The diversity of aquatic macrophytes can offer different local conditions required to support an increased number of microhabitats, therefore resulting in diverse biotic communities. This study assessed the influence of macrophyte diversity on the ecological attributes of the associated invertebrates (diversity, richness and abundance), as well as the diet composition of a small fish, Moenkhausia forestii, that inhabits the Upper Paraná River floodplain in abundance, and present great contributions of invertebrates in its diet. The richness and diversity of invertebrates increased with increasing macrophyte diversity, while the abundance of invertebrates didn’t show a significant relationship. The diet of M. forestii differed among stands and the consumption of invertebrates increased with increasing macrophyte diversity, while the consumption of aquatic plants decreased. Moreover, the trophic niche breadth of M. forestii expanded, a probable result of the increase in the ecological opportunity promoted by higher macrophyte diversity. Our study emphasizes the importance of the diversity of these plants as they structure the environment and the associated communities, and changes in the attributes of these plants could be reflected on other trophic levels and even on a local scale.

水生植物的多样性可以提供支持增加数量的微生境所需的不同当地条件，因此导致了多样化的生物群落。这项研究评估了大型植物多样性对相关无脊椎动物的生态属性（多样性，丰富性和丰度）的影响，以及栖息在巴拉那河上游泛滥平原上的小鱼Moenkhausia forestii的饮食组成，目前无脊椎动物在饮食中的巨大贡献。无脊椎动物的丰富度和多样性随着大型植物多样性的增加而增加，而无脊椎动物的丰度则没有显着关系。森林小菜的饮食林分之间的差异很大，无脊椎动物的消耗随着大型植物多样性的增加而增加，而水生植物的消耗则减少。此外，M。forestii的营养生态位宽度得到了扩大，这可能是大型植物的多样性促进了生态机会增加的结果。我们的研究强调了这些植物的多样性，因为它们构成了环境和相关社区，并且这些植物的属性变化可能反映在其他营养水平甚至本地规模上。