Serpentine ecosystems are characterised by multiple environmental stressors: high levels of trace metals such as nickel (Ni), low availability of macronutrients and low water retention. These harsh environmental conditions exert a strong selective force on the vegetation, but their effect on community assembly processes and the functional trait composition remains unknown. In 26 plots on four serpentine sites on Lesbos Island (Greece), we measured six leaf functional traits related to resource acquisition and stress resistance on the 20 most abundant plant species. We quantified the proportion of variance explained by inter‐ and intraspecific trait differences and tested if individual species showed changes in trait values explained by soil Ni content. We investigated the adaptive value and the community level changes for each trait along the natural soil Ni gradient using a mixed model approach and functional diversity analyses. We tested the role of the abundant serpentine endemic and Ni‐hyperaccumulating species Odontarrhena lesbiaca in driving these patterns. Intraspecific variation explained by soil Ni content is smaller than 4%, and most of the variance is explained by interspecific differences in trait values. Most species do not show significant changes in trait values in response to soil Ni. At the community level, low specific leaf areas, small and thick leaves are selected on high Ni soils. Functional diversity analyses suggest a shift towards a stress tolerance syndrome (thick and small leaves with low SLA values) and an increase in functional diversity on Ni‐rich soils. However, these patterns are driven by the increasing abundance of O. lesbiaca. The endemic Ni hyperaccumulator has a stress tolerance strategy with small thick leaves and low SLA, while the community of broadly distributed species show an increase in trait values related to dominance and fast growth. Synthesis. Intraspecific variation in leaf trait responds little to soil metal toxicity. Endemic species harbour unique trait values compared to species with broad distribution which should justify their conservation as a priority.

中文翻译：

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种间性状差异驱动蛇纹石土壤上的植物群落反应


蛇纹岩生态系统的特点是多种环境压力源：镍 （Ni） 等微量金属含量高、常量营养素可用性低和保水性低。这些恶劣的环境条件对植被施加了强大的选择性力量，但它们对群落组装过程和功能性状组成的影响仍然未知。在莱斯博斯岛（希腊）的 4 个蛇纹石样地的 26 个样地中，我们测量了 20 种最丰富的植物物种与资源获取和抗逆性相关的 6 个叶片功能性状。我们量化了由种间和种内性状差异解释的方差比例，并测试了单个物种是否表现出由土壤 Ni 含量解释的性状值的变化。我们使用混合模型方法和功能多样性分析研究了沿天然土壤 Ni 梯度的每个性状的适应性值和群落水平变化。我们测试了丰富的蛇纹石特有物种和 Ni 过度积累物种 Odontarrhena lesbiaca 在驱动这些模式中的作用。土壤 Ni 含量解释的种内变异小于 4%，大部分方差由性状值的种间差异解释。大多数物种在响应土壤 Ni 时没有表现出性状值的显着变化。在群落水平上，在高镍土壤上选择低比叶面积、小而厚的叶子。功能多样性分析表明，在富镍土壤上，向耐逆综合征（低 SLA 值的厚而小的叶子）转变，并且功能多样性增加。然而，这些模式是由 O. lesbiaca 的日益丰富驱动的。特有的 Ni 超蓄积器具有小而厚的叶子和低 SLA 的抗逆策略，而广泛分布的物种群落显示出与优势和快速生长相关的性状值增加。合成。叶片性状的种内变异对土壤金属毒性几乎没有反应。与分布广泛的物种相比，特有物种具有独特的性状价值，这应该证明将其作为优先事项是合理的。