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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]

Information from diversity inventories was used to study patterns of biodiversity and species distribution, to identify potential priority areas for conservation, and to guide future sampling efforts. In this context, we compiled information on non‐volant small mammal communities from the high Andes (>2000 m). Here, we present an open source dataset containing information on diversity (species composition, number of individuals captured), inventory design (type of traps, sampling efforts), and environment (habitat) for both unpublished and published information. This study covers 630 mammalian communities, geographically distributed throughout the Andes in Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina, and Chile. We compiled a total of 26,412 individual records belonging to 240 species; the order with greatest number of records was Rodentia (n = 25,319, 96.06%), followed by Didelphimorphia (n = 373, 1.42%), Eulipotyphla (n = 358, 1.36%) and Paucituberculata, (n = 307, 1.16%). Andean non‐volant small mammal communities harbor a range from 1 to 17 species, with 93.06% of sites being composed of one to five species, 27.78% of sites with species richness varying from 6 to 10 species, and 4.17% sites composed of more than 10 species. Multiple sampling methods were used to survey non‐volant small mammals; the most representative methods were snap‐traps and Sherman traps, or a combination of both, in more than 81% of the studies. This data paper represents the first large dataset of faunal species inventories for the Andes. There are no copyright restrictions associated with the use of this dataset. Please cite this data paper when its data are used total or partially in research or teaching. [ABSTRACT FROM AUTHOR]

A coincidence in the timing of floods and their drivers can be used as a proxy for the causality of flood generation. Here, we investigate the relationship between the seasonality of floods, maximum annual rainfall, and maximum annual soil moisture data of 886 basins in Brazil for 1980–2015 to shed light on process controls of flood generation. Floods tend to occur at the same time of year as soil moisture peaks and lag behind rainfall peaks by 3 weeks. In Amazonia, central and northern Brazil, flood timing is more correlated with the timing of soil moisture peaks than with that of rainfall peaks, which is interpreted as resulting from high subsurface water storage capacities. In southern and southeastern Brazil, on the other hand, flood timing is highly correlated with both soil moisture and rainfall because of low subsurface water storage capacities. These findings can support flood forecasting and climate impact studies. Plain Language Summary: In warm regions, floods are usually generated by a combination of intense rainfall and wet soils. In this paper, we analyze the average timing within the year of floods, extreme rainfall, and soil moisture to elucidate how floods come about in the main Brazilian rivers. We find that in some regions, such as Amazonia and central Brazil, floods tend to occur when soils are wet. In other regions, such as southern Brazil, floods tend to occur when rainfall is most extreme. We believe that these differences are related to differences in the soil water storage capacity. The understanding of the regional importance of each of these components helps increase the efficiency of flood prevention measures and climate change adaptation. Key Points: Flood peaks tend to occur at the same time of year as annual soil moisture peaks and lag behind annual rainfall peaks by 3 weeksFlood seasonality is linked mainly with soil moisture peaks in Amazonia and central Brazil, where soil storage capacity is highFlood timing is highly correlated with rainfall and soil moisture peaks in the south and southeast, where soil storage capacity is low [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]

The Peruvian Province, from 6° S in Peru to 42° S in Chile, is a highly productive coastal marine region whose biology and fossil record have long been studied separately but never integrated. To understand how past events and conditions affected today's species composition and interactions, we examined the role of extinction, colonization, geologic changes to explain previously unrecognized peculiar features of the biota and to compare the Peruvian Province's history to that of other climatically similar temperate coasts. We synthesized all available data on the benthic (or benthically feeding) biota, with emphasis on fossilizable taxa, for the interval from the Miocene (23–5.4 Ma) and Pliocene (5.4–2.5 Ma) to the present. We outline the history of ecological guilds including primary producers, herbivores, predators, and suspension‐feeders and document patterns of extinction, colonization, and geographic restriction. We identify twelve unusual attributes of the biota, most of which are the result of repeated episodes of extinction. Several guilds present during the Miocene and Pliocene are not represented in the province today, while groups such as kelps and perhaps intertidal predatory sea stars are relative newcomers. Guilds on soft bottoms and in sheltered habitats were severely affected by extinction, whereas those on hard bottoms were most affected by colonists and held their own in diversity. The Peruvian Province has not served as a biogeographic refuge, in contrast to the coasts of Australasia and Argentina, where lineages no longer present in the Peruvian Province survive. The loss of sheltered habitats since the Pliocene explains many of the present‐day peculiarities of the biota. The history of the province's biota explains its unique attributes. High productivity, a rich Southern Hemisphere heritage, and colonization from the north account for the present‐day composition and unusual characteristics of the biota. [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]

In this paper, we used geostatistical approaches to describe bi-dimensional spatial patterns in species richness of South American birds of prey (Falconiformes and Strigiformes). They indicated strong spatial patterns both across latitude and longitude, for the two groups. These patterns were then correlated with those expected by a bi-dimensional null model constructed to take into account South America continental edges. As considerable departures from the null model were observed, there may be other ecological or evolutionary explanations for spatial patterns in species richness. Variation seems to be related to habitat heterogeneity across the continent, especially when considering differences between habitats in the central and south-eastern portion of the continent and in the Andean region. This supports previous conclusions that habitat type and heterogeneity affect species richness and abundance at different spatial scales. [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]

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 We analysed body-size variation in relation to latitude, longitude, elevation and environmental variables in Ctenomys (tuco-tucos), subterranean rodents in the Ctenomyidae (Caviomorpha). We tested the existence of inter- and intraspecific size clines to determine if these rodents follow Bergmann's rule, to compare intra- and interspecific size trends and to assess the relevance of the subterranean lifestyle on these trends. Location South America, south of 15° latitude. Methods This paper is based on 719 specimens of tuco-tucos from 133 localities of Argentina, Bolivia, Chile, Paraguay, Peru and Uruguay, representing 47 named species and 32 undescribed forms. Intraspecific analyses were performed for Ctenomys talarum Thomas, 1898 and the Ctenomys perrensi Thomas, 1896 species complex. Head and body length and weight were used for estimating body size. Geographical independent variables included latitude, longitude and altitude. Environmental independent variables were mean minimal and maximal monthly temperature, mean annual temperature, mean minimal and maximal precipitation, and total annual precipitation. To estimate seasonality, the annual variability of the climatic factors was calculated as their coefficients of variation and the difference between maximum and minimum values. Mean annual actual evapotranspiration (AET), and mean annual, January (summer) and July (winter) potential evapotranspiration (PET) values were also calculated for each locality, as well as annual, summer and winter water balance (WB). Statistical analyses consisted of simple and multiple regression and nonparametric correlation. Results Body size of Ctenomys decreases interspecifically from 15°00′ S to 48°15′ S and from 56°33′ W to 71°46′ W, and is positively correlated with ambient temperature and precipitation. The best predictors of body size according to multiple regression analyses were mean annual temperature, the difference between mean maximum and minimum annual temperatures, annual PET, the difference between summer and winter PET, and annual and winter water balance. These patterns are repeated, but not identically, at a smaller geographical scale within the species C. talarum and the superspecies C. perrensi. Main conclusions Tuco-tucos follow the converse to Bergmann's rule at the interspecific level. At the intraspecific level some parallel trends were observed, but the smaller scale of these analyses, involving a very reduced variation of environmental factors, necessitates caution in interpreting results. The subterranean lifestyle probably insulates these rodents from the external temperature. The observed latitudinal body-size gradients are more probably related to seasonality, ambient energy, primary productivity and/or intensity of predation. [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]

Aim During the last 20 years, the austral cordgrass Spartina densiflora has been recorded aggressively invading estuarine environments in the USA, Spain and Morocco. Whereas this species is one of the three most widely distributed worldwide, it is among the least studied within the genus. The objective of this work is to integrate baseline information about the taxonomy, global distribution, centre of origin, and general ecology of S. densiflora in native and invaded marshes worldwide in order to help to strengthen management efforts currently directed at controlling or eradicating it from locations where it has been introduced. Location World-wide. Methods I review, update and discuss relevant information about S. densiflora published in peer-reviewed papers, including those in journals with limited international distribution. I also review theses and major technical reports containing critical up-to-date information. Results This work indicates that, although S. densiflora remains in need of thorough scientific attention, key information on its taxonomy, distribution and invasive biology has been overlooked because it was published in languages other than English, and/or in journals with restricted distribution. Main conclusions Spartina densiflora seems to have originated along the east coast of South America; today, however, many other regions worldwide serve as donors for this invasive species, including Chile, the USA, Spain and Morocco. Spartina densiflora is a bioengineer organism, tolerant of a broad spectrum of environmental conditions and able to re-shape the structure of invaded communities not just in mudflats, but also on sandy, muddy, and rocky shores as well as on cobble beaches. Only by integrating local-scale research conducted in different geographical regions will we be able to understand the between-site variations of its biological cycle, which in turn will aid in the design of more effective conservation strategies. [ABSTRACT FROM AUTHOR]

Aim Climate change has the potential to have an impact on the distribution of ticks and tick-borne diseases. This paper identifies the changes in climate suitability for the tick Rhipicephalus (Boophilus) microplus in the Americas by analysing climate data for the period 1950–99. Location The model was applied to the American continent. Methods A model based on Environmental Niche Modelling was used on a gridded (0.5°) long-term (1950–99) climate data set. A map of the core range of the species was constructed, and areas where habitat suitability (HS) changes suddenly over short time periods were identified as regions of high sensitivity. Tendency of climate in the continent was evaluated and scenarios constructed for 2025 and 2050. Results Regions of high sensitivity included the southern USA, Mexico and western and central Argentina. Analysis of climate variables in these regions identified water vapour pressure deficit and evaporation as underlying the high sensitivity of habitat suitability in the USA and Mexico, and showed that episodes of high variability are linked to the El Niño Southern Oscillation. Projections of the tendency of HS as observed for the 1950–99 period point to an increase in this value in parts of the southern USA and in central Argentina, a finding that can be attributed to the progressive increase in minimum and yearly averaged temperatures. Conclusions Short-term changes in climate may drive the system into unstable situations with sudden changes in habitat suitability for the target tick in specific zones of the Americas. Results suggest an increased abiotic (climate) suitability for R. microplus in areas whose habitat is currently unsuitable for this species. [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]

Abstract The aim of this paper was to test the hypothesis that the presence of overwintering Calomys venustus males or females at the beginning of the breeding period reduced the survival of juveniles belonging to the first cohort of each year (C1). The study was carried out in four 0.25-ha enclosures (two control and two experimental), each situated on natural pasture. This study was conducted between August 1997 and February 1999 and had two parts: removal of overwintering males (ROM) and removal of overwintering females (ROF). For the ROM treatment, overwintering males were removed immediately after C1 juveniles were born, in the ROF treatment overwintering females were removed after the C1 were weaned. Weekly censuses were taken for 3 successive days over 6 weeks. Juvenile survival was examined through a survivorship schedule. The survivorship values were compared by sex and treatment (removal of overwintering males or females) using repeated-measures anova. Removal of overwintering males and females did not improve the survival of C1 juveniles. This result could be related to the delay in maturation of C1 juvenile males. [ABSTRACT FROM AUTHOR]

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Premise: The Lower Cretaceous Crato Konservat‐Lagerstätte (CKL) preserves a rich flora that includes early angiosperms from northern Gondwana. From this area, the recently described fossil genus Santaniella was interpreted as a ranunculid (presumably Ranunculaceae). However, based on our examination of an additional specimen and a new phylogenetic analysis, we offer an alternative interpretation. Methods: The new fossil was collected from an active quarry for paving stones in the state of Ceará, northeastern Brazil. We assessed support for alternative phylogenetic hypotheses using a combined analysis of morphological data and DNA sequence data using Bayesian inference. We used a consensus network to visualize the posterior distribution of trees, and we used RoguePlot to illustrate the support for alternative positions on a scaffold tree. Results: The new material includes a flower‐like structure not present in the original material and also includes follicles preserved at early stages of development. The flower‐like structure is a compact terminal cluster of elliptical sterile laminar organs surrounding internal filamentous structures that occur on flexuous axes. Phylogenetic analyses did not support the fossil placement among eudicots. Instead, Santaniella appears to belong in the magnoliid clade. Conclusions: The presence of seeds in a marginal‐linear placentation and enclosed in a follicle supports the fossil as an angiosperm. However, even though most characters are clearly recognizable, its combination of characters does not provide strong support for a close relationship to any extant order of flowering plants. Its position in the magnoliid clade is intriguing and, based on plicate carpels, it is definitely a mesangiosperm. [ABSTRACT FROM AUTHOR]

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]

Aim: Roads are a major threat for wildlife, degrading habitat and causing mortality via wildlife–vehicle collisions. In Latin America, the conjunction of high biodiversity and a rapidly expanding road network is reason for concern. We introduce an approach that combines species traits and habitat preferences to describe vulnerability and map areas of high roadkill risk. Thus, we present the first assessment of roadkill impacts for Latin American birds and mammals. Location: Latin America. Time period: 1994–2020. Major taxa studied: Birds and mammals. Methods: We compiled data from 85 roadkill surveys from Latin America that provided 1,691 roadkill rate estimates for 346 bird and 159 mammalian species, from which 520 rates from 249 birds and 457 rates from 103 mammals were used for analyses. We applied random forest models to predict observed roadkill rates considering species traits, habitat preferences and the geographical coordinates of each study to control for local and regional variation. Fitted models were used to predict spatial risks on Latin American roads for roadkilled birds and mammals across their areas of habitat. Results: We found higher roadkill rates for larger birds and medium‐sized mammals with faster reproduction (more clutches/litters per year and early maturity ages), higher population densities and wider use of habitats that included anthropized areas. In mammals, scavengers and those with diets based on invertebrates showed higher rates. Spatial predictions revealed higher rates on roads across Central America, northern Andean regions, eastern Brazil, Uruguay, central and eastern Argentina and southern Chile. Main conclusions: This first comprehensive assessment for Latin America explores various drivers of roadkill risk for birds and mammals and identifies species and areas where existing roads can impact wildlife. Trait‐based models fine‐tuned with realistic spatial information that accounts for habitat suitability provide a valuable tool for the assessment of human impacts, including roads and traffic. [ABSTRACT FROM AUTHOR]

Addressed here is the biogeographical‐vexing question of why the guanaco (Lama guanicoe) is the only large mammal on the big island of Tierra del Fuego, answered by comparing alternative colonisation hypotheses. A multidisciplinary examination was conducted into the archaeological, ecological, evolutionary, geographical, genomic, glacial and zoological past, plus distribution of native terrestrial vertebrates in the Patagonia of southern South America. Notable disparities exist between main Patagonia (2.5 species/10,000 km2) compared with Tierra del Fuego (1.8). In the similar‐sized area of mainland Patagonia just north of the Strait of Magellan there are 12 reptiles, 7 amphibians and 34 mammals = 53 total species; Tierra del Fuego has 13. Despite being the size of Switzerland and only 3.1 km from the mainland, Tierra del Fuego has no species of snakes, salamanders, frogs or turtles, only one lizard, one toad, nine small mammals, one carnivore and one ungulate, the Guanaco. An innovative proposal is made contrary to traditional thinking: Tierra del Fuego has relatively few native‐terrestrial vertebrates because they were decimated by major tephra‐ash fallout (2 to >15 cm) from the Holocene 7750 YBP (years before present) Hudson volcano, the biggest and most destructive eruption in Patagonia during the past 10,000 years that eradicated indigenous peoples, most terrestrial vertebrates and all Guanacos. Neither terrestrial vertebrates nor man were replenished from the adjacent mainland for 1000 years because the Strait of Magellan was a complete biogeographical barrier. Guanacos on Tierra del Fuego have lower genetic diversity compared with the mainland, suggesting it is a younger population. Empirical evidence and pivotal events of Patagonia's prehistory support one of three hypotheses: guanacos were introduced to Tierra del Fuego by early Holocene, guanaco‐dependent, indigenous peoples from the mainland who repopulated Tierra del Fuego utilising the newly invented, skilfully crafted, seaworthy bark canoe (Appendix S1–Resumen en Español). [ABSTRACT FROM AUTHOR]

Geodetically constrained interseismic interplate coupling has been widely used to assess seismic potential in subduction zones. Modeling interseismic deformation is challenging, as it involves interplate coupling and often ignores continental internal deformation processes. We present a novel methodology to jointly estimate interplate coupling along with upper plate rigid motion and surface strain, constrained by GNSS‐derived velocities. We use a least squares inversion with a spatially variable Equal Posterior Information Condition Tikhonov regularization, accounting for observational and elastic structure uncertainties. Our modeling reveals three megathrust regions with high tsunamigenic earthquake potential located within the Atacama Seismic Gap (Chile). This study indicates the presence of a downdip segmentation located just above the 1995 (Mw8.0) Antofagasta earthquake rupture, raising concerns for the potential of tsunamigenic earthquake occurrence at shallower depths. Additionally, we show that surface motion is dominated by strain, with rather negligible rigid motion, dismissing the rigid Andean microplate model typically assumed in previous studies. Plain Language Summary: We present a novel methodology to investigate the degree of coupling (a measure of the earthquake potential) along the plate interface in subduction zones. Here, we infer deformation and rotation of the continental plate together with the degree of coupling, all using Global Positioning System (GPS) measurements of continental surface deformation. We apply this approach for the subduction margin formed by the convergence of Nazca and South‐American plates, and located between the Chilean cities of Antofagasta and La Serena. We find three regions with high seismic potential, raising concerns for future occurrence of large tsunamigenic earthquakes. The first region is located westward of the rupture area of the 1995 (Mw8.0) Antofagasta earthquake, the second region extends for 200 km between the cities of Taltal and Copiapo and the third region extends for 100 km between the cities of Vallenar and La Serena. Our results highlight the importance of estimating continental strain jointly with coupling models. Key Points: Improved subduction strain accumulation model between 23° and 30°S taking advantage of newly developed inversion schemesNegligible rigid Andean block motion and fore‐arc extension dominates the Atacama Region (23°–30°S)Above the 1995 Mw8.0 earthquake, the megathrust remains coupled with high seismic potential [ABSTRACT FROM AUTHOR]

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]

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]

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]

Aim This paper presents a spatial classification of the environmental and ecological diversity of the cerrado region of Brazil, as well as an appraisal of the levels of conversion to agriculture and of the extent of land protection. Location The cerrado region of Brazil, located in the centre of Brazil, occupies c. 2.5 million square kilometres. Our study area represents roughly 85% of the total. This ecologically heterogeneous region is dominated by savannas, but also contains several types of forests and xerophytic communities that often form mosaics with the savannas. Its high biodiversity is seriously threatened by the accelerated process of conversion to agriculture and a deficiency in the extent and the representativeness of protected areas. Methods We selected 124 land systems from a previous study of the lowlands of South America. The maps were digitized and 41 parameters, where environmental information was available, were used to build a matrix. A cluster analysis was then performed and the results used to classify the land systems into units at two scales. The larger units, characterized by the dominant landform and vegetation, were considered as landscape units. Within each of these, smaller units called ecological units were defined by the physiognomy and phenology of the dominant vegetation, topography and drainage. Using GIS, we mapped the resulting ecological units and incorporated the information on land use from the municipal agricultural census of 1996. In addition, data on the extent of protected land units was used to assess the status of land protection in each ecological unit. Results Five landscape units and 15 ecological units were identified, mapped and explained. These units were not continuous but were represented by disjunct patches located in different parts of the study region. Brief descriptions are given including the geographical locations and dominant ecological features. They also include the extent of land conversion to agriculture (1996 census figures) in each of the various patches as well as the number and area of units of conservation. Main conclusions The high level of land conversion to agriculture is a major threat to the conservation of the remarkable biodiversity of the cerrado region. This, together with the poor status of land protection, represents the major environmental problem facing this region. However, the fact that areas with similar general ecological conditions have a disjunct distribution is important for conservation purposes, even though the details of floristic similarities and biogeographic influences have still to be worked out. Our detailed spatial classification has made this disjunction clearly apparent and has allowed us to map ecologically similar areas accurately. This allows the evaluation of the status of these areas in terms of land use and land protection and may be used in the design of conservation strategies. [ABSTRACT FROM AUTHOR]

Aim: We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate (1) whether its current widespread distribution in the Southern Hemisphere is due to recent long‐distance dispersal or long‐term diversification; and (2) the age and origin of sub‐Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: Boeckella poppei. Location: South America, sub‐Antarctic islands, maritime Antarctica, continental Antarctica and Australasia. Methods: To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution. Results: Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two main clades during the late Cretaceous (ca. 80 Ma). The first clade diversified in Australasia, and the second clade is currently distributed in South America, various sub‐Antarctic islands and Antarctica. Dispersal from South America to the Kerguelen and Crozet archipelagos occurred during the Eocene/Oligocene (B. vallentini) and in the late Pliocene (B. brevicaudata), while South Georgia and the maritime Antarctic were likely colonized during the late Pleistocene (B. poppei). Main conclusions: Boeckella has a Gondwanan origin, with further diversifications after the physical separation of the continental landmasses. Extant populations of Boeckella from the Scotia Arc islands and Antarctic Peninsula originated from South America during the Pleistocene, suggesting that original Antarctic Gondwanan lineages did not survive repeated glacial cycles during the Quaternary ice ages. A continuous decline in the species accumulation rate is apparent within the genus as the early Eocene, suggesting that Boeckella diversification may have decreased due to progressive cooling throughout the Cenozoic era. [ABSTRACT FROM AUTHOR]

Rodents are the most diverse order of extant mammals, and caviomorph rodents, or New World hystricognaths, have a remarkable morphological disparity and a long fossil record that begins in the Eocene. Chinchilloidea is a poorly understood clade within Caviomorpha, from an evolutionary and phylogenetic perspective. It includes the extant families Chinchillidae and Dinomyidae, the extinct Neoepiblemidae and Cephalomyidae, and several extinct chinchilloids without a clear phylogenetic position, like Eoincamys, Borikenomys, Chambiramys, Ucayalimys, Incamys, Saremmys, Garridomys and Scotamys. The family Chinchillidae includes the extant Chinchilla and Lagidium, grouped in Chinchillinae, and the only living Lagostominae, Lagostomus maximus. Among extinct chinchillids, Eoviscaccia (early Oligocene‐early Miocene of Argentina, Bolivia and Chile), Prolagostomus (early‐middle Miocene of Argentina, Bolivia and Chile) and Pliolagostomus (early‐middle Miocene of Argentina) are the only genera originally described as members of the family. Based on the study of specimens with unworn or little‐worn cheek teeth, belonging to extinct and extant taxa, we propose homologies of the cheek teeth structures and perform a combined molecular and morphological phylogenetic analysis including extinct and extant taxa of all families of Chinchilloidea and all genera of Chinchillidae. Our phylogenetic analysis recovered three major lineages in the evolutionary history of Chinchilloidea. The first major lineage is composed of the extant taxa Chinchilla, Lagidium and Lagostomus, and the extinct genera Eoviscaccia, Prolagostomus, Pliolagostomus, Garridomys, Incamys, Loncolicu and Saremmys. Cephalomyid (Banderomys, Cephalomys, Litodontomys, Soriamys) and neoepiblemid (Neoepiblema, Perimys, Phoberomys, Scotamys) genera are part of the second major lineage, while dinomyids such as Dinomys, Drytomomys, Scleromys, 'Scleromys' and Tetrastylus constitute the third major lineage within Chinchilloidea. The phylogenetic position of some taxa previously considered as incertae sedis chinchilloids or without a clear suprageneric group (i.e. Incamys, Saremmys, Garridomys and Loncolicu) show that they belong to pan‐Chinchillidae and conform the stem Chinchillidae along with Eoviscaccia. The euhypsodont crown Chinchillidae includes the living subfamilies Chinchillinae and Lagostominae. Dinomyidae and Eoincamys pascuali are recovered as the sisters of a major clade composed by 'Cephalomyidae'+Neopiblemidae and pan‐Chinchillidae, and Chambiramys sylvaticus occupies a basal position to the same clade. Four major radiation events are identified in the evolutionary history of Chinchilloidea. The analysis of new morphological characters linked with molecular evidence as well as the addition of taxa of uncertain or unstable phylogenetic position or not considered in previous studies allowed us resolve part of the relationships within Chinchilloidea, particularly that of Chinchillidae, supporting preceding morphological hypotheses. [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]

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]

Recent seizures of jaguar body parts in Bolivia have prompted concern about illegal trade to China, but a detailed understanding of this emerging trade continues to be lacking. We interviewed 1,107 people in a rural area implicated in the trade, using direct and indirect questions through the Ballot Box Method (BBM) to explore the prevalence and characteristics of the illegal jaguar trade and its links to foreign demand. Jaguar trade is a common, and mostly non‐sensitive practice; 46% of respondents reported some involvement over the past 5 years. The most common behavior was owning jaguar body parts, such as skins, fat and teeth for decorative, medicinal, and cultural purposes. The most mentioned traders were Bolivian, followed by traders of Asian descent. However, regression analysis shows that the presence of traders of European descent was more significantly and positively associated with jaguar trade related behaviors, ahead of Asian descent and regional traders. Overall, jaguar trade in Bolivia has more diverse actors and drivers than seizures may suggest. Therefore, conservation interventions, in addition to targeting demand from Chinese wildlife markets, should address other foreign and domestic markets and trade chains. [ABSTRACT FROM AUTHOR]

PREMISE: With over 1500 species, the globally distributed Vernonieae is one of the most successful members of the largest family of flowering plants, the Compositae. However, due to its morphological complexity and limited geographic representation in previous studies, subtribal and biogeographic relationships are unclear. Here, new DNA sequence data spanning the geographic range of the tribe provides a taxonomically robust time‐calibrated phylogeny, estimates migration pathways and timing of important biogeographic events, and allows inference of environmental factors that have contributed to the success of the Vernonieae worldwide. METHODS: Phylogenetic relationships were estimated for 368 taxa representing all Vernonieae subtribes. Molecular clock and ancestral range estimation analyses provide a framework for inference of the biogeographic history of the tribe. RESULTS: Relationships among the subtribes were established and correct placement determined for problematic taxa, along with the first model‐based assessment of the biogeographic history of the tribe. The Vernonieae were estimated to have evolved ~50 mya. Africa was the first center of diversity, from which a single dispersal event established the monophyletic New World lineage. Long‐distance dispersal from Africa and Brazil established the tribe on five continents and Oceania. CONCLUSIONS: The New World lineage is monophyletic, but Old World taxa are not. New subtribal taxonomies are needed. Moquinieae are nested in Vernonieae. Long‐distance dispersal from Africa beginning 45 mya was key to establishing the tribe's near‐global distribution. Migration corridors created by volcanic mountain chains and iron‐rich soils in Africa and the Americas promoted radiation and range expansion. [ABSTRACT FROM AUTHOR]

A characterization of ambient air levels of PM2.5, O3, SO2, NO2 and CO in the Galapagos Islands of Ecuador is presented from in situ and remote sensing observations. PM2.5 was derived from aerosol optical depth (AOD; AERONET) measured at the Universidad San Francisco de Quito, Galapagos Campus (2017–2019). Boundary layer (BL) ozone was obtained from Southern Hemisphere Additional Ozonesondes (SHADOZ) profiles (1998–2016). Background SO2 and pollution events during volcanic eruptions (2005–2018) were estimated from Ozone Monitoring Instrument (OMI) total column measurements through a well‐mixed volume approach. Similarly, ambient NO2 was estimated from OMI data (2012–2019). CO was obtained from Measurement Of Pollution In The Troposphere (MOPITT) observations (2012–2017). The study was complemented using Modern‐Era Retrospective Analysis for Research and Applications (MERRA‐2) reanalysis products and backward trajectory model runs. From the results, baseline levels of the analysed species (PM2.5 = 3.8 μg·m−3, O3 = 17 ppbv, SO2 = 3.6 ppbv, CO = 80 ppbv, NO2 in populated islands = 23 pptv as one year averages) are comparable with other pristine regions, but some factors can cause increased concentrations. First, high tourism seasons (February–April and July–September) raise background PM2.5, NO2 and CO. Furthermore, signals in July–September can be augmented by transport from biomass‐burning regions in the Amazon. This latter factor episodically causes ozone to increase up to 45–75 ppbv (1 hr mean). Lastly, volcanic eruptions raise SO2 up to almost 700 ppbv (24 hr mean) and increase PM2.5 to 29.5 μg·m−3 (1 hr mean). The present study provides for the first time baseline levels of air contaminants in the Galapagos, and identifies specific sources whose effect in time is necessary to monitor given global conditions of vulnerable environmental quality. [ABSTRACT FROM AUTHOR]

With increasing availability of plant distribution data, the information about global plant diversity is improving rapidly. Recently, Ulloa Ulloa et al. (2017) presented the first comprehensive overview of the native vascular flora of the Americas, yielding a total count of 124,993 native species. Of these, 51,241 occur in North America and 82,052 in South America. By combining these data with the information in the Global Naturalized Alien Flora (GloNAF) database of naturalized alien floras, we point out that for a complete picture of the regional and continental plant richness, the naturalized alien species need to be considered. Ignoring this novel component of regional floras can lead to an inaccurate picture of overall change in biodiversity in the Anthropocene. We show that North and South America might face contrasting challenges in terms of potential threats to biodiversity posed by alien plant species, because of the different past and present dynamics of invasions and predictions of future development. In total, there are 7,042 naturalized alien plants occurring in the Americas, with 6,122 recorded in North America and 2,677 in South America; if only introductions from other continents are considered additions to the native continental flora make up 6.9 and 1.4 %, respectively. Nevertheless, predictions of naturalized plant trajectories based on global trade dynamics and climate change suggest that considerable increases in naturalized plant numbers are expected in the next 20 years for emerging South American economies, which could reverse the present state. [ABSTRACT FROM AUTHOR]

Convergence is a pervasive phenomenon in the Tree of Life, and evolution of similar phenotypes sharing the same environmental conditions is expected in phylogenetically closely related species. In contrast, contingent factors are probably more influential in shaping phenotypic diversity for distantly related taxa. Here, we test putative convergent evolution of lizard head morphologies among relatively closely related desert dwelling Liolaemus species, and the very distantly related Ctenoblepharys adspersa. We estimated a multilocus time‐calibrated phylogeny of 57 species of South American liolaemus lizards, based on seven molecular markers. We collected head shape data for 468 specimens, and used three phylogenetic comparative methods (SURFACE, CONVEVOL, and WHEATSHEAF index) to test for and estimate the strength of convergence. We found strong evidence for convergence among Pacific desert lizard C. adspersa, Liolaemus audivetulatus, Liolaemus insolitus, Liolaemus poconchilensis, Liolaemus stolzmanni, and a candidate species (Liolaemus "Moquegua"). Our results suggest that, despite the long divergence and phylogenetic distance of C. adspersa with respect to convergent Liolaemus species, natural selection was probably more important than historical contingency in shaping phenotypic evolution in these desert lizards. Convergent evolution in South American lizards. In this study we test if natural selection was stronger than historical contingency in the putative convergence of head traits between an old lizard lineage (Ctenoblepharys adspersa) and younger lizards (Liolaemus species) living in the extreme desert environments of the South American Pacific coast. We found a strong case of convergence between the younger lizards, and between these and C. adspersa. Our results suggest that natural selection was probably more important than historical contingency in the independent evolution of these head traits. [ABSTRACT FROM AUTHOR]

Premise of the Study: The fossil record is critical for testing biogeographic hypotheses. Menispermaceae (moonseeds) are a widespread family with a rich fossil record and alternative hypotheses related to their origin and diversification. The family is well‐represented in Cenozoic deposits of the northern hemisphere, but the record in the southern hemisphere is sparse. Filling in the southern record of moonseeds will improve our ability to evaluate alternative biogeographic hypotheses. Methods: Fossils were collected from the Salamanca (early Paleocene, Danian) and the Huitrera (early Eocene, Ypresian) formations in Chubut Province, Argentina. We photographed them using light microscopy, epifluorescence, and scanning electron microscopy and compared the fossils with similar extant and fossil Menispermaceae using herbarium specimens and published literature. Key Results: We describe fossil leaves and endocarps attributed to Menispermaceae from Argentinean Patagonia. The leaves are identified to the family, and the endocarps are further identified to the tribe Cissampelideae. The Salamancan endocarp is assigned to the extant genus Stephania. These fossils significantly expand the known range of Menispermaceae in South America, and they include the oldest (ca. 64 Ma) unequivocal evidence of the family worldwide. Conclusions: Our findings highlight the importance of West Gondwana in the evolution of Menispermaceae during the Paleogene. Currently, the fossil record does not discern between a Laurasian or Gondwanan origin; however, it does demonstrate that Menispermaceae grew well outside the tropics by the early Paleocene. The endocarps’ affinity with Cissampelideae suggests that diversification of the family was well underway by the earliest Paleocene. [ABSTRACT FROM AUTHOR]

The Koppen-Trewartha (K-T) classification is used to investigate the biomes change in the future climate over South America (SA). For the middle (2035-2060) and end (2075-2100) of the 21st century mean ensemble of Regional Climate Model version 4 simulations for the Representative Concentration Pathway 8.5 scenario are presented. The global-coupled models of Coupled Model Intercomparison Project Phase 5 drive the members for the period 1970-2100 using different physics configurations. The delta change approach is applied to filter out the bias of the model simulation. Notable changes of the K-T climates are found in SA, mainly in Brazil. Replacement of tropical wet-dry (Aw) by dry semiarid (Bs) occurs over Northeast Brazil (NEB). Reduction of tropical humid (Ar) and an increase of Aw is projected in the North Brazil and Amazon. Retreat of subtropical humid (Cr) replaced by Aw is found in the Southeast Brazil. An increase of subtropical winter-dry (Cw) and decrease Cr is noted in Argentina and in Paraguay Cr is replaced by Ar. In the south of SA, a retreat of subarctic oceanic (Eo) and an increase of temperate oceanic (Do) and dry arid (Bw) occur. In general, the projected changes of K-T climate types in the 21st century over SA show a tendency for a drier climate. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Historical patterns and processes of plants with an American amphitropical disjunct (AAD) distribution have long interested botanists and biogeographers. Here we update examples of AAD vascular plants, their biogeographic history, and aspects of their biology elucidated by recent studies to make inferences about common patterns of AAD plants and formulate future research questions. METHODS: All known examples of AAD vascular plants were tabulated, along with data on plant duration and habit, chromosome number, dispersal direction, and divergence time. The data were then compared with regard to taxonomic categories, AAD bioregions, and character evolution. KEY RESULTS: We clarify the definition of amphitropical and summarize features of AAD plants. We identify 237 AAD plant divergence events. Timing of these events generally corresponds with taxonomic category. Plant duration and habit are associated with AAD bioregions. Increases in chromosome number mostly occurred in members of the recipient area. The AAD plants of bipolar or temperate bioregions entirely or largely dispersed from North to South America, whereas almost half of desert plants dispersed from South to North America. CONCLUSIONS: Tabulating AAD plants by taxonomic group and bioregion yields insight into character evolution and processes of divergence. Phylogenetic studies provide information on the timing and direction of dispersal. However, more research on AAD plants is needed to draw inferences regarding general patterns and processes, especially those at the clade level. Our AAD Working Group website provides current information on AAD vascular plants to aid workers doing research in this field. [ABSTRACT FROM AUTHOR]

Bipolar disjunct distributions are a fascinating biogeographic pattern exhibited by about 30 vascular plants, whose populations reach very high latitudes in the northern and southern hemispheres. In this review, we first propose a new framework for the definition of bipolar disjunctions and then reformulate a list of guiding principles to consider how to study bipolar species. Vicariance and convergent evolution hypotheses have been argued to explain the origin of this fragmented distribution pattern, but we show here that they can be rejected for all bipolar species, except for Carex microglochin . Instead, human introduction and dispersal (either direct or by mountain-hopping) - facilitated by standard and nonstandard vectors - are the most likely explanations for the origin of bipolar plant disjunctions. Successful establishment after dispersal is key for colonization of the disjunct areas and appear to be related to both intrinsic (e.g., self-compatibility) and extrinsic (mutualistic and antagonistic interactions) characteristics. Most studies on plant bipolar disjunctions have been conducted in Carex (Cyperaceae), the genus of vascular plants with the largest number of bipolar species. We found a predominant north-tosouth direction of dispersal, with an estimated time of diversification in agreement with major cooling events during the Pliocene and Pleistocene. Bipolar Carex species do not seem to depend on specialized traits for long-distance dispersal and could have dispersed through one or multiple stochastic events, with birds as the most likely dispersal vector. [ABSTRACT FROM AUTHOR]

The dynamics of wave propagation and energy associated with frosts in extratropical versus tropical South American latitudes is studied. A double wave train propagates through the southern hemisphere following the polar and subtropical jets. If, in the previous day, both trains coincide in phase over the southeast Pacific (southwest Atlantic) Oceans, it will contribute to generate generalized frosts (strong frosts) at extratropical (tropical) latitudes, not affecting tropical (extratropical) latitudes given the wave train zonal propagation. The vertically averaged eddy kinetic energy composites show three maxima associated with those trains over the South Pacific Ocean and South American region. [ABSTRACT FROM AUTHOR]

Aim While geographical patterns of species richness are reasonably well explored for single well-studied taxa, less is known about aggregate patterns of total richness for major biomes and their environmental correlates. Here we analyse continental-scale aggregate patterns of macrofaunal diversity for sandy beaches, a dominant habitat along the Atlantic and Pacific coasts of South America. Location South American coastlines. Time period Present day (data amassed from studies performed since 1971). Major taxa studied Benthic macrofauna, including crustaceans, polychaetes and molluscs. Methods We compiled richness information for all macrofaunal groups on 263 sandy beaches in South America using standard criteria. We further matched these data with environmental variables including sea surface temperature (SST), chlorophyll a, grain size, beach slope, tide range and various morphometrics. We used generalized linear mixed models to relate environmental factors to observed variation in total macrofaunal richness across all beaches, testing competing hypotheses about environmental correlates and possible drivers of latitudinal diversity. Results Macrofaunal richness decreased from tropical to temperate beaches in the Pacific and followed a parabolic trend in the Atlantic, with the highest biodiversity found at tropical and mid-latitudinal bands. Beach slope, tidal range and chlorophyll a mostly explained latitudinal trends in macrofaunal richness, followed by grain size, SST and ocean basin. Main conclusions This study indicates that richness of macrofaunal species at a given beach is most closely related to characteristics of the physical habitat, such as beach slope, area and grain size. At this scale, planktonic food supply also appeared to be more important than temperature, which is a dominant explanatory variable of global-scale variation in species richness. [ABSTRACT FROM AUTHOR]

A diverse assemblage of extinct mammals of early-middle Eocene age (Ypresian-Lutetian boundary) come from the Patagonian localities of La Barda and Laguna Fría around Paso del Sapo in northwestern Chubut Province (Argentina). Metatherians are well represented, mostly by dental remains of 'Didelphimorphia', Paucituberculata, Sparassodonta, Microbiotheria, and Polydolopimorphia. Here we analyse three calcanea and one astragalus referable to the same, indeterminate taxon, from La Barda, showing the fusion of their ectal and sustentacular facets. This facet arrangement characterizes the Australidelphia, a marsupial clade represented by Microbiotheria from South America and Antarctica, plus all Australasian lineages. Other australidelphian features shown by these tarsals include: in the calcanea, a reduced peroneal process and a tripartite cuboid facet; in the astragalus, a round, very small astragalar head in relation to the body; a convex trochlea with a half for the tibia and half, in slightly lower position, for the fibula. Their size and other anatomical features suggest that the new tarsals cannot be referred to the Microbiotheria. Phylogenetic analysis suggests that the La Barda taxon lies within the Australidelphia, and that it is either closely related or belongs to, the Diprotodontia. The existence of advanced australidelphians in Patagonia adds further evidence of the close relationship between Patagonia, Antarctica, and Australia during the Late Cretaceous - early Palaeogene. [ABSTRACT FROM AUTHOR]

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In forest-grassland mosaics, patches can result from two processes: forest expansion over grassy ecosystems and forest fragmentation. We tested the hypothesis that patches produced by these processes differed in structure and spatial context in a forest-grassland mosaic in the southern Brazilian highlands. We compared a present-day land cover map with a past vegetation map to identify natural forest patches and forest fragments. Patches were described according to structure (size, core area and shape metrics) and spatial context (distance from roads and urban areas, edge contrast). Principal component analyses were used to examine gradients of patch types, and differences were tested by analysis of variance with randomization test. We found 878 natural patches and 214 fragments. Natural forest patches, riparian forest patches and forest fragments differed in structure and spatial context. In comparison to natural forest patches, fragments tend to be larger, with larger core areas, and more irregular and complex in shape. Fragments are situated in a different spatial context, tending to be closer to roads and urban areas and to present higher edge contrast. Riparian natural forest patches are similar to natural forest patches, except for shape. The smaller area and regular shape of natural patches probably result from the mechanisms involved in nucleus formation in the grassland matrix and from current grassland management. Natural patches are less exposed to some anthropogenic stresses, since most of them remain in a native grassland matrix context. Our results show that inferring process from pattern is not trivial, because different processes - forest expansion and forest fragmentation - may lead to either distinct or similar patterns of patch shape and spatial context. Studying patch structure and spatial context may then provide further insight into understanding changes in vegetation pattern at landscape scale, and in disentangling the effects of concurrent processes. [ABSTRACT FROM AUTHOR]

At micro-site scale, the spatial pattern of a plant species depends on several factors including interactions with neighbours. It has been seen that unfavourable effects generate a negative association between plants, while beneficial effects generate a positive association. In grasslands, the presence of shrubby species promotes a particular microenvironment beneath their canopy that could affect differently the spatial distribution of plants with different tolerance to abiotic conditions. We measured photosynthetic active radiation, air temperature and wind speed under shrub canopies and in adjacent open sites and analysed the spatial distribution of four grass species (two C3 and two C4) in relation to shrub canopy in a grazed sub-humid natural grassland in southern Uruguay. Radiation, air temperature and wind speed were lower under shrubs than in adjacent open sites. The spatial distribution of grasses relative to the shrub canopy varied depending on the photosynthetic metabolism of grasses. C4 grasses showed a negative association or no correlation with the shrubs, whereas C3 grasses showed a positive association. Our results highlight the importance of the photosynthetic metabolism of the grasses in the final outcome of interactions between grasses and shrubs. Micro-environmental conditions generated underneath shrubs create a more suitable site for the establishment of C3 than for C4 grasses. These results show that facilitation could be more important than previously thought in sub-humid grasslands. [ABSTRACT FROM AUTHOR]

Phylogenetic properties of communities (phylogenetic diversity and phylogenetic structure) allow for the characterisation of phylogenetic patterns and provide the information necessary to infer mechanisms of species assembly. Because humans have introduced exotic species and modified the physical conditions of landscapes, the phylogenetic properties of communities should change according to the proportion of natives to exotics hosted by sites and to the strength of the conditions that act as habitat filters in human-disturbed habitats. To assess the effects of the introduction of exotic plant species, we characterized the phylogenetic properties of 67 plant communities with different degrees of exotic species dominance in a region of central Chile with a Mediterranean climate. Five indices were used to estimate the phylogenetic properties. The Faith index ( FPD), the mean pairwise distance ( MPD) and the mean nearest neighbour distance ( MNND) were used to estimate phylogenetic diversity, and the nearest relative index ( NRI) and the nearest taxon index ( NTI) were used as estimators of the phylogenetic structure (the phylogenetic distribution of taxa in a community) of species assemblages. We observed greater phylogenetic diversity of natives versus exotic plants despite the fact that natives accounted for a fewer number of taxa among the studied communities. Second, assemblages exhibited a phylogenetically clustered structure, which is attributable to an over-representation of some families of exotic flora ( Asteraceae, Brassicaceae, Fabaceae, Papaveraceae, Poaceae) and suggests habitat filtering processes that could have acted by selecting species with traits that permit adaptation to the harsh conditions of human-disturbed sites. [ABSTRACT FROM AUTHOR]

The application of the species names included in the previously invalidly published "Acalypha sect. Communes", mostly around the widely cited A. communis, has been confusing almost since their publication. After a thorough study of the literature, from which we recorded 56 scientific names associated to this section, as well as the study of ca. 1500 herbarium specimens, including nomenclatural types, we propose a deep nomenclatural and taxonomic reorganization of this group. Acalypha sect. Communes is validly published and circumscribed to include five species: Acalypha communis, A. variabilis, A. vellamea, A. senilis and A. hassleriana. Regarding A. communis, we delimit its taxonomic status and propose five subspe-cies: A. communis subsp. communis, subsp. apicalis, subsp. paraguariensis, subsp. saltensis and subsp. tracheliifolia, four of them new combinations. Twenty-two lectotypes and three neotypes are designated, and 20 new synonyms are proposed. A key based on morphological characters to the species and subspecies of this section is also provided. [ABSTRACT FROM AUTHOR]

The phylogenetic relationships of notoungulates, an extinct group of predominantly South American herbivores, remain poorly resolved with respect to both other placental mammals and among one another. Most previous phylogenetic analyses of notoungulates have not included characters of the internal cranium, not least because few such features, including the bony labyrinth, have been described for members of the group. Here we describe the inner ears of the notoungulates Altitypotherium chucalensis (Mesotheriidae), Pachyrukhos moyani (Hegetotheriidae) and Cochilius sp. (Interatheriidae) based on reconstructions of bony labyrinths obtained from computed tomography imagery. Comparisons of the bony labyrinths of these taxa with the basally diverging notoungulate Notostylops murinus (Notostylopidae), an isolated petrosal from Itaboraí, Brazil, referred to Notoungulata, and six therian outgroups, yielded an inner ear character matrix of 25 potentially phylogenetically informative characters, 14 of them novel to this study. Two equivocally optimized character states potentially support a pairing of Mesotheriidae and Hegetotheriidae, whereas four others may be diagnostic of Notoungulata. Three additional characters are potentially informative for diagnosing more inclusive clades: one for crown Placentalia; another for a clade containing Kulbeckia, Zalambdalestes, and Placentalia; and a third for Eutheria (crown Placentalia plus stem taxa). Several other characters are apomorphic for at least one notoungulate in our study and are of potential interest for broader taxonomic sampling within Notoungulata to clarify currently enigmatic interrelationships. Measures of the semicircular canals were used to infer agility (e.g. capable of quick movements vs. lethargic movements) of these taxa. Agility scores calculated from these data generally corroborate interpretations based on postcranial remains of these or closely related species. We provide estimates of the low-frequency hearing limits in notoungulates based on the ratio of radii of the apical and basal turns of the cochlea. These limits range from 15 Hz in Notostylops to 149 Hz in Pachyrukhos, values comparable to the Asian elephant ( Elephas maximus) and the California sea lion ( Zalophus californianus) when hearing in air, respectively. [ABSTRACT FROM AUTHOR]

In South America, autochthonous archaeocyathan faunas preserved in Early Cambrian limestones have not been found yet. Nevertheless, a few well-documented occurrences of these fossils in clasts contained in coarse-grained rocks of a wide age range have been discovered in recent years. Erratic limestone blocks from the Late Carboniferous-Early Permian Fitzroy Tillite Formation in the Falkland/Malvinas Islands yielded three archaeocyath taxa. Also, seven taxa were reported from archaeocyathan limestone clasts in a metaconglomerate of the Cambro-Ordovician El Jagüelito Formation in northern Patagonia. In addition, a new record from the Late Carboniferous-Early Permian Sauce Grande Formation diamictites in Sierras Australes, Buenos Aires Province, Argentina, is presented herein. Preservation of this scarce new material is poor, but at least three different taxa can be distinguished. The most likely source of all archaeocyathan limestone clasts found in southern South America is the Shackleton Limestone from the Transantarctic Mountains in East Antarctica. The new record from the Sauce Grande Formation and the inferred clast provenance reinforce the correlation between this unit, the Dwyka Tillite (South Africa) and the Fitzroy Tillite Formation (Falklands/Malvinas), suggesting a very wide distribution of these Antarctic occurrences during the Late Carboniferous-Early Permian Gondwana glaciation (Episode III). Thus, even though being allochthonous, archaeocyaths are emerging as a new key biological feature for Gondwana palaeogeographic reconstructions. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]