We examined trophic relationships in estuarine planktonic food webs by focusing on the assemblages and functional groups of copepods and their effects on prey and predator. We also studied the relationship between biodiversity and ecosystem functioning in estuaries using different taxonomic and functional diversity indices of copepod assemblages and copepod biomass as a proxy of ecosystem functioning. We collected samples every 2 months over a 2-year period in four Brazilian estuaries. Taxonomic diversity indices showed a positive and negative relationship with chaetognath densities and ecosystem functioning, respectively. The functional indices were negatively related to the effect of predator diversity on prey. Different functional groups of copepods were positively correlated with chaetognath density, consistent with their generalist feeding habits. Thus, multifaceted approaches that use different indices and functional groups are recommended to provide a more realistic view of the trophic relationships and ecosystem functioning in estuaries.

我们通过研究co足类动物的组合和功能组及其对猎物和掠食者的影响，研究了河口浮游食物网中的营养关系。使用不同的分类和桡足类组合的功能多样性指数和桡足类生物质作为我们还研究了生物多样性和生态系统功能河口之间的关系代理生态系统功能。我们在2年的时间内每2个月在四个巴西河口收集样本。分类学多样性指数分别与菱角藻密度和生态系统功能成正相关和负相关。功能指数与捕食者多样性对猎物的影响负相关。pe足类的不同功能组与菱角e密度呈正相关，与它们的一般喂养习惯一致。因此，建议使用使用不同指标和功能组的多角度方法，以更真实地了解河口的营养关系和生态系统功能。