Above- and belowground drivers of intraspecific trait variability across subcontinental gradients for five ubiquitous forest plants in North America
Above- and belowground drivers of intraspecific trait variability across subcontinental gradients for five ubiquitous forest plants in North America
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北美五种普遍存在的森林植物在次大陆梯度上种内性状变异的地上和地下驱动因素
DOI：
10.1111/1365-2745.13894
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发表时间：
2022-05-08
影响因子：
5.5
通讯作者：
Aubin, Isabelle
中科院分区：
文献类型：
--
作者：
Cardou, Francoise;Munson, Alison D.;Aubin, Isabelle
1.种内性状变异为物种适应环境变化提供了物质基础。为了加深我们对ITV如何促进物种适应各种环境条件的了解，我们研究了暴露于大陆尺度气候梯度以及当地土壤和干扰梯度的五种广泛分布的林下森林物种。我们研究了地间叶和根性状变异的环境驱动因素，并检验了较高的地间ITV是否与性状对环境变异的敏感性（即环境适应性）增加有关.我们测量了形态（比叶面积：SLA，比根长：SRL）和化学性状（叶和根N，P，K，Mg，Ca）的五个森林林下维管植物物种在加拿大各地的78个站点。总共有261个物种的网站组合跨越类似的4300公里进行了采样，捕捉重要的非生物和生物环境梯度（邻里组成，冠层结构，土壤条件，气候）。我们使用多变量和单变量线性混合模型来识别ITV的驱动因素，并测试站点间ITV与环境适应度的关联。叶性状的站点间ITV主要由冠层结构和气候驱动。相比之下，环境驱动因素只解释了一小部分的变化，在根性状：这些关系是性状特异性，包括土壤条件（根P），冠层结构（根N）和邻里组成（SRL，根K）。地点间ITV仅对少数性状与环境适应性增加相关，主要是对气候的响应（SLA，叶氮，SRL）。合成.通过研究ITV是如何沿着环境梯度在适应各种条件的物种之间构建的，我们可以开始了解单个物种如何对环境变化做出反应。我们的研究结果表明，可概括的性状与环境的关系主要发生在地上，只占一小部分的变异。对于我们这组具有广泛生态位的物种，性状的变异很少与较高的环境适应性相关，主要是沿着气候梯度。这些结果指出，有前途的研究途径的各种方式，性状变异可以影响物种的性能沿着不同的环境梯度。
1. Intraspecific trait variability (ITV) provides the material for species' adaptation to environmental changes. To advance our understanding of how ITV can contribute to species' adaptation to a wide range of environmental conditions, we studied five widespread understorey forest species exposed to both continental-scale climate gradients, and local soil and disturbance gradients. We investigated the environmental drivers of between-site leaf and root trait variation, and tested whether higher between-site ITV was associated with increased trait sensitivity to environmental variation (i.e. environmental fit).2. We measured morphological (specific leaf area: SLA, specific root length: SRL) and chemical traits (Leaf and Root N, P, K, Mg, Ca) of five forest understorey vascular plant species at 78 sites across Canada. A total of 261 species-by-site combinations spanning similar to 4300km were sampled, capturing important abiotic and biotic environmental gradients (neighbourhood composition, canopy structure, soil conditions, climate). We used multivariate and univariate linear mixed models to identify drivers of ITV and test the association of between-site ITV with environmental fit.3. Between-site ITV of leaf traits was primarily driven by canopy structure and climate. Comparatively, environmental drivers explained only a small proportion of variability in root traits: these relationships were trait specific and included soil conditions (Root P), canopy structure (Root N) and neighbourhood composition (SRL, Root K). Between-site ITV was associated with increased environmental fit only for a minority of traits, primarily in response to climate (SLA, Leaf N, SRL).4. Synthesis. By studying how ITV is structured along environmental gradients among species adapted to a wide range of conditions, we can begin to understand how individual species might respond to environmental change. Our results show that generalisable trait-environment relationships occur primarily aboveground, and only accounted for a small proportion of variability. For our group of species with broad ecological niches, variability in traits was only rarely associated with higher environmental fit, and primarily along climatic gradients. These results point to promising research avenues on the various ways in which trait variation can affect species performance along different environmental gradients.