Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 291
Filtrar
1.
J Environ Manage ; 374: 124102, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39799773

RESUMO

The Eastern Boundary Upwelling Systems (EBUS) sustains some of the most productive marine systems on Earth. Within each of these systems, the upwelling process exhibits spatial and temporal variation resulting in marked differences in upwelling intensity and seasonality along extensive coastlines. The study of this variation is well needed, given the magnitude of the services provided by upwelling, and the impending impacts of global warming on EBUS. The critical link between the physical variability associated with upwelling intensity and its consequences on socio-ecological variables remain severely understudied. This study aimed to address such a gap by exploring the influence of coastal upwelling intensity on socio-ecological attributes of co-management units named Marine Exploitation Areas for Benthic Resources (MEABRs), along one the most productive ecosystems of the world: The southern Humboldt Current system. We evaluated the non-linear influence of upwelling on 1) the harvest of economically important resources, 2) the number of exploited species, 3) number and gender distribution of fishers involved, and 4) fishery activities. Our data indicated that on the one hand the annual harvest of commercial species, and all the exploited resources combined, were consistently higher in MEABRs associated with intermediate to high upwelling intensities. On the other hand, the harvest of kelp, the number of species harvested, and the number of fishers per MEABR increased towards low upwelling intensities, showing signals of fishery diversification. Interestingly, representation of female fishers increased towards high upwelling intensities, suggesting that multiple factors account for the variation in this, and other socio-ecological variables examined. Our study provides first-hand information about harvest levels and the allocation of fishery activities and gender distribution when MEABRs associated with different upwelling intensities are compared. Such information will assist in the identification of ecological and social vulnerabilities in a global warming scenario.


Assuntos
Ecossistema , Pesqueiros , Conservação dos Recursos Naturais , Animais , Aquecimento Global
2.
Glob Chang Biol ; 30(12): e17623, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39648972

RESUMO

Predicting how rising temperatures will impact different species and communities is imperative and increasingly urgent with ongoing global warming. Here, we describe how thermal-death time curves obtained in the laboratory can be combined with an envelope model to predict the mortality of freshwater fish under field conditions and their distribution limits. We analyze the heat tolerance and distribution of 22 fish species distributed across North America and demonstrate that high temperatures imposed a distribution boundary for 11 of them, employing a null model. Importantly, predicted thermal boundaries closely match the warmest suitable locality of the envelope model. Simulated warming suggests that the distribution of fish species with lower heat tolerances will be disproportionately affected by rising temperatures, and the rate of local extinctions will be higher across fish communities in warmer localities. Ultimately, our analyses illustrate how physiological information can be combined with distribution models to forecast how warming temperatures are expected to impact different species and ecological communities.


Assuntos
Peixes , Água Doce , Animais , Peixes/fisiologia , América do Norte , Temperatura Alta , Resposta ao Choque Térmico/fisiologia , Distribuição Animal , Modelos Biológicos , Modelos Teóricos , Aquecimento Global , Mudança Climática
3.
An Acad Bras Cienc ; 96(suppl 2): e20240592, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39699521

RESUMO

Regional sea level rise varies from the global average and is influenced by climate variability. We studied sea level anomalies in southern Brazil from 1993 to 2022, finding increasing trend from 1993 to 2022. We used oceanic and atmospheric dynamics to understand the rapid sea level rise. Positive trends in the Southern Annular Mode and the South Atlantic Ocean subtropical gyre intensified wind stress curl and Ekman transport. If global warming continues and the Southern Annular Mode remains in a positive trend, sea level rise in southern Brazil is likely to persist and increase risks for the population in this low-lying coastal area.


Assuntos
Elevação do Nível do Mar , Brasil , Oceano Atlântico , Aquecimento Global , Mudança Climática
4.
J Environ Manage ; 372: 123376, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39579575

RESUMO

CONTEXT OR PROBLEM: Most of the research evaluating rice varieties, a major global staple food, for greenhouse gas (GHG) mitigation has been conducted under continuous flooding. However, intermittent irrigation practices are expanding across the globe to address water shortages, which could alter emissions of methane (CH4) compared to nitrous oxide (N2O) for reducing overall global warming potential (GWP). To develop climate-smart rice production systems, it is critical to identify rice varieties that simultaneously reduce CH4 and N2O emissions while maintaining crop productivity under intermittent irrigation. OBJECTIVE: This study assessed CH4 and N2O emissions, grain yield, and GWP of four rice varieties cultivated under intermittent irrigation in Colombia. METHODS: Four common commercial rice varieties were evaluated over two seasons-wet and dry in 2020 and 2021-in two Colombian regions (Tolima and Casanare). RESULTS: Wet-season crop productivity was similar among varieties. However, F68 in Tolima and F-Itagua in Casanare significantly reduced yields in the dry season, likely due to periods of crop water stress. Overall, CH4 emissions and GWP were relatively low due to frequent field drainage events, with GWP ranging from 349 to 4704 kg CO2 equivalents ha-1. Accordingly, N2O emissions contributed 73% to GWP across locations, as wet-dry cycles can increase N2O emissions, creating a tradeoff for GWP when reducing CH4 through drainage. Varieties F67 in Tolima and F-Itagua in Casanare significantly reduced GWP by 32-61% across seasons, primarily by decreasing N2O rather than CH4 emissions. CONCLUSIONS: Rice varietal selection achieved significant GWP mitigation with limited impacts on grain yield, mainly due to reduced N2O emissions under non-continuously flooded irrigation. IMPLICATIONS/SIGNIFICANCE: This research underscores the critical role of rice varietal selection in addressing global climate-change and water-scarcity challenges, which drive the adoption of intermittent irrigation practices. By focusing on reducing N2O emissions through appropriate variety selection, this study provides valuable insights for rice systems worldwide that are adapting to these pressing environmental challenges.


Assuntos
Irrigação Agrícola , Metano , Óxido Nitroso , Oryza , Metano/metabolismo , Óxido Nitroso/análise , Óxido Nitroso/metabolismo , Oryza/crescimento & desenvolvimento , Aquecimento Global , Gases de Efeito Estufa/análise , Colômbia
5.
Sci Rep ; 14(1): 27729, 2024 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-39533054

RESUMO

Anastrepha ludens (Mexican fruit-fly) is a highly polyphagous fruit fly species (Tephritidae) attacking wild and commercial fruit from Mexico to Panama. Here we report on a recent habitat and host range expansion as A. ludens lately started to attack apples (Malus domestica) in Mexico, a phenomenon likely influenced by global warming. We document natural infestations in apple-growing regions in the States of Nuevo León and Hidalgo, Mexico where A. ludens has started to attack the cultivars 'Golden Delicious', 'Rayada' and 'Criolla'. No infestations were found in the apple-growing region of Zacatlán, Puebla. To determine apple cultivar susceptibility to the attack of this emerging pest, we ran forced infestation assays in enclosed fruit-bearing branches in all three apple-growing regions and studied the metabolome of all fruit. A clear pattern emerged indicating that the cultivar 'Golden Delicious' was the most susceptible, with 'Criolla' exhibiting complete resistance in one location (Puebla). Although A. ludens can develop in this new host, development rates (egg-adult) and adult emergence were affected when compared with the performance in the natural host 'Marsh' grapefruit. Warmer temperatures and specific secondary metabolites of some apple cultivars are likely contributing to the territorial and host expansion of A. ludens.


Assuntos
Ecossistema , Aquecimento Global , Malus , Tephritidae , Animais , Malus/parasitologia , Tephritidae/fisiologia , Tephritidae/crescimento & desenvolvimento , México , Frutas
6.
Parasit Vectors ; 17(1): 434, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39434158

RESUMO

BACKGROUND: Climate change is driving the occurrence of several infectious diseases. Within a One Health action to complement the ongoing preventive chemotherapy initiative against human fascioliasis in the Northern Bolivian Altiplano hyperendemic area, field surveys showed a geographical expansion of its lymnaeid snail vector. To assess whether climate change underlies this spread of the infection risk area, an in-depth analysis of the long-term evolution of climatic factors relevant for Fasciola hepatica development was imperative. METHODS: We used monthly climatic data covering at least a 30-year period and applied two climatic risk indices, the water-budget-based system and the wet-day index, both of verified usefulness for forecasting fascioliasis transmission in this endemic area. To reveal the long-term trends of the climatic factors and forecast indices, we applied procedures of seasonal-trend decomposition based on locally weighed regression and trend analysis on the basis of linear models. To further demonstrate the changes detected, we depicted selected variables in the form of anomalies. RESULTS: This study revealed a notorious climatic change affecting most of the hyperendemic area, with a strong impact on crucial aspects of the fascioliasis transmission. Trends in maximum and mean temperatures show significant increases throughout the endemic area, while trends in minimum temperatures are more variable. Precipitation annual trends are negative in most of the localities. Trends in climatic risk indices show negative trends at lower altitudes or when farther from the eastern Andean chain. However, monthly and yearly values of climatic risk indices indicate a permanent transmission feasibility in almost every location. CONCLUSIONS: Warmer temperatures have enabled lymnaeids to colonize formerly unsuitable higher altitudes, outside the endemicity area verified in the 1990s. Further, drier conditions might lead to an overexploitation of permanent water collections where lymnaeids inhabit, favoring fascioliasis transmission. Therefore, the present preventive chemotherapy by annual mass treatments is in need to widen the area of implementation. This study emphasizes the convenience for continuous monitoring of nearby zones for quick reaction and appropriate action modification.


Assuntos
Doenças Endêmicas , Fasciola hepatica , Fasciolíase , Aquecimento Global , Fasciolíase/epidemiologia , Fasciolíase/transmissão , Animais , Humanos , Fasciola hepatica/fisiologia , Bolívia/epidemiologia , Temperatura , Mudança Climática , Estações do Ano
7.
Santiago de Chile; MINSAL; sept. 2024. 35 p.
Monografia em Espanhol | LILACS, BIGG - guias GRADE, BRISA/RedTESA, MINSALCHILE, PIE | ID: biblio-1581109

RESUMO

ANTECEDENTES Y OBJETIVOS: Las enfermedades vectoriales y zoonóticas se transmiten por mosquitos u otros animales. A raíz del cambio climático se ha visto una modificación en su dinámica. En este contexto el Departamento de Gestión Territorial ha solicitado una síntesis con el objetivo de conocer el efecto del calentamiento global en la incidencia de casos para Chile. METODOLOGIA: Se realizó la búsqueda en las bases de datos MEDLINE, EMBASE y EBM utilizando conceptos "global warming", "rodent-borne", "pathologies transmitted", "climate-sensitive diseases"; el 5 de agosto del 2024, dos revisores independientes seleccionaron los estudios que respondieron a la pregunta basándose en criterios de inclusión y exclusión acordados. La extracción de cada artículo la realizó una persona. Para resumir los resultados y valorar la certeza de la evidencia se utilizó la metodología GRADE. RESULTADOS: Con alta certeza de la evidencia, el aumento de 1°C de temperatura aumenta la incidencia de dengue en un 13 %, lo cual puede aumentar a 20% si es que se analiza exclusivamente áreas de clima subtropical húmedo Con alta certeza de la evidencia, se observa que el aumento de 1°C de temperatura en regiones templadas aumenta un 52% la razón de tasa de incidencia del virus del nilo occidental Si bien, el aumento de casos de dengue y VNO podría ser trivial, el impacto para el sistema de salud chileno podría ser relevante por su infrecuencia. Para el resto de las asociaciones entre eventos climáticos y enfermedades vectoriales, se observo que el aumento de la temperatura o de precipitaciones y el calentamiento global, podría aumentar la incidencia de Malaria, Zika y Chikungunya, mentiras que las sequías podrían relacionarse con el dengue . De todos modos, la evidencia es limitada y existe alta incertidumbre respecto a estas asociaciones No está clara la asociación entre Puumala Hantavirus y el calentamiento global. Es necesario fortalecer los sistemas de vigilancia de estas patologías, adaptando métodos sensibles a los diferentes hábitats de Chile, considerando factores climáticos y sociales de cada región


Assuntos
Zoonoses , Vetores de Doenças , Aquecimento Global , Chile
8.
Sci Rep ; 14(1): 16414, 2024 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014072

RESUMO

We present a methodology designed to study the spatial heterogeneity of climate change. Our approach involves decomposing the observed changes in temperature patterns into multiple trend, cycle, and seasonal components within a spatio-temporal model. We apply this method to test the hypothesis of a global long-term temperature trend against multiple trends in distinct biomes. Applying this methodology, we delve into the examination of heterogeneity of climate change in Brazil-a country characterized by a spectrum of climate zones. The findings challenge the notion of a global trend, revealing the presence of distinct trends in warming effects, and more accelerated trends for the Amazon and Cerrado biomes, indicating a composition between global warming and deforestation in determining changes in permanent temperature patterns.


Assuntos
Mudança Climática , Ecossistema , Brasil , Temperatura , Estações do Ano , Conservação dos Recursos Naturais , Aquecimento Global
9.
Sci Total Environ ; 948: 174752, 2024 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-39004360

RESUMO

Global warming has significantly altered fish distribution patterns in the ocean, shifting towards higher latitudes and deeper waters. This is particularly relevant in high-latitude marine ecosystems, where climate-driven environmental changes are occurring at higher rates than the global average. Species Distribution Models (SDMs) are increasingly being used for predicting distributional shifts in habitat suitability for marine species as a response to climate change. Here, we used SDMs to project habitat suitability changes for a range of high-latitude, pelagic and benthopelagic commercial fish species and crustaceans (10 species); from 1850 to two future climate change scenarios (SSP1-2.6: low climate forcing; and SSP5-8.5: high climate forcing). The study includes 11 Large Marine Ecosystems (LME) spanning South America, Southern Africa, Australia, and New Zealand. We identified declining and southward-shifting patterns in suitable habitat areas for most species, particularly under the SSP5-8.5 scenario and for some species such as Argentine hake (Merluccius hubbsi) in South America, or snoek (Thyrsites atun) off Southern Africa. Geographical constraints will likely result in species from Southern Africa, Australia, and New Zealand facing the most pronounced habitat losses due to rising sea surface temperatures (SST). In contrast, South American species might encounter greater opportunities for migrating southward. Additionally, the SSP5-8.5 scenario predicts that South America will be more environmentally stable compared to other regions. Overall, our findings suggest that the Patagonian shelf could serve as a climate refuge, due to higher environmental stability highlighting the importance of proactive management strategies in this area for species conservation. This study significantly contributes to fisheries and conservation management, providing valuable insights for future protection efforts in the Southern Hemisphere.


Assuntos
Mudança Climática , Ecossistema , Peixes , Animais , Nova Zelândia , América do Sul , Austrália , Pesqueiros , África Austral , Aquecimento Global
10.
J Therm Biol ; 123: 103917, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38991264

RESUMO

Global warming poses a threat to lizard populations by raising ambient temperatures above historical norms and reducing thermoregulation opportunities. Whereas the reptile fauna of desert systems is relatively well studied, the lizard fauna of saline environments has not received much attention and-to our knowledge-thermal ecology and the effects of global warming on lizards from saline environments have not been yet addressed. This pioneer study investigates the thermal ecology, locomotor performance and potential effects of climate warming on Liolaemus ditadai, a lizard endemic to one of the largest salt flats on Earth. We sampled L. ditadai using traps and active searches along its known distribution, as well as in other areas within Salinas Grandes and Salinas de Ambargasta, where the species had not been previously recorded. Using ensemble models (GAM, MARS, RandomForest), we modeled climatically suitable habitats for L. ditadai in the present and under a pessimistic future scenario (SSP585, 2070). L. ditadai emerges as an efficient thermoregulator, tolerating temperatures near its upper thermal limits. Our ecophysiological model suggests that available activity hours predict its distribution, and the projected temperature increase due to global climate change should minimally impact its persistence or may even have a positive effect on suitable thermal habitat. However, this theoretical increase in habitat could be linked to the distribution of halophilous scrub in the future. Our surveys reveal widespread distribution along the borders of Salinas Grandes and Salinas de Ambargasta, suggesting a potential presence along the entire border of both salt plains wherever halophytic vegetation exists. Optimistic model results, extended distribution, and no evidence of flood-related adverse effects offer insights into assessing the conservation status of L. ditadai, making it and the Salinas Grandes system suitable models for studying lizard ecophysiology in largely unknown saline environments.


Assuntos
Lagartos , Animais , Lagartos/fisiologia , Argentina , Regulação da Temperatura Corporal , Extremófilos/fisiologia , Ecossistema , Aquecimento Global , Mudança Climática , Modelos Biológicos , Temperatura Alta
11.
J Therm Biol ; 123: 103893, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38924931

RESUMO

Species are expected to migrate to higher latitudes as warming intensifies due to anthropogenic climate change since physiological mechanisms have been adapted to maximize fitness under specific temperatures. However, literature suggests that upwellings could act as thermal refugia under climate warming protecting marine ecosystem diversity. This research aimed to predict the effects of climate warming on commercial and non-commercial fish species reported in official Mexican documents (>200 species) based on their thermal niche to observe if upwellings can act as potential thermal refugia. Present (2000-2014) and Representative Concentration Pathway (6.0 and 8.5) scenarios (2040-2050 and 2090-2100) have been considered for this work. Current and future suitability patterns, species distribution, richness, and turnover were calculated using the minimum volume ellipsoids as algorithm. The results in this study highlight that beyond migration to higher latitudes, upwelling regions could protect marine fishes, although the mechanism differed between the innate characteristics of upwellings. Most modeled species (primarily tropical fishes) found refuge in the tropical upwelling in Northern Yucatan. However, the highest warming scenario overwhelmed this region. In contrast, the Baja California region lies within the Eastern Boundary Upwelling Systems. While the area experiences an increase in suitability, the northern regions have a higher upwelling intensity acting as environmental barriers for many tropical species. Conversely, in the southern regions where upwelling is weaker, species tend to congregate and persist even during elevated warming, according to the turnover analysis. These findings suggest that tropicalization in higher latitudes may not be as straightforward as previously assumed. Nevertheless, climate change affects numerous ecosystem features, such as trophic relationships, phenology, and other environmental variables not considered here. In addition, uncertainty still exists about the assumption of increasing intensity of upwelling systems.


Assuntos
Mudança Climática , Peixes , Animais , Peixes/fisiologia , Refúgio de Vida Selvagem , México , Ecossistema , Aquecimento Global , Temperatura
12.
Econ Hum Biol ; 54: 101407, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38879898

RESUMO

Global warming is changing precipitation patterns, particularly harming communities in low-and-middle income countries (LMICs). Whilst the long-term effects of being exposed to rainfall shocks early in life on school-achievement tests are well-established, there is little population-based evidence from LMICs on the mechanisms through which these shocks operate. Executive functions (EFs) are key for children's learning abilities. This paper analyses the effects of early exposure to rainfall shocks on four foundational cognitive skills (FCSs), including EFs that have been found to be key predictors of educational success. These skills were measured via a series of tablet-based tasks administered in Peru as part of the Young Lives longitudinal study (YLS). We combine the YLS data with gridded data on monthly precipitation to generate monthly, community-level rainfall shock estimates. The key identification strategy relies on temporary climatic shocks being uncorrelated with other latent determinants of FCSs development. Our results show significant negative effects of early life exposure to rainfall shocks on EFs-especially, on working memory-measured in later childhood. We also find evidence of rainfall shocks decreasing households' abilities to invest in human capital, which may affect both FCSs and domain-specific test scores. Finally, there is suggestive, but not conclusive, evidence that a conditional-cash-transfer program providing poor households with additional financial resources might partially offset the effects of the rainfall shocks.


Assuntos
Cognição , Função Executiva , Chuva , Humanos , Peru , Masculino , Feminino , Estudos Longitudinais , Criança , Fatores Socioeconômicos , Memória de Curto Prazo , Pré-Escolar , Adolescente , Aquecimento Global
13.
Acta amaz ; Acta amaz;54(spe1): e54es22098, Apr.-June 2024. tab, graf, ilus, mapas
Artigo em Inglês | VETINDEX | ID: biblio-1581517

RESUMO

This review discusses observed hydroclimatic trends and future climate projections for the Amazon. Warming over this region is a fact, but the magnitude of the warming trend varies depending on the datasets and length of the analyzed period. The warming trend has been more evident since 1980 and has further enhanced since 2000. Long-term trends in climate and hydrology are assessed. Various studies have reported an intensification of the hydrological cycle and a lengthening of the dry season in the southern Amazon. Changes in floods and droughts, mainly due to natural climate variability and land use change, are also assessed. For instance, in the first half of the 20th century, extreme flood events occurred every 20 years. Since 2000, there has been one severe flood every four years. During the last four decades, the northern Amazon has experienced enhanced convective activity and rainfall, in contrast to decreases in convection and rainfall in the southern Amazon. Climate change in the Amazon will have impacts at regional and global scales. Significant reductions in rainfall are projected for the eastern Amazon.


Essa revisão discute tendências hidroclimáticas observadas e projeções climáticas futuras para a Amazônia. O aquecimento sobre esta região é um fato, mas a magnitude da tendência de aquecimento varia dependendo dos conjuntos de dados e da duração do período analisado. A tendência de aquecimento tornou-se mais evidente a partir de 1980 e aumentou ainda mais desde 2000. São avaliadas as tendências de longo prazo no clima e na hidrologia. Vários estudos relataram uma intensificação do ciclo hidrológico e um prolongamento da estação seca no sul da Amazônia. Mudanças nas cheias e secas, em grande parte devido à variabilidade natural do clima e mudanças no uso da terra, também são avaliadas. Por exemplo, na primeira metade do século XX, eventos extremos de inundação ocorreram a cada 20 anos. Desde 2000, houve uma inundação severa a cada quatro anos. Durante as últimas quatro décadas, o norte da Amazônia experimentou aumento da atividade convectiva e precipitação, em contraste com a diminuição da convecção e precipitação no sul da Amazônia. As mudanças climáticas na Amazônia terão impactos em escalas regional e global.


Assuntos
Mudança Climática , Ecossistema Amazônico , Secas , Inundações , Aquecimento Global
14.
PeerJ ; 12: e16986, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38685936

RESUMO

Environmental heterogeneity poses a significant influence on the functional characteristics of species and communities at local scales. Environmental transition zones, such as at the savanna-forest borders, can act as regions of ecological tension when subjected to sharp variations in the microclimate. For ectothermic organisms, such as lizards, environmental temperatures directly influence physiological capabilities, and some species use different thermoregulation strategies that produce varied responses to local climatic conditions, which in turn affect species occurrence and community dynamics. In the context of global warming, these various strategies confer different types of vulnerability as well as risks of extinction. To assess the vulnerability of a species and understand the relationships between environmental variations, thermal tolerance of a species and community structure, lizard communities in forest-savanna transition areas of two national parks in the southwestern Amazon were sampled and their thermal functional traits were characterized. Then, we investigated how community structure and functional thermal variation were shaped by two environmental predictors (i.e., microclimates estimated locally and vegetation structure estimated from remote sensing). It was found that the community structure was more strongly predicted by the canopy surface reflectance values obtained via remote sensing than by microclimate variables. Environmental temperatures were not the most important factor affecting the occurrence of species, and the variations in ecothermal traits demonstrated a pattern within the taxonomic hierarchy at the family level. This pattern may indicate a tendency for evolutionary history to indirectly influence these functional features. Considering the estimates of the thermal tolerance range and warming tolerance, thermoconformer lizards are likely to be more vulnerable and at greater risk of extinction due to global warming than thermoregulators. The latter, more associated with open environments, seem to take advantage of their lower vulnerability and occur in both habitat types across the transition, potentially out-competing and further increasing the risk of extinction and vulnerability of forest-adapted thermoconformer lizards in these transitional areas.


Assuntos
Lagartos , Microclima , Floresta Úmida , Animais , Lagartos/fisiologia , Pradaria , Brasil , Aquecimento Global
15.
Plant Biol (Stuttg) ; 26(4): 495-498, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38477075

RESUMO

There is growing concern about the fate of tropical forests in the face of rising global temperatures. Doughty et al. (2023) suggest that an increase in air temperature beyond ∼4 °C will result in massive death of tropical forest leaves and potentially tree death. However, this prediction relies on assumptions that likely underestimate the heat tolerance of tropical leaves.


Assuntos
Florestas , Folhas de Planta , Árvores , Clima Tropical , Folhas de Planta/fisiologia , Árvores/fisiologia , Temperatura , Mudança Climática , Termotolerância/fisiologia , Aquecimento Global , Temperatura Alta
16.
Nature ; 629(8010): 114-120, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38538797

RESUMO

Mountain ranges contain high concentrations of endemic species and are indispensable refugia for lowland species that are facing anthropogenic climate change1,2. Forecasting biodiversity redistribution hinges on assessing whether species can track shifting isotherms as the climate warms3,4. However, a global analysis of the velocities of isotherm shifts along elevation gradients is hindered by the scarcity of weather stations in mountainous regions5. Here we address this issue by mapping the lapse rate of temperature (LRT) across mountain regions globally, both by using satellite data (SLRT) and by using the laws of thermodynamics to account for water vapour6 (that is, the moist adiabatic lapse rate (MALRT)). By dividing the rate of surface warming from 1971 to 2020 by either the SLRT or the MALRT, we provide maps of vertical isotherm shift velocities. We identify 17 mountain regions with exceptionally high vertical isotherm shift velocities (greater than 11.67 m per year for the SLRT; greater than 8.25 m per year for the MALRT), predominantly in dry areas but also in wet regions with shallow lapse rates; for example, northern Sumatra, the Brazilian highlands and southern Africa. By linking these velocities to the velocities of species range shifts, we report instances of close tracking in mountains with lower climate velocities. However, many species lag behind, suggesting that range shift dynamics would persist even if we managed to curb climate-change trajectories. Our findings are key for devising global conservation strategies, particularly in the 17 high-velocity mountain regions that we have identified.


Assuntos
Altitude , Migração Animal , Biodiversidade , Mapeamento Geográfico , Aquecimento Global , Animais , África Austral , Brasil , Conservação dos Recursos Naturais , Aquecimento Global/estatística & dados numéricos , Umidade , Indonésia , Chuva , Refúgio de Vida Selvagem , Imagens de Satélites , Especificidade da Espécie , Temperatura , Fatores de Tempo
17.
Sci Total Environ ; 918: 170354, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38307276

RESUMO

The bioenergetic status of fishes has been used to study their physiological responses to temporal changes at interannual scales. We evaluated the physiological responses of swordfish at an interannual scale from the El Niño Southern Oscillation (ENSO): warm phase "El Niño" in 2015 to the cold phase "La Niña" in 2017 and under neutral conditions as well in 2019. Herein, muscle samples from females and males were analyzed to evaluate the bioenergetic status from their biochemical constituents (L: lipids, P: proteins and G: glucose, E: total energy, and FAs: fatty acid profile), elemental composition (C: carbon, N: nitrogen, H: hydrogen), and nutritional indices (L:P, C:N, DHA/C18:1n-3, DHA/C16:0 and ω3/ω6 FAs). The physiological response of swordfish showed an interaction between the year and sex. Herein, the L and E showed similar trends, with the lowest female values found in 2015 and the highest in 2019. Contrary, males showed their highest values in 2015 and lowest in 2019. FA profile differed among years and highlighted significant differences between females and males in 2019. Although the female L:P and C:N ratios were lower in 2015 than in 2017, a decreasing trend in these ratios was found from 2017 to 2019. Moreover, DHA/C18:1n-3, DHA/C16:0 and ω3/ω6 showed higher ratios in females than males in 2019. Our results coincide with the beginning of the ENSO phases; it is therefore likely that the swordfish diet changed in response to the disturbances in environmental conditions. Furthermore, the degree of individual dietary specialization found under the neutral conditions could indicate differences in the feeding behaviors of males vs. females, which may be an adaptive strategy in this species. These findings will aid in understanding the bioenergetic status of swordfish under different climatic scenarios and the current global warming, providing relevant information for the management of this resource.


Assuntos
El Niño Oscilação Sul , Perciformes , Animais , Masculino , Feminino , Oceano Pacífico , Aquecimento Global , Peixes
18.
Artigo em Inglês | MEDLINE | ID: mdl-38397701

RESUMO

Bat species have been observed to have the potential to expand their distribution in response to climate change, thereby influencing shifts in the spatial distribution and population dynamics of human rabies cases. In this study, we applied an ensemble niche modeling approach to project climatic suitability under different future global warming scenarios for human rabies cases in Brazil, and assessed the impact on the probability of emergence of new cases. We obtained notification records of human rabies cases in all Brazilian cities from January 2001 to August 2023, as reported by the State and Municipal Health Departments. The current and future climate data were sourced from a digital repository on the WorldClim website. The future bioclimatic variables provided were downscaled climate projections from CMIP6 (a global model ensemble) and extracted from the regionalized climate model HadGEM3-GC31-LL for three future socioeconomic scenarios over four periods (2021-2100). Seven statistical algorithms (MAXENT, MARS, RF, FDA, CTA, GAM, and GLM) were selected for modeling human rabies. Temperature seasonality was the bioclimatic variable with the highest relative contribution to both current and future consensus models. Future scenario modeling for human rabies indicated a trend of changes in the areas of occurrence, maintaining the current pace of global warming, population growth, socioeconomic instability, and the loss of natural areas. In Brazil, there are areas with a higher likelihood of climatic factors contributing to the emergence of cases. When assessing future scenarios, a change in the local climatic suitability is observed that may lead to a reduction or increase in cases, depending on the region.


Assuntos
Aquecimento Global , Raiva , Humanos , Brasil/epidemiologia , Raiva/epidemiologia , Ecossistema , Mudança Climática
19.
Nature ; 626(7999): 555-564, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38356065

RESUMO

The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern1-3. For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system1. Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions and potentially exacerbate regional climate change. Using examples of disturbed forests across the Amazon, we identify the three most plausible ecosystem trajectories, involving different feedbacks and environmental conditions. We discuss how the inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action. Keeping the Amazon forest resilient in the Anthropocene will depend on a combination of local efforts to end deforestation and degradation and to expand restoration, with global efforts to stop greenhouse gas emissions.


Assuntos
Florestas , Aquecimento Global , Árvores , Secas/estatística & dados numéricos , Retroalimentação , Aquecimento Global/prevenção & controle , Aquecimento Global/estatística & dados numéricos , Árvores/crescimento & desenvolvimento , Incêndios Florestais/estatística & dados numéricos , Incerteza , Recuperação e Remediação Ambiental/tendências
20.
Environ Pollut ; 344: 123323, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38190876

RESUMO

One of the main disturbances caused by coastal nuclear power plants is the discharge of thermal effluents capable of affecting a number of marine systems, including macroalgal forests that support key ecosystem services such as carbon uptake, fisheries increment and coastal protection. This study aimed at describing the long-term trend (1992-2022) in the abundance of Sargassum forests from sites located inside and outside areas affected by the thermal effluent discharged by the Brazilian Nuclear Power Station (BNPS) and at evaluating the relationship between Sargassum cover and seawater temperature. This information is interesting to provide insights on whether and how Sargassum populations would likely be affected by increasing temperature due to climate change. We detected a long-term decline in Sargassum cover inside, but not outside the area affected by the BNPS thermal plume. Mean summer surface seawater temperature above 30 °C was identified as an important factor driving the decline of Sargassum abundance. This study highlights the impact caused by decades of discharge of the BNPS thermal effluent on Sargassum forests, which leads to predict the likely disappearance of marine forests under a climate change scenario in other sites situated in warm temperate regions.


Assuntos
Ecossistema , Aquecimento Global , Brasil , Florestas , Água do Mar , Temperatura , Mudança Climática
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA