It is essential to understand biodiversity’s contribution to maintaining river ecosystem functioning and stability, which will us help to develop more effective strategies for river ecosystem conservation. However, knowledge regarding the relationship between multidimensional characteristics of biodiversity and ecosystem functioning and stability in aquatic ecosystems remains limited. This study examined the relationships between macroinvertebrate multidimensional diversity, secondary productivity, and secondary productivity/biomass (P/B) ratios in natural river ecosystems to examine which kind of diversity could best indicate community stability. In this study, macroinvertebrates were extensively sampled from Chishui River (CSH, an undammed river) and Heishui River (HSH, a dammed river) in April and September 2019. We comparatively analyzed seasonal variations in different types of diversity (species diversity, SD; phylogenetic diversity, PD; and functional diversity, FD), secondary productivity, and P/B ratios between the two rivers. Structural equation models were used to reveal the relationships between multidimensional diversity, secondary productivity, and P/B ratios. The results showed that SD significantly decreased during September both in the undammed CSH which has dramatic seasonal hydrological fluctuations, and in dammed HSH which has stable seasonal hydrological conditions. These findings indicated that SD could not clearly distinguish the key factors that cause changes in biodiversity. Conversely, both PD and FD significantly declined during September in the undammed CSH, but they did not significantly change in the dammed HSH. This result indicated that PD and FD are more sensitive than SD for identifying the effects of disturbances on biodiversity in these natural river ecosystems. After severe hydrological disturbance, although species abundance, biomass, biodiversity, and secondary productivity decreased in CSH, the still high value of P/B ratios indicated the high functional redundancy of communities, which further demonstrated the high stability of macroinvertebrates in CSH. Structural equation models revealed that the effects of PD and FD on secondary productivity and P/B ratios were more significant than those of SD in both rivers, which suggested that PD and FD may be better indicators of macroinvertebrate community stability than SD in these natural river ecosystems. Our study provides evidence that biological functional traits and evolutionary history can help achieve a more complete understanding of biodiversity patterns that maintain river ecosystem functioning and stability.

了解生物多样性对维持河流生态系统功能和稳定性的贡献至关重要，这将有助于我们制定更有效的河流生态系统保护策略。然而，关于生物多样性的多维特征与水生生态系统的生态系统功能和稳定性之间关系的知识仍然有限。本研究考察了天然河流生态系统中大型无脊椎动物多维多样性、次级生产力和次级生产力/生物量 (P/B) 比率之间的关系，以研究哪种多样性最能表明群落稳定性。本研究于 2019 年 4 月和 9 月从赤水河（CSH，未设坝的河流）和黑水河（HSH，有坝的河流）中广泛采集大型无脊椎动物样本。我们比较分析了两条河流之间不同类型多样性（物种多样性，SD；系统发育多样性，PD；和功能多样性，FD）的季节性变化、次级生产力和 P/B 比。结构方程模型被用来揭示多维多样性、次级生产力和市净率之间的关系。结果表明，9月份水文季节性波动剧烈的无坝CSH和季节性水文条件稳定的有坝HSH的SD均显着降低。这些发现表明，SD 无法明确区分导致生物多样性变化的关键因素。相反，9 月份未筑坝 CSH 的 PD 和 FD 均显着下降，但未筑坝 HSH 的 PD 和 FD 没有显着变化。该结果表明，PD 和 FD 在识别干扰对这些自然河流生态系统中生物多样性的影响方面比 SD 更敏感。严重水文扰动后，虽然CSH的物种丰度、生物量、生物多样性和次级生产力下降，但P/B比值仍然较高，表明群落功能冗余度高，进一步证明了CSH大型无脊椎动物的高稳定性。结构方程模型显示，PD和FD对两条河流的次级生产力和P/B比的影响比SD更显着，这表明PD和FD可能是这些天然河流中大型无脊椎动物群落稳定性的更好指标生态系统。