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Abstract：
High-elevation species are predicted to have larger elevational ranges compared with species of lower elevations. The reasoning is that temperature variability is greater at higher elevation, selecting for wider niche breadth and more plastic genotypes. We used macroevolutionary comparisons involving 90 Brassicaceae species of the central Alps to test for associations among median elevation of occurrence, elevational range size and thermal variability over space and time on the one hand, and their associations with performance breadth or trait plasticity on the other hand. Performance breadth and trait plasticity were estimated by raising replicate plants per species under three temperature treatments (mild, recurrent frost, recurrent heat). Against prediction, we found that mid-elevation species had the largest elevational ranges, and their ranges were associated with increased spatial thermal variability. Nevertheless, variability in the thermal regime was positively associated neither with niche breadth nor with plasticity. Evidence for adaptive constraints was limited to a trade-off between acclimation-based increases in frost and heat resistance, and phylogenetic niche conservatism for median elevation of occurrence and temporal thermal variability. Results suggest that large elevational range size is associated with divergent adaptation within species, but not with more niche breadth or trait plasticity. This article is part of the theme issue \'Species\' ranges in the face of changing environments (part I)\'.
摘要：
与低海拔物种相比，高海拔物种的海拔范围预计更大。原因是温度变化在海拔较高时较大，选择更宽的生态位宽度和更多的可塑性基因型。我们使用涉及阿尔卑斯山中部90种十字花科物种的宏观进化比较来测试发生的中位数升高之间的关联，一方面，在空间和时间上的海拔范围大小和热变异性，以及它们与表现广度或特质可塑性的关联。通过在三种温度处理（温和，经常性霜冻，循环热)。与预测相反，我们发现中海拔物种的海拔范围最大，它们的范围与空间热变异性增加有关。然而，热态的变异性与生态位宽度和可塑性都不相关。适应性约束的证据仅限于基于适应的霜冻和耐热性增加之间的权衡，和系统发育生态位保守性，用于发生的中位数升高和时间热变异性。结果表明，较大的海拔范围与物种内的不同适应性有关，但没有更多的生态位宽度或性状可塑性。本文是主题问题\'物种\'在不断变化的环境中的范围（第一部分）\'的一部分。
