Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy.
Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Melle-Gontrode, Belgium.
Glob Chang Biol. 2019 Jul;25(7):2485-2498. doi: 10.1111/gcb.14646. Epub 2019 May 6.
Elevational gradients are often used to quantify how traits of plant species respond to abiotic and biotic environmental variations. Yet, such analyses are frequently restricted spatially and applied along single slopes or mountain ranges. Since we know little on the response of intraspecific leaf traits to elevation across the globe, we here perform a global meta-analysis of leaf traits in 109 plant species located in 4 continents and reported in 71 studies published between 1983 and 2018. We quantified the intraspecific change in seven morpho-ecophysiological leaf traits along global elevational gradients: specific leaf area (SLA), leaf mass per area (LMA), leaf area (LA), nitrogen concentration per unit of area (Narea), nitrogen concentration per unit mass (Nmass), phosphorous concentration per unit mass (Pmass) and carbon isotope composition (δ C). We found LMA, Narea, Nmass and δ C to significantly increase and SLA to decrease with increasing elevation. Conversely, LA and Pmass showed no significant pattern with elevation worldwide. We found significantly larger increase in Narea, Nmass, Pmass and δ C with elevation in warmer regions. Larger responses to increasing elevation were apparent for SLA of herbaceous compared to woody species, but not for the other traits. Finally, we also detected evidences of covariation across morphological and physiological traits within the same elevational gradient. In sum, we demonstrate that there are common cross-species patterns of intraspecific leaf trait variation across elevational gradients worldwide. Irrespective of whether such variation is genetically determined via local adaptation or attributed to phenotypic plasticity, the leaf trait patterns quantified here suggest that plant species are adapted to live on a range of temperature conditions. Since the distribution of mountain biota is predominantly shifting upslope in response to changes in environmental conditions, our results are important to further our understanding of how plants species of mountain ecosystems adapt to global environmental change.
海拔梯度通常用于量化植物物种的特征如何响应非生物和生物环境变化。然而，这些分析通常在空间上受到限制，并且仅沿着单个斜坡或山脉进行应用。由于我们对全球范围内种内叶片特征对海拔的响应知之甚少，因此我们在这里对 109 种植物物种的叶片特征进行了全球元分析，这些植物物种分布在 4 个大陆，报道于 1983 年至 2018 年期间发表的 71 项研究中。我们量化了全球海拔梯度上 7 种形态-生理叶片特征的种内变化：比叶面积（SLA）、叶质量与面积比（LMA）、叶面积（LA）、单位面积氮浓度（Narea）、单位质量氮浓度（Nmass）、单位质量磷浓度（Pmass）和碳同位素组成（δ C）。我们发现 LMA、Narea、Nmass 和 δ C 随海拔升高而显著增加，而 SLA 则随海拔升高而降低。相反，LA 和 Pmass 在全球范围内与海拔没有显著关系。我们发现，在温暖地区，Narea、Nmass、Pmass 和 δ C 随海拔升高的增幅更大。与木本植物相比，草本植物的 SLA 对海拔升高的响应更大，但其他特征则不然。最后，我们还在同一海拔梯度内检测到形态和生理特征之间的协变证据。总之，我们证明了全球范围内种内叶片特征随海拔梯度变化存在共同的跨物种模式。无论这种变化是通过局部适应还是表型可塑性来决定的，这里量化的叶片特征模式表明，植物物种适应了一系列温度条件。由于山地生物群的分布主要是由于环境条件的变化而上移，因此我们的研究结果对于进一步了解山地生态系统中的植物物种如何适应全球环境变化具有重要意义。
