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In a jungle environment where jaguars are considered human, systems thinking has evolved in unexpected ways. Although systems thinking is commonly seen as a product of the Western world, other cultures have developed their own versions with unique characteristics. In this article, we explore Amazonian systems thinking, which has similarities to modern Western systems thinking, as well as differences that may inspire the evolution of systems approaches worldwide. We will discuss the contributions of Amazonian systems thinking particularly to find answers to the planet's ecological and sustainability problems, such as climate change and mass extinction of species, among others. We will present the systems thinking that emerged in some Amazonian communities, how it relates to mainstream Western systems thinking, and focus on some unique aspects of Amazonian systems thinking. This paper is based on the ethnographic work of Gerardo Reichel‐Dolmatoff and other anthropologists who have studied Amazonian communities for decades. [ABSTRACT FROM AUTHOR]

As a global industry, sport makes potentially significant contributions to climate change through both carbon emissions and influence over sustainability practices. Yet, evidence regarding impacts is uneven and spread across many disciplines. This paper investigates the impacts of sport emissions on climate and identifies knowledge gaps. We undertook a systematic and iterative meta‐analysis of relevant literature (1992–2022) on organized and individual sports. Using a defined search protocol, 116 sources were identified that map to four sport‐related themes: (1) carbon emissions and their measurement; (2) emissions control and decarbonization; (3) carbon sinks and offsets; and (4) behavior change. We find that mega sport events, elite sport, soccer, skiing, and golf have received most attention, whereas grass‐roots and women's sport, activity in Africa and South America, cricket, tennis, and volleyball are understudied. Other knowledge gaps include carbon accounting tools and indicators for smaller sports clubs and active participants; cobenefits and tradeoffs between mitigation‐adaptation efforts in sport, such as around logistics, venues, sports equipment, and facilities; geopolitical influence; and scope for climate change litigation against hosts and/or sponsors of carbon‐intensive events. Among these, researchers should target cobenefits given their scope to deliver wins for both climate mitigation and risk management of sport. [ABSTRACT FROM AUTHOR]

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

Pasturelands are globally extensive, sensitive to climate, and support livestock production systems that provide an essential source of food in many parts of the world. In this paper, we integrate information from remote sensing, global climate, and land use databases to improve understanding of the resilience and resistance of this ecologically vulnerable and societally critical land use. To characterize the effect of climate on pastureland productivity at global scale, we analyze the relationship between satellite‐derived enhanced vegetation index data from MODIS and gridded precipitation data from CHIRPS at 3‐ and 6‐month time lags. To account for the effects of different production systems, we stratify our analysis by agroecological zones and by rangeland versus mixed crop‐livestock systems. Results show that 14.5% of global pasturelands experienced statistically significant greening or browning trends over the 15‐year study period, with the majority of these locations showing greening. In arid ecosystems, precipitation and lagged vegetation index anomalies explain up to 69% of variation in vegetation productivity in both crop‐livestock and rangeland‐based production systems. Livestock production systems in Australia are least resistant to contemporaneous and short‐term precipitation anomalies, while arid livestock production systems in Latin America are least resilient to short‐term vegetation greenness anomalies. Because many arid regions of the world are projected to experience decreased total precipitation and increased precipitation variability in the coming decades, improved understanding regarding the sensitivity of pasturelands to the joint effects of climate change and livestock production systems is required to support sustainable land management in global pasturelands. Plain Language Summary: Pastures, which provide food for livestock, are the most extensive land use on the planet, and their productivity depends on the timing and amount of rainfall they receive. In this paper, we use data on vegetation productivity, rainfall, and land use in order to determine the ability of pastures to remain unaffected by a disturbance and the time required for pastures to recover following a disturbance. To determine the effects of rainfall on pastures, we analyze the relationship between productivity and rainfall at 3‐ and 6‐month time intervals. We also take into account pasture management and whether pastures are located in dry or humid areas of the world. In dry regions, rain from the current season, rain from the last two seasons, and vegetation productivity from the previous growing season explain nearly 70% of current season vegetation productivity. Pastures in Australia are least capable of withstanding rainfall deficits, while pastures in Latin America recover more slowly after drought compared to other regions. Dry regions of the world are predicted to receive less rain less regularly in the coming decades, so improved understanding of the sensitivity of pastures to expected changes in rainfall will help support sustainable management of global pastures. Key Points: In Australia, pasturelands have both low resistance and low resilience relative to other regions across the worldSouthern South America has the lowest resilience globally, which is indicative of slow vegetation recovery after a disturbanceA total of 14.5% of global pasturelands experienced greening or browning trends, with the majority of these locations showing greening [ABSTRACT FROM AUTHOR]

Peatlands are carbon‐rich ecosystems that cover 185–423 million hectares (Mha) of the earth's surface. The majority of the world's peatlands are in temperate and boreal zones, whereas tropical ones cover only a total area of 90–170 Mha. However, there are still considerable uncertainties in C stock estimates as well as a lack of information about depth, bulk density and carbon accumulation rates. The incomplete data are notable especially in tropical peatlands located in South America, which are estimated to have the largest area of peatlands in the tropical zone. This paper displays the current state of knowledge surrounding tropical peatlands and their biophysical characteristics, distribution and carbon stock, role in the global climate, the impacts of direct human disturbances on carbon accumulation rates and greenhouse gas (GHG) emissions. Based on the new peat extension and depth data, we estimate that tropical peatlands store 152–288 Gt C, or about half of the global peatland emitted carbon. We discuss the knowledge gaps in research on distribution, depth, C stock and fluxes in these ecosystems which play an important role in the global carbon cycle and risk releasing large quantities of GHGs into the atmosphere (CO2 and CH4) when subjected to anthropogenic interferences (e.g., drainage and deforestation). Recent studies show that although climate change has an impact on the carbon fluxes of these ecosystems, the direct anthropogenic disturbance may play a greater role. The future of these systems as carbon sinks will depend on advancing current scientific knowledge and incorporating local understanding to support policies geared toward managing and conserving peatlands in vulnerable regions, such as the Amazon where recent records show increased forest fires and deforestation. [ABSTRACT FROM AUTHOR]

We describe new Late Miocene mammalian specimens from the Maimará Formation (Late Miocene to Early Pliocene) exposed at Humahuaca Basin (23°–24°S), northwestern Argentina (NWA), and analyse their taxonomy and relevance for our understanding of the initial stages of the Great American Biotic Interchange (GABI). The stratigraphical and geochronological control of the studied specimens indicates a time window of c. 6.6–5.8 Ma. These data are crucial for establishing the oldest records of the Holarctic immigrants of the GABI. The first record of cricetid rodents from the Maimará Formation is reported. Moreover, with an age of c. 6 Ma it is the first appearance datum (FAD) of these rodents in South America. The age of the procyonid Cyonasua recorded in this unit is estimated between c. 6.6 and c. 6.4 Ma. The record of procyonids and cricetids in the same continuous sedimentary sequence suggests that the time interval between the dispersion of both groups into the continent during GABI was c. 1 myr. Of the autochthonous mammals from the Maimará Formation, the first records of litopterns, chlamyphorid and mylodontine xenarthrans, and caviomorph rodents (including new species Pithanotomys? solisae and Palaeocavia humahuaquense) are described. FADs of immigrant and autochthonous mammals in NWA suggest a major faunal turnover during GABI at the Messinian, probably linked to global climatic changes and the tectonic activity that affected the Humahuaca Basin at that time. Hypsodonty, a dominant feature among Maimaran mammals, may be related to a landscape strongly influenced by the Andean uplift. [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]

Lightning activity has been predicted to increase with global warming, though estimates of lightning sensitivity to a change of temperature vary widely. Since lightning is a small‐scale process, it must be represented by parametrizations in climate models. This article uses large‐scale meteorological parameters tied to thunderstorm generation to improve existing empirical models that simulate regional thunderstorm behaviour. The response of the number of thunderstorms (as presented here) to climate change is rarely analysed in global studies. This study focuses on Tropical America, and uses the ERA5 higher‐resolution reanalysis data (ERA5) to develop our empirical model. Thunderstorm data were taken from the World Wide Lightning Location Network (WWLLN) and processed using the clustering algorithm developed by Mezuman et al. (2014). The two meteorological parameters that correlated best with thunderstorm clusters in Tropical America were specific humidity (SH) and convective available potential energy (CAPE). The resulting empirical model was run from 1979 to 2019 using ERA5 reanalysis data as input. This approach approximates the long‐term trends in the behaviour of thunderstorms in the regions, in the absence of a complete historical lightning record. To our surprise, Tropical American thunderstorms exhibited a negative trend over this period, with an 8% decrease in thunderstorm clusters since the 1980s even with a rise of 1 K in temperature over the same period. The regions of largest decreases in thunderstorm activity align well with estimates of deforestation. We estimate that for every 1 Tg C lost due to deforestation, there is a 10% decrease in thunderstorm number. [ABSTRACT FROM AUTHOR]

Mountains are renowned for their bountiful biodiversity. Explanations on the origin of such abundant life are usually regarded to their orogenic history. However, ancient mountain systems with geological stability also exhibit astounding levels of number of species and endemism, as illustrated by the Brazilian Quartzitic Mountains (BQM) in Eastern South America. Thus, cycles of climatic changes over the last couple million years are usually assumed to play an important role in the origin of mountainous biota. These climatic oscillations potentially isolated and reconnected adjacent populations, a phenomenon known as flickering connectivity, accelerating speciation events due to range fragmentation, dispersion, secondary contact, and hybridization. To evaluate the role of the climatic fluctuations on the diversification of the BQM biota, we estimated the ancient demography of distinct endemic species of animals and plants using hierarchical approximate Bayesian computation analysis and Ecological Niche Modelling. Additionally, we evaluated if climatic oscillations have driven a genetic spatial congruence in the genetic structure of codistributed species from the Espinhaço Range, one of the main BQM areas. Our results show that the majority of plant lineages underwent a synchronous expansion over the Last Glacial Maximum (LGM, c. 21 thousand years ago), although we could not obtain a clear demographic pattern for the animal lineages. We also obtained a signal of a congruent phylogeographic break between lineages endemic to the Espinhaço Range, suggesting how ancient climatic oscillations might have driven the evolutionary history of the Espinhaço's biota. [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]

Reference evapotranspiration (ETo) is a variable used to characterize the evaporative demand of the atmosphere and its impact on the water balance. During the last decades, significant ETo variabilities have been observed, especially at mid‐latitudes. These variabilities respond mainly to local variations in their physical drivers, such as solar radiation, vapour pressure deficit or wind speed. In this study, the annual and seasonal ETo estimates are generated using the Penman–Monteith method (FAO). Surface weather stations for the Argentine territory and reanalysis data for southern South America of the last four decades (1981–2020) are used. Contributions of both aerodynamic (ETaero) and radiative (ETrad) effects are evaluated to analyse their driving role. Significant positive ETo trends are observed from reanalysis data throughout Argentina, especially on the central east side of the Andes Mountain range with values up to 10 mm·year−1. Most of these ETo changes respond to positive trends in air temperature in the study area, while those in the central Andes also respond to negative trends in dew point temperatures. On the other hand, the increase in energy availability through positive trends in net surface radiation produced a slightly higher ETo in the northern regions of the country. Regional ETo values have shown to be more sensitive to variations in air temperature in the northeastern areas, although changes in humidity and solar radiation could also play a role. In a context of climate change, given that temperature and rainfall are expected to increase in the central and northeastern region of the country and decrease along the eastern side of the Andes Mountains in the coming decades, the characteristics observed over the 1981–2020 period are expected to intensify in the near future. [ABSTRACT FROM AUTHOR]

The representation of the South American Monsoon System (SAMS) by general circulation models (GCMs) is of key relevance for a better understanding of the physical rationale behind the recent climate changes over South Tropical South America (STSA) and their expected changes in a global warming scenario. During the last four decades, STSA experienced a lengthening of the dry season associated with diverse forcings. In this work, a set of 16 GCMs historical Coupled Model Intercomparison Project Phase 6 coupled simulations were evaluated during 1979–2014 in terms of how well they reproduced the atmospheric circulation over STSA through a circulation‐patterns (CPs) approach. Nine CPs were first identified based on low‐level winds from the ERA5 reanalysis. Focus was put on the representation of CPs during the dry‐to‐wet transition season (July‐October). Model performance depended on the seasonal cycle and spatial structure of the CPs. GCMs adequately reproduced the different CPs, with lower skills in the transition seasons. GCMs tended to go from dry to wet conditions too quickly, evidencing deficiencies in the representation of the SAMS onset, related to a poor representation of the southerly wind intrusions to STSA and the variability of the South American low‐level jet. Some GCMs were able to associate the occurrence of anomalous dry and wet years with specific CPs, suggesting well‐represented physical mechanisms controlling precipitation variability. This study could identify a few GCMs that adequately simulated the CPs in STSA (among them, CESM2, CMCC‐CM2‐HR4 and MPI‐ESM1‐2‐HR), which is relevant for driving high‐resolution models and the analysis of future projections. Key Points: Some general circulation models (GCMs) adequately represented both the seasonal cycle and spatial structure of circulation patternsGCMs often struggled in representing the monsoon initiation and the variability of the South American low‐level jetGCMs tended to go from dry to wet conditions too quickly [ABSTRACT FROM AUTHOR]

Aim: The interconnectedness and biotic interchange among Neotropical biomes are thought to play an important role in driving adaptation and diversification. However, how these processes are in synteny to trait evolution in species of open and xeric areas is poorly studied. Here, we investigate the spatial and temporal dimensions of evolution and candidate traits associated with biome shifts in xeric vegetation, focusing on the family Cactaceae. Location: Xeric and open areas of South America. Taxon: Genus Cereus Mill. (Cactaceae, Cereeae). Methods: We applied biogeographical reconstructions on a time-calibrated phylog- eny inferred from multilocus data (ddRAD-Seq) using Bayesian analyses on BEAST2, species distribution modelling in Maxent, the reconstruction of biome affinities and niche shift analyses based on abiotic traits (climate and soil) using Mk-model in BioGeoBEARS, and phenotypic trait-based analysis in Mesquite. Results: The Cerrado domain is the ancestral area of Cereus, with most diversification events occurring in a time of intense orogenesis, climatic changes, and marine regressions within the last 5 Mya. Events of biome transition from the seasonally dry tropical forest (SDTF) were also associated with trait and niche shifts. Main conclusions: The diversification of the xerophyte genus Cereus is associated with the climatic and geomorphological instabilities of the Pliocene and Pleistocene epochs. The Cerrado domain states an important region of dispersal for the genus. Some geographical range movements involved biome shifts associated with niche evolution while others were restricted to a simple biogeographical transition without niche change. Particular clades that experienced biome shifts displayed some phenotypic state changes, suggesting a role of biotic traits for environment transition. The results observed in Cereus may be a biogeographical pattern that should be tested with other cactus species, such as Pilosocereus spp., or species of xeric habitats, such as Annonaceae and Vochysiaceae. [ABSTRACT FROM AUTHOR]

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

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

Aim: Biological invasions represent one of the main anthropogenic drivers of global change with a substantial impact on biodiversity. This impact can be particularly acute in biodiversity hotspots. Ligustrum lucidum W.T. Aiton is a tree species native of China that, from as early as the eighteenth century, has been introduced broadly around the globe, becoming a serious invasive species. We aim to predict L. lucidum's current and future potential distributions at a global scale and assess the degree to which biodiversity hotspots are at risk of invasion. Location: All continents. Methods: Using global presence data, climatic and edaphic variables, we developed an ensemble model to predict current and future periods (2050 and 2080) global distribution of L. lucidum. Susceptible countries and hotspots of biodiversity were identified. Results: Important regions within China and neighbouring countries are likely to be environmentally suitable, but they are not currently occupied. Biodiversity hotspots in South America are highlighted as being at current risk of invasion. Notably, climate change may increase risks across large extents of biodiversity hotspots, mainly in South America and Africa, especially by 2080 period. Main conclusions: Current and future potential distribution of L. lucidum overlaps with biodiversity hotspots worldwide. Control of L. lucidum is a challenge once established. Thus, species distribution modelling helps to identify risk areas, guiding their early detection in current or future suitable areas. Our findings can be useful as a guide to develop region‐specific invasion management strategies to prevent and/or control this species' spread. [ABSTRACT FROM AUTHOR]

Aim: Future climate changes may affect species distribution and their genetic diversity, hampering species adaptation to a new climate or tracking the suitable conditions. Amphibians have high sensitivity to environmental degradation and changes in temperature and humidity. Thus, the expected climatic changes by the end‐of‐century (EOC 2100) may cause local or complete extinction of some species. Here, we address the effects of climate change on genetic and phylogeographical diversity, together with the geographical distribution of the South American treefrog Scinax squalirostris Lutz, 1925. Furthermore, we assess how protected areas will conserve its genetic variation. Location: South America. Methods: We combined Ecological Niche Modelling and genetic simulations to predict the effects of climate change on the geographical distribution, genetic diversity, structure and phylogeographical diversity of Scinax squalirostris, using two scenarios of CO2 emission. We also performed a spatial analysis to investigate the effectiveness of the current Protected Areas (PAs) to preserve the species' genetic and phylogeographical diversity. Results: Scinax squalirostris' geographical range will potentially increase in the future due to the expansion of suitable areas towards its southern distribution, despite the shrinking of suitable areas in the northern part of its current distribution. Besides the shifts in suitable areas, our findings point to a genetic homogenization across the geographical range of S. squalirostris due to the displacement and loss of genetic ancestry clusters. Although existing PAs are conserving the current genetic diversity, they conserve less phylogeographical diversity than expected by chance. Scinax squalirostris may shift its distribution into areas with lower number of PAs, compromising its future conservation. Main conclusions: Climate change will potentially increase S. squalirostris range size, however, not towards regions where most of the current established PAs are located, hence driving to homogenization and loss of genetic diversity, and leading to a gap of conservation within PAs. [ABSTRACT FROM AUTHOR]

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

Aim: Global changes will redistribute biodiversity, reshaping ecological interactions and ecosystem processes. The decoupling in the distribution of plants and their mutualistic seed dispersers, for instance, may have overlooked eco‐evolutionary effects. How animal‐dispersed plants will respond to changes in the distribution of their seed dispersers remains largely an open question. Here, we forecast the consequences of climate change and frugivory interactions for the spatial distribution and seed size evolution of a Neotropical palm species. Location: Atlantic forests of South America. Time period: Present day, end of 21st century. Major taxa studied: Thirty‐two species of frugivorous birds, and a palm (Euterpe edulis). Methods: Future patterns of animal–plant co‐occurrence were derived from ecological niche models, climate forecasts, projections of future forest loss, and seed dispersal simulations. We further explored the evolutionary effect of the spatial reorganization of interactions by modelling palm seed sizes as a function of changes in the distribution of frugivore traits. Results: Our models indicate that future climate change and deforestation may reduce the palm's suitable distribution by 20%–50%. However, our simulations suggest that 66% of all remaining future suitable distribution (76,200 km2) would still be inaccessible to the palm without the active dispersal of seeds by frugivores. In addition, novel frugivore communities are projected to have smaller mean body mass and gape size (−23% and −10%, respectively), due to the loss of large frugivores, which may translate into a 6%–17% reduction of seed sizes across the palm's remaining distribution. Main conclusions: Our projections indicate that frugivore seed dispersal may be critical to allow occupancy of future habitat by animal‐dispersed plants. However, loss of large frugivores may affect trait selection regimes, creating hotspots of plant evolution towards smaller seeds. We argue that such complex dynamics emerging from species‐specific responses to global change may reshape the distribution and evolution of several interacting partners worldwide. [ABSTRACT FROM AUTHOR]

Aim: Forest composition and distribution are determined by a myriad of factors, including climate. As models of tropical rain forest, palms are often used as indicator taxa, particularly the Mauritiinae. We question, what characterizes the Mauritiinae pollen in the global fossil record? And when did the Mauritiinae become endemic to South America? Location: Global tropics. Taxon: Mauritiinae palms (Arecaceae: Lepidocaryeae). Methods: Pollen trait data from extinct and extant Mauritiinae pollen were generated from light‐, scanning‐, and transmission electron microscopy. Statistical morphometric analysis was used to define species and their relationships to other Mauritiinae. We also compiled a comprehensive pollen database for extinct and extant Mauritiinae and mapped their global geographical distribution from Late Cretaceous to present, using GBIF and fossil data. Results: Our morphometric analysis identified 18 species (11 extinct and seven extant), all exhibiting exine indentations, a synapomorphy of the subtribe. The fossil taxa and early divergent extant Lepidocaryum are all monosulcate, whereas the extant Mauritia and Mauritiella species are all monoulcerate. Paleobiogeographical maps of fossil Mauritiinae pollen occurrences suggest the taxon originated in equatorial Africa during the Cretaceous, and expanded their range to South America, and to India in the Paleocene. Range retraction started in the early Eocene with extirpation from India, and reduction in diversity in Africa culminating at the Eocene–Oligocene Transition (EOT). In contrast, in South America, the distribution is maintained, and since the Neogene Mauritiinae palms are mostly restricted to swampy, lowland habitats. Main conclusions: Morphometric analysis shows that since their origin Mauritiinae pollen are relatively species poor, and Mauritiidites resembles Lepidocaryum. We also conclude that the biogeographical history of the Mauriitinae and, by extension, tropical forests was strongly affected by global climatic cooling events. In particular, the climate change at the EOT was a fundamental determinant of current tropical forest distribution. [ABSTRACT FROM AUTHOR]

Climatic change effects on crop yields are expected to be crop- and site specific. Here, Decision Support System for Agrotechnology Transfer models were used to evaluate climatic change effects and mitigation strategies on maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] yields in soils of the subtropical and semi-arid region of Chaco. Simulations were performed for the DK747 and A8000 genotypes, calibrated for the CERES-Maize model in a previous report and for the CROPGRO-Soybean model in the present study, respectively. Both crops markedly differ in their response to climatic change and putative levels of atmospheric CO2 concentration. The observed significant reductions in maize yields in future climate scenarios (5-42% compared with the baseline, 1986-2010) were more associated with increased temperatures that shortened the crop cycle than with water stress. Delaying the sowing date is a feasible strategy to mitigate this effect. Projected temperature increases are expected to play a secondary role in determining soybean yields. Instead, water stress will continue to be an important constraint to soybean yield in the context of global warming, but this effect is strongly affected by rainfall regimes. Responses to raising CO2 levels were more pronounced in soybean (+10-40%) than in maize (+2-4%). Soil degradation exacerbated the negative effects of global warming on crop yields, especially on maize, which highlights the importance of soil conservation practices. The observed high interannual climatic variability and the different sensitivities of maize and soybean to climatic variables indicate that crop diversification would be the key to improve the resilience of the agrosystems under the future scenarios. [ABSTRACT FROM AUTHOR]

The purpose of this study is to assess the ability of a set of large ensembles (LE) of Global Climate Model (GCM) simulations from the Multi‐Model Large Ensemble Archive, Coupled Model Intercomparison Project Phase 6 (CMIP6) and database for Policy Decision making for Future climate change in reproducing the variability and change of the austral summer precipitation observed in South America along the second part of the 20th century and beginning of the 21st. LE show similar biases in the mean austral summer rainfall and interannual variability than those detected in previous model sets, such as the Coupled Model Intercomparison Project Phase 5 (CMIP5). The positive trends in south‐eastern South America (SESA) and negative ones in the southern Andes (SAn), that are the most significant observed regional features, are identified to some extent in LE simulations. The negative trend in SAn is a feature consistently shown among different models. For all models, mean trend is negative in that particular region and larger than the inter‐member dispersion for each large ensemble. Trend magnitudes in the SESA region show a larger dispersion between models than the SAn region. While the mean trend among models is consistent with the observations, models underestimate the observed trend. The multi‐model ensemble of selected models that best reproduce both mean and interannual variability features of rainfall in South America shows an 18% larger positive mean trend in SESA rainfall than those that have the worst performance. However, internal variability uncertainty is still higher than the mean trend for both sets of multi‐model ensembles [5% (18%) for selected (non‐selected) models]. Improvements in the representation of the main features of mean rainfall and variability are needed in order to better describe and reduce the uncertainties associated with the main climate change related signals in the continent. [ABSTRACT FROM AUTHOR]

Assessing the regional and local impacts of climate changes on rainfall and streamflow patterns is often challenging, as most results tend to be very dispersed and inconsistent across models. We offer a complementary alternative for climate change impact studies by focusing primarily on climate indices. In particular, we analyse the historical and future variability of key climate indices associated with the South America Monsoon System (SAMS) as simulated by Coupled Model Intercomparison Project—Phase 5 (CMIP5) models. We use climate indices related to the tropical Atlantic interhemispheric surface temperature gradient, associated with the meridional position of the Intertropical Convergence Zone (ITCZ), as well as the land‐ocean temperature contrast in the tropical Atlantic‐South America region, and the intensity and position of the South Atlantic Subtropical High (SASH). We selected 14 CMIP5 models to estimate climate indices for the retrospective period (1980–2005) and future period (2006–2099), the latter under the RCP 4.5 and RCP 8.5 scenarios. For comparison purposes during the retrospective period, the indices were also calculated using data from the Era‐Interim reanalysis. The seasonal behaviour of the Era‐Interim based indices is well reproduced by CMIP5 models, although the magnitude is significantly higher. For the future period, most models under both scenarios showed a consistent and asymmetrical intensification of the dipole index, suggesting, in a future climate, a potential wider displacement of the ITCZ during its seasonal cycle. As for the land‐ocean contrast index, the CMIP5 simulations indicated consistent increase in the magnitude for the positive phase (land warmer than ocean) and a decrease for the negative phase (land colder than ocean). Finally, CMIP5 models consistently predict a strengthening and southward displacement of the SASH centre. To the best of our knowledge, this is the first study to reveal future changes in climate indices associated with the SAMS that shows relevant coherences across models and scenarios. [ABSTRACT FROM AUTHOR]

Humans have fragmented, reduced or altered the biodiversity in tropical forests around the world. Climate and land‐use change act synergistically, increasing drought and fire frequencies, converting several tropical rainforests into derived savannas, a phenomenon known as "savannization." Yet, we lack a full understanding of the faunal changes in response to the transformation of plant communities. We argue that the composition of vertebrate assemblages in ecotone regions of forest–savanna transitions from South America will be increasingly replaced by open savanna species, a phenomenon we name "faunal savannization." We combined projections from ecological niche models, habitat filter masks and dispersal simulations to forecast the distribution of 349 species of forest‐ and savanna‐dwelling mammal species across South America. We found that the distribution of savanna species is likely to increase by 11%–30% and spread over lowland Amazon and Atlantic forests. Conversely, forest‐specialists are expected to lose nearly 50% of their suitable ranges and to move toward core forest zones, which may thus receive an influx of more than 60 species on the move. Our findings indicate that South American ecotonal faunas might experience high rates of occupancy turnover, in a process parallel to that already experienced by plants. Climate‐driven migrations of fauna in human‐dominated landscapes will likely interact with fire‐induced changes in plant communities to reshape the biodiversity in tropical rainforests worldwide. [ABSTRACT FROM AUTHOR]

Analyses of biota at lower latitudes may presage impacts of climate change on biota at higher latitudes. Macroinvertebrate assemblages in depressional wetlands may be especially sensitive to climate change because weather‐related precipitation and evapotranspiration are dominant ecological controls on habitats, and organisms of depressional wetlands are temperature‐sensitive ectotherms. We aimed to better understand how wetland macroinvertebrate assemblages were structured according to geography and climate. To do so, we contrasted aquatic‐macroinvertebrate assemblage structure (family level) between subtropical and temperate depressional wetlands of North and South America using presence–absence data from 264 of these habitats across the continents and more‐detailed relative‐abundance data from 56 depressional wetlands from four case‐study locations (North Dakota and Georgia in North America; southern Brazil and Argentinian Patagonia in South America). Both data sets roughly partitioned wetland numbers equally between the two climatic zones and between the continents. We used ordination methods (PCA and NMDS) and tests of multivariate dispersion (PERMDISP) to assess the distribution and the homogeneity in variation in the composition of macroinvertebrate assemblages across climates and continents, respectively. We found that macroinvertebrate assemblage structures in the subtropical depressional wetlands of North and South America were similar to each other (at the family level), while assemblages in the North and South American temperate wetlands were unique from the subtropics, and from each other. Tests of homogeneity of multivariate dispersion indicated that family‐level assemblage structures were more homogeneous in wetlands from the subtropical than the temperate zones. Our study suggests that ongoing climate change may result in the homogenization of macroinvertebrate assemblage structures in temperate zones of North and South America, with those assemblages becoming enveloped by assemblages from the subtropics. Biotic homogenization, more typically associated with other kinds of anthropogenic factors, may also be affected by climate change. [ABSTRACT FROM AUTHOR]

The Piacenzian (3.60–2.58 Ma) covers the last stage of the Neogene just before the Earth's climate turned from relatively stable warm conditions to the cooler climate with high amplitude glacial‐interglacial oscillations of the Pleistocene. Even during this period early fluctuations towards cooler conditions occurred, and sea surface temperature (SST) reconstructions show stepwise increasing gradients. The zonal Pacific SST gradient which indicates the strength of the Walker circulation appears to have increased in two steps starting in the Piacenzian. We investigated vegetation and climate change in western equatorial South America under the influence of the Walker circulation and to detect signs for the onset of cooling in the tropics. We studied vegetation changes in western Ecuador using palynological analysis of 88 sediment samples from marine Ocean Drilling Program Site 1239 dated between 3.9 and 2.7 Ma. A general trend towards more open vegetation is observed. The climate changes towards cooler conditions, which is manifested by a lowering of the forest line from 3.3 Ma on. The increase of Amaranthaceae pollen after 3.1 Ma suggests drier conditions along the coast. A comparison with mid‐Piacenzian warm period (mPWP) modeling shows that data and models agree regarding a drier coastal climate during the mPWP. The isochronous occurrence of environmental changes in the presented record, that is, cooling and coastal drying, with the first major pulse of ice‐rafted debris and cooling temperatures in the Northern Hemisphere (between 3.28 and 3.31 Ma) suggests that these changes might have been a precursor of the intensification of the Northern Hemisphere glaciation. Plain Language Summary: Around 3.6 to 2.6 million years ago was a time in Earth's history when many conditions were similar to today like the arrangement of the continents, vegetation, and greenhouse gas concentrations. However, the Arctic was not yet covered by ice sheets, and the global climate was warmer, making this time period well suited to study the drivers and mechanisms of warm climates. Towards the end of this period, global climate started to cool, which is known mainly from Northern Hemisphere climate reconstructions. We wanted to find out if cooling and drying conditions found in other records also occurred in the South American tropics. Fossil pollen assemblages preserved in marine sediments can tell us which plants grew in our study area (broadly western Ecuador). Since plants have different (known) climatic requirements, we can reconstruct past rainfall and temperatures as well. We find cooling and drying of neotropical climate, possibly linked to the period preceding the intensification of the Northern Hemisphere glaciations. Studying past climates can help us to better understand and constrain present and future climate developments. Key Points: We present a marine pollen record of climate and vegetation change in western equatorial South America during the PiacenzianFrom around 3.3 Ma, the vegetation became more open, the climate became cooler and the coastal area became drierThe inferences from the pollen record are in agreement with climate modeling results for the mid‐Piacenzian warm period [ABSTRACT FROM AUTHOR]

The jaguar (Panthera onca) is the dominant predator in Central and South America, but is now considered near‐threatened. Estimating jaguar population size is difficult, due to uncertainty in the underlying dynamical processes as well as highly variable and sparse data. We develop a stochastic temporal model of jaguar abundance in the Peruvian Amazon, taking into account prey availability, under various climate change scenarios. The model is calibrated against existing data sets and an elicitation study in Pacaya Samiria. In order to account for uncertainty and variability, we construct a population of models over four key parameters, namely three scaling parameters for aquatic, small land, and large land animals and a hunting index. We then use this population of models to construct probabilistic evaluations of jaguar populations under various climate change scenarios characterized by increasingly severe flood and drought events and discuss the implications on jaguar numbers. Results imply that jaguar populations exhibit some robustness to extreme drought and flood, but that repeated exposure to these events over short periods can result in rapid decline. However, jaguar numbers could return to stability—albeit at lower numbers—if there are periods of benign climate patterns and other relevant factors are conducive. [ABSTRACT FROM AUTHOR]

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Aim: Previous work demonstrated the global variability of synchrony in tree growth within populations, that is, the covariance of the year‐to‐year variability in growth of individual neighbouring trees. However, there is a lack of knowledge about the causes of this variability and its trajectories through time. Here, we examine whether climate can explain variation in within‐population synchrony (WPS) across space but also through time and we develop models capable of explaining this variation. These models can be applied to the global tree cover under current and future climate change scenarios. Location: Global. Time period: 1901–2012. Major taxa studied: Trees. Methods: We estimated WPS values from a global tree‐ring width database consisting of annual growth increment measurements from multiple trees at 3,579 sites. We used generalized linear mixed effects models to infer the drivers of WPS variability and temporal trends of global WPS. We then predicted WPS values across the global extent of tree cover. Finally, we applied our model to predict future WPS based on the RCP 8.5 (2045–2065 period) emission scenario. Results: Areas with the highest WPS are characterized by a combination of environments with both high mean annual temperature (>10°C) and low precipitation (<300 mm). Average WPS across all temperate forests has decreased historically and will continue to decrease. Potential implications of these patterns include changes in forest dynamics, such as higher tree growth and productivity and an increase in carbon sequestration. In contrast, the WPS of tropical forests of Central and South America will increase in the near future owing to reduced annual precipitation. Main conclusions: Climate explains WPS variability in space and time. We suggest that WPS might have value as an integrative ecological measure of the level of environmental stress to which forests are subjected and therefore holds potential for diagnosing effects of global climate change on tree growth. [ABSTRACT FROM AUTHOR]

Premise: Eocene floras of Patagonia document biotic response to the final separation of Gondwana. The conifer genus Araucaria, distributed worldwide during the Mesozoic, has a disjunct extant distribution between South America and Australasia. Fossils assigned to Australasian Araucaria Sect. Eutacta usually are represented by isolated organs, making diagnosis difficult. Araucaria pichileufensis E.W. Berry, from the middle Eocene Río Pichileufú (RP) site in Argentine Patagonia, was originally placed in Sect. Eutacta and later reported from the early Eocene Laguna del Hunco (LH) locality. However, the relationship of A. pichileufensis to Sect. Eutacta and the conspecificity of the Araucaria material among these Patagonian floras have not been tested using modern methods. Methods: We review the type material of A. pichileufensis alongside large (n = 192) new fossil collections of Araucaria from LH and RP, including multi‐organ preservation of leafy branches, ovuliferous complexes, and pollen cones. We use a total evidence phylogenetic analysis to analyze relationships of the fossils to Sect. Eutacta. Results: We describe Araucaria huncoensis sp. nov. from LH and improve the whole‐plant concept for Araucaria pichileufensis from RP. The two species respectively resolve in the crown and stem of Sect. Eutacta. Conclusions: Our results confirm the presence and indicate the survival of Sect. Eutacta in South America during early Antarctic separation. The exceptionally complete fossils significantly predate several molecular age estimates for crown Eutacta. The differentiation of two Araucaria species demonstrates conifer turnover during climate change and initial South American isolation from the early to middle Eocene. [ABSTRACT FROM AUTHOR]

This study assesses the evolution of major anthropogenic drivers of environmental impacts on Neotropical mangroves, the changes in the environmental pressures acting upon them, and the respective societal responses during the past 40 years. It reviews the impacts of new drivers, in particular those resulting from global climate change and the expansion in aquaculture and the effectiveness of local societal responses aimed at addressing them.Adaptation and mitigation actions are proposed to cope with the impacts and their socio‐economic consequences for Latin America and Caribbean mangroves. By comparing the situation in Latin America and the Caribbean with other regions, the knowledge gaps and priority research needs are discussed to support delineating a preliminary unifying framework to address the environmental pressures affecting mangroves.This scenario necessarily includes the interaction of climate change with human interventions and their effects on ecosystem goods and services, as well as their respective adaptation and management options. Results show that drivers of environmental impacts have changed in the past 40 years, reducing the effectiveness of some important societal responses towards conservation and sustainable management with a great potential to increase rates of mangrove deforestation and conversion to human uses.Although efforts in conservation and restoration have contributed to decreasing pressure on these ecosystems, the coupling of old drivers, such as damming, with climate change, and the appearance of new drivers in the region, such as shrimp aquaculture, may eclipse the gains made through these conservation efforts. Despite the negative trend, we discuss some successful efforts to curb negative impacts of human activities on mangroves.We also recommend regional assessments based on primary sources in the representative mangrove‐bearing countries throughout the continent to allow the upscaling of their experiences towards a regional response to the challenges facing Neotropical mangrove conservation and sustainable use. [ABSTRACT FROM AUTHOR]

The use of bioclimatic models to predict areas subject to invasion by exotic species has been important in the development of preventive conservation measures. The native New Zealand mudsnail Potamopyrgus antipodarum is an invasive mollusc, now with a worldwide distribution, that causes economic and ecological problems in invaded areas and has recently been designated as one of the 100 worst invasive species in Europe.In this study we sought to determine the potential distribution of and areas susceptible to invasion by P. antipodarum in South America and worldwide, in present and future scenarios (2070), using MaxEnt models. The models were developed using georeferenced occurrence data and bioclimate and hydroclimate variables to predict scenarios of the geographical distribution of P. antipodarum. Possible routes of invasion into South America were predicted.Present‐day scenario of the worldwide distribution (all known occurrences) of P. antipodarum, based on the bioclimatic and hydroclimatic models, are highly accurate, with area under curve higher than of 0.87. The models indicated that environmentally suitable areas exist in South America and in other regions of the world where the species has not yet been recorded. The predicted susceptibility includes approximately 80 protected areas in the South American continent.Models projected in an optimistic and pessimistic future scenario, based on the worldwide distribution, show increased environmental suitability of regions outside the current species distribution, including Brazil (south‐west), Uruguay (near Mirim Lagoon), Nigeria, Ethiopia (lakes Tana and Chomen), Tanzania, Cameroon (bordering lakes Bamendjing, Bankim, and Mbakaou), Equatorial Guinea, Congo, Rwanda, Burundi (Lake Tanganyika environs), Uganda, Tanzania (Naivasha), and South Africa (surrounding Gordon's Bay).The main vector for dispersal to South America would be ballast water coming from waterways and ports located in the predicted areas. Fish farming is also a possible route, since the mudsnail is resistant to the digestive tract of rainbow trout (Oncorhynchus mykiss). Current records and predicted susceptible areas coincide with port areas and sites where this fish is farmed.Geographical distribution modelling proved to be helpful in identifying environmentally suitable areas for the invasion of P. antipodarum. The model also suggests a future expansion of the species distribution, possibly affected by climate change. [ABSTRACT FROM AUTHOR]

The responses of forest communities to interacting anthropogenic disturbances like climate change and logging are poorly known. Subtropical forests have been heavily modified by humans and their response to climate change is poorly understood. We investigated the 9‐year change observed in a mixed conifer‐hardwood Atlantic forest mosaic that included both mature and selectively logged forest patches in subtropical South America. We used demographic monitoring data within 10 1 ha plots that were subjected to distinct management histories (plots logged until 1955, until 1987, and unlogged) to test the hypothesis that climate change affected forest structure and dynamics differentially depending on past disturbances. We determined the functional group of all species based on life‐history affinities as well as many functional traits like leaf size, specific leaf area, wood density, total height, stem slenderness, and seed size data for the 66 most abundant species. Analysis of climate data revealed that minimum temperatures and rainfall have been increasing in the last few decades of the 20th century. Floristic composition differed mainly with logging history categories, with only minor change over the nine annual census intervals. Aboveground biomass increased in all plots, but increases were higher in mature unlogged forests, which showed signs of forest growth associated with increased CO2, temperature, and rainfall/treefall gap disturbance at the same time. Logged forests showed arrested succession as indicated by reduced abundances of Pioneers and biomass‐accumulators like Large Seeded Pioneers and Araucaria, as well as reduced functional diversity. Management actions aimed at creating regeneration opportunities for long‐lived pioneers are needed to restore community functional diversity, and ecosystem services such as increased aboveground biomass accumulation. We conclude that the effects of climate drivers on the dynamics of Brazilian mixed Atlantic forests vary with land‐use legacies, and can differ importantly from the ones prevalent in better known tropical forests. [ABSTRACT FROM AUTHOR]

The bias correction of the General Circulation Model (GCM) outputs has become a routine step that is taken in climate change impact assessments. To responsibly support the decision‐making processes, the climate‐modeling community has been debating about the conceptual requirements that bias‐correction methods should fulfill. Bearing in mind these requirements, we propose to decompose atmospheric variables into three temporal elements that represent the climate mean state, the interannual variability, and the daily variability. This decomposition is aimed at correcting the biases at one time scale without affecting the simulated climate (mean state) trend or the distributional properties at other time scales. The novelty of the proposed approach is, nevertheless, marked by the adjustment of interannual and daily variability that is made by replacing the GCM‐simulated data with synthetic samples drawn from Stable Distributions (SDs) that are fitted to the observed variability. The replacement prevents the transfer of the sampling variability of the calibration period and gives the corrected data the distributional properties of the observed climate. The employment of SDs was motivated by the fact that the climate‐change‐induced changes in the scale, the symmetry, and the frequency of extremes can be measured and applied to the SDs of the observed data. We correct the biases in the GCM‐simulated temperature and precipitation over northern South America using our proposed approach and two other existing ones. Our proposed method is capable of not only preserving the simulated climate trends but also reproducing the observed extremes as well as a more flexible method based on nonparametric distributions. Key Points: We decompose GCM's daily time series into terms that represent the climate mean state, the interannual variability, and the daily variabilityWe replace the modeled daily variability using trend‐preserving synthetic samples that are drawn from stable distributionsThe mathematical properties of stable distributions allow the inclusion of simulated climate change in the correction process [ABSTRACT FROM AUTHOR]

We investigated spatial patterns of evolutionary relatedness and diversification rates to test hypotheses about the historical biogeographic processes underlying the radiation of Neotropical rats and mice (Sigmodontinae, ~400 species). A negative correlation between mean phylogenetic distance and diversification rates of rodent assemblages reveals a pattern of species co‐occurrence in which assemblages of closely related species are also the fastest diversifying ones. Subregions of the Neotropics occupied by distantly related species that are on average more slowly diversifying include Central America, northern South America, and the Atlantic forest. In southern South America, recent species turnover appears to have been higher. Ancestral locations for the main tribes of sigmodontines were also estimated, suggesting eastern South America and the Amazonian lowlands were colonized before some central Andean regions, even though the latter are now centers of species richness for these rodents. Moreover, a past connection between the tropical Andes and the Atlantic Forest is suggested by our results, highlighting a role for a hypothetical arc connecting the two biomes, which would have impacted many other groups of organisms. Whether rapid, recent speciation in some regions is related to Quaternary climatic fluctuations and the young age of sigmodontines (~12.7 Ma crown age) or instead to intrinsic traits of these rodents remains an open question. If the former is true, we hypothesize that contrasting trends will characterize older Neotropical clades. [ABSTRACT FROM AUTHOR]

Global climate models (GCMs) have, in general, problems representing precipitation over southern southeastern South America (SSESA), namely southern Brazil, Uruguay and eastern Argentina. In this study, 18 models were selected from the Coupled Model Inter‐comparison Project Phase 5 to evaluate rainfall of the warm semester (October–March) when most of the rain takes place. Though GCMs reproduce the main features of the two main low‐level circulation variability modes over southeastern South America, east of the Andes, particularly the two flow patterns associated with the active and weak SACZ, most of them underestimate the northern flow that brings water vapour into SSESA, as well as the mean precipitation in this region. According to an index that stands for the northern flow towards SSESA, all models, except one, have lower northern flow into SSESA than the observed reanalysis field. In addition, this index has a significant correlation across GCMs with mean SSESA precipitation, indicating that lower northern flow into SSESA is generally associated with a greater underestimation in the model precipitation. Hence, it is concluded that the weaker northern flow into SSESA simulated by most GCMs is a cause of their simulated lower precipitation in this region. Though Global climate models (GCMs) reproduce the main features of the low‐level circulation variability field over southeastern South America (SESA) and of the surrounding region, most of them underestimate the northern flow that brings water vapor into this region. Since, there is a significant correlation across GCMs between the underestimation of this flow and the average SESA precipitation, it is concluded that underestimation of the northern flow into SESA is one cause of the precipitation deficit by GCMS over this region. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Niche properties, such as breadth and position along environmental gradients, are hypothesized to determine plant responses to climate change. We explored the properties of different plant niches in a biodiversity hotspot, over a wide span of elevational and latitudinal ranges, to assess the relationship between niche characteristics and the modelled distributional shifts due to climate change. Location: South American temperate forests. Methods: We assessed the niche breadth and position of 118 plant species of South American temperate forests, using an Outlying Mean Index (OMI). Bioclimatic information was gathered for each species from WorldClim, and both present and future distributions were modelled using BIOMOD, considering migration constraints with MIGCLIM. The relationships between niche properties and shifts in elevational and latitudinal distributions were explored using linear regressions. Results: Niche differences among species were related to two bioclimatic dimensions: the first one correlated with the mean diurnal temperature range and precipitation seasonality following the mediterranean—temperate—sub‐Antarctic climatic gradient; the second one correlated with minimum winter temperature along a gradient from oceanic‐influenced habitats to cold tree line habitats. The projected elevational shifts were inversely related to niche breadth and the forecast latitudinal shifts were directly related to niche breadth. The shifts in elevation and latitude for understorey plants were not consistent with the shifts of dominant trees. Main conclusions: The plant niches were successfully discerned by OMI analyses and they were associated with specific morphological or physiological traits. South American temperate forest plants showed an inverse relationship between niche breadth and elevational shifts, but a positive relationship regarding expected latitudinal shifts. This may be related to the fact that niche drivers followed a latitudinal orientation and the species showed the Rapoport's effect. Thus, the niche breadth and latitudinal position of the species should be considered in climatic change studies. [ABSTRACT FROM AUTHOR]

Ecosystems where carbon fluxes are being monitored on a global scale are strongly biased toward temperate Northern Hemisphere latitudes. However, forest and moorland ecosystems in the Southern Hemisphere may contribute significantly to the global and regional C balance and are affected by different climate systems. Here, we present the first data from an old-growth forest representative of temperate, broad-leaved rainforests from southern South America. Carbon fluxes monitored over two years using the eddy covariance technique showed that this rainforest acts as an annual sink (-238 ± 31 g C/m²). However, there were significant pulses of carbon emission associated with dry episodes during the summer months (i.e., peak of the growing season) and periods of significant carbon fixation during the cold austral winter, indicating that the carbon balance in this forest is very sensitive to climate fluctuations. The carbon fixation surges in winter seem to be related to the mild temperatures recorded during this period of the year under the prevailing oceanic climate. Winter carbon gain was more relevant in determining the annual carbon balance than summer pulse emissions. Regarding the annual carbon balance, this southern forest resembles the patterns observed in montane tropical forests more than the behavior of narrow-leaved evergreen temperate forests from the Northern Hemisphere. These patterns make this southern forest type relevant to understanding the mechanisms and thresholds that control ecosystem shifts from carbon sinks and sources and will provide key data to improve global dynamic vegetation models. [ABSTRACT FROM AUTHOR]

ABSTRACT The dominant seasonal surface air temperature ( SAT) anomalous modes over entire South America ( SA) for the 1951-2010 period were investigated. The El Niño-Southern Oscillation ( ENSO) and non- ENSO (residual - RES) characteristics of the SAT anomalous modes and the associated precipitation and temperature advection anomalies were discussed. The SAT (referred to as TOT) and RES modes were obtained from the empirical orthogonal function analyses, and the ENSO modes from the correlation analyses between the SAT anomalies and the Oceanic Niño index. The SAT TOT modes are in general, weakly linked to the ENSO, except for the first summer and the fourth spring TOT modes. For these two modes, the precipitation variations are more crucial than the temperature advection variations in defining the SAT anomaly patterns. On the other hand, the first winter and autumn TOT modes contain mostly the non- ENSO components and feature an extensive warmed area in tropical and subtropical SA. For these modes, the subtropical warming is due to the temperature advection. The TOT modes with a weak relation to the ENSO and the corresponding RES modes show a dipolar pattern with a warm node in tropical SA and the cold one in extratropical SA, and is determined mostly by the precipitation. Nevertheless, the cold advection reinforces the cold node of the winter and summer modes. In some cases, the regional systems contribute to the SAT anomalies. The South American low-level jet contributes to the positive SAT anomalies in central and eastern Brazil for the second winter and first spring RES modes and the South Atlantic Convergence Zone influences the first summer RES mode. The SAT modes describe mostly the interannual variations of the SAT patterns over SA, but some of them also contain decadal and multidecadal time scale variations. [ABSTRACT FROM AUTHOR]

Here we review the literature preferentially concerned with modern glacier-climate modeling along the Andes. We find a diverse range of modeling approaches, from empirical/statistical models to relatively complex energy balance procedures. We analyzed these models at three different spatial scales. First, we review global approaches that have included the Andes. Second, we depict and analyze modeling exercises aimed at studying Andean glaciers as a whole. Our revision shows only two studies dealing with glacier modeling at this continental scale. We contend that this regional approach is increasingly necessary because it allows for connecting the 'average-out' tendency of global studies to local observations or models, in order to comprehend scales of variability and heterogeneity. Third, we revise small-scale modeling, finding that the overwhelming number of studies have targeted glaciers in Patagonia. We also find that most studies use temperature-index models and that energy balance models are still not widely utilized. However, there is no clear spatial pattern of model complexity. We conclude with a discussion of both the limitations of certain approaches, as for example the use of short calibration periods for long-term modeling, and also the opportunities for improved understanding afforded by new methods and techniques, such as climatic downscaling. We also propose ways to future developments, in which observations and models can be combined to improve current understanding of volumetric glacier changes and their climate causes. [ABSTRACT FROM AUTHOR]

This article is a review of the science goals and activities initiated within the framework of the Pollution and its Impacts on the South American Cryosphere ( PISAC) initiative. Air pollution associated with biomass burning and urban emissions affects extensive areas of South America. We focus on black carbon ( BC) aerosol and its impacts on air quality, water availability, and climate, with an emphasis on the Andean cryosphere. BC is one of the key short-lived climate pollutants that is a topic of growing interest for near-term mitigation of these issues. Limited scientific evidence indicates that the Andean cryosphere has already responded to climate change with receding glaciers and snow cover, which directly affect water resources, agriculture, and energy production in the Andean region of South America. Despite the paucity of systematic observations along the Andes, a few studies have detected BC on snow and glaciers in the Andes. These, in addition to existing and projected emissions and weather patterns, suggest a possible contribution of BC to the observed retreat of the Andean cryosphere. Here we provide an overview of the current understanding of these issues from scientific and policy perspectives, and propose strategic expansions to the relevant measurement infrastructure in the region. [ABSTRACT FROM AUTHOR]

ABSTRACT The 1976-1977 cold-to-warm sea surface temperature ( SST) shift in the tropical Pacific Ocean, which has been associated with a phase change of the Pacific Decadal Oscillation ( PDO) index, separated a 'La Niña-like' decadal regime from an 'El Niño-like' one. In this article, we analyse the differences of mean of annual and austral-summer ( DJF) temperature, precipitation, and sea-level pressure ( SLP) over South America ( SA) between 1961-1973 and 1978-1990, and explore the occurrence of significant shifts in their time series. Our sources are instrumental records, gridded interpolated data, and reanalyses. Although major regional differences in the intensity of the signal are detected, the climate shift is identified in all variables. In the mid-1970s at annual level, reanalysis SLP data reveal the onset of a step-like anticyclonic circulation anomaly in the southern tip of SA and an abrupt weakening of the Southeast Pacific Subtropical Anticyclone ( SEPA). This latter feature may have partly induced the rapid warming observed along the tropical-extratropical west coast of the continent through the weakening of the cold Humboldt current system. An abrupt warming was also detected in surface air temperature ( SAT) composites located along the coast of the northern part of SA and in Southeastern SA ( SESA). During summer, we found a particularly conspicuous shift-like warming over Southern South America ( SSA, comprising Patagonia). Besides, a shift-like increase (decrease) in annual mean precipitation is observed over Central Argentina and in the tropics, to the south (north) of 10°S. In line with previous studies, we conclude that both the interannual (El Niño-Southern Oscillation, ENSO) and the interdecadal ( PDO) variability modes seem to have had an incidence in the manifestation of the 1970s climate shift, and that its magnitude appears to be unprecedented during the 20th century, as shown in particular by century-long SAT composites from northern Chile and SSA. [ABSTRACT FROM AUTHOR]

Climate changes during the Pleistocene produced shifts, reductions, and expansions of biomes that, in turn, have been hypothesized to have driven speciation and extinction and shaped patterns of biodiversity. Here, we explore effects of Late Pleistocene climatic changes on environmentally and geographically cohesive areas mimicking species' distributions. We analyzed persistence of these 'species' over the transition from the warm Last Interglacial period to the cool Last Glacial Maximum period to warm present-day conditions, for four levels of environmental restriction (5, 10, 15 and 20% of overall variation; akin to niche breadths). African environments were overall much less conserved over these periods than those of South America, matching diversity contrasts between the two continents. Results thus indicate that biodiversity patterns relate closely to historical patterns of environmental grain and their stability through time; this view is a step toward an integral understanding of the role of environmental and geographic factors in the process of biological diversification. [ABSTRACT FROM AUTHOR]