Oliveira Dos Anjos Talles Bruno, Polazzo Francesco, Arenas-Sánchez Alba, Cherta Laura, Ascari Roberto, Migliorati Sonia, Vighi Marco, Rico Andreu
IMDEA Water Institute Science and Technology Campus of the University of Alcalá Alcalá de Henares Spain.
University of Koblenz-Landau Landau in der Pfalz Germany.
Ecol Evol. 2021 Mar 7;11(9):4046-4057. doi: 10.1002/ece3.7305. eCollection 2021 May.
Pesticides, nutrients, and ecological stressors such as competition or predation co-occur in freshwater ecosystems impacted by agriculture. The extent to which combinations of these stressors affect aquatic populations and the role of nutrients availability in modulating these responses requires further understanding. In this study, we assessed how pesticides affecting different taxonomic groups and predation influence the response of populations under different trophic conditions. An outdoor experiment was designed following a factorial design, with the insecticide chlorpyrifos, the herbicide diuron, and the predation by sp. individuals as key stressors. The single impact of each of these stressors, and their binary and tertiary combinations, was evaluated on abundance and population structure under mesotrophic and eutrophic conditions for 21 days. Data were analyzed using generalized linear mixed models estimated by means of a novel Bayesian shrinkage technique. Our study shows a significant influence of each of the evaluated stressors on abundance; however, the impacts of the herbicide and predation were lower under eutrophic conditions as compared to the mesotrophic ones. We found that binary stressor interactions were generally additive in the mesotrophic scenario, except for the herbicide-predation combination, which resulted in synergistic effects. The impacts of the binary stressor combinations in the eutrophic scenario were classified as antagonistic, except for the insecticide-herbicide combination, which was additive. The tertiary interaction resulted in significant effects on some sampling dates; however, these were rather antagonistic and resembled the most important binary stressor combination in each trophic scenario. Our study shows that the impact of pesticides on freshwater populations depends on the predation pressure, and demonstrates that the combined effect of pesticides and ecological stressors is influenced by the food availability and organism fitness related to the trophic status of freshwater ecosystems.
在受农业影响的淡水生态系统中，农药、养分以及竞争或捕食等生态压力源同时存在。这些压力源的组合对水生生物种群的影响程度以及养分有效性在调节这些反应中的作用，仍需进一步了解。在本研究中，我们评估了影响不同分类群的农药和捕食作用如何影响不同营养条件下的种群反应。按照析因设计开展了一项室外实验，将杀虫剂毒死蜱、除草剂敌草隆以及特定物种个体的捕食作用作为关键压力源。在中营养和富营养条件下，对这些压力源各自的单一影响、二元组合影响和三元组合影响进行了为期21天的丰度和种群结构评估。使用一种新颖的贝叶斯收缩技术估计的广义线性混合模型对数据进行了分析。我们的研究表明，每个评估的压力源对丰度都有显著影响；然而，与中营养条件相比，富营养条件下除草剂和捕食的影响较小。我们发现，在中营养情况下，二元压力源相互作用通常是相加的，但除草剂 - 捕食组合除外，该组合产生了协同效应。在富营养情况下，二元压力源组合的影响被归类为拮抗作用，但杀虫剂 - 除草剂组合除外，该组合是相加的。三元相互作用在某些采样日期产生了显著影响；然而，这些影响相当拮抗，并且类似于每个营养情况下最重要的二元压力源组合。我们的研究表明，农药对淡水种群的影响取决于捕食压力，并证明农药和生态压力源的综合效应受与淡水生态系统营养状况相关的食物可利用性和生物适应性的影响。
