Dataset - Intraspecific diversity loss in a predator species alters prey community structure and ecosystem functions

Loss in intraspecific diversity can alter ecosystem functions, but the underlying mechanisms are still elusive, and intraspecific biodiversity-ecosystem function relationships (iBEFs) have been restrained to primary producers. Here, we manipulated genetic and functional richness of a fish consumer (<i>Phoxinus phoxinus</i>), to test whether iBEFs exist in consumer species, and whether they are more likely sustained by genetic or functional richness. We found that both genotypic and functional richness affected ecosystem functioning, either independently or in interaction. Loss in genotypic richness reduced benthic invertebrate diversity consistently across functional richness treatments, whereas it reduced zooplankton diversity only when functional richness was high. Finally, both losses in genotypic and functional richness altered essential functions (e.g. decomposition) through trophic cascades. We concluded that iBEFs lead to substantial top-down effects on entire food chains. The loss of genotypic richness was similarly prejudicial than the loss of functional richness, probably because it sustains “cryptic” functional diversity.

种内多样性丧失可改变生态系统功能，但其潜在机制仍难以捉摸，且种内生物多样性-生态系统功能关系（intraspecific biodiversity-ecosystem function relationships，iBEFs）此前仅局限于初级生产者类群的研究。本研究以鱼类消费者Phoxinus phoxinus为实验对象，通过实验操控其遗传丰富度与功能丰富度，旨在验证消费者类群中是否存在iBEFs，以及该关系更易由遗传丰富度还是功能丰富度维持。研究结果显示，遗传丰富度与功能丰富度均可独立或通过交互作用影响生态系统功能；在所有功能丰富度实验处理组中，遗传丰富度丧失均会持续降低底栖无脊椎动物多样性，而浮游动物多样性的降低仅在功能丰富度较高的处理组中出现。最终，遗传与功能丰富度的丧失均可通过营养级联效应改变关键生态系统功能（如有机质分解）。本研究结论表明，iBEFs会对整条食物链产生显著的下行调控效应，遗传丰富度丧失与功能丰富度丧失的有害程度相当，这可能是因为前者维持了“隐秘”功能多样性。