Environmental heterogeneity leads to higher plasticity in dry-edge populations of a semi-arid Chilean shrub: insights into climate change responses
Environmental heterogeneity leads to higher plasticity in dry-edge populations of a semi-arid Chilean shrub: insights into climate change responses
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DOI：
10.1111/1365-2745.12372
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发表时间：
2015-03-01
影响因子：
5.5
通讯作者：
Valladares, Fernando
中科院分区：
文献类型：
--
作者：
Lazaro-Nogal, Ana;Matesanz, Silvia;Valladares, Fernando
在半干旱生态系统的气候变化研究中应考虑气候条件的年际变化。它可能决定种群间表型可塑性的差异，经历较高环境异质性的种群表现出较高水平的可塑性。种群进化关键功能性状和可塑性的能力可能决定植物种群在半干旱生态系统预期的干燥和多变气候下的生存。通过与半干旱智利灌木番泻叶的整个分布范围的种群合作，我们评估了功能性状及其功能性状的种群间和种群内变异。响应水可用性的可塑性。我们在田间条件和温室实验中测量了与抗旱性相关的形态和生理特征，其中在两种可用水处理下评估了干旱反应。所有种群均做出可塑性反应，但与生长在中温地区和更均匀环境条件下的种群相比，干边种群中较高的降水异质性似乎选择了更多的可塑性基因型。综合。我们的结果表明适应性可塑性，因为较高水平的表型可塑性与植物性能呈正相关。然而，我们没有发现种群内可塑性遗传变异的证据。在某种程度上，表型可塑性可能在未来的持久性中发挥关键作用，中温地区的种群可能更容易受到气候变化的影响，因为它们的可塑性较低，而且目前在进化新的反应规范方面存在局限性。相反，尽管干边的番泻叶种群面临更高水平的压力，但由于其可塑性更大，它们可能不太容易受到气候变化的影响。我们强调需要考虑平均特征及其可塑性的种群差异，以模拟气候变化下物种分布的现实情景。
Interannual variability in climatic conditions should be taken into account in climate change studies in semi-arid ecosystems. It may determine differentiation in phenotypic plasticity among populations, with populations experiencing higher environmental heterogeneity showing higher levels of plasticity.The ability of populations to evolve key functional traits and plasticity may determine the survival of plant populations under the drier and more variable climate expected for semi-arid ecosystems.Working with populations of the semi-arid Chilean shrub Senna candolleana along its entire distribution range, we assessed inter- and intra-population variation in functional traits as well as in their plasticity in response to water availability. We measured morphological and physiological traits related to drought resistance in both field conditions and in a greenhouse experiment, where drought response was evaluated under two water availability treatments.All populations responded plastically, but higher precipitation heterogeneity in dry-edge populations seemed to have selected for more plastic genotypes compared to populations growing at mesic sites and with more homogeneous environmental conditions.Synthesis.Our results suggest adaptive plasticity since higher levels of phenotypic plasticity were positively associated with plant performance. However, we did not find evidence for genetic variation for plasticity within populations. To the extent that phenotypic plasticity may play a key role in future persistence, populations at mesic sites may be more vulnerable to climate change due to their lower plasticity and their current limitations to evolve novel norms of reaction. Conversely, although Senna candolleana populations at the dry edge are exposed to higher levels of stress, they may be less susceptible to climate change in view of their greater plasticity. We highlight the need to consider population differentiation in both mean traits and their plasticity to model realistic scenarios of species distribution under climate change.