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The classification of Cystoclonium obtusangulum has been questioned since the species was first described by Hooker and Harvey as Gracilaria? obtusangula. The objective of this study was to provide the first comprehensive taxonomic analysis of Cystoclonium obtusangulum, based on DNA sequences coupled with morphological observations made on syntype specimens and new collections. Sequence divergences of rbcL, UPA, and COI‐5P, and maximum‐likelihood phylogenies for rbcL and 18S demonstrated that specimens identified as Cystoclonium obtusangulum represent a clade of two distinct species that are distantly related to the generitype Cystoclonium purpureum. A new genus, Meridionella gen. nov., is proposed for this clade. The two species placed in this new genus were morphologically indistinguishable cryptic species, but have disjunct distributions, with Meridionella obtusangula comb. nov. found from temperate to cold coasts of South America and the Falkland Islands and Meridionella antarctica sp. nov., occurring in Antarctic waters. Vegetative and reproductive characters of Meridionella gen. nov. are described, and implications of our results for the biogeography of the family Cystocloniaceae are discussed. [ABSTRACT FROM AUTHOR]

We analyzed the single‐grain mineralogical composition of aeolian dust transported to central East Antarctica for provenance purposes. Comparison with data from the last glacial period shows for the first time disappearance of carbonates during the Holocene related to sea level rise and suppressed deflation from the Argentinean continental shelf, exposed during Marine Isotope Stage 2. Zeolites, related to alteration of volcanic glass in the subglacial/periglacial environment of Patagonia, show a similar behavior. The remaining minerals, remarkably similar between the two climatic periods, are compatible with a Pampean and Patagonian provenance, but Holocene data show a more pronounced volcanic and metamorphic imprint and presence of minerals related to warm climate weathering environments compatible with an additional contribution from subtropical latitudes of South America. These results do not imply a major large‐scale reorganization of atmospheric circulation after the last climatic transition. Plain Language Summary: Aeolian mineral dust particles transported through the atmosphere from the austral continents to the Antarctic ice sheet represent a tracer of atmospheric circulation and transport, as well as being a source of information about environmental conditions within dust source regions. Many lines of evidence suggest that central East Antarctic dust is sourced from South America during the last glacial period, whereas there is not a general consensus about dust provenance during the Holocene. A major limitation to this problem is represented by the extremely low dust concentration in Antarctic ice during interglacials. In this study, we analyzed the single‐grain mineralogy of more than 2,300 mineral dust particles transported by winds to Dome C during four different time windows within the Holocene, the current interglacial. Comparing results with those obtained from dust deposited during the last glacial period, we observe that some minerals that are typically associated to glacial climate conditions in Patagonia almost disappear during Holocene, while the remaining minerals are compatible with a South American provenance in both climate periods. Data thus suggest that the dominant atmospheric circulation patterns did not experience a significant change with climate. However, data suggest an additional contribution from subtropical South American latitudes during Holocene. Key Points: The mineralogy of more than 2,300 aeolian dust particles windblown to central East Antarctica (Dome C) during the Holocene was identifiedDisappearance of carbonate dust during the Holocene relates to sea level rise and suppressed deflation from the Argentinean shelfAeolian dust suggests Pampean and Patagonian provenance in the Holocene and a lower latitude contribution, without major circulation changes [ABSTRACT FROM AUTHOR]

Contrasting the extensive research on summer atmospheric rivers (ARs) in the Antarctic Peninsula (AP), winter AR impacts are less understood. This study examines a unique warming event from 1 to 3 July 2023, using in situ winter observations and ERA5 reanalysis. On 2 July, Frei station experienced an extreme warm event with a temperature of 2.7°C and a significant rise in the freezing level, coinciding with winter rainfall. A pressure dipole pattern over the AP, with contrasting circulations over Bellingshausen and Weddell Seas, facilitated an AR, carrying warm, humid air initially from South America/Atlantic and then the southeast Pacific. This shift resulted in anomalous water stable isotope composition in precipitation. Trends suggest a strengthening winter pressure dipole, associated with increased AR frequency and higher temperatures in northern AP. These findings highlight the importance of winter observations in exploring AR impacts, bridging knowledge gaps about winter AR behaviors. Plain Language Summary: The Antarctic Peninsula is increasingly witnessing climate extremes during summer, while the understanding of such extremes in winter remains limited. Our study explores a significant warming event in the northern Peninsula in early July 2023, utilizing recent winter in situ observations and atmospheric analysis. On 2 July, an exceptional temperature of 2.7°C was recorded, significantly altering the atmospheric freezing level and causing rainfall instead of snow. Our analysis revealed a unique atmospheric pattern around the Peninsula, characterized by varying air movements over the Bellingshausen and Weddell Seas. This pattern facilitated an "atmospheric river," a flow of warm and moist air from lower latitudes, including continental South America/Atlantic and the southeast Pacific, as reflected in the precipitation's water stable isotope composition. This event is indicative of a potential trend toward more frequent and severe occurrences, emphasizing the urgent need for comprehensive winter research in the Antarctic Peninsula to understand the broader implications of extreme weather events and climate change. Key Points: Early July 2023 had extreme winter warmth with rainfall in the northern Antarctic Peninsula, favored by an atmospheric riverIn recent decades, strengthened winter pressure dipole has directed northerly warm and moist air, resulting in warm events in the regionWe highlight the need for expanded winter research in the Antarctic Peninsula to better understand climate change and extreme weather events [ABSTRACT FROM AUTHOR]

Lepidoziaceae are the third‐largest family of liverworts, with about 860 species distributed on all continents. The evolutionary history of this family has not been satisfactorily resolved, with taxa such as Micropterygioideae yet to be included in phylogenetic analyses. We inferred a dated phylogeny of Lepidoziaceae using a data set consisting of 13 genetic markers, sampled from 147 species. Based on our phylogenetic estimate, we used statistical dispersal‐vicariance analysis to reconstruct the biogeographic history of the family. We inferred a crown age of 197 Ma (95% credible interval 157–240 Ma) for the family in the Australian region, with most major lineages also originating in the same region. Micropterygioideae are placed as the sister group to Lembidioideae, with these two lineages diverging from each other about 132 Ma in the South American–Australian region. With South America and Australia being connected through Antarctica at the time, our results suggest a circum‐Antarctic link between Micropterygioideae and the rest of the family. Crown Micropterygioideae were inferred to have arisen 45 Ma in South America before the continent separated from Antarctica. Extinction from southern temperate regions might explain the present‐day restriction of Micropterygioideae to the Neotropics. Our study reveals the influence of past geological events, such as continental drift, on the evolution and distribution of a widespread and diverse family of liverworts. [ABSTRACT FROM AUTHOR]

Aim: The homogenisation of historically isolated gene pools has been recognised as one of the most serious conservation problems in the Antarctic. Lichens are the dominant components of terrestrial biotas in the Antarctic and in high mountain ranges of southern South America. We study the effects of dispersal strategy and migration history on their genetic structure to better understand the importance of these processes and their interplay in shaping population structure as well as their relevance for conservation. Location: Maritime Antarctic and southern South America. Methods: Populations of three fruticose lichen species, Usnea aurantiacoatra, U. antarctica and Cetraria aculeata, were collected in different localities in the Maritime Antarctic and southern South America. Usnea aurantiacoatra reproduces sexually by ascospores, whereas the other two species mostly disperse asexually by symbiotic diaspores. Samples were genotyped at 8–22 microsatellite loci. Different diversity and variance metrics, Bayesian cluster analyses and Discriminant Analysis of Principal Components (DAPC) were used to study population genetic structure. Historical migration patterns between southern South America and the Antarctic were investigated for U. aurantiacoatra and C. aculeata by approximate Bayesian computation (ABC). Results: The two vegetative species display lower levels of genetic diversity than U. aurantiacoatra. Antarctic populations of C. aculeata and South American populations of U. aurantiacoatra display much stronger genetic differentiation than their respective counterparts on the opposite side of the Drake Passage. Usnea antarctica was not found in South America but shows comparably low levels of genetic differentiation in Antarctica as those revealed for U. aurantiacoatra. Phylogeographic histories of lichens in the region differ strongly with recent colonisation in some instances and potential in situ persistence during Last Glacial Maximum (LGM) in others. Patterns of genetic diversity indicate the presence of glacial refugia near Navarino Island (South America) and in the South Shetland Islands. ABC analyses suggest that C. aculeata colonised the Antarctic from Patagonia after the LGM. Results for U. aurantiacoatra are ambiguous, indicating a more complex population history than expressed in the simplified scenarios. Main Conclusions: Mode of propagation affects levels of genetic diversity, but the location of glacial refugia and postglacial colonisation better explains the diversity patterns displayed by each species. We found evidence for glacial in situ survival of U. aurantiacoatra on both sides of the Drake Passage and postglacial colonisation of Antarctica from South America by C. aculeata. Maintaining the strong genetic differentiation of Antarctic populations of C. aculeata requires strict conservation measures, whereas populations of U. aurantiacoatra are exposed to a much lower risk due to their higher diversity and connectivity. [ABSTRACT FROM AUTHOR]

Aim: Antarctica's remote and extreme terrestrial environments are inhabited by only two species of native vascular plants. We assessed genetic connectivity amongst Antarctic and South American populations of one of these species, Colobanthus quitensis, to determine its origin and age in Antarctica. Location: Maritime Antarctic, sub‐Antarctic islands, South America. Taxon: Antarctic pearlwort Colobanthus quitensis (Caryophyllaceae). Methods: Four chloroplast markers and one nuclear marker were sequenced from 270 samples from a latitudinal transect spanning 21–68° S. Phylogeographic, population genetic and molecular dating analyses were used to assess the demographic history of C. quitensis and the age of the species in Antarctica. Results: Maritime Antarctic populations consisted of two different haplotype clusters, occupying the northern and southern Maritime Antarctic. Molecular dating analyses suggested C. quitensis to be a young (<1 Ma) species, with contemporary population structure derived since the late‐Pleistocene. Main conclusions.: The Maritime Antarctic populations likely derived from two independent, late‐Pleistocene dispersal events. Both clusters shared haplotypes with sub‐Antarctic South Georgia, suggesting higher connectivity across the Southern Ocean than previously thought. The overall findings of multiple colonization events by a vascular plant species to Antarctica, and the recent timing of these events, are of significance with respect to future colonizations of the Antarctic Peninsula by vascular plants, particularly with predicted increases in ice‐free land in this area. This study fills a significant gap in our knowledge of the age of the contemporary Antarctic terrestrial biota. Adding to previous inferences on the other Antarctic vascular plant species (the grass Deschampsia antarctica), we suggest that both angiosperm species are likely to have arrived on a recent (late‐Pleistocene) time‐scale. While most major groups of Antarctic terrestrial biota include examples of much longer‐term Antarctic persistence, the vascular flora stands out as the first identified terrestrial group that appears to be of recent origin. [ABSTRACT FROM AUTHOR]

Worldwide, the implementation of forest management guidelines has tried to mimic natural forest dynamics. The Oliver forest stand dynamics model has been successful in bridging natural forest dynamics associated with the disturbances of various spatial scales and silviculture also related to various spatial scales of management. However, the application of this model (and others) is restricted to tall forests.We claim here that the general research and commercial interest bias towards tall tree species has permeated silviculture and forest management, and that both the stand dynamics of short‐stature tree species and their treatment have remained largely unexplored and unknown.Using one short‐stature tree species, Nothofagus antarctica, as a model system, we show that this species indeed follows a stand dynamic different from other tall Nothofagus‐dominated forests in southern South America. This species forms short, mature, even‐aged stands without large canopy gaps that promote tree regeneration. With this in mind, we propose a conceptual ecology‐based silvicultural guideline focusing on the creation of strip cuts or gaps along with topsoil scarification to ensure regeneration and forest reorganization after disturbances.Policy implications. The acknowledgement that short‐stature tree species follow a stand dynamic different from tall tree species necessarily implies that they must be managed differently. This recognition, along with the implementation of ecology‐based silvicultural recommendations, represents strong arguments to make modifications to forest legislation that, together, must be aimed at conservation and sustainable forest management. [ABSTRACT FROM AUTHOR]

Despite strong historical biogeographical links between benthic faunal assemblages of the Magellan region of South America and the Antarctic Peninsula, very few studies have documented contemporary movement and gene flow in or out of the Southern Ocean, especially across the Antarctic Polar Front (APF). In fact, oceanographic barriers such as the APF and Antarctica's long geologic isolation have substantially separated the continents and facilitated the evolution of endemic marine taxa found within the Antarctic region. The Southern Ocean benthic sea slug complex, Doris "kerguelenensis," are a group of direct‐developing, simultaneous hermaphrodites that lack a dispersive larval stage. To date, there are 59 highly divergent species known within this complex. Here, we provide evidence to show intraspecific genetic connectivity occurs across the APF for multiple species within the D. "kerguelenensis" nudibranch species complex. We addressed questions of genetic connectivity by examining the phylogeographic structure of the three best‐sampled D. "kerguelenensis" species and another three trans‐APF species using the protein coding mtDNA gene, cytochrome oxidase I. We also highlight alternative refugia uses among species with the same life history traits (i.e., benthic and direct developers) and for some species, extremely large distributions are established (e.g., circumpolarity). By improving our sampling of these nudibranchs, we gain better insight into the population structure and connectivity of the Antarctic region. This work also demonstrates how difficult it is to make generalizations across Antarctic marine species, even among ecologically‐similar, closely related species. [ABSTRACT FROM AUTHOR]

Electric field measurements at Vostok station in Antarctica reveal that the El Niño—Southern Oscillation (ENSO) has a statistically significant effect on the global electric circuit, as earlier predicted by simulations. Analysis of 10 October‐February periods during 2006–2016 indicates that the shape of the diurnal variation of the surface electric field is significantly different for El Niño and La Niña years, with an especially pronounced deviation during the super El Niño of 2015/16. During strong El Niños the potential gradient relative to the diurnal mean is generally higher than usual around 8:00–14:00 UTC and lower than usual around 16:00–0:00 UTC; La Niñas are characterized by the opposite behavior. Simulations with the Weather Research and Forecasting model imply that the observed patterns are the result of changes in the global distribution of electrified clouds over the Pacific Ocean, Maritime Continent, and South America during ENSO events. Plain Language Summary: The El Niño—Southern Oscillation (ENSO) is one of the most remarkable modes of climate variability on Earth. Being made up of irregularly alternating warm (El Niño) and cold (La Niña) phases, the ENSO affects atmospheric circulation, global temperature and rainfall patterns, agriculture, and economic output. Recent simulations have suggested that changes in global convection patterns due to ENSO should also affect surface atmospheric electric fields and currents in remote regions of the planet. Here, we present electric field measurements performed during 2006–2016 at Vostok station in the Antarctic that reveal clear patterns related to ENSO as earlier predicted by simulations. Measurements show that the shape of the diurnal variation of the surface electric field is significantly different for El Niño and La Niña years (with an especially pronounced effect during the super El Niño of 2015/16), which, according to simulations, is the result of changes in the global distribution of electrified clouds over the Pacific Ocean, Maritime Continent, and South America during ENSO events. This provides further evidence of the influence of climate fluctuations on the Earth's global electromagnetic environment. Key Points: Electric field measurements in Antarctica show that strong El Niños and La Niñas consistently impact the atmospheric global circuitFor the super El Niño event of 2015/16, the anomalies in the global electric circuit are especially pronouncedSimulations show that the observed effect is due to changes in deep convection over the Pacific Ocean, Maritime Continent, and South America [ABSTRACT FROM AUTHOR]

Plate reconstructions provide basic constraints on the tectonic evolution of the Antarctic Peninsula but they are limited by a scarcity of paleomagnetic data. Here, using a combination of new and published paleomagnetic data and geological evidence, we present an updated reconstruction of the plate rotation and spatio‐temporal history of magmatism of the northern Antarctic Peninsula since ∼90 Ma. The Phoenix Plate‐Antarctic Peninsula convergence variation and back‐arc extension of the Scotia Plate are correlated to five distinct plate rotation periods. The initiation of the ancestral South Sandwich subduction zone and the late Paleocene separation between the Antarctic Peninsula and South America may be explained by the small‐ and large‐scale clockwise rotation of the Antarctic Peninsula starting at ∼80 and 62 Ma, respectively. Furthermore, we have identified five pulses of magmatism, which are correlated to the Phoenix Plate‐Antarctic Peninsula convergence rates. The Antarctic Peninsula plate rotation fits well with the process observed in the Phoenix Plate subduction, long‐term variation of the magmatism and tectonic evolution in the Scotia Sea, clarifying the relationship between these geological events. Plain Language Summary: In this study, we update the northern Antarctic Peninsula‐South Shetland Islands plate rotation process since ∼90 Ma. Five new enhanced magmatic events are identified in the northern Antarctic Peninsula‐South Shetland Islands, and we also reconstruct the migration of magmatism. Then, we compare plate rotation and magmatic migration to the Phoenix Plate‐Antarctic Peninsula convergence, and find a strong correlation between these events. The abrupt change in the convergence rate is attributed to the enhanced magmatic events. The clockwise rotation of the northern Antarctic Peninsula also corresponds to the Late Cretaceous initiation of the ancestral South Sandwich subduction zone and the late Paleocene separation of the northern Antarctic Peninsula from South America, indicating a causal relationship. The counterclockwise rotation of the northern Antarctic Peninsula after ∼47 Ma facilitated lithospheric extension and basin opening in the South Scotia Ridge region, contributing to the opening of the Scotia Sea. Therefore, this study provides a comprehensive interpretation of the geological process in Scotia Sea regions, from slab subduction and overlaying plate rotation to magmatic evolution and continental separation. Key Points: We provide an updated reconstruction of the plate rotation and magmatic process of the northern Antarctic Peninsula since ∼90 MaThe relationship between Phoenix Plate subduction, northern Antarctic Peninsula plate rotation, and magmatic migration is reconstructedThe northern Antarctic Peninsula's plate rotation is linked to Weddell Sea crust subduction and the late Paleocene opening of the Scotia Sea [ABSTRACT FROM AUTHOR]

Aedes vexans is the inland floodwater mosquito widely distributed in every continent excepting Antarctica and South America. They are opportunistic feeders preferring blood meal of larger animals including cattle, horses, deer, and humans. Further, the mosquito species is a compatible vector of several diseases, including West Nile virus and dog heartworm. In this study, we performed transcriptome characterization of Ae. vexans using Illumina HiSeq 4,000 sequencing and assembly of sequenced reads using Trinity. A total of 55,813,852 raw read and 54,630,771 clean reads (97.88% of raw reads) were obtained after Illumina paired‐end sequencing and pre‐processing steps. After Trinity de novo assembly, TransDecoder and TGICL clustering, a total of 37,111 unigenes were obtained. Out of the total unigenes count, 28,733, 17,893, 14,626, and 17,055 showed homologous matches against the PANM, UniGene, SwissProt, and KOG databases. A total of 9,483 unigenes were assigned to Gene Ontology (GO) terms, and 3,741 unigenes were mapped to 483 KEGG pathways. The zinc finger (C2H2‐type), reverse transcriptase, integrase (catalytic core), protein kinase, and RNA recognition motif domain among others showed as the top InterProScan domains. The obtained datasets serves as a basis for future studies towards understanding ecology, metabolism, and parasitism potential of Ae. vexans. [ABSTRACT FROM AUTHOR]

The Southern Ocean is an important region of ocean carbon uptake, and observations indicate its air‐sea carbon flux fluctuates from seasonal to decadal timescales. Carbon fluxes at regional scales remain highly uncertain due to sparse observation and intrinsic complexity of the biogeochemical processes. The objective of this study is to better understand the mechanisms influencing variability of carbon uptake in the Drake Passage. A regional circulation and biogeochemistry model is configured at the lateral resolution of 10 km, which resolves larger mesoscale eddies where the typical Rossby deformation radius is O (50 km). We use this model to examine the interplay between mean and eddy advection, convective mixing, and biological carbon export that determines the surface dissolved inorganic carbon and partial pressure of carbon dioxide variability. Results are validated against in situ observations, demonstrating that the model captures general features of observed seasonal to interannual variability. The model reproduces the two major fronts: Polar Front (PF) and Subantarctic Front (SAF), with locally elevated level of eddy kinetic energy and lateral eddy carbon flux, which play prominent roles in setting the spatial pattern, mean state and variability of the regional carbon budget. The uptake of atmospheric CO2, vertical entrainment during cool seasons, and mean advection are the major carbon sources in the upper 200 m of the region. These sources are balanced by the biological carbon export during warm seasons and mesoscale eddy transfer. Comparing the induced advective carbon fluxes, mean flow dominates in magnitude, however, the amplitude of variability is controlled by the eddy flux. Plain Language Summary: The Southern Ocean, which surrounds Antarctica, is a critical component of global climate and carbon cycling. The Drake Passage is the region south of the tip of South America. It is one of the most well sampled sectors of the Southern Ocean, and the narrowest and southernmost constriction of the Antarctic Circumpolar Current. While the region is an overall carbon sink, its carbon uptake can fluctuate over time, and its uncertainty comes from sparse observations and the complex nature of the contributing processes. We use a regional ocean circulation and biogeochemical model to better understand the influencing mechanisms on the variability of carbon uptake to the region. Model results demonstrate that absorbed atmospheric carbon, strong wintertime mixing and vertical water movement, and mean ocean currents are the major source of carbon in the upper 200 m of the Drake Passage. These inputs of carbon into the ocean are balanced by smaller scale (10–100 km) movements called ocean eddies and the biological drawdown of carbon. This research allows for better comprehension of regional carbon fluxes and analysis of biophysical dynamics influencing the annual and interannual fluctuation. Key Points: A regional, eddy‐resolving ocean model is used to simulate the ocean carbon uptake in Drake PassageFronts and eddies play prominent roles in setting spatial pattern, mean state, and variability of the regional carbon budgetCarbon sources of gas exchange, vertical entrainment, and mean advection are balanced by biological pump and mesoscale eddy transfer [ABSTRACT FROM AUTHOR]

Haplogloia andersonii (Farlow) Levring is an antitropical species that occurs on cold on cold and warm-temperate Pacific coasts of both Americas. In its habit it resembles the subantarctic species Chordaria limearis (Hooker et Harvey) Cotton. Culture studies show that the species differ in morphology and ecophysiology of their microscopic gametophytes and in gamete behavior. Details of sporophyte anatomy are presented that also allow the distinction of field plants. In South America, H. andersonii occurs only on the Pacific coast, from central Perú (14°S) to southern Chile (50°S). Chordaria linearis occurs on the Pacific coast from Chiloé Island (43°S) to Cape Horn (56°S). In the shared area the species may co-occur. On the Atlantic Coast, C. linearis was newly collected at a locality in northern Patagonia (41°S). In addition, C. linearis occurs in Antarctica. Haplogloia moniliformis Ricker, recently described from Macquarie Island, is probably synonymous with Chordaria linearis. [ABSTRACT FROM AUTHOR]

Mineral dust accumulated on the ocean floor is an important archive for reconstructing past atmospheric circulation changes and climatological conditions in the source areas. Dust emitted from Southern Hemisphere dust sources is widely deposited over the oceans. However, there are few records of dust deposition over the open ocean, and a large need for extended geographical coverage exists. We present a large data set (134 surface sediment samples) of Late Holocene dust deposition from seafloor surface sediments covering the entire South Atlantic Ocean. Polymodal grain‐size distributions of the lithogenic fraction indicate that the sediments are composed of multiple sediment components. By using end‐member modeling, we attempt to disentangle the dust signal from non‐aeolian sediments. Combined with 230Th‐normalized lithogenic fluxes, we quantified the specific deposition fluxes for mineral dust, crrent‐sorted sediments and ice‐rafted debris (IRD). Although the method could not completely separate the different components in every region, it shows that dust deposition off the most prominent dust source for the South Atlantic Ocean—southern South America—amounts up to approximately 0.7 g cm−2 Kyr−1 and decreases downwind. Bottom‐current‐sorted sediments and IRD are mostly concentrated around the continental margins. The ratio of the coarse to fine dust end members reveals input from north African dust sources to the South Atlantic. The majority of the observations are in good agreement with new model simulations. This extensive and relevant data set of dust grain size and deposition fluxes to the South Atlantic could be used to calibrate and validate further model simulations. Plain Language Summary: Ocean records of mineral dust can be used to reconstruct past climatic changes such as wind strength and aridity in the source regions, and also marine biological productivity. However, in the remote open ocean, dust samples are difficult to obtain and therefore records are sparse. We present a large data set of dust deposition, determined from the top centimeter of ocean floor sediments, covering the entire South Atlantic Ocean. These appeared to be complex mixtures of different sediment types, which we attempted to unmix mathematically. This resulted in four individual components, which are fine and coarse mineral dust, current‐sorted sediments and ice‐rafted debris (IRD). Although the unmixing has its limitations, it shows that the dust deposition off the most prominent dust source for the South Atlantic Ocean—southern South America—is significant and decreases downwind as dust settles during transport across the ocean. Current‐sorted sediments and IRD are mostly concentrated around the continental margins. The results also reveal dust transport across the equator from north African dust sources and show similarities with new model simulations. This extensive and relevant data set of dust grain size and deposition fluxes to the South Atlantic can be used to calibrate and validate further model simulations. Key Points: End‐member (EM) modeling is used to disentangle different sediment components from polymodal grain‐size distributionsCombined with 230Th‐normalized lithogenic fluxes, specific fluxes for dust, current‐sorted sediments and ice‐rafted debris are obtainedThis independent quantification provides more specific dust fluxes compared to global compilations of lithogenic fluxes [ABSTRACT FROM AUTHOR]

Spheniscus urbinai represents one of four extinct Spheniscus species from the Cenozoic of southern South America, known from several poorly described diversely complete skulls and postcranial elements. Here, we present a review of the cranial osteology of all known specimens (collected in Argentina, Chile, and Peru), including a paleoneurological analysis using CT scans, and an exploration of its cranial pneumaticity compared to other extinct and living seabirds. Our results show that among Spheniscus species, S. urbinai exhibits slightly greater cranial pneumaticity than the living species. Additionally, we confirm previous findings which indicate that the marked reduction of cranial pneumaticity—which is characteristic of living penguins—occurred early during the Eocene (as observed in the Antarctic penguin MLP 12‐I‐20‐1, but not in the coeval Anthropornis). [ABSTRACT FROM AUTHOR]

This study examined the overall performance of the climate models in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) in simulating the key energy and water fluxes over land. For this purpose, this study selected multiple land flux products as reference data sets and assessed the global spatial means, patterns, trends, seasonal cycles, and regional mean estimates of the sensible heat (SH), latent heat (LH), net radiation (RN), runoff (RF), and precipitation (PR) simulated by 32 CMIP6 models in recent decades. The global (Antarctica, Greenland, and hot deserts are not included) mean SH, LH, RN, RF, and PR simulated by the CMIP6 models are 37.55 ± 4.81 W m−2, 49.88 ± 5.31 W m−2, 89.10 ± 4.45 W m−2, 351.31 ± 95.28 mm yr−1, and 948.35 ± 88.77 mm yr−1, respectively. The ensemble median of CMIP6 simulations (CMIP6‐MED) can provide robust estimates of global and regional land fluxes, which are within the ranges given by the reference data sets, and highly consistent spatiotemporal patterns of these fluxes. The comparison of CMIP6‐MED with the first preferred reference data sets shows that CMIP6‐MED generally overestimates the water and energy fluxes over land, except for the simulated RF and PR in the Amazon region. The most disagreements between CMIP6‐MED and the reference data sets occur in South America (particularly the Amazon region) and the Tibetan Plateau. Finally, the sources of model biases are discussed. It is suggested that current land flux products should be widely used to optimize the structures and parameters of climate models in future work. Plain Language Summary: Land surface models are an indispensable part of weather and climate models. Sensible heat (SH), latent heat (LH), net radiation (RN), runoff (RF), and precipitation (PR) are the key components of the energy and water cycles over global land. This study evaluated these five fluxes from 1979 to 2014 simulated by 32 climate models in Phase 6 of the Coupled Model Intercomparison Project (CMIP6), with multiple global land products. The RN and RF estimated by the CMIP6 models exhibit the lowest and highest uncertainties, respectively. The ensemble median of CMIP6 simulations (CMIP6‐MED) provides robust estimates of global and regional land fluxes, which are within reference ranges. We select the first preferred reference data sets from multiple global land products according to the evaluations against site observations and previous studies, and find that CMIP6‐MED generally overestimates the water and energy fluxes over land. The most disagreements between CMIP6 simulations and references occur in South America and the Tibetan Plateau. This study is helpful for determining the overall performance of the current climate models in simulating land surface processes. Key Points: Performance of CMIP6 models on land surface energy and water fluxes during 1979–2014 is comprehensively evaluated using multiple land flux productsEnsemble median of CMIP6 simulations can provide robust estimates of global and regional land fluxes, which are within the ranges given by reference data setsThe most disagreements between CMIP6 simulations and reference data sets occur in South America (particularly the Amazon region) and the Tibetan Plateau [ABSTRACT FROM AUTHOR]

Buriti (Mauritia flexuosa) is a palm tree widely distributed in South America. The oil extracted from its fruit is an added value product for its high carotenoids content. The aim of this work was to evaluate the alkaline (magnesium oxide—MgO) and enzymatic (lipase B from Candida antarctica immobilized on macroporous acrylic resin) glycerolysis of buriti oil to obtain non‐ionic emulsifiers and evaluate the carotenoids degradation during this process. Alkaline glycerolysis was carried out using a 3:1 glycerol/oil molar ratio, temperatures of 170 and 210 °C, and MgO contents of 0.5 and 1%wt. Enzymatic glycerolysis reactions were performed using 3%wt. of a lipase catalyst and varying the following parameters: glycerol: oil molar ratio (3:1, 6:1, and 9:1), solvent (tert‐butyl alcohol) concentration (50%, 150%, and 250%, vol./substrate mass), and temperature (40, 55 and 70 °C). The products were analyzed by liquid chromatography and UV–visible spectroscopy (370–520 nm). Enzymatic glycerolysis was superior in terms of conversion and selectivity to monoacylglycerols (MAG). MAG yields were close to 80% or higher for most conditions tested for enzymatic glycerolysis, while the maximum yield for alkaline glycerolysis was of 58%. UV–Vis data showed that carotenoids were severally degraded in alkaline glycerolysis, while the enzymatic product exhibited high preservation of carotenoids and color and odor similar to those of the pure buriti oil. Based on the final composition of the non‐ionic emulsifiers obtained from buriti oil by enzymatic glycerolysis, they can be considered potential raw materials for cosmetic and food industries. [ABSTRACT FROM AUTHOR]

Presents a study which evaluated two hypotheses on the origins of platyrrhines in South America, namely, the Antarctic migration hypothesis and the floating island hypothesis. Background information on the two hypotheses and environments; Methodology; Results and discussion.

The tropical conservatism hypothesis ( TCH) suggests that phylogenetic niche conservatism (the tendency for traits to be maintained during diversification) should be the main driver of latitudinal diversity gradients. For example, the tropical-temperate diversity gradient for woody angiosperms should reflect the tropical, older origin of most clades, the constrained evolution of cold tolerance, and the fact that few clades were able to persist in temperate zones after the beginning of the global cooling in the Eocene. Evidence for this explanation has been discussed primarily from a Northern Hemisphere perspective. Recently, two studies have presented diversity and clade-age relationships in South American forests that are inconsistent with the TCH, with older woody families being more frequent at higher latitudes and higher elevations in the Andes. We argue that a broader framework considering the ancient history of the Southern Hemisphere flora and the recent history of the Andean flora can help explain these discordant patterns. Here, we provide an initial discussion of this new perspective, emphasizing the historical development of a unique and rich palaeoflora of Gondwanan ancestry at mid- to high latitudes of South America and Antarctica. We suggest that the idea of Austral niche conservatism ( ANC) of a warm-temperate Antarctic-South American biota should be explored further to improve our understanding of biogeographical patterns in the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Mineral dust is an important component of the Earth system due to its role in oceanic nutrient supply, cloud formation and its radiative properties. Changes in transport pathways and fluxes of mineral dust have attracted increased attention using radiogenic isotope analysis for detailed investigation of changing dust sources through time. However, multi‐isotope studies provide complex datasets of dust provenance, often without exact quantification of source contributions. Here we use Bayesian mixing models and existing radiogenic isotope data to quantify changes in South Pacific dust provenance for the Holocene and the Last Glacial Maximum (LGM; ∼18–24 ka BP). Testing different model configurations showed grouping small source regions to single continental scale end members prior to modeling can lead to biased results, and so we group model outputs post‐modeling. During the LGM, a higher proportion (mean 53%) of dust entering the South Pacific was South American in origin, compared to a Holocene mean of 31%. In contrast, Australian dust contributions were lower during the LGM (mean 38%) than Holocene (mean 55%), with significant spatial gradients for both time slices. In the subpolar South Pacific, the high representation of South American dust during the LGM (up to ∼75%) coincides with larger dust particles; together indicating that far‐traveled dust transport was facilitated by long atmospheric residence times and an accelerated westerly wind circulation during this time. Our study shows how Bayesian mixing models provide valuable constraints for dust source contributions, an approach which may help in the calibration of atmospheric models, using complex isotopic datasets. Plain Language Summary: Mineral dust can influence the Earth's radiation budget, cloud formation, and the supply of nutrients to marine and terrestrial ecosystems. Southern Hemisphere oceans are of particular interest due to airborne nutrient supply from mineral dust promoting primary productivity. The geochemical fingerprint of dust can help to identify sources and transport pathways of dust in the Southern Hemisphere. Here, we model existing geochemical data to identify changes in dust sources in the South Pacific between the current warm interval (the Holocene) and the peak of the last ice age. Our results show that dust delivered to the South Pacific is generally related to emissions from Australia (dominating during the Holocene) and South America (dominating during the last ice age), with distinct gradients in the distribution of dust across the study area during the two time periods. The ice age dust input coincided with the delivery of larger particles to the study area, indicating dust remained in the atmosphere longer, driven by higher wind speeds in the circumpolar westerly wind system. Key Points: Bayesian mixture modeling of multi‐isotope datasets allows for precise apportionment of mineral dust sources to the South PacificSouth Pacific mineral dust input from South America was greater during the Last Glacial Maximum (53%) than during the Holocene (31%)Modeling individual mineral dust mixtures reveal zonal and meridional gradients in Holocene and Last Glacial Maximum data [ABSTRACT FROM AUTHOR]

Four new genera ( Apomorphyto gen.n. from Costa Rica, Bixinia gen.n. from Australia, Rhinodonia gen.n. from New Caledonia, Rhinopeza gen.n. from Papua New Guinea) and nine new species ( Apomorphyto inbio sp.n., Bixinia collessi sp.n., B. solitaria sp.n., B. spei sp.n., B. variabilis sp.n., B. winkleri sp.n., Rhinodonia antiqua sp.n., R. flavicera sp.n., Rhinopeza gracilis sp.n.) of Rhinophoridae ( Diptera: Calyptratae, Oestroidea) are described. All new species were included in a morphology-based phylogenetic analysis to provide arguments for the justification and monophyly (when nonmonotypic) of the new genera and for including these in the Rhinophoridae. The New Caledonian Rhinodonia is a candidate sister taxon to all other rhinophorids, and the Australasian 'axiniine' species emerge inside a clade of all Neotropical taxa thus suggesting migration from South America across Antarctica into Australia. This published work has been registered in ZooBank, . [ABSTRACT FROM AUTHOR]

The out‐of‐sight groundwater and visible but much less extensive surface waters on land constitute a linked terrestrial water system around the planet. Research is crucial for our understanding of these terrestrial water system links and interactions with other geosystems and key challenges of Earth System change. This study uses a scoping review approach to discuss and identify topical, methodological and geographical gaps and priorities for research on these links and interactions of the coupled ground‐ and surface water (GSW) system at scales of whole‐catchments or greater. Results show that the large‐scale GSW system is considered in just a small part (0.4%–0.8%) of all studies (order of 105 for each topic) of either groundwater or surface water flow, storage, or quality at any scale. While relatively many of the large‐scale GSW studies consider links with the atmosphere or climate (8%–43%), considerably fewer address links with: (a) the cryosphere or coastal ocean as additional interacting geosystems (5%–9%); (b) change drivers/pressures of land‐use, water use, or the energy or food nexus (2%–12%); (c) change impacts related to health, biodiversity or ecosystem services (1%–4%). Methodologically, use of remote sensing data and participatory methods is small, while South America and Africa emerge as the least studied geographic regions. The paper discusses why these topical, methodological and geographical findings indicate important research gaps and priorities for the large‐scale coupled terrestrial GSW system and its roles in the future of the Earth System. Plain Language Summary: The water on the land surface (surface water) and that beneath it (groundwater), along with the water that is continuously and increasingly used and managed in human societies, are connected and constitute a coherent natural‐social water system around the world. Many unknowns and open questions remain for how the small‐scale variations add up to large‐scale variability and change of this water system on land, as an integral part of the whole Earth System. Relevant research is crucial for reducing the unknowns and answering the questions, and this study's scoping review aims to assess how they have been addressed in published research so far. The aim is to identify key research gaps and priorities for further research on how the integrated water system on land functions and evolves on large scales, from whole hydrological catchments and in multiple catchments around the world up to global scale. The scoping review results show key research gaps and priorities to be the coupling of surface water and groundwater on land, and the interactions of this coupled water system with other parts and major challenges of the Earth System. Geographically, the gaps and priorities emerge as particularly large and urgent for South America and Africa. Key Points: Coupling of the ground‐surface water system is a key gap in terrestrial water research, particularly at large scalesResearch on terrestrial water interactions with other geospheres and key challenges of Earth System change is rare but impactfulMajor geographic gaps in research on the large‐scale coupled terrestrial water system emerge for South America and Africa [ABSTRACT FROM AUTHOR]

Copyright of Journal of Latin American & Caribbean Anthropology 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.)

South America, particularly within its tropical belt, is renowned for its unparalleled high levels of species richness, surpassing other major biomes. Certain neotropical areas harbor fragmented knowledge of insect diversity and face imminent threats from biodiversity loss and climate change. Hence, there is an urgent need for rapid estimation methods to complement slower traditional taxonomic approaches. A variety of algorithms for delimiting species through single‐locus DNA barcodes have been developed and applied for rapid species diversity estimates across diverse taxa. However, tree‐based and distance‐based methods may yield different group assignments, leading to potential overestimation or underestimation of putative species. Here, we investigate the performance of different DNA‐based species delimitation approaches to rapidly estimate the diversity of Polypedilum (Chironomidae, Diptera) in South America. Additionally, we test the hypothesis that significant differences exist in the community structure of Polypedilum fauna between South America and its neighboring regions, particularly the Nearctic. Our analysis encompasses a dataset of 1492 specimens from 598 locations worldwide, with a specific focus on South America. Within this region, we analyzed a subset of 247 specimens reported from 37 locations. Using various methods including the Barcode Index Number (BIN), Bayesian Poisson tree processes (bPTP), multi‐rate Poisson tree processes (mPTP), single‐rate Poisson tree processes (sPTP), and generalized mixed Yule coalescent (sGMYC), we identify molecular operational taxonomic units (MOTUs) ranging from 267 to 520. Our results indicate that the sGMYC method is the most suitable for estimating putative species in our dataset, resulting in the identification of 75 species in the Neotropical region, particularly in South America. Notably, this region exhibited higher species richness in comparison to the Palearctic and Oriental realms. Additionally, our findings suggest potential differences in species composition of Polypedilum fauna between the Neotropical and the adjacent Nearctic realms, highlighting high levels of endemism and species richness in the first. These results support our hypothesis that there are substantial differences exist in species composition between the Polypedilum fauna in South America and the neighboring regions. [ABSTRACT FROM AUTHOR]

The subduction of an active spreading center generates a clear signature in the temporal evolution of subduction zones. It disrupts the typical arc‐type magmatism and intraplate seismicity, enhances the emplacement of backarc plateau lava and profoundly change the tectonics and topographic relief. These distinct observations are commonly linked to a slab window opening and mantle upwelling. The Chile Triple Junction provides the ideal setup to study the mid‐ocean ridge subduction process where both sides of the spreading center continue to subduct. Here, we use 2‐D numerical petrological‐thermomechanical modeling to focus on transient geodynamic processes caused by mid‐ocean ridge subduction. Model results show slab separation along the ridge axis with the opening of a slab window. During the opening, partial melts from the spreading center migrate toward the subcontinental mantle and high temperatures in the forearc are predicted. The temporal evolution of the modeled temperature is consistent with observed heat flow data, and with magmatism and high‐temperature metamorphism recorded in Chilean forearc rocks. Such migrated partial melts might explain the low viscosity inferred and low seismic velocity anomalies imaged in the slab window beneath South America, and the common geochemical signature of the Chile Ridge, the Taitao Ophiolite and the backarc magmatism. Following slab separation, our models suggest forearc uplift and changes in the stress regime, processes which are consistent with deformation records. Summarizing, our model of the geodynamic evolution of the Chile Ridge subduction provides a consistent framework that explains diverse records of magmatism, metamorphism, deformation and mantle physical properties. Key Points: 2‐D models of mid‐ocean ridge subduction using petrological‐thermomechanical modelingSlab separation leads to the opening of a slab window and the migration of partial melts from the mid‐ocean ridge to the subcontinental mantleModels are consistent with geological, geophysical and geochemical observations in the Chile Triple Junction [ABSTRACT FROM AUTHOR]

In Tierra del Fuego, the Magallanes‐Fagnano Fault System (MFFS) accommodates a significant portion of the relative motion between the South America and Scotia plates. However, it remains unclear whether some of the deformation is partitioned southwards, along the Beagle Channel Fault System (BCFS). In this paper, high‐resolution seismic reflection profiles were used to identify fault‐related ruptures in the submerged Quaternary sediments of the Beagle Channel. Some faults reach the seafloor, affecting marine sediments, indicating they are Holocene in age. The correlation with outcrop data and lineaments mapped onshore suggests the post‐glacial reactivation of two structures: the E‐W striking BCFS and the NW‐SE‐trending Lapataia Fault Zone (LFZ). Whereas the BCFS displays along‐strike variation in throw, the LFZ shows significant normal displacements. These results imply that deformation occurs in a wider and more complex manner than previously thought and highlight the need for a thorough hazard assessment of the area. [ABSTRACT FROM AUTHOR]

The impacts of hot, dry, and compound hot‐dry extremes are significant for societies, economies, and ecosystems worldwide. Such events therefore need to be assessed in the light of anthropogenic climate change so that suitable adaptation measures can be implemented by governments and stakeholders. Here we show a comprehensive analysis of hot, dry, and compound hot‐dry extremes over global land regions using 25 Coupled Model Intercomparison Project Phase 6 models and four future emissions scenarios from 1950 to 2100. Hot, dry, and compound hot‐dry extremes are projected to increase over large parts of the globe by the end of the 21st century. Hot and compound hot‐dry extremes show the most widespread increases and dry extreme changes are sensitive to the index used. Many regional changes depend on the strength of greenhouse‐gas forcing, which highlights the potential to limit the changes with strong mitigation efforts. Plain Language Summary: Heatwaves, drought and their joint occurrences can negatively impact populations, economies, and natural systems worldwide. It is therefore of paramount importance that governments and stakeholders assess the risk from such events and adapt accordingly. In this study we use 25 climate models and four emission scenarios from 1950 to 2100 to assess how hot, dry, and compound hot‐dry extremes are expected to change in the future when compared to current climate conditions. We find that such extremes are projected to increase by the end of the 21st century over large parts of global land areas under the highest‐emission, no‐policy, climate change scenario. Hot and compound hot‐dry extremes show the most widespread increases, whereas dry extreme changes are sensitive and more regionally limited depending on the method by which they are computed. Most of the regional changes in hot, dry, and compound hot‐dry extremes can be reduced with strong climate change mitigation efforts to limit future green‐house gas emissions. Key Points: Hot extremes are projected to increase in frequency and intensity over almost all land areas by the end of the 21st centuryDrought changes depend on measure but increase robustly over central and northern South America, the Mediterranean, and southern AfricaCompound hot and dry extremes are sensitive to the drought measure but projected to increase in most regions globally [ABSTRACT FROM AUTHOR]

Copyright of People & Nature 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.)

The global impacts of El Niño on precipitation have been long‐recognized, but more understanding of the mechanisms behind this influence is needed. For instance, previous studies have largely overlooked the potential impacts of El Niño on terrestrial moisture recycling (TMR). We perform a 40‐year forward tracking simulation to derive a global climatology of recycled precipitation and use a composite analysis to investigate how El Niño affects TMR. We identify seven regions where the El Niño impact on TMR is most significant and find that, in these regions, changes in precipitation and TMR are directly related: they increase or decrease together. In addition, we find a marked latitudinal contrast between the Southern Hemisphere, where TMR increases during El Niño, and the Northern Hemisphere and the tropics, where it decreases. Our results indicate that the weakening and strengthening of TMR can be behind precipitation changes caused by El Niño globally. Plain Language Summary: El Niño is recognized as a climate variability phenomenon with significant impacts on precipitation worldwide. However, the mechanisms behind these impacts are not fully understood. Here we use model simulations to argue that one of those mechanisms is the effect of El Niño on terrestrial moisture recycling (TMR), that is, the fraction of precipitation fed by atmospheric moisture originating not in the ocean but on the continents. We show that El Niño significantly affects TMR globally, especially in seven regions of South America, Africa, North America, Europe, and Asia. In these regions, precipitation and TMR increase or decrease together. We find a contrast between the South and North of the planet: during El Niño, TMR increases in the Southern Hemisphere while decreasing in the Northern Hemisphere and the tropics. Overall, our results indicate that TMR weakening or strengthening are previously overlooked mechanisms behind precipitation changes caused by El Niño globally. Key Points: El Niño exerts significant effects on terrestrial moisture recycling worldwideEl Niño's impacts on terrestrial moisture recycling are most significant in seven regions worldwidePrecipitation and terrestrial moisture recycling increase or decrease together due to El Niño [ABSTRACT FROM AUTHOR]

Pouteria splendens is the only native species of Sapotaceae in Chile, a species once placed in the monotypic genus Gayella and known as G. valparadisaea, but for a long time treated as a Pouteria. In a phylogenetic analysis, this species was placed in an Australasian clade, not with its presumed relatives in South America. We used Bayesian inference under a relaxed molecular clock in BEAST, nuclear ribosomal DNA (ETS, ITS), the nuclear gene RPB2, indel information, and 201 terminals to find the closest relative of P. splendens and to estimate the age of the disjunction between Australasia and South America. The taxon has an isolated phylogenetic position, being part of the cladeʼs backbone, and is placed with weak support as sister to Van‐royena, another monotypic genus, but endemic to Australia. Our results justify reinstatement of Gayella with its single species G. valparadisaea. Gayella has a unique combination of morphological features including alternate, opposite or 3‐whorled leaves, often on the same plant, a usually 6‐lobed, rotate corolla with revolute corolla lobes giving the flower a star‐like appearance, lacerate to dentate staminodes, and yellow‐orange‐red fruit with plano‐convex cotyledons and an exserted radicle below the cotyledon commissure. The split between Gayella and Van‐royena is estimated to the late Eocene at about 40.0 Ma (50.5–25.3 Ma). The hypothesis that the presence of Gayella in South America is a result of vicariance is consistent with the timing of the geological splits of southern Gondwana, as well as with evidence from fossil pollen, but long‐distance dispersal is an alternative explanation that cannot be excluded. Gayella is restricted to an area with a Mediterranean‐type climate in coastal central Chile, where it occurs in rocky places, ravines, and gullies, usually below 100 m altitude within reach of sea mist. Gayella valparadisaea is a rare plant, listed as Endangered (EN) in Chile, but it does not occur in any protected area. Considering the isolated phylogenetic position of this old lineage, we urge the Chilean authorities to increase the efforts towards protection of this species. [ABSTRACT FROM AUTHOR]

Since the mid‐20th century, the so‐called Great Acceleration (sensu Steffen et al., 2007, https://doi.org/10.1579/0044-7447(2007)36[614:TAAHNO]2.0.CO;2) has amplified processes of ecosystem degradation, extinction of biological species, displacement of local peoples, losses of languages, and cultural diversity. These losses are still underperceived by the academic community, and by a global society that is disconnected from biocultural diversity. To reconnect society with biocultural diversity, we integrate temporal and spatial dimensions of seasonal cycles, by combining two conceptual frameworks: ecological calendars and the "3Hs" model of the biocultural ethic (sensu Rozzi, 2012, https://doi.org/10.5840/enviroethics20123414). The latter values the vital links between human and other‐than‐human co‐inhabitants, their life habits (e.g., cultural practices of humans or life cycles of other‐than‐human species), and the structure and processes of their shared habitats. This integration enhances an understanding of links between cultural practices and the life cycles of biocultural keystone species. As a synthesis, we use the term biocultural calendars to emphasize their co‐constitutive nature that result from interactions between dynamic biophysical and cultural processes embedded in specific ecosystems and cultures. These calendars link astronomical, biological, and cultural seasonal cycles that sustain life and enhance the integration of Indigenous and scientific knowledge to confront challenges of climate change faced from local to global scales. To illustrate this integration, we examine cultural practices and socio‐environmental changes across four contrasting ethnolinguistic communities in southwestern South America, from southern to northern Chile along a marked climatic gradient to show the broad application of the concept of biocultural calendars. Plain Language Summary: We combine ecological calendars and the biocultural ethic. The first refers to natural or seasonal calendars and focuses on the temporal scale of life cycles and other ecological phenomena observed at a given place. The second emphasizes the vital links among human and non‐human co‐inhabitants, their habits (e.g., cultural practices of humans or life cycles of other‐than‐human species) in shared habitats (the "3Hs" of the biocultural ethic). Close observation of biological and cultural diversity, and their interrelationships (in short, biocultural diversity), synchronizes cultural practices with natural processes at specific places. This synchrony is particularly relevant in the context of climate change because by being locally attuned, communities enhance their capacity to adapt their activities to the variability of temperature, rainfall, and other climatic events. In this article we use the term biocultural calendars to more closely understand the links between different life habits in contrasting habitats and annual seasons. In this way, biocultural calendars provide an understanding of biological and cultural heterogeneity in different seasons and regions of the world that can help us adapt to a rapidly changing world. Key Points: Biocultural calendars are co‐constitutively generated through interactions between dynamic biophysical and cultural processesThe biocultural ethic's 3Hs model values the vital links among human and other‐than‐human co‐inhabitants, their habits, and shared habitatsBiocultural calendars are based on seasonal cycles of keystone species that are part of communities of co‐inhabitants [ABSTRACT FROM AUTHOR]

Aim Past climatic and geological events can be used to interpret present distributions of organisms. We use chronological and spatial analyses of the species of Myrceugenia in southern South America to help explain their present distribution. Location Southern South America (Argentina, Brazil, Chile, Paraguay and Uruguay). Methods Chronological analyses were completed for the tribe Myrteae (Myrtaceae) using two nuclear DNA sequences and for the genus Myrceugenia using four chloroplast and two nuclear sequences. A biogeographical analysis of Myrceugenia was carried out. Based on calibration points from fossils and estimations, a relaxed molecular clock was used to estimate divergence times and rates of speciation within each lineage. Ancestral states were reconstructed through Bayesian analysis. Results The chronogram implies that tribe Myrteae diversified at the end of the Cretaceous, but that the majority of the individual lineages originated more recently . Myrceugenia diverged into four lineages during the early Miocene. Three of these lineages diversified in Chile, with dispersal to the north and south of the country plus a recent dispersal to the Juan Fernández archipelago. The fourth lineage diversified through vicariant events in south-eastern Brazil. The ancestors of Blepharocalyx, Myrceugenia fernandeziana and Luma are very ancient lineages that originated between the Palaeocene and Eocene, and which have remained stable with little or no subsequent diversification. Main conclusions The estimated age for diversification of tribe Myrteae is consistent with the known fossil evidence from southern South America. The distribution of Myrceugenia may be explained by a combination of three events occurring in the early-middle Miocene: uplift of the Andes, a rain-shadow effect and a marine transgression. These events may also have led to disjunct distributions in several other genera in southern South America. [ABSTRACT FROM AUTHOR]

To understand the main orographic and non‐orographic sources of gravity waves (GWs) over South America during an Experiment (Rapp et al., 2021, https://doi.org/10.1175/BAMS-D-20-0034.1), we propose the application of a rotational spectral analysis based on methods originally developed for oceanographic studies. This approach is deployed in a complex scenario of large‐amplitude GWs by applying it to reanalysis data. We divide the atmospheric region of interest into two height intervals. The simulations are compared with lidar measurements during one of the flights. From the degree of polarization and the total energy of the GWs, the contribution of the upward and downward wave packets is described as a function of their vertical wavenumbers. At low levels, a larger downward energy flux is observed in a few significant harmonics, suggesting inertial GWs radiated at polar night jet levels, and below, near to a cold front. In contrast, the upward GW energy flux, per unit area, is larger than the downward flux, as expected over mountainous areas. The main sub‐regions of upward GW energy flux are located above Patagonia, the Antarctic Peninsula and only some oceanic sectors. Above the sea, there are alternating sub‐regions dominated by linearly polarized GWs and sectors of downward GWs. At the upper levels, the total available GW energy per unit mass is higher than at the lower levels. Regions with different degrees of polarization are distributed in elongated bands. A satisfactory comparison is made with an analysis based on the phase difference between temperature and vertical wind disturbances. Plain Language Summary: Atmospheric gravity waves (GWs) are of great importance in the transport of energy and momentum through the atmosphere. Their sources can be broadly classified as stationary and non‐stationary. The southern tip of South America represents one of the most important natural laboratories for detecting the coexistence of large‐amplitude GWs. We present a spectral method to establish a semi‐quantitative classification of the different groups of GWs and their main vertical direction of propagation. We apply the method on the basis of global model data. We divide the lower and middle atmosphere into two vertical intervals and compare the model with data from one of the instruments deployed during the experiment. Based on the direction of rotation of the vector defined by the GW oscillations of the two horizontal wind components, we describe the net contribution of the upward and downward wave packets as a function of their spectral harmonics. The main sub‐regions of upward GW energy flux alternate with sub‐regions dominated by linearly polarized GWs and downward GW sectors mainly above the ocean. At the upper levels, the total available GW energy per unit mass is higher than at the lower levels. A comparison is made between these results and an independent analysis based on the known polarization relations for GWs. Key Points: A rotary spectral analysis is proposed to classify possible sources of gravity waves (GWs) according to their degree of polarizationFrom reanalysis data, the method is applied at a selected position during one of the flights of the SOUTHTRAC‐GW ExperimentUpward and downward GW structures from orographic and non‐orographic origin with different degrees of polarization are observed [ABSTRACT FROM AUTHOR]

Background: A wide range of sunscreen products are available globally. Designed to meet various customer needs, they differ in formulations type, textures, ingredients, ultraviolet (UV) protection capabilities, and other properties. Knowing the factors influencing the purchase of sunscreens and the UV filters commonly used in each global region would be beneficial for dermatologists, consumers, and regulators. Methods: Data on 50 best‐selling sunscreens from each of 20 countries on 5 continents (1000 products in all) were retrieved from Amazon Marketplace during the period from January to July 2021. Results: Among the 5 continents, Asia had the highest proportion of consumers (71.1%) choosing high sun protection factor (SPF) sunscreens (SPF ≥50). In contrast, Europe had the highest percentage (11.8%) purchasing <30 SPF sunscreens. The lack of standard UVA protection labeling was significantly highest in South America. The use of inorganic‐based sunscreen was highest in North America, and across all continents, those products were significantly more expensive than organic‐based sunscreens. Globally, lotions were the most favored formulation type. "Nongreasy/dry touch" (45.1%) and "lightweight texture" (40.4%) were the most common promotional terms used. The most common UV filters differed among regions. Iron oxide, which can function as a visible light filter, was most frequently found in sunscreens in South America (20%) and North America (19.3%). Conclusions: The regional factors influencing the purchase of sunscreen products differed. A considerable number of sunscreens may not provide adequate sun protection for consumers. Dermatologists should recommend sunscreens with sufficient UV protection that suit the skin of individual consumers. [ABSTRACT FROM AUTHOR]

Premise: To address the biodiversity crisis, we need to understand the evolution of all organisms and how they fill geographic and ecological space. Syntrichia is one of the most diverse and dominant genera of mosses, ranging from alpine habitats to desert biocrusts, yet its evolutionary history remains unclear. Methods: We present a comprehensive phylogenetic analysis of Syntrichia, based on both molecular and morphological data, with most of the named species and closest outgroups represented. In addition, we provide ancestral‐state reconstructions of water‐related traits and a global biogeographic analysis. Results: We found 10 major well‐resolved subclades of Syntrichia that possess geographical or morphological coherence, in some cases representing previously accepted genera. We infer that the extant species diversity of Syntrichia likely originated in South America in the early Eocene (56.5–43.8 million years ago [Mya]), subsequently expanded its distribution to the neotropics, and finally dispersed to the northern hemisphere. There, the clade experienced a recent diversification (15–12 Mya) into a broad set of ecological niches (e.g., the S. caninervis and S. ruralis complexes). The transition from terricolous to either saxicolous or epiphytic habitats occurred more than once and was associated with changes in water‐related traits. Conclusions: Our study provides a framework for understanding the evolutionary history of Syntrichia through the combination of morphological and molecular characters, revealing that migration events that shaped the current distribution of the clade have implications for morphological character evolution in relation to niche diversity. [ABSTRACT FROM AUTHOR]

The use if the general circulation model (GCM) as a boundary condition for the dynamic regionalization process, without robust technical criteria, is one of the problems responsible for increasing the uncertainties of simulations and projections of climate scenarios, mainly affecting the observed trends and consequently the representation of future trends. Based on this premise, the present study evaluated the historical ability of 30 models that make up phase 5 of the Coupled Model Intercomparison Project using the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method. The meteorological variables used in this assessment were precipitation and near‐surface air temperature from 1975 to 2005 in the southern sectors of the Amazon Basin (SAMZ), Eastern Northeast Brazil (ENEB), and the intersection area between these regions, called MATOPIBA, was used to select the best GCM. The annual cycle, Taylor diagram and TOPSIS method were used as metrics of similarity between the models and the reference dataset. In general, the models simulated the temperature more accurately than the precipitation, with lower dispersions. According to the TOPSIS, over SAMZ, the HadGEM2‐ES (MIROC5) model was ranked with greater (less) ability to represent precipitation. In turn, for temperature the ensmean_cmip5 (IPSL‐CM5A‐MR) was the best (worst). Over ENEB, the model that showed the greatest (lowest) ability to simulate precipitation was CSIRO‐ACESS1.0 (HadGEM2‐AO). For temperature, the NorESM‐ME model (INMCM4) was ranked first (last). Over MATOPIBA, the CSIRO‐ACESS1.0 (NorESM‐ME) model was selected as having the best performance and the MPI‐ESM‐LR (MPI‐ESM‐LR) as the worst performance when representing precipitation (temperature). The similarities and discrepancies in the capacity of the GCM presented in the different metrics covered in this study can assist in the selection of more appropriate climate models in other regions for future studies of climate change. [ABSTRACT FROM AUTHOR]

Apple is one of the most widely cultivated fruit crops world‐wide, and apple yield benefits from pollination by insects. The global decline in wild pollinator populations raises concern about the adequacy of pollination services in apple production.Here, we present a global meta‐analysis of pollination in apple. We assembled from the literature a dataset comprising results of 48 studies across five continents on fruit set and seed set in apple with insect pollination, artificial pollination and pollinator exclusion, and analysed the effects of explanatory factors such as variety and continent.Fruit set was on average 41% lower with open pollination than with artificial pollination, while seed set was 20% lower. These pollination deficits varied across continents and cultivars. Pollination deficits for fruit set were greatest in Asia (63%) followed by Europe (30%), whereas pollination deficits for seed set were greatest in Asia (47%) and South America (40%). Important differences in pollination deficit were also identified between cultivars but these differences were confounded with continent effects.Fruit set and seed set were 71% and 62% higher, respectively, when insects had open access to flowers than when they were artificially excluded, while results varied among cultivars.Synthesis and applications. Globally, there are substantial contributions of pollinators to fruit set and seed set in apple, as well as considerable limitations in apple pollination services, particularly in Asia, Europe and South America. Several management strategies could be applied to reduce the pollination deficits in apple production: (1) conserving wild bees and enhancing their abundance and diversity, (2) using managed bees for pollination, (3) using varieties with low pollinator dependency and/or (4) artificial pollination. These strategies should be tailored to the regional situation, considering the potential of landscapes for restoring wild pollinators, the acceptability of cultivated varieties for available pollinators, the acceptance in the market of self‐compatible varieties and the costs of management, such as artificial pollination, pollinator conservation, beekeeping and planting self‐compatible varieties. Conservation of wild pollinators is preferred in regions with sufficient potential for wild pollinators as it contributes to biodiversity conservation and improves pollination in both crops and wild plants. [ABSTRACT FROM AUTHOR]

The Triassic Cuyo rift Basin is one of the renowned petroleum systems in South America that records distinctive alluvial, lacustrine and fluvial settings with volcanic input. The present study focuses on the clay mineral assemblages that represent the syn‐rift to post‐rift fills. Four clay mineral assemblages are defined based on X‐ray diffraction, optical and electron microscopy analyses. The illite/mica‐dominated assemblage is documented in the syn‐rift I (Cerro de las Cabras Formation). Such mineral phases are inherited and derived from the erosion of pre‐rift units, suggesting that physical weathering associated with a warm and semi‐arid climate played a leading role in their occurrence. Authigenic smectite clays are diagnostic in organic‐lean mudstones of the syn‐rift II (lower Potrerillos Formation) which point to alteration of pyroclastic material under a warm and semi‐arid to humid climate. A warm and humid climate prevailed during the deposition of lacustrine hydrocarbon source rocks (upper Potrerillos and Cacheuta formations). Organic‐rich mudstones show the illite/mica–kaolinite–smectite assemblage in conjunction with amorphous organic matter and restricted terrigenous elements. Diagenetic kaolinite booklets and bipyramidal quartz are attributed to the acidification of pore‐water related to kerogen transformation during burial diagenesis. Vitrinite reflectance values (ca 0.63%) confirm that organic‐rich sediments reached the earliest oil window; however, smectite is devoid of illite layers throughout the Triassic succession, probably related to the absence of potassium in the system and the high crystallinity of the smectite, which delayed the transformation of smectite into mixed layers illite–smectite. Red mudstones of the post‐rift II (the fluvial‐lacustrine Rio Blanco Formation) show the kaolinite‐dominated assemblage where the authigenic kaolinite is interpreted to be derived from the alteration of volcaniclastic detritus and indicative of warm climate with markedly wet periods. [ABSTRACT FROM AUTHOR]

Meteoritical Bulletin 100 contains 1943 meteorites including 8 falls (Boumdeid [2011], Huaxi, Košice, Silistra, Sołtmany, Sutter's Mill, Thika, Tissint), with 1575 ordinary chondrites, 139 carbonaceous chondrites, 96 HED achondrites, 25 ureilites, 18 primitive achondrites, 17 iron meteorites, 15 enstatite chondrites, 11 lunar meteorites, 10 mesosiderites, 10 ungrouped achondrites, 8 pallasites, 8 Martian meteorites, 6 Rumuruti chondrites, 3 enstatite achondrites, and 2 angrites, and with 937 from Antarctica, 592 from Africa, 230 from Asia, 95 from South America, 44 from North America, 36 from Oceania, 6 from Europe, and 1 from an unknown location. This will be the last Bulletin published in the current format. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database ( MBD) available online at [ABSTRACT FROM AUTHOR]

Summary: The biogeography of neotropical fungi remains poorly understood. Here, we reconstruct the origins and diversification of neotropical lineages in one of the largest clades of ectomycorrhizal fungi in the globally widespread family Russulaceae.We inferred a supertree of 3285 operational taxonomic units, representing worldwide internal transcribed spacer sequences. We reconstructed biogeographic history and diversification and identified lineages in the Neotropics and adjacent Patagonia.The ectomycorrhizal Russulaceae have a tropical African origin. The oldest lineages in tropical South America, most with African sister groups, date to the mid‐Eocene, possibly coinciding with a boreotropical migration corridor. There were several transatlantic dispersal events from Africa more recently. Andean and Central American lineages mostly have north‐temperate origins and are associated with North Andean uplift and the general north–south biotic interchange across the Panama isthmus, respectively. Patagonian lineages have Australasian affinities. Diversification rates in tropical South America and other tropical areas are lower than in temperate areas.Neotropical Russulaceae have multiple biogeographic origins since the mid‐Eocene involving dispersal and co‐migration. Discontinuous distributions of host plants may explain low diversification rates of tropical lowland ectomycorrhizal fungi. Deeply diverging neotropical fungal lineages need to be better documented. [ABSTRACT FROM AUTHOR]

The diversity and distribution of poroid wood‐inhabiting fungi in South America are relatively well known. However, the information from Chile is scarce and scattered. The host preference differs among fungi in this group, as some species depend on a specific host, whereas others are associated with multiple hosts. At the same time, their occurrence is influenced by climatic conditions. Thus, information about the host‐fungi relationship and climatic conditions of this group is needed to understand their distribution. Chile has 83 poroid wood‐inhabiting fungal species in six orders and 21 families, mainly Polyporales and Hymenochaetales, distributed from 30°S in Fray Jorge National Park to 56°S in Cape Horn, but Polyporales grow predominantly in forests with a higher precipitation range than Hymenochaetales. The biggest diversity resides in deciduous forests and sclerophyll forests in warm climates. Many species are specialist and mostly associated with angiosperms rather than gymnosperms. Poroid Gloeophyllales, Agaricales and Russulales are narrowly distributed. [ABSTRACT FROM AUTHOR]

Tritium, a radioisotope of hydrogen, is an ideal tracer for groundwater and surface dating and tracking since it is part of the water molecule. The knowledge of the history of tritium in precipitation and recharge is the key link for the calculation of groundwater tritium age. However, records of tritium in precipitation are usually sparse and discontinuous, especially in regions like South America, and often need to be reconstructed. To solve this problem, different reconstruction methods of the tritium input function have been analysed and compared. Clustering of Global Network of Isotopes in Precipitation stations by regions and the correlation with the complete and continuous data recorded in Kaitoke (New Zealand) proved to be the most effective approach, having low relative errors and a much more extended coverage in time compared to other interpolation or reference curves methods. Thus, tritium time series for five different regions of the temperate zone of South America were obtained. These curves can be used as representative tritium input curves in future studies for these regions. The results obtained also allow a quick qualitative analysis of groundwater ages in these areas, based on their current or past tritium concentrations. In addition, they contributed to the understanding of the patterns and characteristics of tritium distribution in the atmosphere of the southern sector of South America. [ABSTRACT FROM AUTHOR]

Although being one of the most efficient tools to constrain the stratigraphy of sedimentary basins, detrital zircon geochronology may present limitations under certain conditions, and isotopic ages should be treated with caution before assigning a depositional age. This is the case of depositional environments that lack coeval volcanism, where there may exist a significant time gap between the age of the youngest detrital zircon available and the actual time of deposition of a sedimentary rock. In this paper, we put on a comprehensive analysis in which detrital geochronology is aided with other reliable geological constraints. As a case study, we evaluate the stratigraphic age and provenance of the Lapataia Formation from the Fuegian Andes of southernmost South America, a low‐grade metamorphic unit with a problematic stratigraphic definition in the context of the Rocas Verdes basin. Detrital ages show very wide age spectra, with a younger peak at ca. 267 Ma. However, based on detailed petrography and microstructural observations, as well as stratigraphic correlations at a regional scale, we conclude that the Lapataia Formation represents the earliest stages of Jurassic rifting during the opening of the Rocas Verdes basin. Erosion from older basement blocks in an environment lacking coeval volcanic activity explains the occurrence of Paleozoic and older grains, and the lack of younger zircons. This work offers a multifaceted approach, which may be essential to assist radiometric detrital geochronology at certain stages during basin evolution. [ABSTRACT FROM AUTHOR]

Pseudocrossidium is a genus of 21 species belonging to the Pottiaceae with the highest concentration of taxa and morphological variation found in South America. To investigate the evolutionary relationships among the species of Pseudocrossidium and other members of the Pottioideae, molecular phylogenetic reconstructions, using the nuclear ITS1‐5.8S‐ITS2, and the plastid atpB‐rbcL, trnG, and trnL‐F, has been performed because this genus has only been partially tested using molecular markers. Bayesian and maximum likelihood topologies show that the genus, as presently circumscribed, is polyphyletic. Consequently, the circumscription of Pseudocrossidium is amended and numerous taxonomic changes resulting from the molecular, morphological, and nomenclatural studies are proposed. The phylogenetic and morphologically divergent Pseudocrossidium mendozense is renamed as Gertrudiella mendozensis. Pseudocrossidium linearifolium and P. porphyreoneurum are representatives of the new genera Barbulastrum and Helicobarbula, respectively. Pseudocrossidium carinatum and P. santiagense are accommodated in a new genus Austrobarbula. Aloinella, nested in a paraphyletic Pseudocrossidium, is maintained at generic rank, apparently derived from Pseudocrossidium. Barbula integrifolia, B. riograndensis, and Tortula jaffuelii are transferred to Pseudocrossidium. The remaining species of Pseudocrossidium are maintained in this genus, pending further studies. Conflicts of the trees observed could be evidence of interspecific or intergeneric gene flow in various lineages in the Pottioideae. [ABSTRACT FROM AUTHOR]

Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. This subgenus is mainly distributed on the American continent and in the Pacific region, and it is the only subgenus almost entirely absent from the Old World and primarily diversified in the Southern Hemisphere. It includes some of the few Carex species with clear epizoochoric traits: the representatives of C. sect. Uncinia possess utricles with an exserted and hooked rachilla that allows the diaspores to attach to feather or hair. We performed phylogenetic (ITS, ETS‐1f, matK), biogeographic, and ancestral state reconstruction analyses to elucidate the systematic structure, origin and dispersal routes, and major morphological evolutionary patterns of the different lineages within the subgenus. Our phylogenetic reconstructions revealed that the subgenus comprises seven different clades that mostly match previously recognized sections. One of the clades, however, represents a new section described herein as C. sect. Wheelerianae. Unispicate lineages evolved repeatedly from ancestors bearing multispicate inflorescences, while the presence of a rachilla, often pictured as a plesiomorphy in Carex, seems to have developed four independent times in the evolution of C. subg. Uncinia. The origin of the subgenus dates back to the beginning of the Miocene, probably in North America from where it colonized the Southern Hemisphere. It first dispersed to South America during the Early Miocene. Later, in the Middle Miocene, representatives of C. sect. Uncinia would reach the Pacific Southwest region (New Zealand, Australasia) from South America in at least two independent dispersal events. The vast majority of the biogeographic events seem to be explained by long‐distance dispersal. The remarkable dispersal ability of C. sect. Uncinia enabled by the hooked rachilla has allowed it to reach remote archipelagos in the Pacific and Subantarctic regions, probably bird‐mediated. [ABSTRACT FROM AUTHOR]

Even though anthropogenic mercury (Hg) emissions to the atmosphere are ∼2.5 times higher in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH), atmospheric Hg concentrations in the NH are only ∼1.5 times higher than in the SH. Global Hg models attribute this apparent discrepancy to large SH oceanic Hg emissions or to interhemispheric exchange of Hg through the atmosphere. However, no observational data set exists to serve as a benchmark to validate whether these coarse‐resolution models adequately represent the complex dynamics of interhemispheric Hg exchange. During the 2015–2016 El Niño, we observed at mount Chacaltaya in the tropical Andes a ∼50% increase in ambient Hg compared to the year before, coinciding with a shift in synoptic transport pathways. Using this event as a case study, we investigate the impact of interhemispheric exchange on atmospheric Hg in tropical South America. We use HYSPLIT to link Hg observations to long‐range transport and find that the observed Hg increase relates strongly to air masses from the tropical Pacific upper troposphere (UT), a region directly impacted by interhemispheric exchange. Inclusion of the modeled seasonality of interhemispheric air mass exchange strengthens this relationship significantly. We estimate that interhemispheric exchange drives Hg seasonality in the SH tropical Pacific UT, with strongly enhanced Hg between July and October. We validate this seasonality with previously published aircraft Hg observations. Our results suggest that the transport of NH‐influenced air masses to tropical South America via the Pacific UT occurs regularly but became more detectable at Chacaltaya in 2015–2016 because of a westward shift in air mass origin. Plain Language Summary: Human activities have released much more mercury, a toxic pollutant, into the Northern Hemisphere (NH) atmosphere than into the Southern Hemisphere (SH) atmosphere. Yet, the difference in mercury concentrations between the two hemispheres is not very large. Model studies attribute this unexpectedly low interhemispheric mercury difference to large emissions from SH oceans or to the exchange of airborne mercury between hemispheres. This interhemispheric mercury exchange is complex, however, and direct observational evidence is lacking. Here, we examine the strong increase in atmospheric mercury during the 2015–2016 El Niño at mount Chacaltaya in tropical South America. We examine and exclude potential SH sources for this increase, such as mercury emissions from wildfires or marine mercury emissions. Instead, we find that this mercury increase was likely caused by interhemispheric mercury exchange at high altitudes over the tropical Pacific Ocean, and the subsequent transport of mercury‐rich NH‐influenced air to tropical South America. We propose that Chacaltaya mercury observations could be used as a reference to test if current mathematical models can correctly predict interhemispheric mercury exchange. Key Points: We use the strong increase in atmospheric Hg at Chacaltaya mountain in tropical South America during the 2015–2016 El Niño for a case studyIn 2015–2016, air mass origin for Chacaltaya shifted westward, with greatly enhanced influence of the tropical Pacific upper troposphere (UT)Our results suggest that interhemispheric exchange in the tropical Pacific UT can bring Northern Hemisphere Hg to Chacaltaya [ABSTRACT FROM AUTHOR]

Aim: Understanding how natural populations respond to climatic shifts is a fundamental goal of biological research in a fast‐changing world. The Southern Ocean represents a fascinating system for assessing large‐scale climate‐driven biological change, as it contains extremely isolated island groups within a predominantly westerly, circumpolar wind and current system. Blue‐eyed shags represent a paradoxical seabird radiation—a circumpolar distribution implies strong dispersal capacity yet their species‐rich nature suggests local adaptation and isolation. Here we attempt to resolve this paradox in light of the history of repeated cycles of climate change in the Southern Ocean. Location: Southern Ocean. Taxa: 16 species and subspecies of blue‐eyed shags (Phalacrocoracidae; Leucocarbo spp.). Methods: We use mitochondrial and nuclear sequence data from individuals across the geographical range of the genus to conduct the first comprehensive, time‐calibrated phylogenetic analyses and ancestral‐range biogeographical reconstructions of the blue‐eyed shags. Results: The origins of many island‐endemic lineages are remarkably recent, consistent with a recent high‐latitude circumpolar radiation in the Pliocene or Early Pleistocene. This recent sub‐Antarctic expansion contrasts with significantly deeper lineages detected in South America and, to a lesser extent, New Zealand. These regions, particularly South America, acted as glacial refugia and sources for multiple waves of post‐glacial dispersal. Main conclusions: The blue‐eyed shag paradox is resolved, with at least two waves of dispersal, linked to interglacial cycles, explaining the current distribution and diversity. Descendants of a Pliocene or Early Pleistocene wave of dispersal out of South America survive in the New Zealand region. In contrast, taxa distributed on sub‐Antarctic islands originated much later, possibly since the Last Glacial Maximum. Blue‐eyed shags therefore represent a powerful model system—comprising several natural replicates—for studying the early stages of founder‐event speciation and adaptation in a Southern‐Ocean bird group. [ABSTRACT FROM AUTHOR]

Summary During an expedition to the Southern Argentinean town of Ushuaia, the Antarctic Peninsula, Antarctic Islands and the Falkland Islands, we collected 94 faecal specimens from wild birds to screen for yeast within the different bird species. The yeast species were identified by morphological features and commercial characterisation kits. From 54% of the specimens, we isolated 122 strains representing 29 yeast species. Debaryomyces hansenii, Candida lambica and Candida krusei were the most frequently isolated species. We found a plethora of yeasts in birds living in proximity to humans, whereas birds living in more remote areas were colonised with a lower number of fungal 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]

Dry lakebeds exposed by shrinking water bodies in arid regions constitute sodium (Na)‐rich mineral dust emission hotspots that may potentially affect agriculture through soil sodification. However, no soluble Na mass balance has so far been attempted. We modeled 13 years (2005–2017) of dust emission from Mar Chiquita (MC), the most extensive shrinking saline lake in South America. Based on a chemical characterization of dust, we found that a mean ∼15–150 mg m−2 of soluble Na was deposited 300 km from the source during the season of strongest dust emissions. We estimated the impact of this atmospheric input on 13 agricultural soils, with different rainfall regimes and water holding capacities. At most sites, dust‐equilibrated infiltrated rainfall water had a Na concentration 8–7,000 times lower than the lowest concentration threshold proposed to trigger sodification. Additionally, this rainfall water is diluted ∼2–20 times as it infiltrates in saturated soils, and its sodium adsorption ratio is probably reduced due to the abundance of soluble calcium and magnesium in the soil solution. Thus, there is no risk of short‐term, seasonal sodification, except possibly at two sites and in close proximity to the dust source (<50 km), where dust deposition is maximum. At these sites, we estimated potential dust‐related rises in the proportion of soil exchangeable Na. Under scenarios of enhanced salt‐rich dust emissions from shrinking lakes in the twenty‐first century, agricultural soils close to salt‐rich dust sources worldwide should be monitored for potential Na enrichment related to Na‐rich dust. Plain Language Summary: When lakes rich in dissolved salts shrink, the lakes' bed becomes exposed, and upon drying, these areas may emit salt‐rich dust to the atmosphere. This dust may be deposited on soils used for agriculture in the surrounding areas, and depending on the dust chemistry it may affect soil productivity, with sodium‐rich dust posing the highest potential threat. In this study, we analyzed dust emission from Mar Chiquita lake, the most extensive shrinking saline lake in South America, and its potential effect on agricultural soils in the region. To do this, we sampled dust, characterized its chemistry, modeled dust emission, transport in the atmosphere and final deposition to the soils, sampled soils at sites located at different distances from the lake, and finally compared the inputs of dust‐derived sodium, magnesium, and calcium with preexisting concentrations of these elements in the soils. We found that the short‐term input of sodium to the soils derived from dust is comparatively low, except close to the lake. However, the long‐term effect remains uncertain. Given that more intense dust emissions from shrinking lakes are projected globally in the twenty‐first century, agricultural soils exposed to salt‐rich dust deposition should be monitored to gauge threats to food production. Key Points: Mar Chiquita, the largest South American shrinking saline lake, has emitted ∼0.5 Tg of dust in August plus September of each year since 2004Despite a marked dust enrichment in soluble sodium, dust inputs are low compared to agricultural soil sodium stocks at most studied sitesWhile short‐term soil sodification risk is low, potential long‐term effects and projected stronger dust emissions merit soil monitoring [ABSTRACT FROM AUTHOR]