Body mass, temperature, and pathogen intensity differentially affect critical thermal maxima and their population‐level variation in a solitary bee

Ecology and Evolution, Год журнала: 2024, Номер 14(2)

Опубликована: Фев. 1, 2024

Climate change presents a major threat to species distribution and persistence. Understanding what abiotic or biotic factors influence the thermal tolerances of natural populations is critical assessing their vulnerability under rapidly changing regimes. This study evaluates how body mass, local climate, pathogen intensity heat tolerance its population-level variation (SD) among individuals solitary bee

Язык: Английский

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Low desiccation and thermal tolerance constrains a terrestrial amphibian to a rare and disappearing microclimate niche

Conservation Physiology, Год журнала: 2021, Номер 9(1)

Опубликована: Янв. 1, 2021

Abstract Drier and hotter conditions caused by climate change threaten species that exist close to their physiological limits, as well those with limited ability move. Habitat specialists may also be particularly vulnerable if they have specific abiotic requirements. Here we assess whether thermal hydric constraints can explain the highly restricted declining distributions of critically endangered terrestrial-breeding frog, Geocrinia alba. We evaluate species’ vulnerability based on similarity current microclimatic limits. found G. alba had low thresholds desiccation tolerance relative other anuran species. The estimated optimum (Topt) critical maxima (CTmax) were 23.3°C 29.6°C, respectively, adult frogs an absorption threshold (AT, lowest water potential at which absorbed from a substrate) −50 kPa, recorded for amphibian. Comparing environmental loss in field using agar models showed riparian habitats where occur provide unique microclimate landscape, offering significantly lower risk during extreme summer compared immediately adjacent terrestrial habitats. Monitoring within occupied frog over 2 years dry hot AT was exceeded six eight sites, Topt two sites. Given apparent rarity suitable microclimates regional drying–warming trend, suggest occupies potentially disappearing niche indicative habitat rely ephemeral drainages. More broadly, this study highlights tightly constrain amphibian need considered along when predicting impacts change.

Язык: Английский

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High thermal tolerance in high‐elevation species and laboratory‐reared colonies of tropical bumble bees

Ecology and Evolution, Год журнала: 2022, Номер 12(12)

Опубликована: Дек. 1, 2022

Abstract Bumble bees are key pollinators with some species reared in captivity at a commercial scale, but significant evidence of population declines and alarming predictions substantial impacts under climate change scenarios. While studies on the thermal biology temperate bumble still limited, they entirely absent from tropics where effects expected to be greater. Herein, we test whether bees' tolerance decreases elevation stable optimal conditions used laboratory‐reared colonies reduces their tolerance. We assessed changes lower (CT Min ) upper Max critical limits four two elevations (2600 3600 m) Colombian Andes, examined effect body size, evaluated wild‐caught individuals Bombus pauloensis . also compiled information potential predictors for broadscale patterns variation. found that CT decreased increasing elevation, while was similar between elevations. slightly higher (0.84°C) than similar, size did not. Latitude is good predictor annual mean temperature, maximum minimum temperatures warmest coldest months both The stronger response , supports Brett's heat‐invariant hypothesis, which has been documented other taxa. Andean appear about as heat tolerant those areas, suggesting aspects besides temperature (e.g., water balance) might more determinant environmental factors these species. Laboratory‐reared adequate surrogates addressing questions global warming impacts.

Язык: Английский

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Factors influencing persistence of a threatened amphibian in restored wetlands despite severe population decline during climate change driven weather extremes

Biodiversity and Conservation, Год журнала: 2022, Номер 31(4), С. 1267 - 1287

Опубликована: Март 1, 2022

Abstract Biodiversity is in global decline during the Anthropocene. Declines have been caused by multiple factors, such as habitat removal, invasive species, and disease, which are often targets for conservation management. However, interventions under threat from climate change induced weather extremes. Weather extremes becoming more frequent devastating an example of this was 2019/2020 Australian drought mega-fires. We provide a case study impacts these extreme events had on population threatened frog Litoria aurea that occurs constructed designed to reduce impact introduced fish chytrid-induced disease. aimed determine what factors influenced persistence so design wetlands can be further optimised future-proof amphibians. achieved with 4 years (2016–2020) intensive capture–recapture surveys austral spring summer across nine ( n = 94 repeat surveys). As hypothesized, sharp reduction size, but achieved. The most parsimonious predictor survival interaction between maximum air temperature rainfall, indicating likely decline. Survival positively correlated wetland vegetation coverage, positing important feature target enhance resilience restoration programs. Additionally, benefits obtained measures chytrid prevalence were not compromised drought, there positive correlation salinity survival. emphasize many species may able persist worse scenarios. Despite potential augmentation buffer effects weather, action needed extinction risk.

Язык: Английский

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Beyond Janzen's Hypothesis: How Amphibians That Climb Tropical Mountains Respond to Climate Variation

Integrative Organismal Biology, Год журнала: 2023, Номер 5(1)

Опубликована: Янв. 1, 2023

Janzen's hypothesis (JH) posits that low thermal variation selects for narrow physiological tolerances, and thus small species distributional ranges high turnover along tropical elevational gradients. Although this has been intensely revisited, it does not explain how many may exhibit broad distributions, encompassing altitudinal Moreover, the responses of remain largely unknown, limiting our understanding on they respond to climate variation. To fill these knowledge gaps, we tested a major component JH, variability (CVH), which predicts broader tolerance breadth (Tbr = CTmax - CTmin) with temperature Specifically, sampled populations five amphibian distributed in two mountain Brazil's Atlantic Forest test CTmin vary Since both water balance traits are pivotal evolutionary history amphibians, also measured rates dehydration rehydration their relations tolerances. We found increasing altitude did always lead Tbr, since changes were species-specific. In addition, show consistent altitude, correlations between hydric traits. While highland at lower risk stress than lowland counterparts, living far from upper limits. As consequence intraspecific spatial context-dependent heterogeneous. Together recent studies showing tolerances some amphibians comparable temperate taxa, findings highlight several conform predictions made by either CVH or other important hypotheses concerning This reinforces need overcome geographical bias data improve change impacts biodiversity. (Portuguese abstract) Resumo A Hipótese de Janzen postula que baixa variação térmica seleciona tolerâncias fisiológicas estreitas e, portanto, amplitudes restritas distribuição das espécies e alta substituição ao longo gradientes altitudinais tropicais. Embora intensamente revisitada, essa hipótese não explica como tropicais podem exibir amplas distribuições geográficas, abrangendo altitudinais. Além disso, as respostas permanecem amplamente desconhecidas, limitando nossa compreensão sobre elas respondem à climática. Para preencher essas lacunas conhecimento, testamos um componente importante da Variabilidade Climática prevê uma maior amplitude tolerância quando temperatura ambiental é mais ampla. Especificamente, amostramos populações cinco anfíbios distribuídas em duas cadeias montanhosas na Mata Atlântica do Brasil para testar variam altitude. Dado parâmetros térmicos balanço hídrico são fundamentais história evolutiva dos anfíbios, também medimos taxas desidratação reidratação suas relações com térmicas. Encontramos ampla o aumento nem sempre conduz Tbr ampla, vez mudanças foram espécie-específicas. encontramos apresentou consistente mudança correlações entre hídricos baixas. maiores altitudes apresentaram menor risco estresse térmico mesma espécie menores, ambas estão vivendo longe seus limites superiores. Em consequência intraespecífica fisiológicos espacial no clima climática contexto-dependentes heterogêneas. Juntamente estudos recentes indicando térmicas alguns comparáveis táxons temperados, nossas descobertas destacam várias estar acordo previsões feitas pela ou outras hipóteses importantes fisiológica. Isso reforça necessidade superar viés geográfico dados aperfeiçoar impactos climáticas biodiversidade. (Spanish Resumen La hipótesis la baja variación selecciona tolerancias estrechas y, por lo tanto, rangos distribución especies restringidos con rotación largo elevación tropicales. Aunque esta ha sido discutida, cómo tropicales pueden exhibir distribuciones amplias, abarcando altitudinales. Además, las respuestas siguen siendo bastante desconocidas, limita comprensión responden llenar estos vacíos conocimiento, examinamos un Hipótesis Variabilidad predice mayor amplitud tolerancia cuando es más amplia. Específicamente, tomamos muestras poblaciones anfibios distribuidas en cadenas montañosas el Bosque Atlántico verificar y varían este gradiente elevación. los rasgos equilibrio son fundamentales historia anfibios, también tasas deshidratación rehidratación sus relaciones una amplia altitud siempre conduce amplia, ya cambios específicos especie. muestra altitud, bajas correlaciones térmicos. Si bien tierras altas tienen riesgo estrés contrapartes bajas, se encuentran lejos límites Como consecuencia fueron dependientes del contexto heterogéneas. Junto estudios recientes muestran algunos comparables taxones zonas templadas, nuestros hallazgos resaltan varias ajustarse predicciones hechas u otras Esto refuerza necesidad sesgo datos mejorar cambio climático biodiversidad.

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Vulnerability of amphibians to global warming

Опубликована: Янв. 11, 2024

Amphibians are the most threatened vertebrates, yet their resilience to rising temperatures remains poorly understood. This is primarily because knowledge of thermal tolerance taxonomically and geographically biased, compromising global climate vulnerability assessments. Here, we employed a novel data imputation approach predict heat 60% amphibian species assessed daily temperature variation in refugia. We found 198 out 5203 currently exposed overheating events shaded terrestrial conditions. Despite accounting for plasticity, 4°C increase would create step-change impact severity, pushing 9.4% beyond physiological limits. In Southern Hemisphere, tropical encounter disproportionally more events, while Northern non-tropical susceptible. Our findings challenge evidence latitudinal gradients risk underscore importance considering climatic variability Notably, our conservative estimates assume access microenvironments, implying that warming’s impacts on amphibians may exceed projections. microclimate-explicit analyses also demonstrate how availability vegetation water bodies critical buffering during waves. Immediate action needed preserve manage these microhabitat features.

Язык: Английский

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Predators like it hot: Thermal mismatch in a predator–prey system across an elevational tropical gradient

Journal of Animal Ecology, Год журнала: 2021, Номер 90(8), С. 1985 - 1995

Опубликована: Май 4, 2021

Climate change may have dramatic consequences for communities through both direct effects of peak temperatures upon individual species and interspecific mismatches in thermal sensitivities interacting organisms which mediate changes interactions (i.e. predation). Despite this, there is a paucity information on the patterns spatial physiological sensitivity (at landscape local scales) could ultimately influence geographical variation climate community processes. In order to assess where these impacts occur, we first need evaluate heterogeneity degree mismatch tolerances between organisms. We quantify magnitude maximum (CTmax ) minimum (CTmin among predator-prey system dragonfly anuran larvae tropical montane (242-3,631 m) habitat (ponds streams) gradients. To compare predator prey, coined parameters predatory tolerance margins (PTMmax PTMmin ), or difference CTmax CTmin sampled across elevational Our analyses revealed that: (a) predators exhibit higher heat than prey (~4°C), trend remained stable habitats elevations. contrast, found no differences groups. (b) Maximum decreased with elevation, but only varied habitats, pond exhibiting stream species. (c) Pond-dwelling from low elevations (0-1,500 m a.s.l.) be more susceptible warming their highland counterparts because are slightly exposed environmental temperatures. The greater relative naiad further increase vulnerability lowland tadpoles due potentially enhanced indirect predation rates by heat-tolerant predators. However, experimental work required establish population-level this biotic such as predator-prey. ​.El cambio climático puede acarrear consecuencias dramáticas en las comunidades, ya sea mediante los efectos directos de temperaturas extremas sobre cada especie particular, o por indirectos interacciones entre especies (p.ej. depredación). Sin embargo, existe actualmente información escala regional patrones geográficos la sensibilidad térmica que interaccionan, última instancia afectar procesos comunidades. Es ello para estimar dónde se van producir impactos del calentamiento, necesitamos primero tener un conocimiento niveles desajustes espaciales puedan presentar biológicas. En este estudio hemos cuantificado interespecíficos tolerancias térmicas al calor y frío sistema depredador-presa, larvas libélulas anfibios, gradientes altitud hábitats (charcas arroyos). Para comparar depredador presa, definimos dos parámetros: margen máximo mínimo tolerancia depredación definiría como diferencia respectiva organimos interaccionan. Nuestros resultados muestran: (1) depredadores muestran mayor presas mantiene invariable altitudes. Por el contrario, encontramos diferencias mínimas estos grupos. (2) Las máximas mínimas, tanto presas, disminuyen con elevación pero sólo varía hábitats, siendo más resistentes charcas frente arroyos. (3) habitan baja son susceptibles recibir calentamiento alta montaña, sus ligeramente superiores registran actualidad. La relativa presentan depredadoras libélulas, incrementar vulnerabilidad renacuajos altitud, pueden infringir ellos depredadoras, tolerantes calor. es necesario realizar investigaciones experimentales, establecer individuales poblacionales desajuste bióticas, depredador-presa. ​.

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Synergistic effects of warming and disease linked to high mortality in cool-adapted terrestrial frogs

Biological Conservation, Год журнала: 2020, Номер 245, С. 108521 - 108521

Опубликована: Май 1, 2020

Язык: Английский

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Functional responses to anthropogenic disturbance and the importance of selected traits: A study case using dung beetles

Ecological Entomology, Год журнала: 2022, Номер 47(4), С. 503 - 514

Опубликована: Фев. 14, 2022

Abstract Functional diversity has been defined as the value, range, distribution, and relative abundance of functional traits individuals that belong to an ecosystem. Thus, response organisms environmental disturbances depends largely on their traits. Here, we evaluated dung beetle associated Atlantic Forest replacement using a matrix with 25 (10 morphological, four ethological, 11 physiological). We compared among native disturbed habitats multi single trait approach. Contrary previous studies, higher disturbance (open pasture) exhibited forests, which could be explained by incorporation physiological Species open showed extreme values such traits, explaining observed pattern. The inclusion several represent both species ecology morphology, physiology, generates different results those in studies. This highlights importance including large variety future propose must (1) carefully chosen according biological basis; (2) physiology; (3) include effect In addition, consider it is extremely relevant approach A combination all these considerations will provide more realistic complete overview patterns potential consequences human ecosystem functioning.

Язык: Английский

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The effect of thermal microenvironment in upper thermal tolerance plasticity in tropical tadpoles. Implications for vulnerability to climate warming

Journal of Experimental Zoology Part A Ecological and Integrative Physiology, Год журнала: 2022, Номер 337(7), С. 746 - 759

Опубликована: Июнь 8, 2022

Abstract Current climate change is generating accelerated increase in extreme heat events and organismal plastic adjustments upper thermal tolerances, (critical maximum ‐CT max ) are recognized as the quicker mitigating mechanisms. However, current research casts doubt on actual role of acclimation to face impacts, due its low magnitude weak environmental signal. Here, we examined these drawbacks by first estimating extent examining known sources variation affecting CT expression, such daily fluctuation heating rates. Second, whether pattern plasticity dependent environment comparing responses six species tropical amphibian tadpoles inhabiting thermally contrasting open shade habitats and, finally, their warming tolerances (WT = – temperatures) estimator risk. We found that improved exposed fluctuating regimens. Slow rates implying longer duration assays determined a depending environment. Shade habitat suffer decline whereas greatly it, suggesting an adaptive differential ability hot quick hardening adjustments. Open although overall acclimate more than species, cannot capitalize this beneficial max, because ambient temperatures very close critical limits, may not be large enough reduce acute stress under ongoing global warming.

Язык: Английский

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