Testing the climate variability hypothesis in thermal tolerance limits of tropical and temperate tadpoles
Testing the climate variability hypothesis in thermal tolerance limits of tropical and temperate tadpoles
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DOI：
10.1111/jbi.12700
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发表时间：
2016-06-01
影响因子：
3.9
通讯作者：
Sole, M.
中科院分区：
文献类型：
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作者：
Gutierrez-Pesquera, L. M.;Tejedo, M.;Sole, M.
目的气候变率假说（CVH）认为，随着纬度的增加，物种的耐热范围与气候变率之间可能存在正相关关系，尤其是陆生外温动物。在CVH下，我们期望找到两个热耐受极限（CTmax和CTmin），环境极端温度和物种的范围大小之间的对应关系。我们研究了这些预测的有效性，在一个低地热带和温带蝌蚪association.Location低地新热带（巴伊亚，巴西）和古北（伊比利亚半岛和北非）。方法我们采用系统发育特征向量回归（PVR）和Pagel的λ分析系统发育信号CTmax和CTmin。我们使用系统发育回归分析（PGLS）来测试之间的关系的热限制，范围大小和温度预测（在宏观尺度和微生境水平测量）和phy-ANOVA比较的生理特征和热方案在热带和温带assemblage.Results我们记录了中度到强的系统发育信号在耐热性和耐寒性。温带蝌蚪比热带蝌蚪有更广泛的耐热性。热耐受范围与范围大小相关，并在全球范围内的季节性温度范围预测解释。宏观和微观气候温度变量都提供了全球范围内热极限的最佳预测多变量模型。小气候预测，但是，CTmax和CTmin变化的主要决定因素，在当地的热带和温带community.Main结论热耐受性范围增加，随着纬度的蝌蚪，由于在温带蝌蚪的耐寒性增加。在全球范围内，宏观和微观环境的热信息是可靠的预测临界热极限和热耐受范围，CVH预测。然而，最好的预测温度的微生境在区域一级的热限制，从而表明，生理热边界可能是由热选择。
Aim The climate variability hypothesis (CVH) states that a positive relationship may exist between the breadth of thermal tolerance range and the level of climatic variability experienced by taxa with increasing latitude, especially in terrestrial ectotherms. Under CVH, we expected to find a correspondence between both thermal tolerance limits (CTmax and CTmin), ambient extreme temperature and the range sizes of species. We examined the validity of these predictions in a lowland tropical and a temperate tadpole assemblage.Location Lowland Neotropics (Bahia, Brazil) and Palaearctic (Iberian Peninsula and North Africa).Method We employed phylogenetic eigenvector regression (PVR) and Pagel's lambda to analyse phylogenetic signals in CTmax and CTmin. We used phylogenetic regression analyses (PGLS) to test the relationships between thermal limits, range size and temperature predictors (measured at the macroscale and microhabitat levels) and phy-ANOVA to compare both the physiological traits and thermal regimen in both tropical and temperate assemblages.Results We documented moderate-to-strong phylogenetic signal in both heat and cold tolerance. Temperate-zone tadpoles had broader thermal tolerances than tropical ones. Thermal tolerance range was correlated with range sizes and was explained by seasonal thermal range predictors at the global scale. Both macro-and microclimate temperature variables provided the best predictive multivariate models of thermal limits at the global scale. Microclimatic predictors, however, were the main determinants of CTmax and CTmin variation at the local level of tropical and temperate communities respectively.Main conclusions Thermal tolerance range increases with latitude in tadpoles due to the higher increase in cold tolerance in temperate tadpoles. At the global scale, both macro-and microenvironment thermal information were reliable predictors of critical thermal limits and thermal tolerance range, as CVH predicts. However, thermal limits were best predicted by temperatures of the micro-habitat at the regional level, thus suggesting that physiological thermal boundaries may be governed by thermal selection.