In this study we analyzed the dynamics of the phytoplankton community in two cascade reservoirs in six sampling periods, to investigate the influence of environmental filters on phytoplankton, and the community concordance with the environmental variability. We addressed several questions, and from phytoplankton biomass data and abiotic variables sampled at the Salto Osório and Salto Santiago reservoirs, Paraná, Brazil, we obtained the answers. A total of 136 taxa distributed in cyanobacteria, diatoms, green algae and mixotrophic flagellates were recorded. Diatoms and mixotrophic flagellated algae contributed most of the phytoplankton biomass in both reservoirs. Environmental filters such as nutrient concentrations, light, pH, depth and temperature had the greatest influence on phytoplankton taxonomic structure, being the community in concordance with the environmental conditions. Although some environmental differences between reservoirs were recorded, the phytoplankton community was similar, probably associated with environmental connectivity, but with differences in biomass, which is possibly associated with seston retention in upstream regions. Our results revealed important drivers that influence the phytoplankton structure and dynamics in reservoirs, and this understanding is of interest, due to the maintenance of ecosystem functions and services.

中文翻译：

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影响梯级水库浮游植物分类结构的环境过滤器

在这项研究中，我们分析了六个采样周期内两个梯级水库浮游植物群落的动态，以研究环境过滤器对浮游植物的影响，以及群落与环境变化的一致性。我们解决了几个问题，从浮游植物生物量数据和在巴西巴拉那州 Salto Osório 和 Salto Santiago 水库采样的非生物变量中，我们得到了答案。共记录了 136 个分类群，分布在蓝藻、硅藻、绿藻和混合营养鞭毛虫中。硅藻和混合营养鞭毛藻在两个水库中贡献了大部分浮游植物生物量。营养浓度、光照、pH、深度和温度等环境过滤器对浮游植物分类结构的影响最大，成为符合环境条件的社区。虽然记录了水库之间的一些环境差异，但浮游植物群落相似，可能与环境连通性有关，但生物量不同，这可能与上游地区的沉积物滞留有关。我们的结果揭示了影响水库浮游植物结构和动力学的重要驱动因素，由于生态系统功能和服务的维护，这种理解很有趣。