Data from: Chlorpyrifos interacts with other agricultural stressors to alter stream communities in laboratory microcosms

Chlorpyrifos is one of the most widely used agricultural insecticides in the world, but to date there is limited empirical information about its potential to interact with other common agricultural stressors. We conducted a 15-day, community-level microcosm experiment evaluating individual and combined effects of chlorpyrifos, nutrient enrichment, and sedimentation on stream invertebrate communities (abundance, biomass, richness, size structure, composition) and ecosystem processes (primary productivity and leaf decomposition). We found that sedimentation was the most detrimental stressor, with significant negative impacts on most invertebrate community and ecosystem function variables. Even though chlorpyrifos did not cause significant invertebrate mortality in the microcosms, it still altered ecosystem function by lowering leaf decomposition rates, probably through sublethal inhibition of invertebrate shredders. Furthermore, we observed a significant reversal interaction between chlorpyrifos and sediment for small-sized invertebrates collected in gravel (abundance in sediment x insecticide microcosms was 2.4 times lower than predicted by additivity), as well as an antagonistic interaction with nutrients on invertebrate richness in the same microhabitat (richness in nutrient x insecticide microcosms was 1.6 times higher than predicted by additivity). Our results suggest that chlorpyrifos has the potential to alter freshwater ecosystem function and interact non-additively with other common agricultural stressors. These findings are in keeping with a growing body of research highlighting that multiple stressor interactions and ecosystem processes should be considered when evaluating the impacts of organic toxicants on freshwater ecosystems.毒死蜱（Chlorpyrifos）是全球使用最广泛的农用杀虫剂之一，但截至目前，关于其与其他常见农业胁迫因子产生潜在交互作用的实证研究仍较为匮乏。本研究开展了一项为期15天的群落级微宇宙（microcosm）实验，评估了毒死蜱、营养富集与沉积作用单独及联合作用对溪流无脊椎动物群落（包括丰度、生物量、物种丰富度、体型结构及群落组成）与生态系统过程（初级生产力与叶片分解速率）的影响。研究发现，沉积作用是危害程度最高的胁迫因子，对多数无脊椎动物群落及生态系统功能变量均产生了显著的负面影响。尽管毒死蜱并未在微宇宙实验中造成无脊椎动物的显著死亡，但其仍通过降低叶片分解速率改变了生态系统功能，这一效应大概率是通过对无脊椎动物碎屑食性者的亚致死抑制作用实现的。此外，我们观察到，在砾石生境中采集的小型无脊椎动物，其丰度在毒死蜱与沉积作用的联合处理组中较加性效应预测值低2.4倍，二者存在显著的反转交互作用；同时，在相同微生境中，营养富集与毒死蜱对无脊椎动物丰富度存在拮抗交互作用，该联合处理组的物种丰富度较加性效应预测值高1.6倍。本研究结果表明，毒死蜱具备改变淡水生态系统功能的潜力，且可与其他常见农业胁迫因子产生非加性交互作用。上述发现与日益增多的研究成果相契合，即评估有机毒物对淡水生态系统的影响时，应将多胁迫因子交互作用与生态系统过程纳入考量范畴。