Data from: How much do phenotypic plasticity and local genetic variation contribute to phenotypic divergences along environmental gradients in widespread invasive plants? A meta-analysis

For introduced species that have spread across a wide distributional range, phenotypic plasticity (PLA) has often been proposed as an important contributor to invasion success, because it increases the survival rate during initial colonization. In contrast, local genetic variation (LOC) has also been proposed to be important, because it could allow invaders to evolve high performance in a new habitat. While evolutionary ecologists have long been interested in understanding genetic mechanisms that allow rapid colonization and spread of species, until recently experimental tests of these concepts have been limited. As a step towards generalization in our understanding of the importance of PLA and LOC, we review the current state of the literature on this topic using meta-analysis. Here, we focused on three fundamental questions: 1) which strategy, PLA or LOC, better explains the phenotypic divergences during invader range expansion across different environmental gradients? 2) Which species characteristics correlate with the occurrence of these different phenomena? And 3) does the detection of PLA versus LOC depend on the trait studied? Using meta-analysis we found that plasticity explained a higher proportion of phenotypic variation regardless of the environmental gradients studied or plant growth forms. PLA predominated in clonal, self-compatible and perennial species, while LOC predominated in annual species. The patterns were trait-dependent: LOC was significantly more important than PLA in phenology, while opposite patterns were found in fecundity and biomass allocation. The frequent simultaneous detection of PLA and genotypic variation in PLA among invasive populations suggested that PLA might benefit from LOC to some extent. Our results also indicate that the contribution of plasticity to the competitive advantages of invasive plants may be more informative than the level of plasticity itself.

对于已广泛扩散的外来引入物种，表型可塑性（phenotypic plasticity, PLA）常被认为是其入侵成功的重要驱动因子，因其可提升物种在初始定殖阶段的存活率。与之相对，本地遗传变异（local genetic variation, LOC）也被证实具有关键作用——它能够帮助入侵物种在新生境中演化出优异的适应性能。尽管进化生态学家长期以来一直致力于探究支持物种快速定殖与扩散的遗传机制，但直至近期，针对这些假说的实验验证仍较为有限。为了深化我们对表型可塑性与本地遗传变异重要性的普遍性认知，本研究通过荟萃分析（meta-analysis）综述了当前该领域的研究现状。本研究聚焦于三个核心科学问题：其一，在不同环境梯度下的入侵物种范围扩张过程中，表型可塑性与本地遗传变异这两种策略，哪种更能解释表型分化现象？其二，哪些物种特征与这两种现象的发生存在关联？其三，表型可塑性与本地遗传变异的检出是否依赖于所研究的性状？通过荟萃分析，我们发现：无论研究涉及何种环境梯度或植物生长型，表型可塑性均可解释更高比例的表型变异。表型可塑性在无性繁殖、自交亲和以及多年生植物中占主导地位，而本地遗传变异则在一年生植物中更为普遍。上述模式存在显著的性状依赖性：在物候性状中，本地遗传变异的重要性显著高于表型可塑性；而在繁殖力与生物量分配性状中则呈现相反格局。研究同时频繁检测到表型可塑性以及入侵种群间可塑性的遗传变异，这表明表型可塑性或许可在一定程度上受益于本地遗传变异。此外，本研究结果还表明，相较于表型可塑性本身的水平，其对入侵植物竞争优势的贡献更具解释价值。