UMR Agronomie, INRAE, AgroParisTech, Université Paris-Saclay, 78 850, Thiverval-Grignon, France.
Sci Rep. 2021 Nov 4;11(1):21635. doi: 10.1038/s41598-021-01160-2.
Plant taxonomic and functional diversity promotes interactions at higher trophic levels, but the contribution of functional diversity effects to multitrophic interactions and ecosystem functioning remains unclear. We investigated this relationship in a factorial field experiment comparing the effect of contrasting plant communities on parasitism rates in five herbivore species. We used a mechanistic trait-matching approach between plant and parasitoids to determine the amount of nectar available and accessible to parasitoids. This trait-matching approach best explained the rates of parasitism of each herbivorous species, confirming the predominant role of mass-ratio effects. We found evidence for an effect of functional diversity only in analyses considering the ability of plant communities to support the parasitism of all herbivores simultaneously. Multi-species parasitism was maximal at intermediate levels of functional diversity. Plant specific richness had a negligible influence relative to functional metrics. Plant communities providing large amounts of accessible nectar and with intermediate levels of functional diversity were found to be the most likely to enhance the conservation biological control of diverse crop herbivores.
植物分类和功能多样性促进了更高营养级的相互作用，但功能多样性效应对多营养级相互作用和生态系统功能的贡献仍不清楚。我们在一个析因野外实验中研究了这种关系，该实验比较了不同植物群落对 5 种草食性物种寄生率的影响。我们使用植物和寄生蜂之间的一种基于机制的特征匹配方法来确定寄生蜂可获得和可利用的花蜜量。这种特征匹配方法最好地解释了每种草食性物种的寄生率，证实了质量比效应的主要作用。我们只在考虑植物群落同时支持所有草食动物寄生能力的分析中发现了功能多样性的影响。功能多样性的中间水平有利于多物种寄生。与功能指标相比，植物特有种丰富度的影响可以忽略不计。具有大量可利用花蜜和中等水平功能多样性的植物群落，最有可能增强对不同作物草食性动物的生物防治保护。
