Bolivian Altiplano Research Articles

Domestic pig prioritized in one health action against fascioliasis in human endemic areas: Experimental assessment of transmission capacity and epidemiological evaluation of reservoir role

The Northern Bolivian Altiplano is the human fascioliasis hyperendemic area where the highest prevalences and intensities in humans have been reported. Preventive chemotherapy was implemented in the last ten years. Surveillance showed high human infection and re-infection rates in between the annual triclabendazole monodose treatments. A complementary One Health control action was launched to decrease the infection risk. Among the multidisciplinary axes, there is the need to establish animal reservoir species priorities for a more efficient control. Laboratory and field studies were performed for the first time to assess the Fasciola hepatica transmission capacity of the pig and its potential reservoir role. The experimental follow-up of altiplanic pig isolates through altiplanic Galba truncatula snail vector isolates were performed at different miracidial doses and different day/night temperatures. Experiments included egg embryonation, miracidial infectivity, lymnaeid snail infection, intramolluscan larval development, cercarial production, chronobiology of the cercarial shedding, vector survival to infection, metacercarial infectivity of mammal host, and adult stage development. Surveys included the assessment of prevalence, intensity, egg measurements and egg shedding rates in nature. Pig contribution was evaluated by comparing with the main altiplanic reservoirs sheep and cattle. Results demonstrated that the pig assures the whole F. hepatica life cycle and participates in its transmission in this area. The fast egg embryonation, high cercarial production, long multi-wave shedding chronobiological pattern in monomiracidial infections at permanent 20 °C temperature, and the high daily egg outputs per pig are worth mentioning. The high infection risk suggests early infection of freely running piglets and evolutionary long-term adaptation of the liver fluke to this omnivorous mammal, despite its previously evoked resistance or non-suitability. Genetic, physiological and immune similarities with humans may also underlie the parasite adaptation to humans in this area. The pig should be accordingly included for appropriate control measures within a One Health action against human fascioliasis. The pig should henceforth be considered in epidemiological studies and control initiatives not only in fascioliasis endemic areas with human infection risk on other Andean countries, but also in rural areas of Latin America, Africa and Asia where domestic pigs are allowed to run freely.

Residential moblity in the Inka sacred valley: Oxygen, strontium, and lead isotopic analysis at Patallaqta, Peru

The Inka Empire (1400–1532 CE) made common practice of relocating individuals, households and entire communities throughout their expansive realm for different reasons depending on subjects’ assigned social status. Reconstructing patterns of residential mobility and both intra- and extra-regional mobility at Inka sites, particularly in the imperial heartland, could therefore permit some estimation of the social status(es) of their constituents, and thereby provide bottom-up insights into Inka statecraft and political economy. However, this is a difficult endeavor using only archaeological lines of evidence. This study presents oxygen, strontium and lead isotopic results from archaeological human remains (N = 81) from the site of Patallaqta, near Machu Picchu in the Sacred Valley of the southern Peruvian highlands. Isotopic data are used to reconstruct patterns of immigration at the site, which are in turn used to estimate the social status of the population. The resulting 87Sr/86Sr show moderate variation, with most individuals clustering within a range higher than the estimated values for the locale, while 206,7,8Pb/204Pb results show greater variation spanning multiple Pb isotope provinces, and δ18O results cluster broadly around estimated local water values. Taken together, these results are consistent with the expected distribution of groups drawn from communities within the vicinity of the Sacred Valley and possibly the Peruvian or Bolivian altiplano. These results are in notable contrast to published isotopic results from the nearby site of Machu Picchu, and suggest distinct compositions among the resident populations of each site. This study provides further insights into the intersection of residential movement and status dynamics in the Inka Empire.

Stable oxygen and radiogenic strontium variability in the Osmore Drainage, Peru: Implications for intra-regional Andean paleomobility studies

The Osmore Drainage of southern Peru has a long and rich history of human occupation. While the utility of stable oxygen and radiogenic strontium isotope values in identifying paleomobility between this region and population centers in the Bolivian altiplano has been well established, many questions about intra-regional mobility remain. To better understand how these methods can be used to detect localized residential mobility, we present new δ18Omw(VSMOW) and 87Sr/86Sr values from water, soil, plant, and faunal samples. Samples were collected primarily from traditionally farmed agricultural fields in the upper, middle, and lower Osmore Drainage. Results are indiscernible between the upper and middle drainage, while marine contribution to the lower drainage produces distinct values. We discuss the methodological limitations and implications of our results for the use of stable oxygen and radiogenic strontium isotope analyses for intra-regional paleomobility studies in the Osmore Drainage.

Drought impact in the Bolivian Altiplano agriculture associated with the El Niño–Southern Oscillation using satellite imagery data

Abstract. Drought is a major natural hazard in the Bolivian Altiplano that causes large agricultural losses. However, the drought effect on agriculture varies largely on a local scale due to diverse factors such as climatological and hydrological conditions, sensitivity of crop yield to water stress, and crop phenological stage among others. To improve the knowledge of drought impact on agriculture, this study aims to classify drought severity using vegetation and land surface temperature data, analyse the relationship between drought and climate anomalies, and examine the spatio-temporal variability of drought using vegetation and climate data. Empirical data for drought assessment purposes in this area are scarce and spatially unevenly distributed. Due to these limitations we used vegetation, land surface temperature (LST), precipitation derived from satellite imagery, and gridded air temperature data products. Initially, we tested the performance of satellite precipitation and gridded air temperature data on a local level. Then, the normalized difference vegetation index (NDVI) and LST were used to classify drought events associated with past El Niño–Southern Oscillation (ENSO) phases. It was found that the most severe drought events generally occur during a positive ENSO phase (El Niño years). In addition, we found that a decrease in vegetation is mainly driven by low precipitation and high temperature, and we identified areas where agricultural losses will be most pronounced under such conditions. The results show that droughts can be monitored using satellite imagery data when ground data are scarce or of poor data quality. The results can be especially beneficial for emergency response operations and for enabling a proactive approach to disaster risk management against droughts.

Postcranial anatomy of the extinct terrestrial slothSimomylodon uccasamamensis(Xenarthra, Mylodontidae) from the Pliocene of the Bolivian Altiplano, and its evolutionary implications

AbstractExtinct terrestrial sloths are common elements of the late Cenozoic South American fossil record. Among them, Mylodontinae species were particularly abundant in the Americas throughout the Pleistocene epoch, and their anatomy is relatively well known. In contrast, less information is available from the Neogene record and particularly from localities at low latitudes, with an additional and considerable bias in favour of craniodental rather than postcranial remains. In this contribution, we provide comparative descriptions of several postcranial bony elements ascribed toSimomylodon uccasamamensis, a moderate‐sized extinct mylodontine from the Andean Altiplano. This species was particularly abundant during latest Miocene – late Pliocene times in the high altitudes of the Andean Cordillera, and so far represents the best known mylodontine from the Neogene of South America. Its anatomy is compared with that of several extinct terrestrial sloths, with the aim of using the observed morphologies to elucidate taxonomy, phylogeny, and locomotion. From a morphofunctional perspective, the postcranium ofS. uccasamamensis is consistent with that of a terrestrial graviportal quadruped, with moderate climbing and digging capabilities.

Age-growth relationships, temperature sensitivity and palaeoclimate-archive potential of the threatened Altiplano cactus Echinopsis atacamensis.

The tall (>4m), charismatic and threatened columnar cacti, pasacana [Echinopsis atacamensis (Vaupel) Friedrich & G.D. Rowley)], grows on the Bolivian Altiplano and provides environmental and economic value to these extremely cold, arid and high-elevation (~4000m) ecosystems. Yet very little is known about their growth rates, ages, demography and climate sensitivity. Using radiocarbon in spine dating time series, we quantitatively estimate the growth rate (5.8 and 8.3cmyr-1) and age of these cacti (up to 430years). These data and our field measurements yield a survivorship curve that suggests precipitation on the Altiplano is important for this species' recruitment. Our results also reveal a relationship between nighttime temperatures on the Altiplano and the variation in oxygen isotope values in spines (δ18O). The annual δ18O minimums from 58years of in-series spine tissue from pasacana on the Altiplano provides at least decadal proxy records of temperature (r = 0.58; P < 0.0001), and evidence suggests that there are longer records connecting modern Altiplano temperatures to sea-surface temperatures (SSTs) in the Atlantic Ocean. While the role of Atlantic SSTs on the South American Summer Monsoon (SASM) and precipitation on the Bolivian Altiplano is well described, the impact of SSTs on Altiplano temperatures is disputed. Understanding the modern impact of SSTs on temperature on the Altiplano is important to both understand the impact of future climate change on pasacana cactus and to understand past climate changes on the Altiplano. This is the best quantitative evidence to date of one of the oldest known cactus in the world, although there are likely many older cacti on the Altiplano, or elsewhere, that have not been sampled yet. Together with growth, isotope and age data, this information should lead to better management and conservation outcomes for this threatened species and the Altiplano ecosystem.

One Health initiative in the Bolivian Altiplano human fascioliasis hyperendemic area: Lymnaeid biology, population dynamics, microecology and climatic factor influences.

Fascioliasis is a freshwater snail-borne zoonotic disease. The Northern Bolivian Altiplano is a very high altitude endemic area where the highest human prevalences and intensities have been reported. Preventive chemotherapy by treatment campaigns is yearly applied. However, liver fluke infection of cattle, sheep, pigs and donkeys assures endemicity and consequent human infection and re-infection risks. A One Health action has therefore been implemented. Activity concerns lymnaeid vectors and environment diversity. Studies included growth, egg-laying and life span in laboratory-reared lymnaeids. Different habitat types and influencing factors were assessed. All populations proved to belong to Galba truncatula by rDNA sequencing. Analyses comprised physico-chemical characteristics and monthly follow-up of water temperature, pH and quantity, and lymnaeid abundance and density. Population dynamics in the transmission foci differed. Mean environmental temperature was lower than fluke development minimum temperature threshold, but water temperature was higher, except during winter. A two generations/year pattern appeared in permanent water habitats, and one generation/year pattern in habitats drying out for months. The multidisciplinary control measures can be extended from one part of the endemic area to another. These studies, made for the first time at very high altitude, constitute a baseline useful for fascioliasis control in other countries.

Geochemical mechanisms of natural arsenic mobility in the hydrogeologic system of Lower Katari Basin, Bolivian Altiplano

Arsenic (As) contamination of drinking water is a worldwide problem. The natural origin of As, its mobility, and transport are of paramount interest in Bolivian Altiplano due to its presence in mineral deposits, brines, hot springs, and volcanic rocks. In this study, a geochemical spatial–temporal approach was used to understand the sources and factors that regulate the mobilization and fate of As in water bodies as well as sediments of Lower Katari Basin (LKB). The study reveals that high levels of As (288 µg/L), boron (B) (2473 µg/L), manganese (Mn) (7259 µg/L), and high salinity (23850 µS/cm) are present in shallow drinking water wells, which exceed the guideline values of the Bolivian regulation (NB-512) and WHO. Seasonal changes (mean monthly rainfall in the dry and rainy period: 6–89 mm) and their impact on water quantity (0.9–5.1 m3/s), in addition to the load of solids and liquids of residual origin (Pallina River), pose health risks for the communities at the banks of the Katari River. The hydrogeological study indicates that the groundwater flows from southeast to northwest (SE–NW), which indicate interaction between groundwater and surface water in this region. The spatial distribution of As varies considerably due to geological characteristics of the area as well as due to the heterogeneously distributed evaporites in the sediments (alluvial, fluvial-lacustrine); however, the highest concentrations of As are observed in the alluvial sediments of the northern region. Sequential extraction (BCR) of sediments along with geochemical modeling (mineral saturation indices) indicates that iron (Fe) and aluminum (Al) (hydr)oxides are the most important adsorbent minerals of As in the central and southern region of LKB. The hydrochemistry of water bodies in LKB is strongly influenced by the interaction with the sediment constituents and by the spatial–temporal variations. Therefore, the determination of the distribution of As among the different geochemical fractions was useful to find the relative proportions of As transported by different chemical mechanisms (adsorption/dissolution) and their spatial–temporal variation.

Campos de experimentação agrícola na Escuela-Ayllu de Warisata

A Escuela-Ayllu de Warisata, localizada no altiplano boliviano entre o lago Titicaca e o nevado de Illampu, foi um projeto de educação indígena e rural ocorrido na Bolívia nos anos 1930 (1931-1940) que pretendeu integrar as concepções e os saberes das populações indígenas locais dentro dos ideais nacionais. A relação com o ambiente biofísico aparece de forma marcante na fonte autobiográfica de Elizardo Pérez, um dos fundadores do projeto. Ademais, a escola se inseria em um contexto de disputa pelo acesso à terra, pela autonomia e pelos modos de organização do espaço que colocavam em conflito as concepções das comunidades indígenas locais frente aos interesses dos grandes proprietários de terra. Nesse artigo, observamos em que medida a escola buscou “revitalizar” esses saberes indígenas e, ainda, uma memória biocultural relacionada com o ambiente do altiplano utilizando o argumento da produtividade como forma de legitimar esse projeto perante a sociedade boliviana.

Donkey Fascioliasis Within a One Health Control Action: Transmission Capacity, Field Epidemiology, and Reservoir Role in a Human Hyperendemic Area.

A One Health initiative has been implemented for fascioliasis control in a human hyperendemic area for the first time. The area selected for this multidisciplinary approach is the Northern Bolivian Altiplano, where the highest prevalences and intensities in humans have been reported. Within the strategic intervention axis of control activities concerning animal reservoirs, complete experimental studies, and field surveys have been performed to assess the fascioliasis transmission capacity and epidemiological role of the donkey for the first time. Laboratory studies with altiplanic donkey-infecting Fasciola hepatica and altiplanic Galba truncatula snail vector isolates demonstrate that the donkey assures the viability of the whole fasciolid life cycle. Several aspects indicate, however, that F. hepatica does not reach, in the donkey, the level of adaptation it shows in sheep and cattle in this high altitude hyperendemic area. This is illustrated by a few-day delay in egg embryonation, longer prepatent period despite similar miracidial infectivity and shorter patent period in the intramolluscan development, lower cercarial production per snail, different cercarial chronobiology, shorter snail survival after shedding end, shorter longevity of shedding snails, and lower metacercarial infectivity in Wistar rats. Thus, the role of the donkey in the disease transmission should be considered secondary. Field survey results proved that liver fluke prevalence and intensity in donkeys are similar to those of the main reservoirs sheep and cattle in this area. Fasciolid egg shedding by a donkey individual contributes to the environment contamination at a rate similar to sheep and cattle. In this endemic area, the pronounced lower number of donkeys when compared to sheep and cattle indicates that the epidemiological reservoir role of the donkey is also secondary. However, the donkey plays an important epidemiological role in the disease spread because of its use by Aymara inhabitants for good transport, movements, and travel from one locality/zone to another, a repercussion to be considered in the present geographical spread of fascioliasis in the Altiplano due to climate change. Donkey transport of parasite and vector, including movements inside the zone under control and potential introduction from outside that zone, poses a problem for the One Health initiative.

Sheep and Cattle Reservoirs in the Highest Human Fascioliasis Hyperendemic Area: Experimental Transmission Capacity, Field Epidemiology, and Control Within a One Health Initiative in Bolivia.

The Northern Bolivian Altiplano is the human fascioliasis hyperendemic area where the highest prevalences and intensities of infection by Fasciola hepatica in humans have been reported. Four animal species are the reservoir species for F. hepatica in this area, namely, sheep, cattle, pigs, and donkeys. Livestock for the Aymara inhabitants is crucial because vegetable cultures are not viable due to the inhospitality of the very high altitude of 3,820–4,100 m. A One Health initiative has been implemented in this area in recent years, as the first such control action in a human endemic area ever. Among the different control axes included, special focus is devoted to the two main reservoirs sheep and cattle. Egg embryonation, miracidial infectivity, intramolluscan development, cercarial production, infected snail survival, and metacercarial infectivity were experimentally studied in altiplanic sheep and cattle isolates. These laboratory studies were performed using altiplanic isolates of the lymnaeid species Galba truncatula, the only vector present in the hyperendemic area. Experiments were made at constant 12 h day/12 h night and varying 20/20°C and 22/5°C photoperiods. Infections were implemented using mono-, bi-, and trimiracidial doses. Results demonstrate that sheep and cattle have the capacity to assure F. hepatica transmission in this very high-altitude area. Field surveys included prevalence studies by coprology on fecal samples from 1,202 sheep and 2,690 cattle collected from different zones of the Northern Bolivian Altiplano. Prevalences were pronouncedly higher and more homogeneous in sheep (63.1%; range: 38.9–68.5%) than in cattle (20.6%; range: 8.2–43.3%) in each one of the different zones. Although similarities between the prevalences in sheep and cattle appeared in the zones of the highest and lowest infection rates, this disappeared in the other zones due to cattle treatments. Comparison with past surveys demonstrates that this hyperendemic area is stable from the disease transmission point of view. Therefore, the control design should prioritize sheep and cattle within the One Health action. Studies performed in the Bolivian Altiplano furnish a baseline for future initiatives to assess the transmission and epidemiological characteristics of fascioliasis in the way for its control in other high altitude Andean endemic areas.

Hydrogeochemical contrasts in the shallow aquifer systems of the Lower Katari Basin and Southern Poopó Basin, Bolivian Altiplano

Drinking water sources in the southeastern part of Lake Titicaca (Lower Katari Basin: LKB) and the southern part of Lake Poopó (Southern Poopó Basin: SPB) have high concentrations of arsenic (As), >10 μg/L compared to the WHO and NB-512 guideline value. These regions belong to the Bolivian Altiplano and are characterized by a semiarid climate, slow hydrological flow, with geological formations of volcanic origin, in addition to brines and other mineral deposits. The present study is focused on comparing the geochemical processes of As in relation to the sources and mobilization in groundwater (GW) in LKB and SPB. Groundwater (GW), surface water (SW) and sediment samples were collected from both basins. The As (LKB: 0.8–288 μg/L and SPB: 2.6–207 μg/L), boron (B) (LKB: 96–2473 μg/L and SPB: 507–4359 μg/L), manganese (Mn) (LKB: 0.6–7259 μg/L) and salinity (LKB: 125–11740 μS/cm) were found to be higher than the WHO guideline values, which is a serious concern about the GW quality for human consumption. The dissolution and exchange of bases are the processes that govern the mineralization of GW. Load of solids and liquids of anthropogenic origin in surface water (LKB) represents an environmental problem for communities on river banks. The spatial distribution of As was attributed to the geology of both the basins and the heterogeneously distributed evaporites in the sediments. The highest As concentrations are found in alluvial sediments of the northern region of LKB and “PACK belt” (an approximately 25 km long belt stretching along the southern shores of the Lake Poopó, between the villages of Pampa Aullagas and Condo K) in SPB. Sequential extraction of sediment and mineral saturation indices indicate that iron (Fe) and aluminum (Al) oxides as well as hydroxides are the most predominant mineral phases as potential sorbents of As.

Frustulia tunariensis sp. nov. (Bacillariophyceae) from the Andes of Bolivia, South America

Frustulia tunariensis sp. nov. is originated from a high-altitude peatland in the Tunari Cordillera, a branch of the Andean range in Bolivia. The new taxon is distinguished by the thick longitudinal ribs, the globose polar nodule with faint helictoglossa that does not produce an apical extension, and by the high areola and stria density, not found in any of the morphologically closely related taxa. Features of the folded valvocopula, such as the presence of a siliceous membrane as pars interior, and poroids present in the tube-like portion opening as slits to the valve interior and as a single row of poroids to the exterior, are also unique characters in the new taxon. Based on a literature review, a comparison of the newly proposed species with morphologically similar taxa was made. Also, published information shows the potential of girdle bands to distinguish groups of species and species themselves within Frustulia. Likewise, remarks on the ecological and distribution aspects of Frustulia in the Bolivian Altiplano are included, focusing on taxonomic quality, geographic coverage and sampling, and potential to represent the genus in the high Bolivian Andean plateau.

Contesting the social license to operate: Competing visions and community exclusion on the Bolivian Altiplano

The concept of a Social License to Operate (SLO) has increasingly been employed in the extractive industries worldwide as a measure of social acceptance and legitimacy, particularly among those local communities most impacted by extractive activities. This study uses the SLO framework to critically evaluate ongoing conflict regarding the social and environmental impacts of the Kori Chaca gold mine in Oruro, Bolivia. Contrasting claims regarding these impacts made by the mining company and the nearest downstream community were analyzed as indicators of each party's perception of SLO. Discrepancies in how these stakeholders understand SLO reveal ways in which the industry uses the concept to legitimize its operations without ensuring genuine participation or dialogue with impacted communities. The community's understanding of SLO was based on the fair distribution of costs and benefits related to the mining project. By contrast, the company's perception of SLO was based on demonstrating the minimum benefit deemed sufficient to meet international sustainability standards. The case of Kori Chaca demonstrates how formal adherence to the principles of SLO can still result in the privileging of company-defined objectives while the unique, place-based concerns of local communities remain overlooked.

Synoptic attributions of extreme precipitation in the Atacama Desert (Chile)

Northern Chile is a region characterised by an extremely dry climate; however, there is a brief rainy season from December to March (austral summer), mainly above 3000 m a.s.l. It is interesting to consider where the humid air masses that generate such rain come from. For this purpose, daily precipitation data from 161 meteorological stations located in this area (18° S–19° S) were considered, and four clusters formed by k-means clustering. For each cluster, days of extreme precipitation (above 90th percentile) were selected to obtain flow strength (F), direction (D), and vorticity (Z) for each event according to the Jenkinson and Collison (JC) method. The back trajectory, for the previous 72 h, of air masses affecting the centroid of each cluster was determined by means of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The analyses were carried out at sea level (1013 hPa) and in the middle (500 hPa) and upper (250 hPa) troposphere. Surface circulation was not a determining factor in the occurrence of extreme events, but it did influence circulation at 500 and 250 hPa. For stations located in the northern Altiplano, moisture advection from the Amazon basin is evident due to the configuration of the Bolivian high—an upper level anticyclone that develops over the Bolivian Altiplano during austral summer. For stations located in the southern part of the study area, the main source of moisture is the Pacific Ocean, and the weather is related to the arrival of frontal systems and to the configuration of cut-off low pressure systems in the mid-troposphere.

Restos de ?Panochthus Burmeister (Xenarthra; Cingulata; Glyptodontidae) registrados en áreas de altura: descripción y comentarios

Panochthus Burmeister constituye uno de los xenartros más abundantes, diversificados y ampliamente distribuidos del Pleistoceno sudamericano, como así también uno de los gliptodóntidos de mayor distribución latitudinal y altitudinal. En esta contribución se analizan aquellos registros asignables al género, efectuados en áreas de altura, en orden decreciente de altitud: (1) MURB 1906: ? 4000 m.s.n.m, Potosí (Bolivia); (2) MUSM 3632: ? 3800 m.s.n.m, Desaguadero (Perú); (3) MHNC-13491: ? 2600 m.s.n.m, Cochabamba (Bolivia); (4) MNPA-V 006598: ? 1870 m.s.n.m, Valle de Tarija (Bolivia); (5) MUFYCA 383: ? 920 m.s.n.m, Valle de Traslasierra (Argentina). Se discute la probable relación existente entre la altitud geográfica y la masa corporal de los ejemplares de P. intermedius Lydekker. En esta especie se observa que los individuos que habitan áreas de altura muestran valores de masa corporal significativamente menores que los de aquellos de la llanura pampeana. Esta relación también se registra en otros xenartros, así como en otros grupos de mamíferos. Estos taxones expresarían un patrón inverso de la regla de Bergmann. De esta manera, la ?reducción de la disponibilidad de recursos? podría ser la razón ecológica que explicaría el menor tamaño de los individuos estudiados. Finalmente, P. hipsilis Zurita, Zamorano, Scillato-Yané, Fidel, Iriondo &amp; Gillette es una especie endémica del Altiplano Boliviano y sus restos son los hallazgos de Panochthus y, posiblemente, de Glyptodontidae realizados a mayores alturas.

Reliability of SM2RAIN precipitation datasets in comparison to gauge observations and hydrological modelling over arid regions

AbstractNumerous satellite‐based precipitation datasets have been successively made available. Their precipitation estimates rely on clouds properties derived from microwave and thermal sensors in a so‐named ‘top‐down’ approach. Recently, a ‘bottom‐up’ approach to infer precipitation from soil moisture (SM) estimates has resulted in the release of two new precipitation datasets (P‐datasets). One uses satellite‐based SM estimates from the European Spatial Agency (ESA) Climate Change Initiative (CCI) (SM2RAIN‐CCI) while the other uses satellite‐based SM from European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) Advanced SCATterometer (ASCAT) (SM2RAIN‐ASCAT). This study assesses SM2RAIN‐ASCAT and ‐CCI reliability over two arid regions: Bolivian and Peruvian Altiplano and Pakistan (South Asia) using (a) direct comparisons with rain gauges and (b) testing the sensitivity of streamflow modelling to the P‐datasets. Selecting two different regions and different indicators helps to assess whether the P‐dataset reliability varies depending on the assessment method and location. For comparison purposes, the most reliable P‐datasets from the literature are also considered (IMERG‐E v.6, IMERG‐L v.6, IMERG‐F v.6, CHIRPS v.2 and MSWEP v.2.2). Compared to rain gauge observations and based on the modified Kling–Gupta Efficiency (KGE) values, the SM2RAIN‐ASCAT and ‐CCI are more accurate in the Altiplano than in Pakistan. This difference is explained by a more favourable physical context for satellite‐based SM estimates in the Altiplano. Over the Altiplano and despite an overall positive bias, SM2RAIN‐ASCAT describes rain gauges temporal dynamics as well as IMERG‐F v.6, CHIRPS v.2 and MSWEP v.2.2 and provides streamflow simulations very close to those obtained when using IMERG‐F v.6, CHIRPS v.2 and MSWEP v.2.2 as forcing data.

Bolivian hornblendite cumulates: Insights into the depths of Central Andean arc magmatic systems

The eruptive products of continental arc volcanoes provide wide-ranging insights into the processes governing storage, differentiation, and final eruption (or emplacement) of magmas from trans-crustal magmatic systems. The important role and fractionation of amphibole in continental arc magmatic systems is well documented even if amphibole is generally absent as a prevalent phenocrystic phase in erupted, differentiated lavas. This study presents a comprehensive textural and geochemical investigation of rare plagioclase-bearing hornblendite cumulates entrained in c. 1.4 Ma (trachy-)andesites at the Quillacas monogenetic center on the Bolivian Altiplano, Central Andes. MicroXRF mapping and imaging via SEM-EDS clearly reveals their mesocumulate, idiomorphic nature characterized by cumulus hornblende (≥90%) with intercumulus sodic plagioclase (~8%), minor Fe-Ti oxides and accessory apatites. The trace element compositions of cumulus amphiboles are consistent with their crystallization from a silicate melt with (La/Yb)N < 5 and low (Pb/Ce)N at <0.6. Amphibole TiO2 contents imply crystallization between 700 and 764 °C consistent with depths in the arc crust of 50–55 km as constrained by the Central Andean geotherm. Bulk hornblendite isotopic signatures (Sr-Nd-Pb) correspond to compositions associated with the Central Andean mid-lower arc crust consistent with the presence of hornblendite cumulate piles at this depth. Intercumulus (titano)magnetite exhibits oxy-exsolution ilmenite lamellae, the formation of which is associated with oxygen fugacity (ƒO2) increase during magmatic cooling and differentiation. The ubiquitous presence of gabbroic dehydration (reaction) rims (20–40 μm in width) on the amphiboles is interpreted to be the result of a decrease in ƒO2 during ascent. The hornblendite mesocumulates from this study validate the extensive “cryptic” fractionation of amphibole at arcs and its important role on the petrogenesis of (continental) arc magmas.

Genetic uniformity, geographical spread and anthropogenic habitat modifications of lymnaeid vectors found in a One Health initiative in the highest human fascioliasis hyperendemic of the Bolivian Altiplano

BackgroundFascioliasis is a snail-borne zoonotic trematodiasis emerging due to climate changes, anthropogenic environment modifications, and livestock movements. Many areas where Fasciola hepatica is endemic in humans have been described in Latin America altitude areas. Highest prevalences and intensities were reported from four provinces of the northern Bolivian Altiplano, where preventive chemotherapy is ongoing. New strategies are now incorporated to decrease infection/re-infection risk, assessment of human infection sources to enable efficient prevention measures, and additionally a One Health initiative in a selected zone. Subsequent extension of these pilot interventions to the remaining Altiplano is key.MethodsTo verify reproducibility throughout, 133 specimens from 25 lymnaeid populations representative of the whole Altiplano, and 11 used for population dynamics studies, were analyzed by rDNA ITS2 and ITS1 and mtDNA cox1 and 16S sequencing to assess their classification, variability and geographical spread.ResultsLymnaeid populations proved to belong to a monomorphic group, Galba truncatula. Only a single cox1 mutation was found in a local population. Two cox1 haplotypes were new. Comparisons of transmission foci data from the 1990’s with those of 2018 demonstrated an endemic area expansion. Altitudinal, northward and southward expansions suggest movements of livestock transporting G. truncatula snails, with increasing temperatures transforming previously unsuitable habitats into suitable transmission areas. Transmission foci appear to be stable when compared to past field observations, except for those modified by human activities, including construction of new roads or control measures undertaken in relation to fascioliasis.ConclusionsFor a One Health initiative, the control of only one Fasciola species and snail vector species simplifies efforts because of the lower transmission complexity. Vector monomorphism suggests uniformity of vector population responses after control measure implementation. Hyperendemic area outer boundary instability suggests a climate change impact. All populations outside previously known boundaries were close to villages, human dwellings and/or schools, and should therefore be considered during disease control planning. The remarkable southward expansion implies that a fifth province, Aroma, should now be included within preventive chemotherapy programmes. This study highlights the need for lymnaeid molecular identification, transmission foci stability monitoring, and potential vector spread assessment.

The origin of continental carbonates in Andean salars: A multi-tracer geochemical approach in Laguna Pastos Grandes (Bolivia)

In continental volcanic settings, abundant carbonate precipitation can occur with atypical facies compared to marine settings. The (bio-)chemical processes responsible for their development and early diagenesis are typically complex and not fully understood. In the Bolivian Altiplano, Laguna Pastos Grandes hosts a 40-km2 carbonate platform with a great diversity of facies and provides an ideal natural laboratory to understand the processes responsible for the precipitation of carbonates in a continental province dominated by volcanism. In order to trace the origin of both water and solutes in the lagoon, the major element and stable isotope compositions (δ2H-δ18O, δ37Cl, δ7Li, δ11B and 87Sr/86Sr) of the spring and stream waters were characterized, as well as the stable isotope compositions (δ13C, δ15N) and noble gas isotope ratios of hydrothermal gases associated with spring waters. The results show that thermal springs discharging on the carbonate platform are close to saturation with calcite. PHREEQC modeling, together with fluid geochemistry and temperature estimated from a combination of geothermometers, indicate that Ca in these springs is inherited from the alteration of the volcanic bedrock by aqueous fluids heated at ∼225 °C and enriched in magmatic mantle-derived CO2. Our results clearly show that the main driver for the precipitation of modern carbonates in Laguna Pastos Grandes is the deeply sourced CO2, which boosts the alteration of volcanic rocks at depth.