Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang, 550001, China.
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
Environ Sci Pollut Res Int. 2018 Jan;25(2):1306-1318. doi: 10.1007/s11356-017-0502-4. Epub 2017 Oct 31.
Lake water level fluctuations (WLF) are an important factor driving the selection and seasonal dynamics of phytoplankton and potentially toxigenic cyanobacteria. Nevertheless, the relative importance of environmental drivers connected to WLF may be completely different, depending on the typology and use of waterbodies, latitude and climatic regimes. In this study, we investigated the impact of WLF in a large subtropical reservoir in south-eastern China (Hongfeng Reservoir, Guizhou Province). The study was based on monthly samplings carried out in 2014 in six stations. The strong increase in the water level observed in early summer caused a radical shift in the phytoplankton community. While in the pre-flooding period phytoplankton was composed of large diatoms, chrysophytes and Oscillatoriales (mostly Limnothrix sp.), the post-flooding period showed an increase in smaller and more competitive chlorophytes, smaller diatoms and cryptophytes better adapted to a fast colonisation of new and nutrient-rich environments. The environmental drivers that drove the change were dilution, flushing and interference with the seasonal water stratification processes. We concluded that, because WLF represents a complex variable integrating different physical effects in one explanatory descriptor, its value as a predictor of phytoplankton and cyanobacteria dynamics in lake ecosystems is difficult to generalise and needs to be investigated on a case-by-case basis. For this reason, considering the year-to-year hydrological variability that potentially characterise reservoirs, definite indications for management should be outlined considering more than 1-year study.
湖泊水位波动（WLF）是驱动浮游植物和潜在产毒蓝藻选择和季节性动态的重要因素。然而，与 WLF 相关的环境驱动因素的相对重要性可能因水体的类型和用途、纬度和气候条件而完全不同。在这项研究中，我们调查了中国东南部一个大型亚热带水库（贵州红枫湖）中 WLF 的影响。该研究基于 2014 年在六个站位进行的每月采样。初夏观测到的水位强烈增加导致浮游植物群落发生了根本性变化。在洪水前时期，浮游植物由大型硅藻、金藻和颤藻纲（主要是 Limnothrix sp.）组成，而洪水后时期则出现了较小且更具竞争力的绿藻、较小的硅藻和更能适应快速殖民新的富营养环境的隐藻的增加。驱动这种变化的环境驱动因素是稀释、冲刷和干扰季节性水层分异过程。我们得出结论，由于 WLF 代表了一个将不同物理效应集成到一个解释性描述符中的复杂变量，因此其作为湖泊生态系统中浮游植物和蓝藻动态的预测因子的价值难以概括，需要逐个案例进行研究。出于这个原因，考虑到水库中可能存在的逐年水文变异性，应该根据 1 年以上的研究来制定明确的管理建议。
