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Although literature about regional integration is substantial, its definition remains controversial. Indeed, it is common nowadays for the terms regional integration and regional economic integration to be used interchangeably in spite of the importance accorded by literature to non‐economic factors. Inspired on the South American integration strategy—the Union of South American Nations (UNASUR), this paper revisits the theory of regional integration and proposes to analyse regional integration projects from three complementary angles: economic integration, political integration and physical integration. Moreover, it asserts that political and physical integration constitute a preliminary, or contemporaneous, step towards economic integration and not a final stage, as the current debate suggests. [ABSTRACT FROM AUTHOR]

The rise in the Earth's global average surface temperature and the increase of extreme weather events have been the focus of scientific discussion in the last decades. Extreme heat combined with other environmental extremes, like high concentrations of air pollution, may induce health problems—especially in socioeconomically vulnerable populations. Spring in South America requires particular attention due to its association with hot, dry weather and air pollution in most parts of the continent. This paper intends to better comprehend the behaviour of heatwaves during the austral winter–spring transition. We propose identifying the spatial coverage, frequency and intensity of heatwaves in homogeneous areas of maximum air temperature near the surface (Tmax). We employed cluster analyses during the period between July and October for 41 years (1979–2019) through the ERA5 reanalysis. Homogeneous Tmax areas in South America were defined by cluster analyses that indicated three homogeneous Tmax regions, as follows: a larger area of the continent including the tropical region (Area 1), eastern and southeastern South America (Area 2) and southernmost and steep areas in the Andes (Area 3). The heatwave events identified via ERA5 reanalysis were classified according to their intensity (intense, moderate and weak events). Spatial frequency and trend analyses were also performed regarding the intensity and persistence of heatwave episodes. These methods allowed the identification of the behavioural aspect of heatwaves spanning the last four decades. The Mann–Kendall statistical test (MK) was applied in order to analyse the heatwave trend with a statistical significance level of 5%. A total of 191 heatwave episodes were identified. Of this total, 47.12, 35.60 and 17.28% of episodes occurred in Areas 2, 3 and 1, respectively. The hotter area extending from northeast to southwest in central South America stood out by its largest frequencies of intense heatwave episodes. Across the continent there was a significant increase in the intensity and persistence of heatwaves over the period of 1979 through to 2019. [ABSTRACT FROM AUTHOR]

This paper develops a spatial rural economy model of adaptation to climate change that accounts for a multitude of rural enterprises across a diversity of ecosystems in South America using household surveys. We model adoptions of crops, livestock, and forests. Both specialized and diversified enterprises are modelled. This paper finds that livestock, forests, and a diversification into crops, livestock, and forests are key adaptation strategies. Under the UKMO (United Kingdom Meteorological Office) scenario, a livestock-only enterprise would expand by 4 per cent, a crops-livestock-forests by 3 per cent, and a forests-only by 3 per cent. Adaptation behaviours are closely tied with ecosystem changes under global warming. A livestock-only would increase especially in the grasslands. A crops-livestock-forests enterprise expands into xeromorphic forests. A crops-livestock expands in Andean grasslands and tall grasslands. A forests-only expands in the coasts and woody zones. A crops-only enterprise decreases across South America. Resumen Utilizando encuestas a hogares, en este artículo se desarrolla un modelo espacial de economía rural para la adaptación al cambio climático, con la capacidad de representar una gran cantidad de empresas rurales dentro de una diversidad de ecosistemas en América del Sur. Se modeliza la adopción de cultivos, ganado y bosques. Se modelizan tanto empresas especializadas como diversificadas. El artículo encontró que el ganado, los bosques, y una diversificación en cuanto a cultivos, ganado y bosques son estrategias claves de adaptación. Bajo un escenario propuesto por la Oficina Meteorológica del Reino Unido (UKMO, siglas en inglés), una explotación dedicada solamente a la ganadería aumentaría en un 4 por ciento, una dedicada a cultivos-ganadería-bosques un 3 por ciento, y una dedicada exclusivamente a bosques un 3 por ciento. Los comportamientos para la adaptación están estrechamente ligados a cambios en los ecosistemas debidos al calentamiento global. Una explotación exclusivamente ganadera aumentaría especialmente en el ecosistema de pastizal. Una explotación de cultivos-ganadería-bosques podría expandir en bosques xeromórficos. Una explotación basada en cultivos-ganado expandiría en áreas de pastizales Andinos y pastizal alto. Las explotaciones basadas solamente en bosque expandirían en las costas y zonas boscosas. Una explotación exclusivamente de cultivos disminuiría en América del Sur. [ABSTRACT FROM AUTHOR]

Southeastern South America is subject to considerable precipitation variability on seasonal to decadal timescales and has undergone very heavy land‐cover changes (LCCs) since the middle of the past century. The influence of local LCC and precipitation as drivers of regional evapotranspiration (ET) long‐term trends and variability remains largely unknown in the region. Here, ensembles of stand‐alone dynamic global vegetation models (DGVMs) with different atmospheric forcings are used to disentangle the influence of those two drivers on austral summer ET from 1950 to 2010. This paper examines the influence of both the El Niño‐Southern Oscillation (ENSO) and the dipole‐like first‐mode of southeastern South American precipitation variability (EOF1) on regional ET. We found that in the lower La Plata Basin, ET was driven by precipitation variability and showed a positive summer trend. Moreover, the region showed marked seasonal anomalies during El Niño and La Niña summers but mainly during EOF1 phases. On the contrary, in the upper La Plata Basin, LCCs forced the negative summer ET trend and particularly reduced the summer anomalies of the late 1990s, a period of ENSO and EOF1‐positive phases. In the South Atlantic Convergence Zone region, the high ET uncertainty across ensemble members impeded finding robust results, which highlights the importance of using multiple DGVMs and atmospheric forcings instead of relying on single model/forcing results. [ABSTRACT FROM AUTHOR]

In a recently published paper, Celestino et al. (2019) investigated the effects of a fish ladder located near the Porto Primavera Dam (Paraná River, Brazil) in order to evaluate if it provided free passage for the migratory fish Prochilodus lineatus. Fish were marked with PIT‐tags and movements were monitored within the ladder over a 3.5‐year period. The main finding was "Our study identified bidirectional movements by P. lineatus through the Porto Primavera fish ladder, including multiple passes by the same fish" (p. 241). It led authors to conclude: "Our results suggest that by providing bidirectional connectivity between upstream and downstream habitats, fishways can be an effective tool for preserving populations of P. lineatus and probably for other species of Prochilodus" (p. 242). Both conclusions, however, may not be correct, because they go beyond the data directly presented in the manuscript. The study overlooked issues related to the spatial scale and experimental design, since it was limited to investigate patterns of movement within the fish ladder alone. In this sense, they encourage the reader to accept patterns and conclusions that were not specifically investigated (e.g., migratory dynamics and conservation success), or that cannot be fully supported by the data (e.g., bidirectional movements and efficient passage). As the conclusions presented in the study have direct implications for the licensing process of hydropower dams and the management/conservation of Neotropical migratory fishes, we provide suggestions to highlight additional important factors and issues that should be considered or addressed in future research. [ABSTRACT FROM AUTHOR]

A characterization of the diurnal cycle of precipitation (DCP) over the whole South America is still lacking in the literature and the scarcity of sub‐daily rain ground measurements limits the data available for analysis and forbids a correct validation of alternative datasets. In this paper we analyse the climatological mean DCP during the monsoon active season using five gridded datasets: two satellite precipitation estimates, two regional climate models and one reanalysis. Amazonia, the Brazilian Highlands, the northeastern South American coast, the Andes and the western Colombian coast are identified as the areas with most prominent DCPs. The afternoon convection triggered by solar heating over land and the coastal and topographic effects are the main modes of sub‐daily variability, based on an EOF decomposition of the 3 hourly mean precipitation fields. We explore the contribution of mean frequency and intensity to amount of precipitation and nighttime–daytime differences. In general, both models precipitate earlier and more frequently than the satellite products and do not reproduce correctly areas of observed predominant nighttime precipitation where mesoscale convective systems are active, like La Plata Basin or Amazonia. Over the analysed areas, the high frequency of precipitation is the driving mechanism of total amount in the models, whereas in the satellite products there is also considerable contribution from intensity. Overall, the reanalysis shows features in between the models and the satellite estimates, sharing characteristics with both types of data. The results presented here point at the diversity of sub‐daily precipitation characteristics in South America, the issues with conventional climate models and the uncertainty in satellite products and reanalyses. The growing interest in the DCP by the scientific community and the development of new techniques like convection permitting modelling will hopefully continue to improve our knowledge of the precipitation dynamics and its influence on climate. [ABSTRACT FROM AUTHOR]

Hundreds of publications dealing with the prevalence of multiple sclerosis (MS) throughout the world exist, but little data have been published from South America. Epidemiological studies of MS vary according to environmental, racial and genetic factors; a better understanding of MS in South America would help us to elucidate the disease pattern in this population. The aim of this study is to review the evidence relevant to MS epidemiology in South America. We performed a systematic review of articles of MS epidemiology in South America, with special emphasis on those providing information on the incidence and prevalence of MS (population-based studies). Six papers provided information on MS epidemiology. One paper used the capture-recapture methodology, while the remainder employed traditional methods to collect the data. Population-based studies showed an MS prevalence rate ranging from 1.48 to 17 per 100 000 inhabitants. Available data suggest that the prevalence of MS is lower in South America than in developed countries. The reason for this observation is unknown. Some investigators suggest that certain environmental factors like sun exposure and vitamin D supplementation or the called ‘hygiene hypothesis’ may protect this population. Future studies will contribute to elucidate the etiology of that difference. [ABSTRACT FROM AUTHOR]

‘geographical pivot of history’ concept, subsequently developed into his famous‘Eurasian heartland thesis’, marginalizes South America, yet his ideas have attracted considerable interest there, including interpretations (and fantasies) of a‘South American heartland’. This paper examines the reception of Mackinder's ideas in Latin American geopolitics and how his heartland thesis was adapted for the South American context. It traces the roots of this adaptation in earlier South American geopolitical writing, and examines these ideas of counter-insurgency policies and global geopolitical strategies, analysing their relationship to military and anticommunist perspectives. [ABSTRACT FROM AUTHOR]

Mountainous grasslands in South America, characterized by their high diversity, provide a wide range of contributions to people, including water regulation, soil erosion prevention, livestock feed provision, and preservation of cultural heritage. Prior research has highlighted the significant role of grazing in shaping the diversity and productivity of grassland ecosystems, especially in highly productive, eutrophic systems. In such environments, grazing has been demonstrated to restore grassland plant diversity by reducing primary productivity. However, it remains unclear whether these findings are applicable to South American mountainous grasslands, where plants are adapted to different environmental conditions. To address this uncertainty, we conducted a meta‐analysis of experiments excluding livestock grazing to assess its impact on plant diversity and productivity across mountainous grasslands in South America. In alignment with studies in temperate grasslands, our findings indicated that herbivore exclusion resulted in increased aboveground biomass but reduced species richness and Shannon diversity. The effects of grazing exclusion became more pronounced with longer durations of exclusion; nevertheless, they remained resilient to various climatic conditions, including mean annual precipitation and mean annual temperature, as well as the evolutionary history of grazing. In contrast to results observed in temperate grasslands, the reduction in species richness due to herbivore exclusion was not associated with increased aboveground biomass. This suggests that the processes governing (sub)tropical grassland plant diversity may differ from those in temperate grasslands. Consequently, further research is necessary to better understand the specific factors influencing plant diversity and productivity in South American montane grasslands and to elucidate the ecological implications of herbivore exclusion in these unique ecosystems. [ABSTRACT FROM AUTHOR]

This paper develops a microeconometric analysis of adapting portfolios in response to climate change using information on South American farmers' adoption of agricultural systems taken from approximately 2,000 household surveys. The results show that farmers in a hotter climate prefer a mixed system over specialized systems either in crops or livestock. Under a hot and dry scenario, the land values of all three systems would fall, but the damage would be much smaller in the mixed system (−10%) than for the farms specializing in crops (−20%). Farmers are predicted to lose 8% of their land's value under the Canadian Climatic Center (CCC) scenario, but only 2% under the Parallel Climate Model (PCM). Losses would increase to 18% if they do not adapt. [ABSTRACT FROM PUBLISHER]

ABSTRACT It is known that the El Niño - Southern Oscillation ( ENSO) episodes have a great influence on South American precipitation and its extreme events during austral autumn (from March until May, MAM) and winter (from June until August, JJA) that occur after the ENSO peak (normally this happens on austral summer). Recent papers have studied the two types of ENSO and their influence on atmosphere-ocean system. This study analysed the influence of Central and East equatorial Pacific ENSO on South American seasonal/monthly mean precipitation and its extreme events during MAM and JJA. The composites of precipitation anomalies, during these two types of ENSO, show that there are different, even opposite patterns over South America. In MAM, there is an increased precipitation in southeastern South America and a decrease in the northeast South America during East El Niño ( EEN) and an increased precipitation in central Brazil during Central El Niño ( CEN). In JJA, the signs of anomaly precipitation are opposite between CEN (less precipitation) and EEN (more precipitation) over southeastern South America. The extreme precipitation events show patterns consistent with the precipitation anomaly patterns, but, normally, the changes in the frequency of extremes precipitation events affect more extensive areas than the total precipitation. If monthly or seasonal atmospheric anomalies in a certain region during one of the types of ENSO are similar (opposite) to the atmospheric anomalies associated with extreme precipitation events in this region, then there is enhancement (suppression) of the frequency of extreme events in this region during this type of ENSO. [ABSTRACT FROM AUTHOR]

The oldest Cenozoic mammalian assemblages in South America have been recovered from levels of the Hansen Member of the Salamanca Formation, Punta Peligro locality in Argentina, and from the Santa Lucía Formation in Tiupampa, Bolivia. These faunas led to the recognition of the Peligran and Tiupampan South American Land Mammal Ages (SALMAs), each alternatively regarded as the oldest Paleocene SALMA. Due to the lack of radioisotopic dates for mammals bearing levels at these localities, no agreement has been reached yet about their relative ages. In this paper, the role of mammal faunas in age inference is discussed. Analysis of the SALMAs shows that the presence of non-therian mammals in the Peligran is of little consequence to the biochronological evaluation, reflecting instead a relict Mesozoic distribution. In contrast, therian mammals are particularly important in that (1) they were Lauraisan immigrants and (2) they support direct comparisons between the Tiupampa and Punta Peligro faunas. Parsimony and cluster analysis were used to quantitatively test hypotheses concerning the relative age of the Peligran and Tiupampan SALMAs. Our results support the hypothesis that the Tiupampan SALMA (early Danian) is older than the Peligran SALMA (early Selandian). This alignment results in an interpretation of the evolutionary history of South American land mammals that is more straightforward than the alternative. [ABSTRACT FROM AUTHOR]

Juan Isern collected ca. 25,000 plant specimens during the Pacific Scientific Commission to South America between 1862 and 1866, but unfortunately he died the same year the expedition returned to Spain. In Chile, lsern exchanged specimens with Philippi, who later described three new species based on those collections which are all deposited at SGO. In the early 1930s, José Cuatrecasas worked intensively with the Isern collections at MA, where most of Isern's South American specimens are deposited. Cuatrecasas, Trelease, Sleumer, Standley and Yuncker described several new species and other taxa using Isern collections as type material. A total of 47 species, 21 varieties and 7 forms were described in 9 families, principally in the Asleraceae, Piperaceae and Gesneriaceae based on Isern collections. Here, the nomenclature of all Isern type specimens is studied for these 75 names. Lectotype specimens for the names of four species, three varieties and five forms described by Cuatrecasas and one species described by Trelease are designated in the present paper. [ABSTRACT FROM AUTHOR]

Aim Species richness depends on climate and land use. Maintaining locations with favourable climate and land-use patterns is critical for protecting biodiversity because the loss of either can reduce the species richness that an area supports. Currently, the Guiana Shield (GS) receives abundant precipitation and has relatively light land use. For species richness this constitutes a good–good combination of climate and land use, respectively. In contrast, much of eastern Brazil receives low levels of precipitation and has heavy land use, which is a bad–bad combination for species richness. Thus, the current distribution of precipitation and land use in northern South America is relatively favourable for biodiversity. Palaeoclimate and model studies suggest, however, that the precipitation patterns for the two regions have switched before and could switch in response to greenhouse gas emissions. This paper examines the potential consequences of reconfiguring climate with respect to existing land-use patterns using South America as an example. Location South America north of 20° S and east of the Andes. Methods Ecosystem structure and function are modelled under (1) historical climate and (2) altered precipitation following a shift in the location of the Inter-Tropical Convergence Zone (ITCZ). The distribution of precipitation, biomes, net primary productivity (NPP) and land use are then used to predict levels of species richness under the two climate scenarios. Results Climate changes could shift the distribution of vegetation and NPP such that conditions favourable for species richness in the GS region disappear. If land-use patterns were not prohibitive in eastern Brazil, the improved climate conditions there could compensate for the GS loss (assuming migratory barriers are overcome). Instead, existing land-use patterns cause the combined species richness projected for the two regions to plummet. Main conclusions Human activities will alter current configurations of land use and climate throughout the world. For species richness, new configurations are likely to include both positive and negative combinations of climate and land use. However, the irreversibility of past extinctions due to land-use patterns loads the dice against species richness. [ABSTRACT FROM AUTHOR]

Through analysis of fossil records, the aim of this paper is to show that fossil representatives of at least three land-mammal clades (pitheciine atelid primates, heteropsomyine echimyid rodents, and megalonychid phyllophagan xenarthrans) that once lived in the Greater Antilles are as old as, if not older than,‘first’ occurrences of these same groups on the South American mainland.Greater Antilles, South America, Antarctic Peninsula.Analysis of Cenozoic land-mammal fossil records for the three areas.Comparison reveals an interesting similarity to the Tertiary vertebrate palaeontological record for the Antarctic Peninsula (Seymour Island), in the sense that the latter also includes early (Eocene) representatives of some typical‘South American’ groups (e.g. meridiungulates, sloths, certain marsupial groups).Given how limited the Antillean and Antarctic records are in quantity and quality, it seems unlikely that these‘first’ appearances have much bearing on real origins (basal divergences). Rather, it suggests that the fossil basis for interpreting the origin and earliest diversification of‘South American’ clades during the latest Cretaceous/early Cenozoic is probably even scantier than generally realized. In particular, the Antillean record strengthens arguments that some crown-group continental lineages are considerably older than fossil evidence currently allows– a point increasingly (if unevenly) supported by molecular studies of many of the same clades. [ABSTRACT FROM AUTHOR]

Copyright of Austral Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Host specificity of fleas affects their biodiversity that plays a major role in determining the potential transmission routes by pathogens through vertebrate hosts, including humans. In the Biogeographic Andean region, numerous systematic and ecological studies have been conducted, revealing a high diversity of flea taxa of mammals and the presence of pathogenic organisms transmitted by fleas; however, the degree of preference with which each flea species associates with a mammal host remains poorly understood in this region. Herein, host specificity in mammal fleas from the Andean region was analysed. We employed the number of host species for each flea species and the index of host specificity STD*. Following the literature, 144 species and 13 subspecies of fleas (31 genera and 10 families) have been described in the Andean biogeographic region; 76 taxa are endemic to this region. To carry out the analyses of host specificity, we considered 1759 records of fleas collected from 124 species and 59 genera of wild and domestic mammals, mostly rodent species (85.9%). Our results indicate that typical Andean fleas are genus or family host specific (mostly STD* less than 3.0). More diverse mammal hosts are parasitized by more diverse flea genera and families and these hosts are phylogenetically related. Otherwise, these hosts are associated with different flea lineages, suggesting the interaction of ecological and evolutionary mechanisms (host‐switching, ecological adaptations and co‐evolutionary alternation). The fields of disease ecology and One Health are considering the host specificity of arthropod vectors as an important point to understand the mechanisms of emergence and re‐emergence of diseases. Our results allow us to estimate the risk of diseases involving fleas in the Andean region. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study examined the spatial and temporal patterns of the canopy layer urban heat islands (UHIUCL) in a small city in southeastern Brazil using the local climate zone (LCZ) system. We analysed the influence of weather conditions, LCZs characteristics, and local surface relief on the UHIUCL magnitudes. Mobile traverses were used to measure air temperatures during representative nights of wet and dry seasons. Daily maximum magnitudes were observed in compact classes (LCZs 3 and 7) under ideal weather conditions (dry, clear skies, and calm) and higher anthropogenic heat release (weekdays). Seasonal effects on LCZ thermal differences were negligible. The peripheral landscapes were warmer than the city centre in both seasons. Among the warmer areas in the city, magnitudes in compact LCZs 3 and 7 were consistently higher than in LCZ 6. In general, representative sites of the main 'built' LCZs in the study area exhibit similar inter‐zone temperature patterns to those reported for cities of different sizes from tropical and midlatitude regions. Thermal contrasts of ΔTLCZ 3 − D in the study area reveal significant evidence that small cities can have as strong heat islands as bigger cities. These findings highlight the importance of the LCZ system to identify the main controlling factors driving such thermal differences and the need to extend the application of this approach in other South American cities to yield systematic data of UHIUCL for urban planning given the coming challenges of climate change over the region. [ABSTRACT FROM AUTHOR]

This study examines the Interdecadal Pacific Oscillation (IPO) modulation of the El Niño–Southern Oscillation (ENSO) teleconnections in its decaying stages with the tropical ocean by focusing on the Indian Ocean Basin‐Wide (IOBW) mode and the precipitation over South America (SA) in the 1901–2012 period. Composite analyses revealed that the ENSO teleconnections are IPO‐modulated due to the differential ENSO decaying speed, which is slower during the positive than negative IPO phase, for both El Niño (EN) and La Niña (LN) cases. Negative precipitation anomalies related to EN persist over northeastern SA until austral winter for the positive IPO phase (POS IPO), while significant opposite sign anomalies occur in this region for the negative IPO phase (NEG IPO). These results are associated with the Walker circulation's reversal during NEG IPO which is, in turn, accompanied by negative IOBW. During the POS IPO, the positive IOBW causes upward movements over there and, by continuity, downward movements over SA. In the NEG IPO, for LN events the wave train originating in the north of Australia propagates toward subtropical SA, which, coupled with the surface circulation, causes dryness in this region. In addition, the rapid decay of LN in the NEG IPO, followed by the emergence of EN, caused changes in the Walker circulation, such that enhanced upward movements occurred over the Pacific and SA region, and downward movements over the Indian Ocean until austral winter. In turn, the slower decay of the LN in the POS IPO maintains strong subsidence over the central Pacific and weak upward motions over western SA. So, the EN (LN) and positive (negative) IOBW during the POS (NEG) IPO prolong the scarcity of precipitation over equatorial (subtropical) SA. Persistent dry periods over these regions during the ENSO decaying stage might have important implications for the seasonal forecasts. [ABSTRACT FROM AUTHOR]

Copyright of Mammal Review is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Latin American Policy is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Premise: Pilosocereus (Cactaceae) is an important dry forest element in all subregions and transitional zones of the neotropics, with the highest diversity in eastern Brazil. The genus is subdivided into informal taxonomic groups; however, most of these are not supported by recent molecular phylogenetic inferences. This lack of confidence is probably due to the use of an insufficient number of loci and the complexity of cactus diversification. Here, we explored the species relationships in Pilosocereus in more detail, integrating multilocus phylogenetic approaches with the assessment of the ancestral range and the effect of geography on diversification shifts. Methods: We used 28 nuclear, plastid, and mitochondrial loci from 54 plant samples of 31 Pilosocereus species for phylogenetic analyses. We used concatenated and coalescent phylogenetic trees and Bayesian models to estimate the most likely ancestral range and diversification shifts. Results: All Pilosocereus species were clustered in the same branch, except P. bohlei. The phylogenetic relationships were more associated with the geographic distribution than taxonomic affinities among taxa. The genus began diversifying during the Plio‐Pleistocene transition in the Caatinga domain and experienced an increased diversification rate during the Calabrian age. Conclusions: We recovered a well‐supported multispecies coalescent phylogeny. Our results refine the pattern of rapid diversification of Pilosocereus species across neotropical drylands during the Pleistocene and highlight the need for taxonomic rearrangements in the genus. We recovered a pulse of diversification during the Pleistocene that was likely driven by multiple dispersal and vicariance events within and among the Caatinga, Cerrado, and Atlantic Forest domains. [ABSTRACT FROM AUTHOR]

The South American low‐level jet (SALLJ) is a narrow northerly wind speed maximum present just above the boundary layer. It is an important component of the tropical–extratropical heat and moisture exchange in South America and can favour deep moist convection in southeastern South America. The main objective of this study is to analyse the SALLJ characteristics at 21 upper‐air stations deployed between the Tropics and the subtropics from just east of the Andes to the eastern plains during the SALLJ Experiment (SALLJEX). The greatest wind speed occurs between 300 and 2,000 m AGL between 0300 and 1200 UTC, mainly in connection with greater northerly winds during an anticlockwise rotation of the wind from sunset to sunrise, thus suggesting the important role of the inertial oscillation in the wind's diurnal cycle. The spatial variation of the LLJ throughout the SALLJEX network shows a weakening of the maximum wind speed from stations near the Andes towards the Plains suggesting the presence of the LLJ core just east of the Andes around Santa Cruz de la Sierra's latitude (17°48′S). Weak, moderate, and strong SALLJ categories defined from a local maximum northerly wind speed threshold at each station are defined to analyse the relationship between the SALLJ intensity and the thermodynamic properties of the lower layers of the atmosphere. Strong SALLJs are frequently observed at night‐time, while weak SALLJs are likely to occur at any time of the day. Strong cases have deeper and less stable nocturnal boundary layers, which could be due to the SALLJ warm advection near the time of wind speed maximum (0600 UTC). Deeper convective boundary layers and higher low‐level temperatures observed at 1800 UTC prior to strong nocturnal SALLJs can potentially lead to larger amplitudes of inertial oscillation and contribute to generating stronger SALLJs. [ABSTRACT FROM AUTHOR]

The effect of multiyear La Niña (LN) events on precipitation in South America (SA) was assessed considering 10 persistent LN events over two successive years, referred to as Y1 and Y2 for the 1901–2012 period. Y1 spans from the austral winter of the first year to autumn of the second year, and Y2 spans from the austral winter of the second year to autumn of the third year. Comparisons were performed season by season of the Y1 and Y2. Composites revealed that the teleconnections related to a multiyear LN event during its Y1 and Y2 years, responsible for distinct seasonal precipitation anomaly patterns in SA, were associated with different tropical ocean conditions. In spring, the negative sea surface temperature (SST) dipole in the Indian Ocean during the Y2 was not observed during Y1. Different LN‐related SST anomaly patterns in the tropical Atlantic between Y1 and Y2 occurred in the other seasons. Over northern/northeastern SA, the positive precipitation anomalies became weaker (stronger) during austral summer and autumn (winter and spring) of the Y2 than Y1 and were associated with changes in the Walker cells. During austral spring and summer, southeastern presented drier conditions during the Y2 than Y1. In the spring of Y2, two Rossby wave trains, one associated with the LN‐related anomalous cooling in the equatorial Pacific and another triggered by the upper‐level anticyclone in the tropical Indian Ocean, characterized the circulation pattern over SA which explains the difference in precipitation anomalies between the Y2 and Y1. These drier (wetter) conditions during austral spring and summer (winter and spring), particularly over southern and southeastern Brazil (Colombia) in the Y2, might have more severe effects on the regional hydrological cycle than those in the Y1. The results here indicate that accurate prediction of LN duration is crucial in a climate‐monitoring context. [ABSTRACT FROM AUTHOR]

El Niño–Southern Oscillation (ENSO) phenomena occur in the equatorial Pacific and differentially affect the global climate. Recently, studies have begun to analyse the influence of ENSO intensity on the global climate, but how this intensity affects South American precipitation remains unclear. This work defined the ENSO intensities each season (versus annually, as is more commonly done) because understanding this seasonal intensity is essential for seasonal forecasting. The atmospheric patterns identified in this study showed that the stronger the sea surface temperature (SST) anomalies (SSTA) in the equatorial eastern Pacific were, the stronger the atmospheric responses. The known South American precipitation pattern occurred at all ENSO intensity categories but had different intensities. However, the most important patterns in this study differed from the main pattern. Central‐eastern South America did not have a notable precipitation pattern during all El Niño (EN) years, but there was a negative pattern of strong ENs. In addition, the intensity of the precipitation anomaly during weak EN and La Niña (LN), mainly in northeastern South America, was stronger in austral autumn than in austral summer because the intensity in a previous season can influence the current season's precipitation pattern and the total SST in autumn is stronger than that in summer. Asymmetries between EN and LN events are important to consider; EN tends to be more intense than LN, and deep convection anomalies during EN are displaced eastward relative to those during LN. In this study, categories were defined based on ENSO intensities, but asymmetries appeared in atmospheric patterns, mainly in omega patterns during strong events. The intensities of SSTAs over the equatorial eastern Pacific affected the intensities of the Walker circulation and Rossby waves and, consequently, the intensity of precipitation patterns in different South American regions. [ABSTRACT FROM AUTHOR]

The land–atmosphere interactions play an important role in the South American climate system. Previous studies have explored the coupling between soil moisture (SM), surface heat fluxes and atmospheric variables such as temperature and precipitation; however, the SM–precipitation feedback is still debated, especially at the diurnal scale. We computed three diurnal local coupling diagnostics between spatial, temporal and heterogeneity morning SM anomalies and the occurrence of afternoon precipitation events. We analyse South America in the period October–March 1983–2012 with the ERA5 reanalysis and the RCA4 regional climate model. Two 30‐year climate simulations are performed: a control and an uncoupled simulation where the SM is prescribed with daily climatological values, limiting the SM–atmosphere interaction. Comparing both simulations we isolate the effect of SM variability, allowing us to confirm that the diagnostics are indeed showing the contribution of the SM–precipitation coupling. We test different methods of calculating the morning SM anomalies and observe that all diagnostics show some methodological sensitivity, especially the spatial and temporal diagnostics. Despite the differences, in eastern Brazil we find a preference for afternoon precipitation to develop when the soil is wetter and heterogeneous, over points that are wetter than their surroundings. Towards southeastern South America, there is a spatial and temporal preference for drier or average conditions, depending on the method, with heterogeneity preference, and the same is observed in southwestern Amazonia in RCA4. Ultimately, it is important that future studies disentangle the spatiotemporal coupling mechanisms that may act simultaneously into its distinct components to avoid erroneous assumptions and contradictory results. [ABSTRACT FROM AUTHOR]

The relationship between frontal systems and extreme precipitation events over southern South America is analysed for the austral winter (May–August) and spring (September–December), on a 39‐year period spanning from 1979 to 2017. Daily gridded data from the CPC Global Unified Precipitation dataset and the ERA5 reanalysis are employed. Fronts are identified by means of an objective front index (FI) that takes into account both dynamic (cyclonic vorticity) and thermodynamic (thermal contrast) characteristics. Extreme precipitation is characterized by the seasonal 95th percentile. Fronts occur in mid‐latitudes in about 10% of the days but there is a seasonal shift with larger occurrence frequencies located at southern latitudes in spring compared to winter. Front intensity—calculated as the seasonal mean of FI—is stronger in winter than in spring but the spatial pattern is similar on both seasons. Fronts explain about 50% of extreme precipitation on winter and 40% on spring; the percentage of total precipitation explained by fronts is lower but the spatial distribution is similar. Comparison between fronts that produce precipitation and the ones associated with extreme precipitation revealed that the latter are more intense on average. Fronts that produce extreme precipitation have a stronger dynamic forcing (i.e., higher cyclonic vorticity values) and a higher moisture availability (higher specific humidity anomaly). These two characteristics are the most promising for enhancing extreme precipitation events forecast. [ABSTRACT FROM AUTHOR]

The Paraná River of South America is one of the largest rivers in the world. Although the connection between Paraná streamflow and El Niño–Southern Oscillation (ENSO) has been studied before, little is known about the long‐term (interdecadal) changes of this connectivity. Here we reveal these changes by analysing long instrumental records of Paraná flow, ENSO indices and other climate variables. We find that flow and ENSO were connected in 1876–1940 and 1983–2016, but disconnected in 1941–1982. Flow variability was more related to central Pacific ENSO fluctuations in 1876–1940 but more linked with eastern Pacific ones in 1983–2016, probably because the ENSO–Paraná basin teleconnection was different in the two periods. ENSO‐related Pacific climate anomalies exhibited their smallest amplitudes during the disconnection period 1941–1982, suggesting that the ENSO–flow link vanishes when ENSO is weak. We also find that the ENSO–flow disconnection coincided with the coldest phase of the Interdecadal Pacific Oscillation (IPO) in the study period. Thus, the IPO may be modulating the ENSO–flow connectivity. Interestingly, during the disconnection years (1941–1982), flow was related to climate variability observed in sectors of the southern South Atlantic and tropical North Atlantic oceans. This and the other empirical results presented here provide new insights into the Paraná response to ENSO and thus provide valuable information for future mechanistic studies on this response. [ABSTRACT FROM AUTHOR]

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Semipalmated sandpipers are Arctic breeding shorebirds that migrate to South America during the non‐breeding season. Little work has been done to understand the daily movements, foraging habits and metabolic state of this species on stationary nonbreeding grounds. Our work was conducted at the Banco dos Cajuais Western Hemisphere Shorebird Reserve Network (WHSRN) site in Northeast Brazil. We captured semipalmated sandpipers in February and March 2019 and 2020 and attached nanotags to monitor their daily movements. Blood samples were taken to measure plasma triglycerides (an index of fattening rate). We also conducted behavioral observations on foraging birds. Using tracking data we determined that most semipalmated sandpipers appeared to use sunrise/sunset as an indicator for movement between salina and tidal flat habitats, and a smaller portion used tidal height. We found birds spent similar amounts of time foraging on tidal flats and in salinas, though different foraging modes were used. Plasma triglyceride measures suggest semipalmated sandpipers had not started preparing to migrate when sampled. We successfully tracked semipalmated sandpipers to North America during northward migration in 2020, detecting eight within the United States. Tracking results suggest many stopped elsewhere in South America to fuel for migration, though some may have fueled at the Banco dos Cajuais. By demonstrating substantial use of both natural and altered habitats in the region by migrant semipalmated sandpipers, these data highlight the need for broader conservation measures throughout coastal regions of South America. [ABSTRACT FROM AUTHOR]

In this work, we describe a new species of Ayenia (Malvaceae, Byttnerioideae). Ayenia albiflora sp. nov. is known from the Cerrado areas of southern Goiás, Central‐West Brazil. It can be distinguished from its relatives by its outlying white bisexual flowers and leaves with irregular dentate margin with obovate to subelliptic shape. A distribution map with known occurrence records, as well as comments on the ecology, morphological features and phenology of the species are provided. Moreover, we present an updated identification key of Ayenia species from Central‐West Brazil, distinguishing A. albiflora from its congeners. [ABSTRACT FROM AUTHOR]

The Madden Julian Oscillation (MJO) is the main source of intraseasonal variability in the tropics. MJO modulates rainfall in remote areas in the Southern Hemisphere by exciting tropical and extratropical wave trains. We use newly released reanalysis data to analyze how the Quasi‐Biennial Oscillation (QBO) can influence the MJO's effects over the Southern Hemisphere, focusing on precipitation anomalies over South America. The anomalies in the intensity of the South Atlantic Convergence Zone (SACZ) and precipitation over Southeastern South America during MJO phases 1 and 4 are intensified during the easterly QBO. The extratropical wave train excited by the anomalous convection over the maritime continent during MJO phase 4 is affected by the QBO, with a stronger, better‐defined pattern during westerly QBO. The conclusions are supported by a perturbation experiment of a case study, conducted using a high‐top atmospheric global climate model where the QBO and MJO are controlled. Plain Language Summary: Subseasonal to seasonal prediction remains challenging in the current forecast models. Previous studies have shown that the Quasi‐Biennial Oscillation (QBO) can influence the intensity and development of the Madden Julian Oscillation (MJO). Here, the consequences of this modulation on the remote effects of the MJO in the Southern Hemisphere are analyzed using reanalysis and perturbation experiments in an atmospheric global climate model. The rainfall anomalies related to the MJO in South America are more intense and widespread during easterly QBO over the South Atlantic Convergence Zone and southern Brazil than during westerly QBO. Thus, the inclusion of the state of the QBO in the estimate of the expected rainfall associated with the MJO is crucial to improve forecasts in the region. Key Points: The Quasi‐Biennial Oscillation (QBO) modulates the impacts of the Madden Julian Oscillation (MJO) in the Southern HemisphereMJO‐related rainfall anomalies in the South Atlantic Convergence Zone are intensified during easterly QBOEThe extratropical wave train forced by the anomalous convection in MJO phase 4 is intensified under QBOW [ABSTRACT FROM AUTHOR]

The South American continental slope hosts a variety of topographic waves. We use a 27‐year‐long global ocean reanalysis (1/12° Spatial resolution) to examine trapped waves (TWs) around South America at periods ranging from 40 to 130 days. The waves propagate from the Equatorial Pacific to the Tropical Atlantic (22°S) with phase velocities between 1.8 and 7 m/s according to the local background characteristics, such as stratification, slope steepness, latitude, mean flow and shelf width. The Madden‐Julian Oscillation (MJO) plays a key role in forcing the TWs in two ways (a) through an oceanic connection implying equatorial Kelvin waves reaching the western American Coast and (b) through an atmospheric teleconnection enhancing southerly winds in the south‐east Pacific. Furthermore, local winds, not necessarily linked with the MJO, modulate and trigger waves in specific locations, such as the Brazil‐Malvinas Confluence. Trapped waves impact the along‐shore currents: during the positive phase of the waves the near‐surface flow is enhanced by about 0.1 m/s. Plain Language Summary: Several waves propagate around South America from the Equatorial Pacific to the Tropical Atlantic (22°S) along the continental slope. The waves propagate relatively fast with velocities varying between 1.8 and 7 m/s depending on the local background for example, the continental slope geometry. Two forcing mechanisms were identified: a Pacific Equatorial forcing associated with climatic indices and a local wind forcing at specific locations such as the south‐east Pacific and the Brazil‐Malvinas Confluence. The waves impact the along‐shore currents: the flow is modulated by about 0.1 m/s. Key Points: Coherent Sea Level Anomalies indicate trapped waves propagation along the slope from the Equatorial Pacific to the Tropical Atlantic (22°S)The Madden‐Julian Oscillation (MJO), through oceanic and atmospheric teleconnections, plays a key role in forcing the trapped wavesFurthermore, local winds trigger waves in specific locations, such as the south‐east Pacific and the Brazil‐Malvinas Confluence [ABSTRACT FROM AUTHOR]

Aim: Ecological niches are complex and result from interactions with biotic and abiotic environments across the entire geographic range of species. One recent distinction is between Grinnellian niche characteristics that reflect influences at large spatial scales such as climate and Eltonian niche characteristics that reflect influences at the local level such as distribution of resources and their allocation among species. Aims of this research were to estimate Grinnellian and Eltonian niche characteristics of phyllostomid bats distributed throughout the Atlantic Forest, examine degree of phylogenetic non‐independence of distribution and niche characteristics, and estimate the relative contribution of niche characteristics to distribution across this large Neotropical region. Location: The Atlantic Forest. Taxon: Phyllostomid bats. Methods: Canonical correlation analysis was used to characterize the association between Grinnellian and Eltonian niche characteristics. Phylogenetic non‐independence of distribution and niche characteristics was estimated with phylogenetic eigenvector regression. Variation partitioning was used to distinguish relative contributions of Grinnellian and Eltonian niche characteristics to the distribution of bats. Results: Grinnellian and Eltonian niche characteristics were strongly and significantly associated. Phylogenetic signal was weak for Grinnellian and strong for Eltonian niche characteristics. Both suites accounted for significant unique variation in the distribution of phyllostomid bats in the Atlantic Forest. Grinnellian niche characteristics accounted for more than five times the variation in distribution than Eltonian characteristics. Main Conclusions: Distinct Grinnellian and Eltonian perspectives on the niche provide valuable insights into the distribution of species. The degree to which these two different sets of characteristics account for distribution is likely scale dependent with Grinnellian characteristics more important at geographic spatial scales and Eltonian characteristics more important at local spatial scales. Grinnellian and Eltonian niches are important corollaries of α‐ and β‐ niches and their associated traits and similarities and differences in the two distinct concepts should be better explored across different taxa and geographic domains. [ABSTRACT FROM AUTHOR]

In this study the simulated extreme and moderate El Niño events (e.g., frequency of occurrence and spatial variability) are characterized and the historical teleconnections on precipitation and temperature climate extremes in South America are analysed. Future projected changes in these teleconnections under a global warming context are also addressed. For this purpose a set of 10 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models (GCMs) simulations derived from three experiments (historical, RCP4.5 and RCP8.5) are considered. The study period is 1916–2100. As El Niño is seasonally phase‐locked, peaking in late austral spring and summer, the present analysis is carried out for these two seasons, as well as annually. Results indicate that extreme El Niño events are projected to double their occurrence considering RCP4.5 and RCP8.5, while a less pronounced increase is projected for moderate El Niño events. Most of these events show a similar pattern of sea surface temperature (SST) anomalies: a positive centre in the central equatorial Pacific that extends eastward to the coast of America. In a global warming context, the resemblance between these events may decrease. Overall, the spatial structure of the impacts of El Niño are expected to be similar between moderate and extreme events, although in some cases (regions and seasons), a higher intensity is observed considering the events characterized as extreme El Niños rather than moderate ones. As extreme El Niño events are expected to be more frequent in the future, the impacts on climate extremes as well as the associated socioeconomic impacts would also take place much more frequently too. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim To investigate whether trait-habitat relations in biological communities converge across three global regions. The goal is to assess the role of habitat templets in shaping trait assemblages when different assembly mechanisms are operating and to test whether trait-habitat relations reflect a common evolutionary history or environmental trait filters. Location Guiana Shield, South America; Upper Guinea Forest Block, West Africa; Borneo rain forests, Southeast Asia. Methods We compared large anuran amphibian data sets at both the regional and cross-continental scale. We applied a combination of three-table ordinations (RLQ) and permutation model-based multivariate fourth-corner statistics to test for trait-habitat relationships at both scales and used phylogenetic comparative methods to quantify phylogenetic signal in traits that enter these analyses. Results Despite the existence of significant trait-habitat links and congruent trait patterns, we did not find evidence for the existence of a universal trait-habitat relationship at the assemblage level and no clear sign for cross-continental convergence of trait-habitat relations. Patterns rather varied between continents. Despite the fact that a number of traits were conserved across phylogenies, the phylogenetic signal varied between regions. Trait-habitat relations therefore not only reflect a common evolutionary history, but also more recently operating environmental trait filters that ultimately determine the trait composition in regional assemblages. Main conclusions Integrating trait-habitat links into analyses of biological assemblages can enhance the predictive power and general application of species assembly rules in community and macroecology, particularly when phylogenetic comparative methods are simultaneously applied. However, in order to predict trait composition based on habitat templets, trait-habitat links cannot be assumed to be universal but rather have to be individually established in different regions prior to model building. Only then can direct trait-based approaches be useful tools for predicting fundamental community patterns. [ABSTRACT FROM AUTHOR]

Manuscript Type: Empirical Research Question/Issue: We examine the relationship between corporate governance and firm value, and evaluate the relatively understudied governance practices in Venezuela. Research Findings/Results: We construct a corporate governance index (CGI) for publicly-listed firms that is free of self-selection and self-reported bias and find that its mean value is below the emerging market average in general, and below the Latin American average in particular. This weak investor protection environment makes Venezuela a good setting to study how corporate governance practices affect firm value. We show that an increase of 1 per cent in the CGI results in an average increase of 11.3 per cent in dividend payouts, 9.9 per cent in price-to-book, and 2.7 per cent in Tobin's Q. These findings are robust after considering the potential endogeneity of our regression variables. Theoretical Implications: Results contrast to those reported in the US due to the higher interfirm variations in CGI. Our findings are consistent with the theoretical models that relate good corporate governance practices to higher investor confidence, and with the agency model of dividend payout. Furthermore, we conjecture that our results are generalizable mainly to other countries where investor protection is low. Practical Implications: Two direct insights to policy makers and practitioners follow from our analysis: first, managers in weak investor protection environments could differentiate their firms adopting corporate policies to improve their governance structure; and second, our measure of governance practices gives investors a quantitative tool to better assess Venezuelan firms. [ABSTRACT FROM AUTHOR]

In tropical regions, particularly in Central and South America (CSA), the projections of climate seasonality under climate change are still uncertain. This is especially true for ecologically‐relevant variables such as precipitation and temperature. However, assessments of model‐based projections of seasonal climate for this region are scarce. We analyzed the simulation of seasonal precipitation and air surface temperature in CSA and six sub‐regions within from 49 models included in the Coupled Intercomparison Project Phase 5 (CMIP5) and 33 models from CMIP6. In general, continental patterns and seasonality of both variables are moderately well resembled, while most models show systematic biases over the oceans, producing unrealistic spatial patterns. To quantify how well CMIP5/CMIP6 models simulate these variables, we used Taylor diagrams with respect to TRMM for precipitation and ERA5 for temperature. Precipitation shows the largest spread among models. Conversely, temperature shows a better simulation. CMIP5/CMIP6 models exhibit a better performance simulating both variables during December–January–February and March–April–May than during the other seasons. This is partly due to the reduced model biases in representing the Intertropical Convergence Zone during these two seasons. In general, biases are reduced in the CMIP6 models with respect to CMIP5. Regarding regional evaluations, precipitation patterns for Mesoamerica, Cerrado and Chaco regions are better reproduced compared to TRMM, while the annual cycles for the Andes hotspot, Central Chile and Guianas are not well simulated, mainly during their wet seasons. However, these biases are reduced in CMIP6 models. In regard to precipitation projections, models only agree over most of the regions with decreasing precipitation. Conversely, temperature exhibits a general consensus on persistent warming even during the historical period, with an average increase of 6°C by the end of the century, according to the CMIP6 models. [ABSTRACT FROM AUTHOR]

Oceanic heat sources disturb the atmosphere, which, to come back to its initial state, disperses waves. These waves affect the climate in remote regions, characterizing the teleconnection patterns. In this study, we describe eight teleconnection patterns that affect South America climate: the El Niño–Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the Tropical Atlantic Dipole (TAD), the South Atlantic Dipole (SAD), the Southern Annular Mode (SAM), the Madden–Julian Oscillation (MJO), and the Indian Ocean Dipole (IOD). Precipitation and winds at 850‐hPa anomalies, considering these teleconnection patterns in ENSO neutral periods, are also presented. Overall, southeastern South America and the north sector of the North and Northeast regions of Brazil are the most affected areas by the teleconnection patterns. In general, there is a precipitation dipole pattern between these regions during each teleconnection pattern. [ABSTRACT FROM AUTHOR]

Temperature extreme indices were analyzed for five continental regions of southern South America defined according to their climatic characteristics. Gridded observations, reanalysis, and global‐coupled climate models from CMIP5 were used with the approach of temperature extreme trend attribution analysis on fixed‐threshold and percentile‐based temperature extremes indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). The largest positive trends are exhibited in the tropical nights index, and a clear anthropogenic signal is evident in the subtropical region. In the subtropical central Andes, there is a decrease in the frost days index and increases in the tropical nights and summer days indices, and an anthropogenic signal is evident. In the Patagonian region, all trends from the historical runs were significant, while the ones from the natural experiment were nonsignificant, showing the marked effect of anthropogenic forcing in this region in the extreme temperature events. Projected changes in extreme indices for the 21st century are consistent with a warming climate, and larger changes are expected in the warm nights index. [ABSTRACT FROM AUTHOR]

We analyse the taxonomic status and diversity of the late Miocene Octodontoidea (Hystricognathi) Cercomys primitiva and related samples, a taxon previously known only from the holotype specimen. New findings associated with an extensive review of late Miocene and early Pliocene rodents have allowed us to recognize the occurrence of this and other related species in several localities of central and western Argentina, and in south‐central Bolivia. We discuss the invalidity of Cercomys and propose the new genus Metacaremys, which includes the type species Metacaremys primitiva comb. nov. and two new species, Metacaremys calfucalel sp. nov. and Metacaremys dimi sp. nov. Osteological, brain and dental morphology show that the new genus is not related to Brazilian Echimyidae, as previously considered, but to the southern family Octodontidae. Although the molar morphology of this genus is quite conservative, comparison of the samples shows a variation in size. We discuss the plausible evolutionary pattern explaining this variation and the implied biochronological and biostratigraphical information. It is recognized as an anagenetic lineage in which an increase in size occurs from the oldest species, M. primitiva comb. nov. (early late Miocene, c. 9.23 Ma), to the youngest species, M. dimi sp. nov. (Miocene–Pliocene boundary, c. 5.28 Ma). Metacaremys calfucalel is intermediate in size and age between these two species. The polarity of this pattern of change is consistent with that shown by other partially synchronous independent lineages of octodontoids, thus providing new evidence for the biochronological and biostratigraphic scheme of the late Miocene and early Pliocene of southern South America. [ABSTRACT FROM AUTHOR]

The tribe Chlamydini was highly diversified in the marine Neogene of southern South America, reaching its maximum taxonomic diversity during the Miocene. However, the evolutionary relationships of South American taxa remain uncertain. This is the first phylogenetic analysis based on a large morphological matrix on Pectinidae, which focuses on South American taxa and species related to Chlamys s.s. The phylogenetic analysis is based on a matrix composed of 145 shell‐characters scored for 48 species, and multiple searches were conducted using equal and implied weighting. Two new monophyletic clades are defined, Multiplicata and Pauciplicata. The first includes Dietotenhosen, Ckaraosippur, Zygochlamys, Moirechlamys (South America), the North‐West Pacific Azumapecten, and the North‐East Pacific Chlamys hastata. Pauciplicata is represented by Chokekenia (Patagonia, Argentina), Laevichlamys (tropical Atlantic and Indo‐Pacific), Semipallium (Indo‐Pacific), Swiftopecten (South America and North Pacific), and Jorgechlamys + Reticulochlamys (Patagonia, Argentina). All of these genera are monophyletic except for the paraphyletic Jorgechlamys. The oldest documented occurrence of the tribe is Semipallium foulcheri from the lower Oligocene, a derived taxon that pushes the divergence time of basal genera to the Eocene–Oligocene boundary, generating ghost lineages in all clades, except Jorgechlamys + Reticulochlamys. Pauciplicata and Multiplicata diverge in the early history of the tribe, at the Eocene–Oligocene boundary. Future analyses are necessary to gain a better understanding of the taxonomic arrangement of this poorly understood tribe. Further insights into the relationships of its deepest nodes may well resolve many ghost lineages. [ABSTRACT FROM AUTHOR]

Precipitation predictions in the sub-seasonal timescale are very important for several sectors such as agriculture and energy in regions of South America that are very much affected by precipitation extremes, both excess and lack of rain. The aim of the present study is to investigate the ability of two S2S project models (ECMWF and NCEP) to detect the Southern Hemisphere teleconnections in model hindcasts and the associated anomalous precipitation over South America. The period of analyses is 1999-2010 for the austral summer season (December-January-February). Both models represented adequately the Southern Annular Mode (SAM) pattern in predictions up to 4 weeks ahead and the Pacific South America (PSA) pattern up to 3 weeks. Atmospheric variables of observed extreme cases of SAM were well predicted by the two models, 2 and 3 weeks in advance. The models predicted well atmospheric variables in observed extreme cases of PSA, 2 weeks in advance and with less intensity in the third week. Precipitation anomaly signals associated with these modes were well predicted 2 weeks in advance, although with different intensities. The good ability of the models hindcast in predicting teleconnection patterns and precipitation anomalies over South America provides more confidence to use predictions at sub-seasonal timescale. [ABSTRACT FROM AUTHOR]

Synthetic infrared GOES‐13 observations are generated from a high‐resolution (4 km) Weather Research and Forecasting (WRF) model run over Argentina for a meteorological event of deep moist convection using two different radiative transfer models. The fast operational Community Radiative Transfer Model (CRTM) and the physics‐based research model Atmospheric Radiative Transfer Simulator (ARTS) are compared with the available observations. CRTM shows good results at a low computational cost, and is a good candidate for operational use in the region. CRTM and ARTS synthetic satellite images show differences due to the treatment of the bulk scattering properties of the frozen hydrometeor species, especially around the cloud shield. With this WRF+CRTM configuration, a long‐term evaluation is conducted over 12 hr forecasts from one month of data in a region of the South American autumn with four different initializations at 0000, 0600, 1200 and 1800 UTC, as operational at the National Meteorological Service of Argentina. The simulated and observed GOES‐16 Advanced Baseline Imager (ABI) brightness temperatures (BTs) in the 6.9 μm channel show good agreement with an averaged bias of −0.1 K (RMSE 21.7 K), whereas the performances in the IR window channels show slightly larger averaged BT differences of 3.5 K (RMSE 15.2 K). BT differences between the 6.9 and 10.3 μm channels indicate that the WRF+CRTM simulations underestimate low to mid‐level clouds and to a lesser extent high‐level clouds. In the BT (10.3 μm) range between approximately 215 and 230 K, there is an overestimation of clouds with BT differences above 0 K between 6.9 and 10.3 μm. This could be due to the misrepresentation of upper‐level clouds. [ABSTRACT FROM AUTHOR]

Conservation policies often promote land privatization to reduce incentives for deforestation. However, empirical evidence on the relationship between land‐tenure form and forest conservation outcomes is inconclusive. We combined key informant mapping and geospatial analyses to test the association between the area under tenure and the area deforested by extra‐local private and local nonprivate agents in the Argentine Dry Chaco over four decades (1976–2016). The study area is a typical commodity production frontier within a global deforestation hotspot. We found a strong spatial and temporal coupling between the area under tenure and the area deforested by extra‐local private agents from 1987 to 2006, when a 59% increase in the former was accompanied by a 508% increase in the latter. Local private agents maintained high levels of forest cover, similarly to local nonprivate agents. Our findings have implications for the adaptive design of the Forest Law in the Argentine Dry Chaco. [ABSTRACT FROM AUTHOR]

The complexity of natural communities is the result of interactions among species that coexist within them. Parasitic interactions are among the most common species interaction types, and analysis of parasite–host ranges can advance understanding of how host–parasite pairs structure community interactions across their geographic distributions.Using network analysis and host preference relative index, we analysed host use by the South American mistletoe, Tristerix corymbosus (Loranthaceae), in 22 localities among two biomes: Chilean matorral and temperate forest.The total number of host species recorded was 27, and 40% of these species were non‐native. The non‐native Populus sp. was shared between biomes. There was a positive relationship between host range and potential host species richness at the studied localities. On average, the mistletoe parasitized each host species relative to its abundance. However, some host species in some localities are more parasitized than expected. Network structure showed a differences in host use between the two biomes: Aristotelia chilensis was central in the temperate forest, with Populus sp. in the Chilean matorral. Host use intensity in the Chilean matorral was higher for non‐native species.Tristerix corymbosus has a wide host range and could be considered a generalist parasite across its full geographic distribution, but at local scales, host preferences differed among localities and are related to host coverage. Alterations in community composition, due to natural events or human activities, can modify the availability of possible hosts. Hence, the mistletoe with the described characteristics may be able to change its infection preference while maintaining the interaction functionality. [ABSTRACT FROM AUTHOR]

This study presents results from an assessment of climate change projections over South America using fifth phase of the Coupled Model Intercomparison Project models. Change in near‐surface temperature, precipitation, evapotranspiration, integrated water vapour transport (IVT), sea level pressure (SLP), and wind at three pressure levels is quantified across the multi‐model suite. Additionally, model agreement for the sign and significance of projected change is assessed within the ensemble. Models are in strong agreement that the highest magnitude of projected warming will be over tropical regions. The CMIP5 models project a decrease in precipitation for all seasons over southern South America, especially along the northern portions of the present‐day mid‐latitude storm track. This is consistent with a robustly projected poleward shift of the Pacific extratropical high‐pressure system and mid‐latitude storm track indicated by a systematic increase in SLP and decrease in westerly wind magnitude over the region. Decreased precipitation for the months of September, October, and November is also projected, with strong model agreement, over portions of northern and northeastern Brazil, coincident with decreases in SLP and increases in evapotranspiration. IVT is broadly projected to decrease over southern South America, coincident with the projected poleward shift of the mid‐latitude storm track, with increases projected in the vicinity of the South Atlantic Convergence Zone in spring and summer. Results provide a comprehensive picture of climate change across South America and highlight where model consensus on change is most robust. [ABSTRACT FROM AUTHOR]

The modern pitheciids (titis, sakis, and uakaris) of northern South America represent one of the earliest radiations of platyrrhines and demonstrate morphological adaptations and ecological strategies for seed eating. While seeds can provide reliable resources for relatively long periods of time, they are often well protected by thick husks and hard seed coverings. Seeds also tend to be rich in lipids, but they may also be high in indigestible fiber. Even though seed eaters are found in each major primate radiation, only the pitheciids demonstrate primary adaptations for eating seeds. In this partly historical, partly contemporary review, I examine the ecological and anatomical correlates of seed eating. It is dedicated to two well‐known field primatologists: ecologist and conservationist J. Márcio Ayres; and anatomist and ecologist Warren G. Kinzey. Using observations in Kinzey (1992, Am J Phys Anthropol, 88, pp. 499–514) as a framework, I provide context and analysis for the intervening three decades of pitheciid research to identify what we know about this understudied group of primates and propose directions for future work. Highlights: Márcio Ayres and Warren Kinzey were pioneers in the study of pitheciid ecology in the late 20th century.The Pitheciidae is one of the oldest radiations of platyrrhines, identifiable by specialized dentition (used to open well‐protected fruit) by the middle Miocene.The subfamily, Pitheciinae (sakis, bearded sakis, and uakaris), are seed‐eating specialists using enlarged canines to open mechanically resistant foods and flat, crenulated molars to crush young and mature seeds.The benefits of seed eating lay in the long‐term availability of resources and relatively high lipid content of seeds. Dietary fiber (neutral detergent fiber [NDF]) appears to be the most significant constraint on eating seeds by pitheciines. [ABSTRACT FROM AUTHOR]

Calyceraceae is a small South American family sister to Asteraceae. Previous phylogenetic analyses revealed that Calyceraceae genera are para‐ or polyphyletic. Fruit and inflorescence characters used historically as diagnostic in Calyceraceae taxonomy have proven unreliable in defining natural groups. Surprisingly, flower morphology does not appear in diagnoses of Calyceraceae genera, and its diversity and evolution has remained unstudied before now. Based on phylogenetic analyses using six molecular markers and an almost complete sampling of the family (43 of 46 species), we propose a taxonomic re‐arrangement of Calyceraceae. In the search for diagnostic morphological characters, we studied flower structure diversity and optimized 12 discrete characters by maximum parsimony and maximum likelihood to reconstruct floral evolution in the family. Calyceraceae species are arranged in eight genera (three monotypic, five with 6 to 13 species). Two genera are new (Anachoretes, Asynthema), one is reinstated (Leucocera), with the remaining five emended (Acicarpha, Boopis, Calycera, Gamocarpha, Moschopsis). Flower morphology is notably diverse but provides only a few diagnostic features. Many floral attributes likely reflect selection for pollination or fruit dispersal rather than phylogenetic affinity. In the context of this taxonomic revision, we include a key to genera, new and emended diagnoses, and new combinations. [ABSTRACT FROM AUTHOR]