Data from: Disentangling the heritable and plastic components of the competitive and facilitative effects of an alpine foundation species

Differences in effects between phenotypes of foundation species on subordinate species have been reported, but no study has separated their heritable and plastic components. In a subalpine community of the French Pyrenees, we observed two phenotypes of Festuca gautieri: tight cushions in dry convex outcrops with few subordinate species, and loose cushions in wet concave slopes with many subordinate species, suggesting differences in effects of the two phenotypes on subordinates. Using two reciprocal transplantation gardens, we studied the responses of the two phenotypes to changes in environmental conditions, thus assessing the contribution of heritability and plasticity to the phenotypic variation. Using a target cross-transplantation experiment, we assessed the plasticity and heritability bases of their contrasting effects. We also quantified the recolonisation of resident plants within the reciprocally transplanted cushions. We found that morphological differences between cushions had both heritability and plasticity bases. The two competition experiments showed heritable increase in competitive effects from loose to tight cushions. This was counteracted by plasticity effects, which decreased competition from the benign to the stressful garden. Synthesis. We conclude that heritable effects overcome plasticity effects resulting in higher diversity in the loose phenotype from the benign habitats.已有研究报道建群种（foundation species）的不同表型对从属种的作用存在差异，但目前尚无研究将其作用的可遗传组分与可塑性组分加以区分。本研究于法国比利牛斯山脉的亚高山群落中，观测到高捷羊茅（Festuca gautieri）存在两种表型：一类为生长于干燥凸形露头、伴生从属种较少的紧密垫状丛；另一类为生长于湿润凹坡、伴生从属种较多的疏松垫状丛，由此暗示两种表型对从属种的作用存在差异。本研究设置两处互置移植圃，探究两种表型对环境条件变化的响应，以此评估可遗传性与可塑性对表型变异的贡献度。通过目标交叉移植实验，本研究解析了二者差异化作用的可塑性与可遗传基础。此外，本研究还量化了互置移植垫状丛内本土植物的重新定植情况。研究发现，垫状丛间的形态差异同时具备可遗传与可塑性基础。两项竞争实验结果显示，从疏松垫状丛到紧密垫状丛，其竞争作用的可遗传组分呈增强趋势。但可塑性效应抵消了这一趋势：在从适宜生境移植园到胁迫生境移植园的梯度中，竞争作用随可塑性响应发生减弱。综合分析表明：可遗传作用强于可塑性效应，最终使得源自适宜生境的疏松表型所伴生物种多样性更高。