Institute of Hydrobiology, Jinan University, Guangzhou 510632, China.
Water Res. 2011 Oct 15;45(16):5099-109. doi: 10.1016/j.watres.2011.07.012. Epub 2011 Jul 23.
Liuxihe reservoir is a deep, monomictic, oligo-mesotrophic canyon-reservoir in the subtropical monsoon climate region of southern China. Phytoplankton functional groups in the reservoir were investigated and a comparison made between the succession observed in 2008, an exceptionally wet year, and 2009, an average year. The reservoir shows strong annual fluctuations in water level caused by monsoon rains and artificial drawdown. Altogether 28 functional groups of phytoplankton were identified, including 79 genera. Twelve of the groups were analyzed in detail using redundancy analysis. Because of the oligo-mesotrophic and P-limited condition of the reservoir, the dominant functional groups were those tolerant of nutrient (phosphorus) deficiency. The predominant functional groups in the succession process were Groups A (Cyclotella with greatest axial linear dimension<10 μm), B (Cyclotella with greatest axial linear dimension>10 μm), LO (Peridinium), LM (Ceratium and Microcystis), E (Dinobryon and Mallomonas), F (Botryococcus), X1 (Ankistrodesmus, Ankyra, Chlorella and Monoraphidium) and X2 (Chlamydomonas and Chroomonas). The development of groups A, B and LO was remarkably seasonal. Group A was dominant during stratification, when characteristic small size and high surface/volume ratio morphology conferred an advantage. Group LO was dominant during dry stratification, when motility was advantageous. Group B plankton exhibited a high relative biomass during periods of reduced euphotic depth and isothermy. Groups LM, E, F, X1 and X2 occasionally exhibited high relative biomasses attributable to specific environmental events (e.g. drawdown, changes in zooplankton community). A greater diversity of phytoplankton functional groups was apparent during isothermy. This study underscores the usefulness of functional algal groups in studying succession in subtropical impoundments, in which phytoplankton succession can be significantly affected by external factors such as monsoonal hydrology and artificial drawdown, which alter variables such as retention time, mixing regime and thermal structure and influence light and nutrient availability.
流溪河水库是中国亚热带季风气候区的一个深、单温跃层、寡营养-中营养峡谷型水库。对水库中的浮游植物功能群进行了调查，并比较了 2008 年（异常湿润年）和 2009 年（平均年）的观测结果。水库受季风降雨和人工降水位的影响，水位呈现强烈的年际波动。共鉴定出浮游植物功能群 28 个，包括 79 属。利用冗余分析对其中 12 个功能群进行了详细分析。由于水库的寡营养和磷限制条件，优势功能群是那些耐受营养（磷）缺乏的功能群。在演替过程中，主要的功能群是 A 组（轴向线性尺寸<10 μm 的 Cyclotella）、B 组（轴向线性尺寸>10 μm 的 Cyclotella）、LO 组（Peridinium）、LM 组（Ceratium 和 Microcystis）、E 组（Dinobryon 和 Mallomonas）、F 组（Botryococcus）、X1 组（Ankistrodesmus、Ankyra、Chlorella 和 Monoraphidium）和 X2 组（Chlamydomonas 和 Chroomonas）。A 组、B 组和 LO 组的发育具有明显的季节性。A 组在分层期占优势，此时其特有的小尺寸和高表面积/体积比形态赋予了其优势。LO 组在干燥分层期占优势，此时运动能力具有优势。B 组浮游生物在透光深度和等温期减少时表现出较高的相对生物量。LM、E、F、X1 和 X2 组在特定环境事件（如降水位、浮游动物群落变化）期间偶尔表现出较高的相对生物量。在等温期，浮游植物功能群的多样性更为明显。本研究突出了功能藻类在亚热带水库演替研究中的作用，在亚热带水库中，浮游植物的演替可能会受到外部因素的显著影响，如季风水文和人工降水位，这些因素会改变滞留时间、混合模式和热结构等变量，并影响光和营养物质的可用性。
