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1.
Nat Commun ; 12(1): 1198, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608528

RESUMO

Understanding how species' thermal limits have evolved across the tree of life is central to predicting species' responses to climate change. Here, using experimentally-derived estimates of thermal tolerance limits for over 2000 terrestrial and aquatic species, we show that most of the variation in thermal tolerance can be attributed to a combination of adaptation to current climatic extremes, and the existence of evolutionary 'attractors' that reflect either boundaries or optima in thermal tolerance limits. Our results also reveal deep-time climate legacies in ectotherms, whereby orders that originated in cold paleoclimates have presently lower cold tolerance limits than those with warm thermal ancestry. Conversely, heat tolerance appears unrelated to climate ancestry. Cold tolerance has evolved more quickly than heat tolerance in endotherms and ectotherms. If the past tempo of evolution for upper thermal limits continues, adaptive responses in thermal limits will have limited potential to rescue the large majority of species given the unprecedented rate of contemporary climate change.

2.
Glob Chang Biol ; 27(6): 1309-1317, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33314537

RESUMO

Species are reportedly shifting their distributions poleward and upward in several parts of the world in response to climate change. The extent to which other factors might play a role driving these changes is still unclear. Land-cover change is a major cause of distributional changes, but it cannot be discarded that distributional dynamics might be at times caused by other mechanisms (e.g. dispersal, ecological drift). Using observed changes in the distribution of 82 breeding birds in Great Britain between three time periods 1968-72 (t1 ), 1988-91 (t2 ) and 2007-2011 (t3 ), we examine whether observed bird range shifts between t1 -t2 and t1 -t3 are best explained by climate change or land-cover change, or whether they are not distinguishable from what would be expected by chance. We found that range shifts across the rear edge of northerly distributed species in Great Britain are best explained by climate change, while shifts across the leading edge of southerly distributed species are best explained by changes in land-cover. In contrast, at the northern and southern edges of Great Britain, range dynamics could not be distinguished from that expected by chance. The latter observation could be a consequence of boundary effects limiting the direction and magnitude of range changes, stochastic demographic mechanisms neither associated with climate nor land-cover change or with complex interactions among factors. Our results reinforce the view that comprehensive assessments of climate change effects on species range shifts need to examine alternative drivers of change on equal footing and that null models can help assess whether observed patterns could have arisen by chance alone.

3.
Medwave ; 20(10): e8066, 2020 Nov 17.
Artigo em Espanhol | MEDLINE | ID: mdl-33361751

RESUMO

Introduction: Since the beginning of the COVID-19 pandemic, extensive research has been done on the prognosis of patients with SARS-CoV-2 associated with age, biodemographic conditions, comorbidities, social factors, clinical parameters, inflammatory blood markers, coagulation, biochemical and blood gas parameters, among others. Few studies have addressed this problem in Latin America, so it is of interest to know how the disease plays out in this region. Objective: The purpose of our study is to evaluate the course of COVID-19 in patients admitted to a tertiary center in Chile and to assess factors measured close to hospital admission that may be associated with death and the need for invasive mechanical ventilation. Methods: We did a retrospective cohort study at Indisa Clinic in Santiago, Chile. We included all patients aged 15 years and older hospitalized between March 11 and July 25, 2020. Hospital mortality and severity of the cases were analyzed, and logistic regression models were applied to identify predictors of outcome variables. Results: The sample included 785 subjects. The mean age was 59 years, 59% were men, and 61.3% had comorbidities. Forty five per cent required intensive care, and 24% invasive mechanical ventilation. The overall hospital fatality rate was 18.7%. In intensive care patients, the case fatality was 32.1%, and in those who received invasive mechanical ventilation, it was 59.4%. Independent risk factors for death included age (odds ratio 1.09; 95% confidence interval: 1.07 to 1.12), diabetes (1.68; 1.06 to 2.67), chronic lung disease (2.80; 1.48 to 5.28), increased C-reactive protein, creatinine, and ferritin. No association with sex, public health insurance, history of heart disease, oxygen saturation upon admission, or D-dimer was found. Similar factors were predictors of invasive mechanical ventilation. Discussion: The prognosis and predictive factors in this cohort of patients hospitalized in Chile for COVID-19 were comparable to those reported in similar studies from higher-income countries. Male sex was not associated with a poor prognosis in this group of patients.


Assuntos
/fisiopatologia , Cuidados Críticos/estatística & dados numéricos , Hospitalização , Respiração Artificial/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , /terapia , Chile , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Centros de Atenção Terciária , Adulto Jovem
4.
Food Chem ; : 128615, 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33223289

RESUMO

Maize (Zea mays L.) is one of the most versatile crops worldwide with high socioeconomic relevance. However, mycotoxins produced by pathogenic fungi are of constant concern in maize production, as they pose serious risks to human and animal health. Thus, the search for rapid detection and/or identification methods for mycotoxins and mycotoxin-producing fungi for application in food safety remain important. In this work, we implemented use of near infrared hyperspectral images (HSI-NIR) combined with pattern recognition analysis, partial-least-squares discriminant analysis (PLS-DA) of images, to develop a rapid method for identification of Fusarium verticillioides and F. graminearum. Validation of the HSI-NIR method and subsequent analysis was realized using 15 Fusarium spp. isolates. The method was efficient as a rapid, non-invasive, and non-destructive assessment was achieved with 100% accuracy, sensitivity, and specificity for both fungi.

5.
Medwave ; 20(10)30-11-2020.
Artigo em Inglês, Espanhol | LILACS | ID: biblio-1145803

RESUMO

Introducción Desde el comienzo de la pandemia de COVID-19, se han desarrollado diversas investigaciones sobre el pronóstico de pacientes con SARS-CoV-2 asociado a factores como edad, condiciones biodemográficas, comorbilidades, factores sociales, parámetros clínicos, hematológicos, marcadores inflamatorios, de coagulación, bioquímicos y gasométricos, entre otros. Hasta ahora, existen escasos estudios que hayan abordado el tema en América Latina, por lo que es de interés conocer el comportamiento de la enfermedad en la región. Objetivo Evaluar el curso del COVID-19 en pacientes ingresados en un centro terciario en Chile y analizar factores predictores, medidos en el período cercano a la admisión, que se asocien al pronóstico vital y al uso de ventilación mecánica invasiva. Métodos Estudio de cohorte retrospectivo realizado en Clínica Indisa de Santiago, Chile. Participaron todos los pacientes de 15 años o más hospitalizados entre el 11 de marzo y el 25 de julio de 2020. Se analizó la letalidad hospitalaria, la complejidad de los casos y se aplicaron modelos de regresión logística para identificar predictores de las variables de resultado definidas. Resultados La muestra estuvo constituida por 785 sujetos. La edad media fue 59 años, 59% fueron hombres y 61,3% tenía comorbilidades. El 45% requirió cuidados intensivos y 24% ventilación mecánica invasiva. La letalidad hospitalaria global fue de 18,7%. En pacientes de unidad de cuidados intensivos fue 32,1% y en quienes recibieron ventilación mecánica invasiva 59,4%. Los factores de riesgo independientes de morir incluyeron la edad (Odds ratio 1,09; intervalo de confianza 95%: 1,07 a 1,12), diabetes (1,68; 1,06 a 2,67), enfermedad pulmonar crónica (2,80; 1,48 a 5,28) y mayores niveles de proteína C reactiva, creatinina y ferritina. No se demostró asociación con el sexo, pertenencia al seguro público de salud, antecedente de cardiopatía, obesidad, ni dímero D. Similares factores fueron predictores de ventilación mecánica invasiva. Conclusiones El pronóstico y factores predictores en esta cohorte de pacientes hospitalizados en Chile por COVID-19 fueron comparables en su mayoría a los reportados en estudios similares de países de mayores ingresos. El sexo masculino no fue un factor de mal pronóstico en este grupo de pacientes.


Introduction Since the beginning of the COVID-19 pandemic, extensive research has been done on the prognosis of patients with SARS-CoV-2 associated with age, biodemographic conditions, comorbidities, social factors, clinical parameters, inflammatory blood markers, coagulation, biochemical and blood gas parameters, among others. Few studies have addressed this problem in Latin America, so it is of interest to know how the disease plays out in this region. Objective The purpose of our study is to evaluate the course of COVID-19 in patients admitted to a tertiary center in Chile and to assess factors measured close to hospital admission that may be associated with death and the need for invasive mechanical ventilation. Methods We did a retrospective cohort study at Indisa Clinic in Santiago, Chile. We included all patients aged 15 years and older hospitalized between March 11 and July 25, 2020. Hospital mortality and severity of the cases were analyzed, and logistic regression models were applied to identify predictors of outcome variables. Results The sample included 785 subjects. The mean age was 59 years, 59% were men, and 61.3% had comorbidities. Forty five per cent required intensive care, and 24% invasive mechanical ventilation. The overall hospital fatality rate was 18.7%. In intensive care patients, the case fatality was 32.1%, and in those who received invasive mechanical ventilation, it was 59.4%. Independent risk factors for death included age (odds ratio 1.09; 95% confidence interval: 1.07 to 1.12), diabetes (1.68; 1.06 to 2.67), chronic lung disease (2.80; 1.48 to 5.28), increased C-reactive protein, creatinine, and ferritin. No association with sex, public health insurance, history of heart disease, oxygen saturation upon admission, or D-dimer was found. Similar factors were predictors of invasive mechanical ventilation. Discussion The prognosis and predictive factors in this cohort of patients hospitalized in Chile for COVID-19 were comparable to those reported in similar studies from higher-income countries. Male sex was not associated with a poor prognosis in this group of patients.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Pneumonia Viral/fisiopatologia , Respiração Artificial/estatística & dados numéricos , Infecções por Coronavirus/fisiopatologia , Cuidados Críticos/estatística & dados numéricos , Hospitalização , Pneumonia Viral/mortalidade , Pneumonia Viral/terapia , Prognóstico , Chile , Fatores Sexuais , Estudos Retrospectivos , Fatores de Risco , Estudos de Coortes , Mortalidade Hospitalar , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/terapia , Centros de Atenção Terciária
6.
J Anim Ecol ; 89(11): 2451-2460, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32745275

RESUMO

Global warming is having impacts across the Tree of Life. Understanding species' physiological sensitivity to temperature change and how they relate to local temperature variation in their habitats is crucial to determining vulnerability to global warming. We ask how species' vulnerability varies across habitats and elevations, and how climatically buffered microhabitats can contribute to reduce their vulnerability. We measured thermal sensitivity (critical thermal maximum-CTmax ) of 14 species of Pristimantis frogs inhabiting young and old secondary, and primary forests in the Colombian Andes. Exposure to temperature stress was measured by recording temperature in the understorey and across five microhabitats. We determined frogs' current vulnerability across habitats, elevations and microhabitats accounting for phylogeny and then ask how vulnerability varies under four warming scenarios: +1.5, +2, +3 and +5°C. We found that CTmax was constant across species regardless of habitat and elevation. However, species in young secondary forests are expected to become more vulnerable because of increased exposure to higher temperatures. Microhabitat variation could enable species to persist within their thermal temperature range as long as regional temperatures do not surpass +2°C. The effectiveness of microhabitat buffering decreases with a 2-3°C increase, and is almost null under a 5°C temperature increase. Microhabitats will provide thermal protection to Andean frog communities from climate change by enabling tracking of suitable climates through short distance movement. Conservation strategies, such as managing landscapes by preserving primary forests and allowing regrowth and reconnection of secondary forest would offer thermally buffered microhabitats and aid in the survival of this group.

8.
Phys Rev Lett ; 124(13): 136405, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32302193

RESUMO

The effect of short-range disorder in nodal line semimetals is studied by numerically exact means. For arbitrary small disorder, a novel semimetallic phase is unveiled for which the momentum-space amplitude of the ground-state wave function is concentrated around the nodal line and follows a multifractal distribution. At a critical disorder strength, a semimetal to compressible metal transition occurs, coinciding with a multi- to single-fractality transition. The universality class of this critical point is characterized by the correlation length and dynamical exponents. At considerably higher disorder, an Anderson metal-insulator transition takes place. Our results show that the nature of the semimetallic phase in nonclean samples is fundamentally different from a clean nodal semimetal.

9.
Neuropathology ; 40(2): 180-184, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31758593

RESUMO

Granulomatous amoebic encephalitis caused by free-living amoebae is a rare condition that is difficult to diagnose and hard to treat, generally being fatal. Anti-amoebic treatment is often delayed because clinical signs and symptoms may hide the probable causing agent misleading the appropriate diagnostic test. There are four genera of free-living amoeba associated with human infection, Naegleria, Acanthamoeba sp., Balamuthia and Sappinia. Two boys were admitted with diagnosis of acute encephalitis. The history of having been in contact with swimming pools and rivers, supports the suspicion of an infection due to free-living amoebae. In both cases a brain biopsy was done, the histology confirmed granulomatous amoebic encephalitis with the presence of amoebic trophozoites.

10.
Nat Commun ; 10(1): 5197, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729393

RESUMO

Nature's complexity is intriguing, but the circumstances determining whether or how order emerges from such complexity remains a matter of extensive research. Using the geographical distributions and food preferences of all terrestrial mammal species with masses >3 kg, we show that large mammals group into feeding guilds (species exploiting similar resources) and that these guilds form trophic structures that vary across biomes globally. We identify five trophic structures closely matching climate variability and named them boreal, temperate, semiarid, seasonal tropical and humid tropical owing to their relative overlap with the distribution of biomes. We also find that human activities simplify trophic structures, generally transitioning them to species-poorer states. Detected transitions include boreal and temperate structures becoming depauperate or seasonal- and humid-tropical becoming semiarid. Whether the observed generalities among trophic structures of large mammals are indicative of patterns across whole food webs is matter for further investigation. The results help refine projections of the effects of environmental change on the trophic structure of large mammals.


Assuntos
Clima , Ecossistema , Mamíferos/fisiologia , Distribuição Animal , Animais , Comportamento Alimentar , Cadeia Alimentar , Atividades Humanas , Humanos , Mamíferos/classificação
11.
Ecol Evol ; 9(19): 11136-11144, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31641461

RESUMO

Ecological Niche Models (ENMs) have different performances in predicting potential geographic distributions. Here we meta-analyzed the likely effects of climate change on the potential geographic distribution of 1,205 bird species from the Neotropical region, modeled using eight ENMs and three Atmosphere-Ocean General Circulation Models (AOGCM). We considered the variability in ENMs performance to estimate a weighted mean difference between potential geographic distributions for baseline and future climates. On average, potential future ranges were projected to be from 25.7% to 44.5% smaller than current potential ranges across species. However, we found that 0.2% to 18.3% of the total variance in range shifts occurred "within species" (i.e., owing to the use of different modeling techniques and climate models) and 81.7% to 99.8% remained between species (i.e., it could be explained by ecological correlates). Using meta-analytical techniques akin to regression, we also showed that potential range shifts are barely predicted by bird biological traits. We demonstrated that one can combine and reduce species-specific effects with high uncertainty in ENMs and also explore potential causes of climate change effect on species using meta-analytical tools. We also highlight that the search for powerful correlates of climate change-induced range shifts can be a promising line of investigation.

12.
Nat Ecol Evol ; 3(8): 1153-1161, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31358950

RESUMO

The productivity of marine ecosystems and the services they provide to humans are largely dependent on complex interactions between prey and predators. These are embedded in a diverse network of trophic interactions, resulting in a cascade of events following perturbations such as species extinction. The sheer scale of oceans, however, precludes the characterization of marine feeding networks through de novo sampling. This effort ought instead to rely on a combination of extensive data and inference. Here we investigate how the distribution of trophic interactions at the global scale shapes the marine fish food web structure. We hypothesize that the heterogeneous distribution of species ranges in biogeographic regions should concentrate interactions in the warmest areas and within species groups. We find that the inferred global metaweb of marine fish-that is, all possible potential feeding links between co-occurring species-is highly connected geographically with a low degree of spatial modularity. Metrics of network structure correlate with sea surface temperature and tend to peak towards the tropics. In contrast to open-water communities, coastal food webs have greater interaction redundancy, which may confer robustness to species extinction. Our results suggest that marine ecosystems are connected yet display some resistance to perturbations because of high robustness at most locations.


Assuntos
Ecossistema , Cadeia Alimentar , Animais , Extinção Biológica , Peixes , Humanos , Oceanos e Mares
13.
Ecology ; 100(11): e02820, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31314929

RESUMO

Pairwise interactions between species have both direct and indirect consequences that reverberate throughout the whole ecosystem. In particular, interaction effects may propagate in a spatial dimension, to localities connected by organismal movement. Here we study the propagation of interaction effects with a spatially explicit metacommunity model, where local sites are connected by dispersal, foraging, or by both types of movement. We show that indirect pairwise effects are, in most cases, of the same sign as direct effects if localities are connected by dispersing species. However, if foraging is prevalent, this correspondence is broken, and indirect effects between species often have a different sign than direct effects. This highlights the importance of indirect interactions across space and their inherent unpredictability in complex settings with species foraging across local patches. Further, the effect of a species over another in a local patch does not necessarily correspond to its effect at the metacommunity scale; this correspondence is again mediated by the type of movement across localities. Every species, despite their trophic position or spatial range, displays a non-zero net effect over every other species in our model metacommunities. Thus we show that local dynamics and local interactions between species can trigger indirect effects all across the set of connected patches, and these effects have a distinct signature depending on whether the prevalent connection between patches is via dispersal or via foraging. However, the magnitude of this effect between any two species strongly decays with the distance between them. These theoretical results strengthen the importance of considering indirect effects across species at both the community and metacommunity levels, highlight the differences between types of movement across locations, and thus open novel avenues for the study of interaction effects in spatially explicit settings.


Assuntos
Ecossistema , Dinâmica Populacional
14.
Sci Adv ; 5(1): eaat4858, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30746437

RESUMO

Demand for models in biodiversity assessments is rising, but which models are adequate for the task? We propose a set of best-practice standards and detailed guidelines enabling scoring of studies based on species distribution models for use in biodiversity assessments. We reviewed and scored 400 modeling studies over the past 20 years using the proposed standards and guidelines. We detected low model adequacy overall, but with a marked tendency of improvement over time in model building and, to a lesser degree, in biological data and model evaluation. We argue that implementation of agreed-upon standards for models in biodiversity assessments would promote transparency and repeatability, eventually leading to higher quality of the models and the inferences used in assessments. We encourage broad community participation toward the expansion and ongoing development of the proposed standards and guidelines.


Assuntos
Biodiversidade , Modelos Teóricos , Monitoramento Ambiental/normas , Guias como Assunto , Revisão por Pares , Análise Espaço-Temporal
15.
J Anim Ecol ; 88(2): 247-257, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30303530

RESUMO

Research addressing the effects of global warming on the distribution and persistence of species generally assumes that population variation in thermal tolerance is spatially constant or overridden by interspecific variation. Typically, this rationale is implicit in sourcing one critical thermal maximum (CTmax ) population estimate per species to model spatiotemporal cross-taxa variation in heat tolerance. Theory suggests that such an approach could result in biased or imprecise estimates and forecasts of impact from climate warming, but limited empirical evidence in support of those expectations exists. We experimentally quantify the magnitude of intraspecific variation in CTmax among lizard populations, and the extent to which incorporating such variability can alter estimates of climate impact through a biophysical model. To do so, we measured CTmax from 59 populations of 15 Iberian lizard species (304 individuals). The overall median CTmax across all individuals from all species was 42.8°C and ranged from 40.5 to 48.3°C, with species medians decreasing through xeric, climate-generalist and mesic taxa. We found strong statistical support for intraspecific differentiation in CTmax by up to a median of 3°C among populations. We show that annual restricted activity (operative temperature > CTmax ) over the Iberian distribution of our study species differs by a median of >80 hr per 25-km2 grid cell based on different population-level CTmax estimates. This discrepancy leads to predictions of spatial variation in annual restricted activity to change by more than 20 days for six of the study species. Considering that during restriction periods, reptiles should be unable to feed and reproduce, current projections of climate-change impacts on the fitness of ectotherm fauna could be under- or over-estimated depending on which population is chosen to represent the physiological spectra of the species in question. Mapping heat tolerance over the full geographical ranges of single species is thus critical to address cross-taxa patterns and drivers of heat tolerance in a biologically comprehensive way.


Assuntos
Lagartos , Termotolerância , Animais , Clima , Mudança Climática , Aquecimento Global
16.
Sci Total Environ ; 625: 1596-1605, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29996456

RESUMO

Several studies estimating the effects of global environmental change on biodiversity are focused on climate change. Yet, non-climatic factors such as changes in land cover can also be of paramount importance. This may be particularly important for habitat specialists associated with human-dominated landscapes, where land cover and climate changes may be largely decoupled. Here, we tested this idea by modelling the influence of climate, landscape composition and pattern, on the predicted future (2021-2050) distributions of 21 farmland bird species in the Iberian Peninsula, using boosted regression trees and 10-km resolution presence/absence data. We also evaluated whether habitat specialist species were more affected by landscape factors than generalist species. Overall, this study showed that the contribution of current landscape composition and pattern to the performance of species distribution models (SDMs) was relatively low. However, SDMs built using either climate or climate plus landscape variables yielded very different predictions of future species range shifts and, hence, of the geographical patterns of change in species richness. Our results indicate that open habitat specialist species tend to expand their range, whereas habitat generalist species tend to retract under climate change scenarios. The effect of incorporating landscape factors were particularly marked on open habitat specialists of conservation concern, for which the expected expansion under climate change seems to be severely constrained by land cover change. Overall, results suggest that particular attention should be given to landscape change in addition to climate when modelling the impacts of environmental changes for both farmland specialist and generalist bird distributions.


Assuntos
Aves/fisiologia , Mudança Climática , Ecossistema , Monitoramento Ambiental/métodos , Animais , Biodiversidade , Espanha
17.
Ecology ; 99(10): 2327-2337, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30030927

RESUMO

No species can persist in isolation from other species, but how biotic interactions affect species persistence is still a matter of inquiry. Is persistence more likely in communities with higher proportion of competing species, or in communities with more positive interactions? How do different components of community structure mediate this relationship? We address these questions using a novel simulation framework that generates realistic communities with varying numbers of species and different proportions of biotic interaction types within and across trophic levels. We show that when communities have fewer species, persistence is more likely if positive interactions-such as mutualism and commensalism-are prevalent. In species-rich communities, the disproportionate effect of positive interactions on persistence is diluted and different combinations of biotic interaction types can coexist without affecting persistence significantly. We present the first theoretical examination of how multiple-interaction networks with varying architectures relate to local species persistence, and provide insight about the underlying causes of stability in communities.


Assuntos
Simbiose
18.
Sci Data ; 5: 180022, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29533392

RESUMO

How climate affects species distributions is a longstanding question receiving renewed interest owing to the need to predict the impacts of global warming on biodiversity. Is climate change forcing species to live near their critical thermal limits? Are these limits likely to change through natural selection? These and other important questions can be addressed with models relating geographical distributions of species with climate data, but inferences made with these models are highly contingent on non-climatic factors such as biotic interactions. Improved understanding of climate change effects on species will require extensive analysis of thermal physiological traits, but such data are both scarce and scattered. To overcome current limitations, we created the GlobTherm database. The database contains experimentally derived species' thermal tolerance data currently comprising over 2,000 species of terrestrial, freshwater, intertidal and marine multicellular algae, plants, fungi, and animals. The GlobTherm database will be maintained and curated by iDiv with the aim to keep expanding it, and enable further investigations on the effects of climate on the distribution of life on Earth.

19.
Glob Chang Biol ; 24(1): e55-e66, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28710898

RESUMO

Intraspecific genetic variability is critical for species adaptation and evolution and yet it is generally overlooked in projections of the biological consequences of climate change. We ask whether ongoing climate changes can cause the loss of important gene pools from North Atlantic relict kelp forests that persisted over glacial-interglacial cycles. We use ecological niche modelling to predict genetic diversity hotspots for eight species of large brown algae with different thermal tolerances (Arctic to warm temperate), estimated as regions of persistence throughout the Last Glacial Maximum (20,000 YBP), the warmer Mid-Holocene (6,000 YBP), and the present. Changes in the genetic diversity within ancient refugia were projected for the future (year 2100) under two contrasting climate change scenarios (RCP2.6 and RCP8.5). Models predicted distributions that matched empirical distributions in cross-validation, and identified distinct refugia at the low latitude ranges, which largely coincide among species with similar ecological niches. Transferred models into the future projected polewards expansions and substantial range losses in lower latitudes, where richer gene pools are expected (in Nova Scotia and Iberia for cold affinity species and Gibraltar, Alboran, and Morocco for warm-temperate species). These effects were projected for both scenarios but were intensified under the extreme RCP8.5 scenario, with the complete borealization (circum-Arctic colonization) of kelp forests, the redistribution of the biogeographical transitional zones of the North Atlantic, and the erosion of global gene pools across all species. As the geographic distribution of genetic variability is unknown for most marine species, our results represent a baseline for identification of locations potentially rich in unique phylogeographic lineages that are also climatic relics in threat of disappearing.


Assuntos
Mudança Climática , Kelp/fisiologia , Refúgio de Vida Selvagem , Oceano Atlântico , Variação Genética , Filogeografia
20.
Glob Chang Biol ; 24(3): 1357-1370, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29152817

RESUMO

Criticism has been levelled at climate-change-induced forecasts of species range shifts that do not account explicitly for complex population dynamics. The relative importance of such dynamics under climate change is, however, undetermined because direct tests comparing the performance of demographic models vs. simpler ecological niche models are still lacking owing to difficulties in evaluating forecasts using real-world data. We provide the first comparison of the skill of coupled ecological-niche-population models and ecological niche models in predicting documented shifts in the ranges of 20 British breeding bird species across a 40-year period. Forecasts from models calibrated with data centred on 1970 were evaluated using data centred on 2010. We found that more complex coupled ecological-niche-population models (that account for dispersal and metapopulation dynamics) tend to have higher predictive accuracy in forecasting species range shifts than structurally simpler models that only account for variation in climate. However, these better forecasts are achieved only if ecological responses to climate change are simulated without static snapshots of historic land use, taken at a single point in time. In contrast, including both static land use and dynamic climate variables in simpler ecological niche models improve forecasts of observed range shifts. Despite being less skilful at predicting range changes at the grid-cell level, ecological niche models do as well, or better, than more complex models at predicting the magnitude of relative change in range size. Therefore, ecological niche models can provide a reasonable first approximation of the magnitude of species' potential range shifts, especially when more detailed data are lacking on dispersal dynamics, demographic processes underpinning population performance, and change in land cover.


Assuntos
Distribuição Animal , Aves/fisiologia , Mudança Climática , Modelos Biológicos , Animais , Ecossistema , Previsões , Dinâmica Populacional , Especificidade da Espécie
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