Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1111/1365-2435.13507
Titel (primär) Heat tolerance is more variable than cold tolerance across species of Iberian lizards after controlling for intraspecific variation
Autor Herrando‐Pérez, S.; Monasterio, C.; Beukema, W.; Gomes, V.; Ferri-Yáñez, F.; Vieites, D.R.; Buckley, L.B.; Araújo, M.B.
Quelle Functional Ecology
Erscheinungsjahr 2020
Department BZF
Band/Volume 34
Heft 3
Seite von 631
Seite bis 645
Sprache englisch
Keywords climate change; CTmax; CTmin; ecophysiology; ectotherm; macroecology; plasticity; resampling
  1. The widespread observation that heat tolerance is less variable than cold tolerance (‘cold‐tolerance asymmetry’) leads to the prediction that species exposed to temperatures near their thermal maxima should have reduced evolutionary potential for adapting to climate warming. However, the prediction is largely supported by species‐level global studies based on single estimates of both physiological metrics per taxon.
  2. We ask whether cold‐tolerance asymmetry holds for Iberian lizards after accounting for intraspecific variation in critical thermal maxima (CTmax) and minima (CTmin). To do so, we quantified CTmax and CTmin for 58 populations of 15 Iberian lizard species (299 individuals). Then, we randomly selected one population from each study species (population sample = 15 CTmax and CTmin values), tested for differences between the variance of both thermal metrics across species, and repeated the test for thousands of population samples as if we had undertaken the same study thousands of times, each time sampling one different population per species (as implemented in global studies).
  3. The ratio of variances in CTmax to CTmin across species varied up to 16‐fold depending on the populations chosen. Variance ratios show how much CTmax departs from the cross‐species mean compared to CTmin, with a unitary ratio indicating equal variance of both thermal limits. Sampling one population per species was six times more likely to result in the observation of greater CTmax variance (‘heat‐tolerance asymmetry’) than cold‐tolerance asymmetry. The probability of obtaining the data (given the null hypothesis of equal variance being true) was twice as likely for cases of cold‐tolerance asymmetry than for the opposite scenario.
  4. Range‐wide, population‐level studies that quantify heat and cold tolerance of individual species are urgently needed to ascertain the global prevalence of cold‐tolerance asymmetry. While broad latitudinal clines of cold tolerance have been strongly supported, heat tolerance might respond to smaller‐scale climatic and habitat factors hence go unnoticed in global studies. Studies investigating physiological responses to climate change should incorporate the extent to which thermal traits are characteristic of individuals, populations and/or species.
dauerhafte UFZ-Verlinkung
Herrando‐Pérez, S., Monasterio, C., Beukema, W., Gomes, V., Ferri-Yáñez, F., Vieites, D.R., Buckley, L.B., Araújo, M.B. (2020):
Heat tolerance is more variable than cold tolerance across species of Iberian lizards after controlling for intraspecific variation
Funct. Ecol. 34 (3), 631 - 645 10.1111/1365-2435.13507