Can amphibians take the heat? Vulnerability to climate warming in subtropical and temperate larval amphibian communities

Predicting the biodiversity impacts of global warming implies that we know where and with what magnitude these impacts will be encountered. Amphibians are currently the most threatened vertebrates, mainly due to habitat loss and to emerging infectious diseases. Global warming may further exacerbate their decline in the near future, although the impact might vary geographically. We predicted that subtropical amphibians should be relatively susceptible to warming‐induced extinctions because their upper critical thermal limits (CT max) might be only slightly higher than maximum pond temperatures (T max). We tested this prediction by measuring CT max and T max for 47 larval amphibian species from two thermally distinct subtropical communities (the warm community of the Gran Chaco and the cool community of Atlantic Forest, northern Argentina), as well as from one European temperate community. Upper thermal tolerances of tadpoles were positively correlated (controlling for phylogeny) with maximum pond temperatures, although the slope was steeper in subtropical than in temperate species. CT max values were lowest in temperate species and highest in the subtropical warm community, which paradoxically, had very low warming tolerance (CT max–T max) and therefore may be prone to future local extinction from acute thermal stress if rising pond T max soon exceeds their CT max. Canopy‐protected subtropical cool species have larger warming tolerance and thus should be less impacted by peak temperatures. Temperate species are relatively secure to warming impacts, except for late breeders with low thermal tolerance, which may be exposed to physiological thermal stress in the coming years.Agencia Española de Cooperación y Desarrollo (AECID)Ministerio de Ciencia e Innovación de España CGL2009-12767-C02-02 y CGL2008-04814- C02-02Ministerio de Educación y Cultura de España. Beca postdoctoral MEC2007-0944Ministerio de Ciencia e Innovación de España. Beca posdoctoral de Juan de la Cierv

El estudio de las tolerancias térmicas para el examen de hipótesis biogeográficas y de la vulnerabilidad de los organismos ante el calentamiento global. Ejemplos en anfíbios

Agencia Española de Cooperación y Desarrollo (AECID) A/016892/08, A/023032/09 y AP/038788/11Ministerio de Ciencia e Innovación de España CGL2009-1276-C02-02 y CGL2008-04814-C02-02Ministerio de Educación y Cultura de España. Beca posdoctoral MEC2007-0944Ministerio de Economía y Competitividad de España. Beca FPI BES-2010-032912Fundação para a Ciência e a Tecnologia de Portugal (FCT). Beca SFRH/BD/60271/200

Thermal tolerance and sensitivity in amphibians

Atualmente vivemos um cenário de alterações climáticas em que se prevê o aumento da temperatura média e da ocorrência de picos de temperatura extrema, entre outros. Sabendo que os anfíbios correspondem a uma parte importante da biodiversidade mundial e que estes possuem um número de características fisiológicas, ecológicas e de história de vida que os tornam bastante susceptíveis a mudanças no ambiente, é fundamental conseguir identificar as espécies/comunidades mais vulneráveis ao aquecimento global. Assim, o estudo da tolerância e da sensibilidade térmica das espécies, e em particular dos anfíbios, é muito importante quando se pretende prever o impacto que o aumento das temperaturas poderá ter na fauna e flora do planeta.We are currently living in a scenario of climate change in which the rise of the average environmental temperatures and the increase of events of extreme temperature peaks is forecasted, among others. The study of the thermal tolerance and sensitivity is very important, particularly in amphibians, when forecasting the impact of rising temperatures on both the fauna and flora of the world. Knowing that amphibians are an essential part of the world’s terrestrial and aquatic biodiversity, and that they possess a series of ecophysiological characteristics and life history traits, which makes them very susceptible to environmental changes, it is essential to identify the species/communities that are more vulnerable to global warming.Agencia Española de Cooperación Internacional para el Desarrollo (AECID) A/016892/08 y A/023032/09Ministerio de Ciencia e Innovación de España (MICINN) CGL2009-12767-C02-02 y CGL2008-04814-C02-0

Contrasting effects of environmental factors during larval stage on morphological plasticity in post-metamorphic frogs

In organisms with complex life cycles, environmentally induced plasticity across sequential stages can have important consequences on morphology and life history traits such as developmental and growth rates. However, previous research in amphibians and other ectothermic vertebrates suggests that some morphological traits are generally insensitive to environmental inductions. We conducted a literature survey to examine the allometric responses in relative hind leg length and head shape of post-metamorphic anuran amphibians to induced environmental (temperature, resource level, predation and desiccation risk) variation operating during the larval phase in 44 studies using 19 species. To estimate and compare plastic responses across studies, we employed both an index of plasticity and effect sizes from a meta-analysis. We found contrasting trait responses to different environmental cues. Higher temperatures increased development more than growth rate and induced smaller heads but not overall shifts in hind leg length. In contrast, an increment in resource availability increased growth more than development, with a parallel increase in hind leg length but no change in head shape. Increases in predation risk decreased both development and growth rates and slightly reduced relative hind leg length, but there was no change in head shape. Pond desiccation induced quick development and low growth rates, with no changes in morphology. Across environments, both hind leg and head shape plasticity were positively correlated with growth rate plasticity. However, plasticity of developmental rate was only correlated with head shape plasticity. Overall, these results suggest that environmental trends predicted by global warming projections, such as increasing pond temperature and accelerating pond desiccation, will significantly influence hind leg and head morphology in metamorphic frogs, which may affect performance and, ultimately, fitness.Fil: Tejedo, Miguel. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Marangoni, Federico. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Pertoldi, Cino. University Aarhus; DinamarcaFil: Richter-Boix, Alex. Uppsala University; SueciaFil: Laurila, Anssi. Uppsala University; SueciaFil: Orizaola, Germán. Uppsala University; SueciaFil: Nicieza, Alfredo G.. Universidad de Oviedo; EspañaFil: Álvarez, David. Universidad de Oviedo; EspañaFil: Gomez Mestre, Iván. Universidad de Oviedo; España. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; Españ

The Amphibian Research in Sierra Norte Natural Park, sw. Spain

A nivel mundial, los anfibios están desapareciendo por causas muy diversas, algunas poco conocidas, como los efectos del cambio climático. Son, en general, especies muy sensibles a los cambios en el medio y, por tanto, resultan especialmente interesantes tanto para los investigadores como para todo aquel interesado en la conservación de la biodiversidad. Desde hace años, investigadores del CSIC y otros centros españoles (Universidad de Sevilla y Granada) y extranjeros (Universidad de Lisboa, Portugal, Universidad de Chile y la Universidad de Western Kentucky, USA) están realizando estudios sobre bioacústica, biología de la reproducción, variación geográfi ca y adaptaciones locales, morfología y dinámica poblacional de algunas especies presentes en el Parque Natural de la Sierra Norte. Los resultados más relevantes de tales estudios se resumen en estas páginas, incluyendo resultados preliminares de un proyecto nacional I+D+i, actualmente en marcha. Además, sus observaciones han permitido detectar y sugerir acciones que están permitiendo mejorar la conservación de algunas de estas poblaciones. Con ello esperamos contribuir a un mejor conocimiento y conservación de estas especies y su medio.Currently, there is a global decline of amphibians due to an array of different factors, including global warming. Amphibians are among the more sensitive vertebrate species to changes in the environment, what target them both for research and for anyone interested in biodiversity conservation. During the last decade, researchers from diff erent institutions, including CSIC, the University of Seville, the University of Granada, the University of Lisbon, the University of Chile, and Western Kentucky University, have conducted studies on population divergence and local adaptations, bioacoustics, reproductive biology, morphology, and population dynamics of some of the anuran species occurring in the Natural Park of Sierra Norte. In this paper, we summarize relevant results from these studies, including preliminary results from an ongoing I+D+i national project. These studies have already help us to detect and suggest some conservation actions for amphibians, which once implemented, will improve the conservation status of some of these amphibian populations. Our hope is to contribute to increase the knowledge and conservation of these species and their habitats