availability in terms of early-Holocene hunter–gatherer adaptations as well as the implications of this strategy for understanding paleoenvironmental scenarios of the Pampas of Argentina are discussed. The well seems to have mitigated an exceptional lack of surface water in the eastern Pampas or offered an alternative for the non-drinkable quality of the available surface water. The strategy of digging water wells was available in the behavioral repertoire of the Pampean hunter–gatherer populations as early as c. 8700–800014C yr BP ( c. 9700–8800 cal. yr BP), as these groups were fairly flexible and resilient in dealing with short-term shortages of water.

Dynamics of glyphosate and AMPA in the soil surface layer of glyphosate-resistant crop cultivations in the loess Pampas of Argentina

This study investigates the dynamics of glyphosate and AMPA in the soil surface layer of two fields growing glyphosate-resistant crops in the loess Pampas of Córdoba Province, Argentina. Glyphosate decay and AMPA formation/decay were studied after a single application, using decay kinetic models. Furthermore, glyphosate and AMPA concentrations were investigated in runoff to evaluate their off-site risk. During a 2.5-month study, cultivations of glyphosate-resistant soybean and maize received an application of 1.0 and 0.81 kg a.e. ha−1, respectively, of Roundup UltraMax©. Topsoil samples (0–1, 1–2 cm) were collected weekly (including before application) and analysed for glyphosate, AMPA and soil moisture (SM) contents. Runoff was collected from runoff plots (3 m2) and weirs after 2 erosive rainfall events, and analysed for glyphosate and AMPA contents (water, eroded-sediment). Under both cultivations, background residues in soil before application were 0.27–0.42 mg kg−1 for glyphosate and 1.3–1.7 mg kg−1 for AMPA. In the soybean area, the single-first-order (SFO) model performed best for glyphosate decay. In the maize area, the bi-phasic Hockey-Stick (HS) model performed best for glyphosate decay, due to an abrupt change in SM regimes after high rainfall. Glyphosate half-life and DT90 were 6.0 and 19.8 days, respectively, in the soybean area, and 11.1 and 15.4 days, respectively, in the maize area. In the soybean area, 24% of the glyphosate was degraded to AMPA. In the maize area, it was only 5%. AMPA half-life and DT90 were 54.7 and 182 days, respectively, in the soybean area, and 71.0 and 236 days, respectively, in the maize area. Glyphosate and AMPA contents were 1.1–17.5 times higher in water-eroded sediment than in soil. We conclude that AMPA persists and may accumulate in soil, whereas both glyphosate and AMPA are prone to off-site transport with water erosion, representing a contamination risk for surface waters and adjacent fields.

Modern plains vizcacha (Lagostomus maximus, Chinchillidae, Rodentia) as a bone accumulating agent in the Argentine Pampas: Application to the study of fossiliferous sites

Lagostomus maximus (Rodentia, Chinchillidae), or Plains vizcacha, is a caviomorph rodent that inhabits semi-arid grasslands and desert scrub of central and northern Argentina, southern Paraguay and southeastern Bolivia. A particular behavior of the Plains vizcacha is the collection and transport of bones, dried dung and branches, among other objects, which are accumulated near the vizcacheras entrances. A bone concentration, originated in active vizcacheras of the southwestern Buenos Aires Province (Argentina), was studied from a taphonomic point of view for one year. The obtained results reflect that Plains vizcacha represents an important bone accumulating agent in the Argentine Pampas, and it is capable of producing large concentrations. Moreover, their vizcacheras act as natural traps that may favor the accumulation and preservation of the bone remains. The information obtained through this actualistic study provides new information on the ecology of this rodent and, in turn, introduces a framework of reference for the identification of similar concentrations in the fossil record.

The South American agricultural frontier: the first direct evidence for maize consumption in San Luis, Argentina

The spread of agriculture across the Andes is a topic of intense archaeological debate, particularly the processes driving the adoption of maize (Zea mays) by mobile hunter-gatherer groups of the Central Pampas of Argentina. This paper presents the first direct botanical evidence of maize from the Late Holocene hunter-gatherer sites of El Durazno and La Alborado in the San Luis province—an area considered climatically unsuited to maize production. These data provide important new information on the production, processing and consumption of maize on a macro-regional scale, and the development of Central Pampas exchange systems.

Species-specific phenological trends in shallow Pampean lakes' (Argentina) zooplankton driven by contemporary climate change in the Southern Hemisphere.

The relationship between the timing of recurrent biological events and seasonal climatic patterns (i.e., phenology) is a crucial ecological process. Changes in phenology are increasingly linked to global climate change. However, current evidence of phenological responses to recent climate change is subjected to substantial regional and seasonal biases. Most available evidence on climate-driven phenological changes comes from Northern Hemisphere (NH) ecosystems and typically involves increases in spring and summer temperatures, which translate into earlier onsets of spring population developments. In the Argentine Pampa region, warming has occurred at a much slower pace than in the NH, and trends are mostly restricted to increases in the minimum temperatures. We used zooplankton abundance data from Lake Chascomús (recorded every two weeks from 2005 to 2015) to evaluate potential changes in phenology. We adopted a sequential screening approach to identify taxa displaying phenological trends and evaluated whether such trends could be associated to observe long-term changes in water temperature. Two zooplankton species displayed significant later shifts in phenology metrics (end date of Brachionus havanaensis seasonal distribution: 31day/decade, onset and end dates of Keratella americana seasonal distribution: 59day/decade and 82day/decade, respectively). The timing of the observed shift in B.havanaensis phenology was coincident with a warming trend in the May lake water temperature (4.7°C per decade). Analysis of abundance versus temperature patterns from six additional shallow Pampean lakes, and evaluation of previous experimental results, provided further evidence that the lake water warming trend in May was responsible for the delayed decline of B. havanaensis populations in autumn. This study is the first report of freshwater zooplankton phenology changes in the Southern Hemisphere (SH).

Soil macrofauna diversity as a key element for building sustainable agriculture in Argentine Pampas

The agricultural activity in the Argentine Pampas, characterized by an important trend towards no-till soybean monocropping, has completely transformed the original Pampas landscape into a monotonous scenario with a continuous succession of farms of very low crop diversity. This process has led to soil physical, chemical and biological degradation in those systems. The increase of crop rotation rates in no-till and reduced tillage systems has been proposed as an alternative with reduced negative impact on soils in the context of conventional agriculture. On the other hand, extensive organic farming is also suggested as an alternative to high-input agriculture systems. In this article, we aim to explore how different variations of farming practices and systems impact soil macrofauna, along an edaphoclimatic gradient in the Pampas region. We studied the following systems: natural grassland (Gr) as indicator of the original community, extensive organic farming (Org), conventional agriculture with no-tillage and three crop rotation levels (Nt-R1, Nt-R2 and Nt-R3), and reduced tillage with two levels of crop rotation (Til and Til-R). We assessed soil macrofauna, with emphasis on earthworm, beetle and ant communities; and soil physical and chemical properties. Macrofaunal taxa composition was significantly affected by both management systems and edaphoclimatic conditions. The Gr community had pronounced differences from all the agricultural systems. The earthworm community from Gr had distinctive features from those of most agricultural systems, with Org and Nt-R3 being the most similar to Gr in native and exotic earthworm species, respectively. The beetle community in Org was the most different one, and the communities from the other systems did not show a pattern related to management. Ant community composition was not determined by management systems, but it was affected by edaphoclimatic conditions. All the studied macrofauna groups had a significant co-variation with soil physical and chemical properties, showing that both the characteristics of each soil relative to the geographic location and the effect of management on abiotic soil attributes have an important effect on soil macrofauna. This study confirms that biodiversity is being lost in Pampas soils, which implies a possible threat to the soil capacity to perform the processes that sustain soil functioning and hence plant productivity. Further considerations about the sustainability of the current agricultural model applied in the Argentine Pampas are needed.

Late Quaternary aeolian and fluvial-aeolian deposits from southwestern Pampas of Argentina, southern South America

The central region of Argentina, southern South America, is characterized by an extensive Quaternary aeolian record. In this context, three locations from the southwestern Pampas, an Andean foreland region bearing a rich fossil mammal record that contributed to the South America biostratigraphic scheme, were selected to carry out a comprehensive sedimentological analysis of the late Quaternary deposits. The case studies are located at the Transverse Valleys of La Pampa province (Chapalcó, Quehué and Utracán-Argentino valleys), and exhibit a high resolution of the late Quaternary in comparison with others areas of the southwestern Pampas. The Toay locality (~36° 41′S, 64° 24′W) records aeolian-dominant activity since the end of the Late Pleistocene (~30 ka) onwards, soil formation at some point during the Holocene and early–mid 20th century reactivation of aeolian process. The Arroyo Quehué locality (~37°04′S, 64°42′W) presents a Late Pleistocene-Holocene succession mostly related to an ephemeral endorheic fluvial system, with an interval of relative surface stabilization and aeolian aggradation during the Late Holocene. The Utracán locality (~37°17′S, 64°35′W) exhibits a prevailing aeolian and fluvial-aeolian interaction succession developed in the mid-to Late Holocene in a sand-mud flat environment of a shallow saline lake. The three studied cases are representative of aeolian aggradation in association with ephemeral fluvial, shallow lake and pedogenic processes in a currently subhumid-dry region. Numerical ages indicate sedimentation during the last ~30 kyr. They allow constraining and evaluating the paleoenvironmental conditions in this inland region of southern South America, and provide age constraints for the regional databases of paleoclimatic proxies. The results are in agreement with other late Quaternary paleoclimatic-paleoenvironmental archives of central Argentina and show a fragile aeolian landscape that is susceptible to deterioration under extreme conditions, including both aeolian reactivation during dry phases and erosion of sandy-silty sediments during wet phases.

Perinatal guanacos (Lama guanicoe) exploited by hunter‐gatherers from the Holocene of Argentine Pampas

AbstractThe guanaco (Lama guanicoe) was the most relevant species in hunter‐gatherer subsistence of the Argentine Pampas during the Quaternary. An early Late Holocene (3,184 ± 50 14C years bp) guanaco assemblage with evidence of exploitation, coming from Cerro del Águila site, Buenos Aires Province, is analysed herein. The assemblage is composed by three perinatal individuals; the estimated age at the moment of death ranges from a few weeks before birth to a few weeks old. Cerro del Águila is interpreted as a site where activities of procurement and processing of perinatal individuals were performed. The available information allows raising a discussion on the hunting and exploitation strategies of guanaco in a regional context.

Using Insights from Prospect Theory to Enhance Sustainable Decision Making by Agribusinesses in Argentina

Farm production often involves family-owned agribusinesses where decisions are made by households or individuals, not corporate managers. As these decisions have important economic, environmental, and social implications, decision-making processes must be understood to foster sustainable agricultural production. Decision experiments, involving lotteries, targeting farmers in the Argentine Pampas were used to estimate prospect theory (PT) parameters. Results suggest that decisions under risk are better represented by prospect theory than by expected utility (EU) theory: Decision makers treat gains and losses differently and use subjective probabilities of outcomes; they are quite loss averse and are more likely to overweigh probabilities of infrequent events, such as large droughts or floods. Statistical testing revealed heterogeneity in the risk tied to land tenure (land owners vs. renters) and agribusiness roles (farmers vs. technical advisors). Perceptions of risk, probability, and outcomes played a large role in the sustainability of production. Due to a strong desire to avoid losses, decision makers have a greater short term focus: Immediate economic outcomes are more salient, and environmental and social investments are framed as costs rather than long-term gains. This research can help design policies, programs, and tools that assist agribusinesses in managing better contradictions across the triple bottom line to ensure greater sustainability.

Spatial difference in the incidence of Argentine Hemorrhagic Fever and composition and abundance of rodents in the assemblage

The Argentine Hemorrhagic Fever (AHF) is a zoonotic disease endemic in a wide area of the humid pampa of Argentina. The etiologic agent is the Junin virus that is maintained in the wild by the rodent Calomys musculinus and transmitted to humans, mainly, through aerosols generated from secretions and excretions. To characterize and compare the assemblages of small rodent composition and diversity inside the epidemic, historic and non-endemic zone of AHF and to register C. musculinus abundance in each zone and in each area within each zone, registering the prevalence of infection in rodent populations. One central and two peripheral areas were delimited to sample rodents in each zone with different incidence of AHF. Thus, 18 localities were selected to do the sampling in two years. Host abundance between zones and among areas inside each zone and among nearby areas between zones were compared applying nested ANOVA's. In each zone, the rodent assemblage showed differences in composition, diversity and numeric representation of C. musculinus. The epidemic zone was the richest of the three, registering also great host abundance; meanwhile in the historic zone, A. azarae was the dominant numeric species with less number of other species. Regarding the non-endemic zone, the assemblage composition and C. musculinus abundance varied respect the sampled year. Junin virus infection was only detected in C. musculinus individuals corresponding to the epidemic zone, with a prevalence of 2.7 and 1.1% for the years 2007 and 2008, respectively. In this system, the abundance of C. musculinus could be impacting over the pathogen dynamic, rather than the assemblage diversity or the A. azarae presence.

Labile soil organic carbon for assessing soil quality: influence of management practices and edaphic conditions

Soil organic carbon (SOC) is a complex set of pools, and to understand its dynamics it is necessary to know which of these pools are sensitive to the edaphic and climatic conditions or the agricultural practices, or to both. The objectives of this study were to evaluate the relationships between permanganate oxidizable C (POX-C) and various soil organic carbon fractions in different land-uses and soil types, and to examine whether the POX-C fraction is sensitive to different agricultural management practices in soils under no-tillage. Three treatments were identified at four sites located in the Argentine Pampas region: two different agricultural scenarios in terms of crop rotation, fertilizers and use of agrochemicals (Good Agricultural Practices and Poor Agricultural Practices, GAP and PAP, respectively) and an undisturbed natural (NE) environment adjacent to the agricultural sites as the control treatment. The following organic fractions were quantified: SOC, coarse and fine particulate organic carbon (POCc and POCf, respectively), hot water and acid extractable organic carbon (HWC and HAC, respectively) and POX-C. Soil POC values ranged from 0.46 to 7.29 g kg−1, HAC values ranged from 1.50 to 6.73 g kg−1, HWC values ranged from 0.20 to 1.10 g kg−1 and POX-C values ranged from 0.41 to 1.04 g kg−1 soil, POCc being the most variable fraction (CV = 72%) and POX-C the least (CV = 22%). Soil POCc and POCf at 0–10 cm, and POCc at 10–20 cm were largely explained by management practices with a component of variance >50%. The relationship between POX-C and SOC was generally stronger (R2 = 0.76–0.92) than POX-C with other organic fractions and where depth and site factors have a greater influence on this relationship than management practices. Among the labile fractions, the most sensitive indicators of soil quality in agricultural soils were POCf and HWC, which displayed the highest F-statistic values. Despite the dilute solution used (0.02 mol L−1 KMnO4) the POX-C demonstrated limited sensitivity to different agricultural practices. However, this methodology could be used to estimate SOC regarding site conditions and depths. The POCf was the fraction most affected by agricultural practices, indicated by high relationships with both the soil physical attributes (macroporosity, bulk density, and density, volume and stability of aggregates) and the agronomic parameters (soybean and maize yields).

Detection and chemical control of Cercospora sojina infecting soybean seed in Argentina

Frogeye leaf spot (FLS) of soybean caused by Cercospora sojina Hara is an important disease in the Argentine Pampas region. The primary inoculum sources of the disease are infected seeds and plant debris. Thus, use of pathogen-free or fungicide-treated seeds is crucial to prevent the introduction and further spread of the disease. The aims of this research were i) to quantify C. sojina incidence in harvested soybean seeds, ii) to compare media-based incubation methods for detection of the pathogen in seeds, and iii) to evaluate the effect of fungicide seed treatments in reducing FLS incidence. Among eight different detection methods evaluated, no difference in pathogen incidence was found, but the water restriction blotter method should be recommended as it is more time and cost-effective. Out of 13 different fungicide seed treatment combinations in three independent experiments, benzimidazole seed treatments resulted in zero FLS incidence. Any other of the tested fungicidal active ingredients either did not control the disease or did so poorly only when initial infection levels were low. Treating seeds with benzimidazole fungicides may help to reduce FLS incidence during initial soybean field stands when using infected seed lots.

Genetic variability in populations of the terrestrial isopod Armadillidium vulgare living in soils with different land uses

The Argentine Pampas region is recognized by its high productivity and fertility, which make its soils suitable for agricultural use. However, the intensification of agricultural activities over the last forty years has led to an intense disturbance regime, characterized by an increase in the soil degradation rate. Soil degradation and its relationship with soil fauna communities are crucial issues in resource management. In this study, we investigated the effects of land-use change on the genetic variability of the terrestrial isopod Armadillidium vulgare, chosen as a biological model. The diversity and population genetic structure of this species were analyzed using inter-simple sequence repeat (ISSR)-PCR markers, in three land uses in two localities of Luján, Buenos Aires, Argentina. Genetic variability was high in natural grassland populations and lower in agricultural land uses. Both conventional FST analysis and Bayesian approach for dominant markers showed significant genetic differences between land uses within each locality. The loss of genetic variability and the population genetic structure can be used as indicators of system disturbance. Thus, in the soils studied, the degree of genetic variability of representative populations of the soil fauna can be a good indicator of the disturbance degree.

Recent environmental changes inferred from sediments in a shallow lake of the Argentinian pampas

Fil: Plastani, Maria Sofia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina