Aquatic macrophytes play an important role in structuring biotic communities. A comparative study of macroinvertebrate community structures associated with Salvinia auriculata Aublet and Eichhornia crassipes (Mart.) Solms was conducted in a Brazilian wetland (São Paulo State) during two periods. Our working hypothesis is that the aquatic macrophyte with the highest root system biomass and volume (E. crassipes) will result in the highest abundance and richness of associated macroinvertebrates. There were significant differences in the taxa richness and density of macroinvertebrates between macrophytes and sampling periods. The density of macroinvertebrates was higher in S. auriculata than in E. crassipes during both sampling periods, but there was little difference in mean taxa richness. Negative correlations between the macrophyte root biomass and volume and macroinvertebrate density were found. Insecta, Crustacea and Annelida were the most numerous groups of invertebrates sampled during the study, and Diptera (Insecta) dominated in the root systems of both macrophytes. Macroinvertebrates associated with E. crassipes roots may have undergone a vertical gradient of decreased oxygen concentration in the water, as well as of the available periphyton biomass, because of the low penetration of light in the region of the root system, which resulted in a lower density of macroinvertebrates.

中文翻译：

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与热带湿地中形成鲜明对比的根系的两种漂浮大型植物物种相关的水生大型无脊椎动物组合

水生大型植物在构建生物群落中起着重要作用。在两个时期内，在巴西湿地（圣保罗州）进行了与Salvinia auriculata Aublet和Eichhornia crassipes（Mart。）Solms相关的大型无脊椎动物群落结构的比较研究。我们的工作假设是，根系生物量和体积最高的水生植物（E. crassipes）将导致相关大型无脊椎动物的丰度和丰度最高。在大型植物和取样期之间，大型无脊椎动物的分类单元丰富度和密度存在显着差异。无脊椎动物的密度为在更高S.蕨比凤眼莲在两个采样期间，但平均分类单元丰富度差异不大。发现大型植物根系生物量与数量和大型无脊椎动物密度之间呈负相关。在研究期间，昆虫纲采样的昆虫种类最多，有昆虫纲，甲壳纲和无翅纲，而双生植物的根系中双翅目（昆虫纲）占主导地位。具有相关联无脊椎动物凤眼莲根可能已经经历氧浓度降低的在水中的垂直梯度，以及可用的附生生物质，由于光在根系统的区域中的低渗透，这导致了较低的无脊椎动物的密度。