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While ubiquitous among ancient Maya sites in Mesoamerica, archaeological analysts frequently overlook the interpretive potential of ground stone tools. The ancient Maya often made these heavy, bulky tools of coarse‐grained, heterogeneous materials that are difficult to chemically source, unlike obsidian. This paper describes an application of handheld, energy‐dispersive X‐ray fluorescence (XRF) to provenance ground stone artifacts (tools and architectural blocks) composed of granite: a nonhomogenous, phaneritic stone. We present a multicomponent methodology that independently tested whole‐rock, thin‐sectioned, and powdered samples by petrographic microscope, conventional, lab‐based XRF, and portable XRF units, which yielded comparable results. After establishing distinct geochemical signatures for the three geographically restricted granite plutons in Belize, we devised a field‐based XRF application on a whole rock that could replicate the compositional readings of lab‐based XRF on powdered materials with sufficient accuracy and reliability. We applied this multishot XRF technique to granite ground stone items from a range of ancient Maya sites throughout Belize; we discuss two specific case studies herein. Our results underscore the widespread potential of multishot XRF applications for determining the provenance of coarse‐grained, heterogeneous rock materials. These results can help push the boundaries from one‐dimensional, functional explanations of ground stone items to their social and ideological dimensions, alongside deeper understandings of granite resource management. [ABSTRACT FROM AUTHOR]

The North American Monsoon (NAM) is a critical component of the hydrologic cycle in southwestern North America. However, our understanding of the long‐term evolution of this monsoon system is incomplete due to a paucity of long‐term paleoclimatic records from the core and periphery of the NAM domain. C. Routson et al. (2022, https://doi.org/10.1029/2022gl099772) leverage a new compilation of Holocene proxy records to generate a new composite index of NAM evolution over the Holocene. They identify a relationship between NAM strength and the latitudinal temperature gradient over the Holocene. The authors suggest that shifts in the strength of the westerlies altered NAM convection via ventilation, a process whereby the large‐scale circulation imports low moist entropy air into the monsoon domain. These results highlight the importance of paleoclimatic records, especially from past "warm" intervals, for generating new insights about the evolution of regional monsoons. Plain Language Summary: The North American Monsoon is a circulation that brings summer rain to regions of the US southwest and western Mexico. Despite the fact that this circulation provides a majority of the precipitation in many parts of the arid southwest, we do not fully understand the factors that govern long‐term changes in this monsoon. A new paper by C. Routson et al. (2022, https://doi.org/10.1029/2022gl099772) uses proxy indicators of past summer rainfall, stretching from Central America to Arizona, to reconstruct changes in the monsoon over the geologic epoch known as the Holocene, or the last 11,000 years of Earth history. The results of this study suggest that Holocene changes in the temperature difference between the equator to pole, known as the "latitudinal temperature gradient," exerted an important influence over monsoon strength in the southwest. This has implications for the future of the summer monsoon, especially as the high latitudes of the northern hemisphere are expected to warm in the future. Key Point: The strength North American Monsoon tracks changes in the position of the midlatitude westerlies over the Holocene [ABSTRACT FROM AUTHOR]

Maya blue is a pigment found in different archaeological sites of different cultures from Mesoamerica, and also in colonial buildings in Mexico and Cuba. The pigment is made from a thermally treated mixture of indigo and palygorskite. Pigment samples from Aztec and non‐Aztec archaeological sites as well as reference Yucatecan palygorskites were studied in this paper to assess their differences. The characterization of the samples was carried out by a combination of a crystal–chemical‐point analyses using electron microscopy to obtain the structural formulae of the palygorskite crystals, and studied using high‐resolution X‐ray diffraction. The data show evidence that the palygorskite used by non‐Aztec cultures, such as the Maya, is compatible with palygorskite from known sources in the Yucatan Peninsula, while the palygorskite used by the Aztec culture is different in its structure and has an origin that is still unknown. [ABSTRACT FROM AUTHOR]

Common distributional patterns have provided the foundations of our knowledge of Neotropical biogeography. A distinctive pattern is the "circum‐Amazonian distribution", which surrounds Amazonia across the forested lowlands south and east of the basin, the Andean foothills, the Venezuelan Coastal Range, and the Tepuis. The underlying evolutionary and biogeographical mechanisms responsible for this widespread pattern of avian distribution have yet to be elucidated. Here, we test the effects of biogeographical barriers in four species in the passerine family Thamnophilidae by performing comparative demographic analyses of genome‐scale data. Specifically, we used flanking regions of ultraconserved regions to estimate population historical parameters and genealogical trees and tested demographic models reflecting contrasting biogeographical scenarios explaining the circum‐Amazonian distribution. We found that taxa with circum‐Amazonian distribution have at least two main phylogeographical clusters: (1) Andes, often extending into Central America and the Tepuis; and (2) the remaining of their distribution. These clusters are connected through corridors along the Chaco–Cerrado and southeastern Amazonia, allowing gene flow between Andean and eastern South American populations. Demographic histories are consistent with Pleistocene climatic fluctuations having a strong influence on the diversification history of circum‐Amazonian taxa, Refugia played a crucial role, enabling both phenotypic and genetic differentiation, yet maintaining substantial interconnectedness to keep considerable levels of gene flow during different dry/cool and warm/humid periods. Additionally, steep environmental gradients appear to play a critical role in maintaining both genetic and phenotypic structure. [ABSTRACT FROM AUTHOR]

Objectives: To explore evolutionary hypotheses for the high frequencies of a substitution in the methylenetetrahydrofolate reductase (MTHFR) gene, in Mexican and Central American Indigenous populations. Materials and methods: We obtained allele frequencies for the C677T variant in the MTHFR gene and ecological information for 37 indigenous samples from Mexico and Central America. We calculated Hardy–Weinberg equilibrium and computed Fst statistics. We computed correlations between the samples' allele frequencies and ecological and geochemical variables. Results: Many of the samples have extremely high frequencies of the T allele (q¯ = 0.62, median = 0.66). In this region, the frequency of the T allele decreases from Southeast to Northwest and is significantly correlated with longitude, latitude, altitude, and insolation. Conclusions: The native people of Central America and Mexico evolved high frequencies of an allele which has been shown to produce deleterious clinical effects including neural tube effects, cardiovascular events, and cancer. This allele has a clinal distribution in the region, perhaps associated with solar irradiation. As (Contreras‐Cubas et al., 2016) noted, the traditional diet of these populations, which is high in folate, has likely mitigated the negative effect of the allele. It is of primary importance that their rights to their homeland and traditional diets be respected. It is a matter of Public Health to investigate whether this allele is a factor in the current wave of cardiovascular diseases affecting the majority population of this region, since it descends from the Native peoples and the Mediterranean population, which also has high frequencies of the allele. [ABSTRACT FROM AUTHOR]

Among geographers, recent focus on the illicit and illegal has tended to fall into two camps. Economic geographers focus on regimes of illicitness and corresponding production of specific forms of economic space; political ecologists and land change scholars, on the other hand, scrutinised how illicit commodity flows shape land and resource use, especially in the global South. This paper offers an initial integration of these two relatively separate subfields, specifically in terms of their complementary attention to uneven development. We use the concept of "global commodity chains" to explore the ways in which the regulation of agricultural commodities shapes how they are trafficked and embed in space, with particular attention to sites of international transshipment. When a commodity is illegal, spaces of transit take on significant analytical importance. As a heuristic, we present a comparative mapping of two agricultural commodity chains linking Colombia and the USA: coffee and cocaine. Their comparison highlights how "illicitness" fundamentally transforms cocaine's spatiality, requiring risk evasion that results in characteristically enlarged transit spaces and huge differentials between producer and consumer price. We show how rents circulate in those transit spaces, socially and ecologically embedding in diffuse, fluid networks with severe consequences for people and environments. We conclude with implications for work on illicit commodities and the collateral social and environmental harms they produce. [ABSTRACT FROM AUTHOR]

There is an increasing interest in the impact assessment of management training programs. Among various types of training, this study focuses on those featuring Kaizen, a standard approach to production management and quality control whose name derives from the Japanese word meaning "improvement." Previous studies of Kaizen training programs evaluate training impacts on management practices, business performance, and the willingness to pay for training, and do not pay attention to impacts on workers. Using the firm‐level data, this study attempts to assess the impacts of an onsite training program held at small and medium enterprises in eight Central American and Caribbean countries. Treated firms are compared with those firms that are selected by the sponsor organization according to the same criteria as the treated counterparts but not yet treated. Propensity score matching is employed to increase comparability between the two groups. This paper presents suggestive evidence that the training program improved work practices and the attitude of workers toward work. It also suggests that the treated firms weaken the linkage between sales revenues and wages, probably to induce workers to pay attention to activities that do not immediately increase sales, such as maintenance and coaching of other workers. [ABSTRACT FROM AUTHOR]

The availability of freshwater from glaciers and snowmelt is of vital importance for people and ecosystems in the context of global climate change. Here, we focus on 25 glaciers located in different climates and latitudes and investigate their recent (1958–2020) and future projected trends (2020–2050 and 2070–2100) in monthly precipitation (Pr), maximum and minimum temperatures, ice mass loss, and their relationships with cloud properties. The study sites are located in Temperate Europe (France), the Inner (Ecuador, Venezuela, and Colombia) and Outer Tropics (Bolivia and Peru), Central America (Mexico), tropical Southeast Asia (Indonesia), Equatorial Africa (Uganda), and the Southern dry and Patagonian Andes (Chile and Argentina). The climate analyses are based on TerraClimate data (Monthly Climate and Climatic Water Balance for Global Terrestrial Surfaces) and 28 CORDEX (Coordinated Regional Climate Downscaling Experiment) climate simulations. Our findings reveal that, extrapolating current glacier volume change trends, almost half of the studied glaciers are likely to vanish (95%–100% volume loss) by 2050, with widespread warming and drying trends since 1958. A shift toward wetter conditions at Pico Humboldt (Venezuela) and Martial Este (Argentina) identifiable in the CORDEX simulation will very likely not have a limiting impact on glacier mass loss owing to increasing temperatures, which will raise the elevation of the rain/snow limit. Our results provide useful new information to better understand glacier‐climate relationships and future scenarios dominated by ice mass loss trends across the globe. These findings suggest serious consequences for future water availability, which exacerbate the vulnerability of local populations and ecosystems. Plain Language Summary: In this study, we employ the monthly TerraClimate data, Coordinated Regional Climate Downscaling Experiment climate projections, and glaciological data to investigate potential associations between climate variables (precipitation and temperatures), cloud conditions, and changes in glacier volume across 25 glaciers worldwide. Over the historical period (1958–2020) and in the future decades (2020–2050 and 2070–2100), none of the glacierized sites exhibit both cooling and wetting trends. In contrast, widespread warmer and drier conditions in recent and future decades are identified for the studied glaciers located in Temperate Europe, Central America, the Southern dry Andes, and Northern Patagonia, where almost half of the glaciers are likely to vanish by 2050 if current or recent trends persist. Relationships between the temperature range and changes in cloud cover are significant at the Outer Tropics and Northern Patagonian sites. These findings could be used by the scientific community to improve climate change projections and by decision‐makers to develop adaptation and mitigation strategies to cope with the consequences of climate change and support regional socioeconomic development. Key Points: TerraClimate and Coordinated Regional Climate Downscaling Experiment data reveal widespread warming and drying trends since 1958 over 25 glaciers located in different climatesConsidering current trends, almost half of the studied glaciers are likely to vanish by 2050. Additional warming would increase this numberTemperatures are more influential predictors than precipitation for glaciers volume [ABSTRACT FROM AUTHOR]

Mountains play a vital role in shaping regional and global climate, altering atmospheric circulation and precipitation patterns. To this end, identifying projected changes in mountain precipitation is significantly challenging due to topographic complexity. This study explains how mountain precipitation could respond to rising greenhouse gases. Using a series of century‐long fully coupled high‐resolution simulations conducted with the Community Earth System Model, we aim to disentangle future changes in mountain precipitation in response to atmospheric carbon dioxide (CO2) perturbations. Our research findings indicate that the warming observed in global mountains is more pronounced when compared to the mean warming rates experienced globally and in the ocean under elevated CO2. We identify five low‐latitude mountain ranges with elevation‐dependent precipitation response, including New Guinea, East Africa, Eastern Himalayas, Central America, and Central Andes. Those mountains are expected to have a mixture of increasing and decreasing precipitation in response to CO2‐induced warming, especially over the summit and steep topography. To elucidate the mechanisms controlling future changes in mountain precipitation, we propose "Orographic moisture omega feedback" in which an increase in low‐level relative humidity enhances local precipitation by strengthening the upward motion through moist processes for the wetting response and vice versa for the drying response. The effects of Mountain precipitation changes can be extended to hydrology and could lead to significant consequences for human societies and ecosystems. Plain Language Summary: Recently, Mountain warming with increasing greenhouse warming has taken attention. However, predicting changes in mountain rainfall is hard and limitedly explored. There is a need to connect predominately idealized studies of change in orographic precipitation with warming to State‐of‐the‐art global climate model simulation (GCM). Therefore, we ran experiment simulations to study how mountain rainfall will change in the future due to the increase in atmospheric carbon dioxide. The impact of warming on mountain precipitation is complex and could result in a combination of results, such as increased and decreased precipitation. To our knowledge, this is the first kind of study that connects the change in mountain precipitation with future greenhouse warming using a 25 km high‐resolution GCM. This study found that the changes in rainfall are expected in high‐elevation mountains located in low‐latitude regions with steep slopes. This analysis concentrates on five major mountain ranges: New Guinea, East Africa, the Himalayas, Central America, and Central Andes. Furthermore, the feedback mechanism could explain how low‐level humidity affects Mountain rainfall and atmospheric convection. By studying mountain meteorology, we can gain insights into the complex interactions between mountains and the atmosphere, contributing to the overall understanding of our earth system. Key Points: This study uses a high‐resolution model experiment to explain how mountain precipitation could respond to rising atmospheric carbon dioxide (CO2) concentrationProjected precipitation changes are dominated over low‐latitude mountains, especially the summit and steep topographyWe propose a mechanism, "Orographic moisture omega feedback," that explains the unprecedented anomalous changes in the mountain climate [ABSTRACT FROM AUTHOR]

Objectives: We examine the prevalence and sociodemographic risk factors of skeletal indicators of stress in forensic samples of undocumented migrants from Mexico and Central America., Materials and Methods: Cranial and dental remains of 319 migrants recovered in the Arizona and Texas borderlands were assessed for porotic hyperostosis (PH), cribra orbitalia (CO), and linear enamel hypoplasias (LEH). Logistic regression models for each condition were estimated to test for associations with biological sex, age, recovery location, and whether individuals were identified. Additional models estimated for a subsample of identified migrants included region of origin, residential context, and community indigeneity., Results: The full sample shows moderate crude prevalence of CO (9.6%) and LEH (34.1%), and a high prevalence of PH (49.6%). Significantly higher odds of PH are associated with being male (2.16 times higher), unidentified (1.89 times higher), and recovered in Arizona (3.76 times higher). Among identified migrants, we fail to find associations significant at the p < 0.05 level between skeletal stress and all sociodemographic variables except age., Discussion: The factors associated with PH may be related to influences on decisions to migrate and diversity among migrant sending regions. The skeletal evidence for early life stress is generally consistent with common public health concerns among impoverished communities in the region. The lesions themselves are viewed as embodied risk of physiological disturbance when resource access is structured by higher-level social, economic, and political forces. Forensic anthropologists would benefit from increased sensitivity to embodied structural violence among the vulnerable individuals and communities they serve., (© 2021 Wiley Periodicals LLC.)

Although the multi‐model average compares well with observations, individually most of the latest climate models do not simulate a realistic size of the Indo‐Pacific Warm Pool in the present‐day climate. This study explores the implications of this warm pool size bias in climate models in Northern Hemisphere winter. The warm pool size bias in phase 6 of the Coupled Model Intercomparison Project models is related to the subtropical jet and precipitation distribution, both in the present‐day climate and in response to climate change, through extratropical Rossby wave trains and tropical circulation pathways. Based on these relationships, emergent constraints are developed to observationally constrain the future subtropical jet response over Asia and the Atlantic Ocean and precipitation response over North and Central America, which can help to reduce uncertainty in future projections of these features. Thus, accurate model simulation of the warm pool in the present‐day climate is important for future projections of the subtropical jet and precipitation. Plain Language Summary: This study examines the impact of a common problem in the latest climate models where they do not accurately simulate the size of the Indo‐Pacific Warm Pool in the present‐day climate. The effects of this issue are investigated in the Northern Hemisphere winter. The warm pool size problem in the models affects the subtropical winds and precipitation, both in the current climate and in response to climate change. Based on the relationships between the present‐day warm pool size and future projections of the subtropical winds and precipitation across models, we can help to constrain future projections of the subtropical winds over Asia and precipitation over North and Central America by ruling out models with biased warm pool size. The results show that having an accurate simulation of the warm pool in the present‐day climate is crucial for more reliable future projections of subtropical winds and precipitation. Key Points: Phase 6 of the Coupled Model Intercomparison Project multi‐model‐mean reproduces the observed Indo‐Pacific warm pool size well, but there is a huge inter‐model spread in warm pool sizeModel biases in warm pool size have local and remote effects on subtropical winds and precipitation in present‐day and future climatesEmergent constraints reduce projection uncertainty of subtropical winds and precipitation by ruling out models with biased warm pool size [ABSTRACT FROM AUTHOR]

High‐quality records of hydroclimate variability in central Mexico during the last 2000 years are necessary to better understand human–environment interactions in Mesoamerica. Of particular interest are the climatic conditions during the Epiclassic period (ad 600–900), as droughts have been associated with a cultural demise occurring around ad 900–1000. We reconstruct the hydroclimate history of the last 2000 years based on a sediment record from a drought‐sensitive lake located near one of the most important Epiclassic city‐states in Mesoamerica. Titanium concentrations, pollen and diatoms give a consistent environmental signal of five droughts occurring at about: (i) ad 50–250, (ii) ad 700–950, (iii) ad 1200–1300, (iv) ad 1450–1550 and (v) ad 1760–1820. Some droughts were associated with cooler climatic conditions, and all of them framed major historical events. Our results show that the great cultural development of the Epiclassic period (ad 600–900) was framed by a scenario of drought conditions followed by abandonment at ad 900–1000. A brief return to moister conditions is recorded before another drought during the time of the fall of the city‐state of Tula (1200). European contact (1521) and the War of Independence (1810–20) also occurred during times of drought. [ABSTRACT FROM AUTHOR]

Aim: Tropical forest succession and associated changes in community composition are driven by species demographic rates, but how demographic strategies shift during succession remains unclear. Our goal was to identify generalities in demographic trade‐offs and successional shifts in demographic strategies across Neotropical forests that cover a large rainfall gradient and to test whether the current conceptual model of tropical forest succession applies to wet and dry forests. Location: Mexico and Central America. Time period: 1985–2018. Major taxa studied: Trees. Methods: We used repeated forest inventory data from two wet and two dry forests to quantify demographic rates of 781 tree species. For each forest, we explored the main demographic trade‐offs and assigned tree species to five demographic groups by performing a weighted principal components analysis to account for differences in sample size. We aggregated the basal area and abundance across demographic groups to identify successional shifts in demographic strategies over the entire successional gradient from very young (<5 years) to old‐growth forests. Results: Across all forests, we found two demographic trade‐offs, namely the growth–survival trade‐off and the stature–recruitment trade‐off, enabling the data‐driven assignment of species to five demographic strategies. Fast species dominated early in succession and were then replaced by long‐lived pioneers in three forests. Intermediate and slow species increased in basal area over succession in all forests, but, in contrast to the current conceptual model, long‐lived pioneers continued to dominate until the old‐growth stage in all forests. The basal area of short‐lived breeders was low across all successional stages. Main conclusions: The current conceptual model of Neotropical forest succession should be revised to incorporate the dominance of long‐lived pioneers in late‐successional and old‐growth forests. Moreover, the definition of consistent demographic strategies that show clear dominance shifts across succession substantially improves the mechanistic understanding and predictability of Neotropical forest succession. [ABSTRACT FROM AUTHOR]

The role of the philanthropic sector in climate change mitigation and biodiversity conservation is gaining renewed attention as new pledges to dramatically increase funding for nature‐based climate solutions mount. Despite their significant role in the conservation space, philanthropies are relatively understudied as donors; in particular, the lack of accountability and transparency in philanthropy have made them a "black box", including in conservation‐related efforts. Based on extensive document and database review alongside interviews with philanthropic grant‐makers and recipients, this article seeks to analyze the conservation‐related efforts of the Ford Foundation—a long‐standing philanthropic actor in international sustainable development. Specifically, we examine how Ford Foundation practices in Mexico and Central America have shifted since 2000 to center Indigenous Peoples and local communities, both in terms of thematic focus and strategic approach. In explaining how Ford Foundation grant‐makers themselves understand the process of change, and their lessons from this process, this article highlights the ongoing challenges to and possible methods for centering inclusive, territorial approaches to produce more effective, lasting conservation outcomes. [ABSTRACT FROM AUTHOR]

The SPLASH project (2004–2006) revealed complex population structure and migratory connections, but no regional effort was made along the southern Mexican Pacific coast until dedicated research was initiated in 2010. It is unclear whether humpback whales documented in this region belong to the Mexican or Central American population units. This study aimed to establish the relationship between humpback whales of southern Mexico and those of the surrounding population units. Humpback whale photo‐identification images were compared from multiple locations in north, central, and southern Mexico and Central America. Whales' movements among regions were estimated using the Interchange Index (InI) and the Movement Index (MI). The results showed higher movements among the southern sampling areas, suggesting that whales from southern Mexico belong to the "Central American population unit." This population unit migrates north to the feeding areas of the US West Coast using a migratory corridor along mainland Mexico to the mouth of the Gulf of California along the Baja California Peninsula. The degree of interaction with humpback whales from other population units is unknown. More studies are needed to understand population structure and disentangle photographic capture of whales on migration from whales where this is their main wintering area. [ABSTRACT FROM AUTHOR]

Seasonal rainfall forecasts provide information several months ahead to support decision making. These forecasts may use dynamic, statistical, or hybrid approaches, but their comparative value is not well understood over Central America. This study conducts a regional evaluation of seasonal rainfall forecasts focusing on two of the leading dynamic climate ensembles: the Copernicus Climate Change Service seasonal forecasting system (C3S) and the North American Multimodel Ensemble (NMME). We compare the multimodel ensemble mean and individual model predictions of seasonal rainfall over key wet season periods in Central America to better understand their relative forecast skill at the seasonal scale. Three types of rainfall forecasts are compared: direct dynamic rainfall predictions from the C3S and NMME ensembles, a statistical approach using the lagged observed sea surface temperature (SST), and an indirect hybrid approach, driving a statistical model with dynamic ensemble SST predictions. Results show that C3S and NMME exhibit similar regional variability with strong performance in the northern Pacific part of Central America and weaker skill primarily in eastern Nicaragua. In the northern Pacific part of the region, the models have high skill across the wet season. Indirect forecasts can outperform the direct rainfall forecasts in specific cases where the direct forecasts have lower predictive power (e.g., eastern Nicaragua during the early wet season). The indirect skill generally reflects the strength of SST associations with rainfall. The indirect forecasts based on Tropical North Atlantic SSTs are best in the early wet season and the indirect forecasts based on Niño3.4 SSTs are best in the late wet season when each SST zone has a stronger association with rainfall. Statistical predictions are competitive with the indirect and direct forecasts in multiple cases, especially in the late wet season, demonstrating how a variety of forecasting approaches can enhance seasonal forecasting. [ABSTRACT FROM AUTHOR]

Climate envelope models have been used to evaluate the predicted impacts of climate change on species of concern and can be a useful planning tool in determining the long‐term suitability of current habitat and potential introduction sites. However, due to model complexity, these models have generally been seen as "black boxes" when it comes to understanding why they make the predictions they do. In this study, we examined current potential ocelot (Leopardus pardalis) habitat using publicly available ocelot records and CHELSA bioclimatic variables combined in an ensemble model approach. We then predicted future potential ocelot habitat under three different emission scenarios using five climate models produced at a 30 arcsec grid cell size. To better understand what was driving model predictions, we used a variety of model interpretability approaches, including variable importance values, Shapley additive explanations, interaction detection, and a local surrogate model. These approaches revealed that ocelot potential habitat was associated with at least 233 mm of precipitation during the warmest quarter (BIO18) and at least 146 mm of precipitation during the wettest month (BIO13). Shapley additive explanations, applied to four protected areas across the species range, were valuable for understanding which climatic predictors drove predicted ocelot habitat at a local scale, with the protected areas with the highest predicted values having consistently more precipitation and higher temperatures. These tools are model agnostic and can be used to assess model predictions for biological validity and to further understand potential underlying relationships. As climate change shifts species range distributions, species distribution models and the tools to interpret them may become increasingly valuable, particularly on the leading edge of range expansion. [ABSTRACT FROM AUTHOR]

Biogeographic disjunction patterns, where multiple taxa are shared between isolated geographic areas, represent excellent systems for investigating the historical assembly of modern biotas and fundamental biological processes such as speciation, diversification, niche evolution, and evolutionary responses to climate change. Studies on plant genera disjunct across the northern hemisphere, particularly between eastern North America (ENA) and eastern Asia (EAS), have yielded tremendous insight on the geologic history and assembly of rich temperate floras. However, one of the most prevalent disjunction patterns involving ENA forests has been largely overlooked: that of taxa disjunct between ENA and cloud forests of Mesoamerica (MAM), with examples including Acer saccharum, Liquidambar styraciflua, Cercis canadensis, Fagus grandifolia, and Epifagus virginiana. Despite the remarkable nature of this disjunction pattern, which has been recognized for over 75 years, there have been few recent efforts to empirically examine its evolutionary and ecological origins. Here I synthesize previous systematic, paleobotanical, phylogenetic, and phylogeographic studies to establish what is known about this disjunction pattern to provide a roadmap for future research. I argue that this disjunction pattern, and the evolution and fossil record of the Mexican flora more broadly, represents a key missing piece in the broader puzzle of northern hemisphere biogeography. I also suggest that the ENA–MAM disjunction represents an excellent system for examining fundamental questions about how traits and life history strategies mediate plant evolutionary responses to climate change and for predicting how broadleaf temperate forests will respond to the ongoing climatic pressures of the Anthropocene. [ABSTRACT FROM AUTHOR]

Total electron content (TEC) and L‐band scintillations measured by several networks of GPS and GNSS receivers that operate in South and Central America and the Caribbean region are used to observe the morphology of the equatorial ionization anomaly (EIA), examine the evolution of plasma bubbles, and investigate the enhancement of L‐band scintillations that occurred on February 12 and 13, 2016. A few weak and short magnetic storms developed these days, and a minor sudden stratospheric warming (SSW) event was initiated a few days before. During these unusual conditions, TEC maps reported a split of the otherwise continuous crests of the EIA and the formation of a large‐scale (thousands of kilometers) almost‐circular structure. The western part of the southern crest faded, and a north‐south aligned segment developed near the center of the South American continent, joining the north and south crests of the EIA, forming an anomaly that resembled a closed loop on the eastern side of the continent. Concurrently with the anomaly events, several GPS stations reported increases in the L‐band scintillation index from 0.4 to values greater than 1. We analyzed TEC values from receivers between ±6° from the magnetic equator to identify and follow TEC depletions associated with plasma bubbles when they reach different stations. Although the magnetic activity was moderate (Kp = 3°), we believe that the anomaly redistribution and the scintillation enhancements are not related to a prompt penetration electric field but to enhancing the semidiurnal lunar tide propitiated by the onset of the minor SSW event. We found that depending on the lunar tide phase cycle, the neutral wind's meridional component can augment sub‐km scale irregularities and enhance L‐band scintillations through the wind gradient instability when U·∇ $\nabla $n < 0 or the action of wind gradients (∇ $\nabla $U) within the bubbles. Our observations imply that the SSW event enables prominent changes in the thermosphere wind system at F‐region altitudes. Plain Language Summary: GPS receivers can measure the total electron content (TEC) between the satellite and the ground receivers. We have used TEC data collected with several networks of GPS receivers in South America to construct maps of TEC over the continent. These maps are used to examine the variability of the low latitude ionosphere during a special event that originates in the northern polar stratosphere called sudden stratospheric warming (SSW), consisting of an increase in the local temperature. In February 2016, a minor SSW produced prominent changes in the equatorial ionization anomaly. The anomaly consists of a pattern of two regions of enhanced densities on both sides of the magnetic equator that develops during the daytime and early evening. A few days after the initiation of the SSW event, the low‐latitude ionosphere dynamics changed, forming a large‐scale structure resembling a closed loop on the continent's eastern side. Concurrently with the anomaly events, several GPS stations reported increases in the level of fadings of the GPS signal‐to‐noise ratio, a process called scintillation. It is indicated that the neutral wind meridional component developed shears and a reversal increasing the level of plasma irregularities at km and sub‐km‐scale lengths, originating a scintillation enhancement. Key Points: Sudden increases in L‐band scintillations coincide with changes in the geometry of the equatorial ionization anomalyThese events occurred on February 12 and 13, 2016, a few days after a minor sudden stratospheric warming eventThe analysis suggests that a meridional neutral wind associated with an increased lunar tide is responsible for anomaly variability [ABSTRACT FROM AUTHOR]

The Regional Atmospheric Modelling System (RAMS) driven by data from the CMIP5 Earth System Model HadGEM2‐ES was used to simulate daily precipitation over the tropical Americas for both current and future climate, including distinct scenarios (representative concentration pathways 4.5 and 8.5) and different time horizons (short‐term, mid‐term and long‐term changes). The major objective was to evaluate possible future changes in extreme events, with emphasis on the intensity of precipitation events and the duration of wet and dry spells. According to RAMS, longer dry spells are expected over most regions of the tropical Americas in the future, with indications for Northeast Brazil, Caribbean, Northern Amazon, and shorter wet spells over Central America and Amazon. With the exception of the Caribbean, there is a general tendency towards the increased frequency of intense precipitation in the tropical Americas. [ABSTRACT FROM AUTHOR]

Rainfall mechanisms in the Central American Isthmus are controlled by complex physical interactions across spatial and temporal scales, which are reflected on the dynamics of atmospheric circulation patterns affecting the region. However, physical mechanisms and their relationships with thermodynamic distributions connected to overturning circulations remain elusive. Here, a set of six recurrent daily atmospheric patterns, or weather types (WT), is defined using a k‐means++ clustering algorithm on standardized fields of Convective Available Potential Energy (CAPE) and winds at 925, 850, and 200 hPa. The relationships between these weather types, their temporal characteristics, and anomalous distributions of moisture flux divergence, equivalent potential temperature (saturated and unsaturated), and observed rainfall are used to describe physical processes controlling the latter, for all seasons. Regional observed rainfall is analysed from a set of 174 automatic stations from all countries from Mexico to Panama. By modulating vertically integrated moisture fluxes, these weather types, and the different climate drivers linked to them, control the temporal and spatial rainfall characteristics in the region, especially over the Pacific side of the isthmus. During some stages of the regional rainy season, described by two weather types, thermal anomalies in convective quasi‐equilibrium characteristic of the upward branch of the Hadley cell force westerly flow over Central America, enhancing rainfall. While during other stages, the enhancement of the trades and the displacement of convection to the ITCZ area over the eastern tropical Pacific, characteristic of the midsummer drought, diminishes rainfall. This study sets the stage for a better understanding of the mechanistic relationship between these weather types and rainfall characteristics in general, like onset, demise, and duration of rainy seasons. Hence, these results can inform process‐based model diagnostics aiming at bias‐correcting climate predictions at multiple timescales. [ABSTRACT FROM AUTHOR]

We analyse the effects of deforestation and the projected differential sea surface temperature (SST) anomalies between the tropical North Atlantic and the eastern North Pacific on the mid‐summer drought (MSD) over southern Mexico and Central America. To address these issues, we performed a set of three 6‐year (1996–2001) sensitivity experiments with RegCM4 driven by the ERA‐Interim reanalysis and employing different SST (projected end of century patterns under the RCP8.5 scenario) and vegetation (turning forest landuse into grass) configurations. The model domain follows the specifications of the COrdinated Regional Downscaling EXperiment (CORDEX) for Central America. Results indicate that projected SST patterns cause the MSD signal to almost disappear from the regional mean annual cycle, with its spatial extent decreasing from ~82 to ~48%. In the vegetation sensitivity experiment, the MSD intensity increases along the Pacific coast and Central America, while the MSD spatial extent remains almost unchanged. These regional changes in MSD can be explained in terms of the regional precipitation response to deforestation, primarily due to changes in vertical moisture advection. [ABSTRACT FROM AUTHOR]

Palms (Arecaceae) represent a challenge for studies of morphological variation for several various reasons. For instance, the height of many species makes them difficult to collect, and in some cases, the size of the leaves or the presence of spines make them hard to process and preserve in herbaria. Arecaceae is one of the most diverse families of monocots (ca 2600 species), and many of its species remain poorly studied. The genus Gaussia has five recognized species. Their distributions are restricted to Central America and the Caribbean islands, and for most of them, their taxonomic descriptions are the only information available. Two species – Gaussia maya and G. gomez‐pompae – are exclusively distributed in Mesoamerica. They occur allopatrically and their populations are isolated from each other. The aim of this work was to evaluate the levels of intra‐ and inter‐population morphological variation in both species and determine the possible factors that influence such a variation. We examined the morphological variation of 13 vegetative structures of 155 adult individuals from nine populations of G. maya and G. gomez‐pompae. The differentiation among populations was significant for almost all the variables and was consistent with an isolation‐by‐distance pattern. A linear discriminant analysis, Mahalanobis distances and UPGMA cluster analysis based on Euclidean distances among populations showed that three morphological groups could be distinguished. One group contained only individuals of G. maya, the second only G. gomez‐pompae, while the third group represents a yet unknown taxon. Pairwise differentiation tests clarified the morphological distinction among the three groups. This work highlights the importance of quantifying morphological variation between populations of little‐studied palms. [ABSTRACT FROM AUTHOR]

This research investigates the effect of well‐being indicators and social globalization on the migration of Unaccompanied Alien Children (UAC) from Central America. The purpose of this study is to determine whether the surge in UAC that began in 2014 at the U.S. southern border is driven primarily by violence or whether other factors are at play. The apprehension of UAC serves as a proxy for measuring unaccompanied child migration to the United States. Unemployment rates of young adults and expected years of schooling are included as a measure of youth engagement in productive activities, while homicide rates measure the threat to leading a productive, healthy life. Global social network links are considered as possible pull factors of migration and measured through a social globalization index. The results of a fixed effects regression model reveal that youth idleness, along with increased social globalization, prove to be significant in explaining heightened UAC migration. [ABSTRACT FROM AUTHOR]

Aim: The biodiversity crisis has highlighted the need to assess and map biodiversity in order to prioritize conservation efforts. Clearwing butterflies (tribe Ithomiini) have been proposed as biological indicators for habitat quality in Neotropical forests, which contain the world's richest biological communities. Here, we provide maps of different facets of Ithomiini diversity across the Neotropics to identify areas of evolutionary and ecological importance for conservation and evaluate their overlap with current anthropogenic threats. Location: Neotropics. Methods: We ran species distribution models on a data set based on 28,986 georeferenced occurrences representing 388 ithomiine species to generate maps of geographic rarity, taxonomic, phylogenetic and Müllerian mimetic wing pattern diversity. We quantified and mapped the overlap of diversity hotspots with areas threatened by or providing refuge from current anthropogenic pressures. Results: The eastern slopes of the Andes formed the primary hotspot of taxonomic, phylogenetic and mimetic diversity, with secondary hotspots in Central America and the Atlantic Forest. Most diversity indices were strongly spatially correlated. Nevertheless, species‐poor communities on the Pacific slopes of the Andes also sheltered some of the geographically rarest species. Overall, tropical montane forests that host high species and mimetic diversity as well as rare species and mimicry rings appeared particularly under threat. Main conclusions: Remote parts of the Upper Amazon may act as refuges against current anthropogenic pressures for a limited portion of Ithomiini diversity. Furthermore, it is likely that the current threat status may worsen with ongoing climate change and deforestation. In this context, the tropical Andes occupy a crucial position as the primary hotspot for multiple facets of biodiversity for ithomiine butterflies, as they do for angiosperms, tetrapods and other insect taxa. Our results support the role of ithomiine butterflies as a suitable flagship indicator group for Neotropical butterfly diversity and reinforce the position of the tropical Andes as a flagship region for biodiversity conservation in general, and insect and butterfly conservation in particular. [ABSTRACT FROM AUTHOR]

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

Location‐specific information is required to support decision making in crop variety management, especially under increasingly challenging climate conditions. Data synthesis can aggregate data from individual trials to produce information that supports decision making in plant breeding programs, extension services, and of farmers. Data from on‐farm trials using the novel approach of triadic comparison of technologies (tricot) are increasingly available, from which more insights could be gained using a data synthesis approach. The objective of our study was to present the applicability of a rank‐based data synthesis approach to several datasets from tricot trials to generate location‐specific information supporting decision making in crop variety management. Our study focuses on tricot data from 14 trials of common bean (Phaseolus vulgaris L.) performed between 2015 and 2018 across four countries in Central America (Costa Rica, El Salvador, Honduras, and Nicaragua). The combined data of 17 common bean genotypes were rank aggregated and analyzed with the Plackett–Luce model. Model‐based recursive partitioning was used to assess the influence of spatially explicit environmental covariates on the performance of common bean genotypes. Location‐specific performance was predicted for the three main growing seasons in Central America. We demonstrate how the rank‐based data synthesis methodology allows integrating tricot trial data from heterogenous sources to provide location‐specific information to support decision making in crop variety management. Maps of genotype performance can support decision making in crop variety evaluation such as variety recommendations to farmers and variety release processes. Core Ideas: We aggregate data from trials established by different organizations across different seasons and locations.We generate location‐specific insights on genotype performance and environmental interaction.We characterize uncertainty of model predictions using Shannon's entropy and area of applicability assessment. [ABSTRACT FROM AUTHOR]

Compound dry and hot events (CDHEs) have increased significantly and caused agricultural losses and adverse impacts on human health. It is thus critical to investigate changes in CDHEs and population exposure in responding to climate change. Based on the simulations of the Coupled Model Intercomparison Project Phase 6 (CMIP6), future changes in CDHEs and population exposure are estimated under four Shared Socioeconomic Pathways climate scenarios (SSPs) at first. And then the driving forces behind these changes are analyzed and discussed. The results show that the occurrence of CDHEs is expected to increase by larger magnitudes by the end of the 21st century (the 2080s) than that by the mid‐21st century (2050s). Correspondingly, population exposure to CDHEs is expected to increase significantly responding to higher global warming (SSP3‐7.0 and SSP5‐8.5) but is limited to a relatively low level under the modest emission scenarios (SSP1‐2.6). Globally, compared to 1985–2014, the exposure is expected to increase by 8.5 and 7.7 times under SSP3‐7.0 and SSP5‐8.5 scenarios by the 2080s, respectively. Regionally, Sahara has the largest increase in population exposure to CDHEs, followed by the Mediterranean, Northeast America, Central America, Africa, and Central Asia. The contribution of climate change to the increase of exposure is about 75% by the 2080s under the SSP5‐8.5 scenarios, while that of population change is much lower. The conclusion highlights the importance and urgency of implementing mitigation strategies to alleviate the influence of CDHEs on human society. Plain Language Summary: Under global warming, the occurrence of compound dry and hot events (CDHEs) is expected to increase, which may cause more severe damage to human society. Based on the Coupled Model Intercomparison Project Phase 6, the changes in population exposure to CDHEs and the driving forces are estimated and discussed in this study. The results show that the occurrence of CDHEs and population exposure are expected to increase substantially, especially under high‐emission scenarios. Sahara is expected to have the largest increase in population exposure to CDHEs, followed by the Mediterranean, Northeast America, Central America, Africa, and Central Asia. The influence of climate change on the increase in exposure is much larger than that of the population change. Therefore, it is important and urgent to make mitigation strategies to alleviate the impacts of CDHEs on human society. Key Points: The occurrence of summertime compound dry and hot events is projected to increase substantially over the 21st century across the globeExposure is expected to increase significantly under SSP3‐7.0 and SSP5‐8.5 but is limited to a low level under SSP1‐2.6 scenariosClimate change determines the increase in population exposure in most regions of the world [ABSTRACT FROM AUTHOR]

Selection of shade tree species for agroforestry systems must take the complexity of these systems into account. Tree species selection should maximize the provision of ecosystem services while minimizing disservices. Selected species must be adapted to local agroecological conditions and cater to farmers' needs, while considering their preferences and constraints.The ShadeTreeAdvice methodology was developed to support said selection process using farmers' local ecological knowledge. It provides the steps to rapidly identify tree species and evaluate their impacts on a range of locally important ecosystem services. Results are uploaded to a decision support tool to tailor tree species recommendations to individual farmers' needs (www.shadetreeadvice.org). During the 5 year timeframe between 2016 and 2020, eight studies following this methodology were conducted in various coffee and cocoa growing regions across Africa, Asia and Central America.This article looks back at these studies to synthesize their findings and evaluate the methodology. We identified similarities in the use of tree species across different study areas, notably regarding leguminous and fruit tree species. We showed that the method was efficient to evaluate tree species' impacts on soil and climate regulation, crop production, and economic benefits. It was less efficient for evaluating impacts related to incidence of pests and diseases, often associated with knowledge gaps. The method also successfully allowed investigating the links between LEK and socio‐economic groups or environmental factors.Furthermore, we suggest a series of improvements in the methodology for future studies. These improvements include (i) broadening the scope of studies beyond tree species provision of ecosystem services to include tree species impact on farming practices; (ii) allowing the comparison of tree performances in agroforestry systems versus in full sun; (iii) providing a clear pathway for validation of the results; (iv) using tree species' functional traits to generalize the results. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Understanding species‐environment relationships at large spatial scales is required for the prioritization of conservation areas and the preservation of landscape connectivity for large carnivores. This endeavour is challenging for jaguars (Panthera onca), given their elusiveness, and the local nature of most jaguar studies, precluding extrapolation to larger areas. We developed an occupancy model using occurrence data of jaguars across five countries of Central America, collected from camera‐trap studies of 2–12 months' duration, deployed over an area of 14 112 km2 from 2005 to 2018. Our occupancy model showed that habitat use of jaguars increased with primary net productivity and distance to human settlements, and distance to rivers. Detection of the species was related to survey effort and research team identity. Within the jaguar extent of occurrence, 73% was deemed suitable for the species, with 47% of it lying within Jaguar Conservation Units (JCU) and 59% of JCU land being legally protected. Suitable areas were divided into four distinct clusters of continuous habitat shared across country borders. However, large areas of predicted low habitat suitability may constrict connectivity in the region. The reliability of these spatial predictions is indicated by the model validation using an independent dataset (AUC = 0.82; sensitivity = 0.766, specificity = 0.761), and concordance of our results with other studies conducted in the region. Across Central America, we found that human influence has the strongest impact on jaguar habitat use and JCUs are the main reservoirs of habitat. Therefore, conservation actions must focus on preventing habitat loss and mitigating human pressure, particularly within the clusters of continuous areas of high suitability, and on restoring habitat to foster connectivity. The long‐term persistence of jaguars in the region will depend on strong international cooperation that secures jaguar populations and their habitat across Central American borders. [ABSTRACT FROM AUTHOR]

Aim: The proximate ecological and evolutionary processes underlying the high biodiversity of neotropical montane cloud forests are still very poorly understood. Climatic oscillations may have contributed to vicariance and cladogenesis, but also promoted secondary contact and erosion of genetic divergence. Here we tested whether geographical diversification – or its lack thereof – in a complex of arboreal alligator lizards is explained by range shifts during Quaternary climatic oscillations. Location: Pine–oak and cloud forests, central Mexico. Taxon: Abronia taeniata–graminea species complex (Squamata: Anguidae: Gerrhonotinae). Methods: We generated genomic data (ddRADseq) to infer patterns of geographical diversification in the complex, reconstruct its demographic history, estimate the timing of lineage split, and test for the presence of contemporary and/or historical hybridization. We evaluated whether the tempo and mode of diversification (i.e. strict isolation vs. secondary contact with introgression) are explained by the contemporary distribution of suitable habitats and/or range shifts experienced by the complex since the Last Glacial Maximum (LGM), as inferred from environmental niche modelling (ENM). Results: Genomic data supported a marked genetic structure within the complex, and phylogenomic and dating analyses revealed cryptic lineage diversification starting at the onset of the Pleistocene followed by secondary contact with limited introgression. ENM pointed to considerable range expansions of the complex during the LGM and a marked fragmentation and scarce connectivity among contemporary populations, which was supported by genomic‐based demographic reconstructions. Main Conclusions: The geographical diversification of the complex has been moulded by vicariant events promoted by Pleistocene geologic and climatic changes impacting the distribution of their pine–oak and cloud forest habitats. Our data supported a model of divergence with introgression, indicating that pulses of population fragmentation and expansion during the Quaternary have led to multiple opportunities for both allopatric isolation and secondary contact. [ABSTRACT FROM AUTHOR]

Objective: The objective of the study was to measure the proportion of patients who consulted for headache and of those who had a final diagnosis of migraine. We also assessed the proportion and characteristics of patients with migraine and the impact of migraine on the daily activities and the professional and social lives of patients visiting private/public medical centers in Guatemala, Costa Rica, Panama, and the Dominican Republic. Background: Underdiagnosis of migraine is high in Central America and Caribbean urban communities. However, there is limited knowledge on characteristics of headache disorders for the appropriate classification of migraine, which is a prerequisite for targeted treatment. Hence, there is a need to improve migraine awareness among patients and medical professionals in this region. Methods: Central America and Caribbean countries epidemioLogy study of Migraine (CALM) was a non‐interventional, cross‐sectional, multinational study in adults aged 18–65 years with a history of or current headache. The primary outcome was the proportion of patients with migraine visiting medical centers due to headache disorders. Using a specially designed migraine survey questionnaire, patients self‐reported migraine characteristics, duration, and severity of attacks and impact on work and social life. Results: Of the 313 enrolled patients, 308 (98.4%) completed the study. Approximately 75.3% (232/308) of patients with headache visiting medical centers had migraine, with episodic migraine being the most common (193 [83.2%]). Overall, 34/308 (11.0%) patients had a new diagnosis of migraine. Among patients with migraine, 66 (28.4%) had a history of migraine for ≥20 years and 59 (25.4%) experienced severe pain. Overall, 52.2% (121/232) of patients reported that migraine affected their professional life and 78.4% (182/232) reported an impact on social life. Conclusion: The CALM study establishes that a high proportion of patients with migraine had a long duration and high severity of migraine attacks, leading to a direct impact on work/social life as well as on costs incurred by patients in these countries. [ABSTRACT FROM AUTHOR]

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

Premise: Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species. Methods: We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden. Results: Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast‐return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast‐return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots). Conclusions: Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants. [ABSTRACT FROM AUTHOR]

Objective: We sought to examine a community engagement (CE) strategy, defined as a monetary contribution, on water filter usage Design: A natural, quasi‐experimental study was conducted in Guatemala following the distribution of water filters. Households in the 2014–2015 group (free water filter) were compared with households in the 2018–2019 group (CE strategy: US$5.50 for water filter) Sample: One‐year post‐distribution, the comparison group (n = 56) and intervention group (n = 38) completed a survey on family health and water filter use Results: Households in the CE group had almost five times higher odds (OR = 4.7, p =.022) of having a working water filter 1 year later. Using a multivariable logistic regression model, the single best predictor to explain working water filters was the CE strategy Conclusions: CE strategies that support ownership and dignity might sustain public health initiatives, in conjunction with collaborative international partnerships. Future research could include linking villages with local and international organizations that support safe drinking water initiatives. [ABSTRACT FROM AUTHOR]

Aim: Artificial light at night (ALAN) and roads are known threats to nocturnally migrating birds. How associations with ALAN and roads are defined in combination for these species at the population level across the full annual cycle has not been explored. Location: Western Hemisphere. Methods: We estimated range‐wide exposure, predictor importance and the prevalence of positive associations with ALAN and roads at a weekly temporal resolution for 166 nocturnally migrating bird species in three orders: Passeriformes (n = 104), Anseriformes (n = 27) and Charadriiformes (n = 35). We clustered Passeriformes based on the prevalence of positive associations. Results: Positive associations with ALAN and roads were more prevalent for Passeriformes during migration when exposure and importance were highest. Positive associations with ALAN and roads were more prevalent for Anseriformes and Charadriiformes during the breeding season when exposure was lowest. Importance was uniform for Anseriformes and highest during migration for Charadriiformes. Our cluster analysis identified three groups of Passeriformes, each having similar associations with ALAN and roads. The first occurred in eastern North America during migration where exposure, prevalence, and importance were highest. The second wintered in Mexico and Central America where exposure, prevalence and importance were highest. The third occurred throughout North America where prevalence was low, and exposure and importance were uniform. The first and second were comprised of dense habitat specialists and long‐distance migrants. The third was comprised of open habitat specialists and short distance migrants. Main conclusions: Our findings suggest ALAN and roads pose the greatest risk during migration for Passeriformes and during the breeding season for Anseriformes and Charadriiformes. Our results emphasise the close relationship between ALAN and roads, the diversity of associations dictated by taxonomy, exposure, migration strategy and habitat and the need for more informed and comprehensive mitigation strategies where ALAN and roads are treated as interconnected threats. [ABSTRACT FROM AUTHOR]

The Amazon and Orinoco Rivers form the largest river system on Earth with wide‐reaching impacts on the biophysical climate of the region. Based on 11 years of satellite observations, here we show strong interannual variability of sea surface salinity (SSS) in the plume region that is about three times larger than in the surrounding region. This variability has been driven mainly by changes in horizontal advection of the plume with smaller contributions from precipitation, river discharge, and vertical mixing. Interannual variability of horizontal advection occurs mainly near the eastern boundary of the plume region and especially in the latitude range of the North Equatorial Countercurrent (3°–10°N). The North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO) strongly modulate SSS in the plume region during the boreal spring‐summer (flood) and fall‐winter (dry) seasons, respectively, through their impacts on the tropical North Atlantic Ocean circulation. Overall, the NAO exerts a stronger influence on plume SSS than ENSO. The plume SSS also shows a significant upward trend during 2010–2016, corresponding to transitions of the NAO and ENSO from negative to positive phases. This was followed by a downward trend during 2017–2020 when both the NAO and ENSO decreased from their 2015–2016 peaks. These results show that year‐to‐year changes in the spatial mean SSS of the Amazon‐Orinoco plume are driven mainly by large‐scale climate forcings and their associated imprints on tropical Atlantic Ocean circulation and very little by changes in river outflow and associated rainfall over land. Plain Language Summary: About 200,000 m3 of fresh water per second is discharged into the tropical North Atlantic by the Amazon and Orinoco Rivers, creating a large low‐salinity plume that sometimes exceeds a million km2. The plume is often more turbid and stable than surrounding waters and can trap more heat from solar radiation, triggering atmospheric convection that can increase rainfall over the Caribbean Sea and Central America and strengthen tropical cyclones. Here, we find strong interannual variability of surface salinity in the Amazon‐Orinoco plume region over the 2010–2020 satellite period. Additional data from an ocean reanalysis reveal that interannual variability of the plume is mainly driven by large‐scale ocean circulation, which in turn is driven by large‐scale climate phenomena: El Niño Southern Oscillation (ENSO) in the dry season and the North Atlantic Oscillation (NAO) in the flood season. The plume surface salinity also shows a significant upward trend (i.e., weakening of the plume) during 2010–2016, corresponding to transitions of the NAO and ENSO from negative to positive phases. Key Points: Horizontal advection influenced by the North Atlantic Oscillation (NAO) is the main driving force for plume interannual variabilityThe NAO and El Niño Southern Oscillation (ENSO) are the ultimate drivers of plume salinity in the flood and dry season, respectivelyPlume salinity shows a significant positive trend during 2010–2016 when NAO and ENSO transitioned from a negative to a positive phase [ABSTRACT FROM AUTHOR]

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

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

The genus Phyllachora contains numerous obligate fungal parasites that produce raised, melanized structures called stromata on their plant hosts referred to as tar spot. Members of this genus are known to infect many grass species but generally do not cause significant damage or defoliation, with the exception of P. maydis which has emerged as an important pathogen of maize throughout the Americas, but the origin of this pathogen remains unknown. To date, species designations for Phyllachora have been based on host associations and morphology, and most species are assumed to be host specific. We assessed the sequence diversity of 186 single stroma isolates collected from 16 hosts representing 15 countries. Samples included both herbarium and contemporary strains that covered a temporal range from 1905 to 2019. These 186 isolates were grouped into five distinct species with strong bootstrap support. We found three closely related, but genetically distinct groups of Phyllachora are capable of infecting maize in the United States, we refer to these as the P. maydis species complex. Based on herbarium specimens, we hypothesize that these three groups in the P. maydis species complex originated from Central America, Mexico, and the Caribbean. Although two of these groups were only found on maize, the third and largest group contained contemporary strains found on maize and other grass hosts, as well as herbarium specimens from maize and other grasses that include 10 species of Phyllachora. The herbarium specimens were previously identified based on morphology and host association. This work represents the first attempt at molecular characterization of Phyllachora species infecting grass hosts and indicates some Phyllachora species can infect a broad range of host species and there may be significant synonymy in the Phyllachora genus. [ABSTRACT FROM AUTHOR]

Copyright of American Anthropologist 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.)

Introduction: The reuse of cardiac implantable electronic devices may help increase access to these therapies in low‐ and middle‐income countries (LMICs). No published data exist regarding the views of patients and family members in LMICs regarding this practice. Methods and Results: An article questionnaire eliciting attitudes regarding pacemaker reuse was administered to ambulatory adult patients and patients' family members at outpatient clinics at Centro Nacional Cardiologia in Managua, Nicaragua, Indus Hospital in Karachi, Pakistan, Hospital Carlos Andrade Marín, and Hospital Eugenio Espejo in Quito, Ecuador, and American University of Beirut Medical Center in Beirut, Lebanon. There were 945 responses (Nicaragua – 100; Pakistan – 493; Ecuador – 252; and Lebanon – 100). A majority of respondents agreed or strongly agreed that they would be willing to accept a reused pacemaker if risks were similar to a new device (707, 75%), if there were a higher risk of device failure compared with a new device (584, 70%), or if there were a higher risk of infection compared to a new device (458, 56%). A large majority would be willing to donate their own pacemaker at the time of their death (884, 96%) or the device of a family member (805, 93%). Respondents who were unable to afford a new device were more likely to be willing to accept a reused device (79% vs. 63%, p <.001). Conclusions: Patients and their family members support the concept of pacemaker reuse for patients who cannot afford new devices. [ABSTRACT FROM AUTHOR]

Smallholder livelihoods throughout Central America are built on rain‐fed agriculture and depend on seasonal variations in temperature and precipitation. Recent climatic shifts in this highly diverse region are not well understood due to sparse observations, and as the skill of global climate products have not been thoroughly evaluated. We examine the performance for several reanalysis and satellite‐based global climate data products (CHIRPS/CHIRTS, ERA5, MERRA‐2, PERSIANN‐CDR) as compared to the observation‐based GPCC precipitation dataset. These datasets are then used to evaluate the magnitude and spatial extent of hydroclimatic shifts and changes in aridity and drought over the last four decades. We focus on water‐limited regions that are important for rain‐fed agriculture and particularly vulnerable to further drying, and newly delineate those regions for Central America and Mexico by adapting prior definitions of the Central American Dry Corridor. Our results indicate that the CHIRPS dataset exhibits the greatest skill for the study area. A general warming of 0.2–0.8°C·decade−1 was found across the region, particularly for spring and winter, while widespread drying was indicated by several measures for the summer growing season. Changes in annual precipitation have been inconsistent, but show declines of 20–25% in eastern Honduras/Nicaragua and in several parts of Mexico. Some regions most vulnerable to drying have been subject to statistically significant trends towards summer drying, increases in drought and aridity driven by precipitation declines, and/or a lengthening of the winter dry season, highlighting areas where climate adaptation measures may be most urgent. [ABSTRACT FROM AUTHOR]

Atta Fabricius is an ecologically dominant leaf‐cutting ant genus, the major herbivore of the Neotropics, and an agricultural pest of great economic importance. Phylogenetic relationships within Atta have until now remained uncertain, and the delimitation and identification of a subset of Atta species are problematic. To address these phylogenetic uncertainties, we reconstruct the most comprehensive phylogenetic estimate to date of Atta by employing ultraconserved elements (UCEs). We recovered 2340 UCE loci from 224 Atta specimens, which include 14 out of the 15 identifiable species from across their geographic distributions, and 49 outgroup specimens. Our results strongly support the monophyly of Atta and of the four clades that coincide with the previously recognized subgenera Archeatta Gonçalves, Atta s.s. Emery, Epiatta Borgmeier, and Neoatta Gonçalves. The Archeatta clade contains three species occurring in North and Central America and the Caribbean and is the sister group of the remainder of all other Atta species. The Atta s.s. clade is composed of two species occupying North, Central, and South America. The Epiatta clade contains seven entirely South American species and the two species of the Neoatta clade occur in Central and South America. Divergence‐dating analyses identify a series of major events in the Miocene, such as the divergence of Acromyrmex Mayr and Atta 16.7 million years ago (Ma) and the crown‐group origin of Atta around 8.5 Ma. Extant Atta species evolved very recently, originating in the early Pleistocene, approximately 1.8–0.3 Ma (crown‐group ages). We provide the first evidence that Atta goiana Gonçalves belongs to the Epiatta clade and that Atta robusta Borgmeier is the species with the youngest crown‐group age of 0.3 Ma. The very young ages of Atta and its component species indicate a recent, rapid radiation. Biogeographic analyses suggest that the range of the most recent common ancestor of Atta consisted of the combined North/Central America and NW South America bioregions and that one daughter lineage subsequently dispersed into South America, rapidly diversifying in the newly formed Cerrado biome and Chaco, and further dispersing into the Atlantic Forest, Caatinga, and Pampas bioregions. [ABSTRACT FROM AUTHOR]

Historical climate changes and interspecific gene flow have played an important role in shaping the distribution and genetic diversity of the biota in the Neotropics. In this study, we explored the role of both the Pleistocene climate changes and hybridization on the contemporary geographic structure of two Neotropical weedy species: Tithonia tubaeformis and T. rotundifolia.Distribution shifts under past and current climate conditions were explored through ecological niche modelling (ENM). We then tested these hypotheses using chloroplast microsatellite (cpSSR) data in T. tubaeformis and compared the patterns deduced with those previously reported for T. rotundifolia using the same cpSSR loci. Lastly, we searched for shared haplotypes between species.Both species exhibited significant downwards altitudinal shifts during the last interglacial (LIG) and the Last Glacial Maximum (LGM). For instance, T. rotundifolia showed large suitable habitat areas since the LIG at xeric conditions in western Mesoamerica. Tithonia tubaeformis showed a ~five‐fold range contraction during the LIG compared to current climate conditions, followed by a range expansion in the LGM. Despite the large shared refugial areas predicted through ENM, we found a low number of shared haplotypes, suggesting a minor role of hybridization in shaping the geographic structure of these species.Our results provide additional patterns of the population history of the northern Neotropics during the Quaternary, and we suggest that weedy widespread species are a well‐suited group for the study of the effects of historic climatic changes on the biota of this region. [ABSTRACT FROM AUTHOR]

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Paleohurricane reconstructions extend the observational record of tropical cyclones (TCs) back thousands of years. However, these records are subject to biases–capturing only close‐moving intense storms at varying resolutions. We devise two pseudo proxy networks drawing from the full suite of published paleohurricane studies in the North Atlantic. We run synthetic storms forced with two global climate model simulations of the past millennium through each pseudo network to assess the theoretical skill of paleohurricane proxies at capturing low‐frequency variability in North Atlantic basin‐wide and intrabasin TCs. We find that basin‐wide and paleohurricane compiled TC counts are significantly correlated with one another for the past millennium on annual to multi‐decadal timescales, but compilation skill is limited by proxy temporal resolution. Current paleohurricane proxy networks predominantly capture storms moving in the Caribbean/Gulf of Mexico. Increasing the quantity of paleohurricane records from the North American coastline substantially improves reconstruction skill. Plain Language Summary: As our climate warms, we need to understand how the statistics of Atlantic hurricanes will change. Scientists use natural archives, such as sediment and tree cores, to reconstruct Atlantic hurricane frequency over the past couple of thousand years. These natural archives, also known as paleohurricane proxies, are biased; they only record storms that move close to the coring site at a high intensity. Over the past few decades, scientists have amassed large networks of paleohurricane proxies from coastlines in the western North Atlantic. Here, we use two different sets of synthetic hurricanes to test if a compilation of the current network of paleohurricane proxies will smooth out the biases of each individual site and provide an accurate representation of Atlantic basin‐wide hurricane frequency over the past 1,000 years. We find that current network of paleohurricane records can be used to reconstruct past Atlantic hurricanes, but most of the current sites only capture storms that form/move through the Caribbean Sea and the Gulf of Mexico. We can improve our estimates of past hurricanes in future work by adding more sites from the U.S. Southeast and Central America. Key Points: The current network of paleohurricane proxies captures annual to multi‐decadal scale variability in Atlantic tropical cyclone (TC) frequencyPaleohurricane records predominantly capture storms that impact the U.S. Gulf Coast and Caribbean SeaMore paleohurricane records, especially from the U.S. Southeast, are needed to reconstruct recurving TCs [ABSTRACT FROM AUTHOR]

The delimitation of species is an essential pursuit of biology, and proper taxonomies are crucial for the assessment and conservation management of organismal diversity. However, delimiting species can be hindered by a number of factors including highly conserved morphologies (e.g., cryptic species), differences in criteria of species concepts, lineages being in the early stages of the speciation or divergence process, and discordance between gene topologies (e.g., mitonuclear discordance). Here we use a taxonomically confounded species complex of toads in Central America that exhibits extensive mitonuclear discordance to test delimitation hypotheses. Our investigation integrates mitochondrial sequences, nuclear SNPs, morphology, and macroecological data to determine which taxonomy best explains the divergence and evolutionary relationships among these toads. We found that a three species taxonomy following the distributions of the nuclear SNP haplotypes offers the best explanation of the species in this complex based off of the integrated data types. Due to the taxonomic instability of this group, we also discuss conservation concerns in the face of improper taxonomic delimitation. Our study provides an empirical and integrative hypothesis testing framework to assess species delimitation hypotheses in the face of cryptic morphology and mitonuclear discordance and highlights the importance that a stable taxonomy has over conservation‐related actions. [ABSTRACT FROM AUTHOR]

Diadromous fishes can exhibit interesting evolutionary and population‐level patterns given their use of freshwater and marine environments as part of their life histories. The River goby genus Awaous are prominent members of riverine ichthyofaunas and occur throughout Atlantic and Pacific slopes of the Americas from the southern United States to Ecuador and Brazil. Here we study the widespread and polymorphic Awaous banana complex to assess phylogeographic patterns and test previous hypotheses that all populations of this species in the Americas belong to the same species. Analysis of sequence data based on the mitochondrial cytochrome oxidase I gene shows multiple clades within the Atlantic and Pacific basins, which correspond to previously described species. Additionally, haplotype analysis demonstrates unique and unconnected networks between these species. Within these clades we document biogeographic patterns that are congruent with results of other co‐occurring diadromous species, as well as a novel biogeographic pattern for the region. Our results support the recognition of distinct species of Awaous in the Atlantic (A. banana and A. tajasica) and Pacific (A. transandeanus) basins. These results are concordant with previously established morphological characters permitting the separation of these species. [ABSTRACT FROM AUTHOR]