CNRS, Station d'Écologie Théorique et Expérimentale du CNRS à Moulis UMR-5321, Université Toulouse III Paul Sabatier, 2 route du CNRS, F-09200, Moulis, France.
EcoLab, Université de Toulouse, CNRS, INPT, UPS, 31062 Toulouse, France.
Biol Rev Camb Philos Soc. 2019 Apr;94(2):648-661. doi: 10.1111/brv.12472. Epub 2018 Oct 7.
Understanding the relationships between biodiversity and ecosystem functioning has major implications. Biodiversity-ecosystem functioning relationships are generally investigated at the interspecific level, although intraspecific diversity (i.e. within-species diversity) is increasingly perceived as an important ecological facet of biodiversity. Here, we provide a quantitative and integrative synthesis testing, across diverse plant and animal species, whether intraspecific diversity is a major driver of community dynamics and ecosystem functioning. We specifically tested (i) whether the number of genotypes/phenotypes (i.e. intraspecific richness) or the specific identity of genotypes/phenotypes (i.e. intraspecific variation) in populations modulate the structure of communities and the functioning of ecosystems, (ii) whether the ecological effects of intraspecific richness and variation are strong in magnitude, and (iii) whether these effects vary among taxonomic groups and ecological responses. We found a non-linear relationship between intraspecific richness and community and ecosystem dynamics that follows a saturating curve shape, as observed for biodiversity-function relationships measured at the interspecific level. Importantly, intraspecific richness modulated ecological dynamics with a magnitude that was equal to that previously reported for interspecific richness. Our results further confirm, based on a database containing more than 50 species, that intraspecific variation also has substantial effects on ecological dynamics. We demonstrated that the effects of intraspecific variation are twice as high as expected by chance, and that they might have been underestimated previously. Finally, we found that the ecological effects of intraspecific variation are not homogeneous and are actually stronger when intraspecific variation is manipulated in primary producers than in consumer species, and when they are measured at the ecosystem rather than at the community level. Overall, we demonstrated that the two facets of intraspecific diversity (richness and variation) can both strongly affect community and ecosystem dynamics, which reveals the pivotal role of within-species biodiversity for understanding ecological dynamics.
理解生物多样性与生态系统功能之间的关系具有重大意义。生物多样性-生态系统功能关系通常在种间水平上进行研究，尽管种内多样性（即种内多样性）越来越被认为是生物多样性的一个重要生态方面。在这里，我们通过跨多种植物和动物物种进行定量和综合综合分析，测试种内多样性是否是群落动态和生态系统功能的主要驱动因素。我们特别测试了：（i）种群中基因型/表型的数量（即种内丰富度）或基因型/表型的特定身份（即种内变异）是否调节群落结构和生态系统功能；（ii）种内丰富度和变异的生态效应在幅度上是否强大；（iii）这些效应是否在分类群和生态响应中变化。我们发现，种内丰富度与群落和生态系统动态之间存在非线性关系，遵循饱和曲线形状，就像在种间水平上测量的生物多样性-功能关系一样。重要的是，种内丰富度以与种间丰富度相当的幅度调节生态动态。我们的研究结果进一步证实，基于包含 50 多种物种的数据库，种内变异也对生态动态有实质性影响。我们表明，种内变异的影响是随机预期的两倍，而且以前可能被低估了。最后，我们发现，种内变异的生态效应并不均匀，实际上在初级生产者中操纵种内变异比在消费者物种中更强，并且当它们在生态系统而不是群落水平上测量时更强。总的来说，我们证明了种内多样性的两个方面（丰富度和变异）都可以强烈影响群落和生态系统动态，这揭示了种内生物多样性对于理解生态动态的关键作用。
