The influence of extreme floods from the River Danube in 2006 on phytoplankton communities in a floodplain lake: Shift to a clear state
The influence of extreme floods from the River Danube in 2006 on phytoplankton communities in a floodplain lake: Shift to a clear state
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DOI：
10.1016/j.limno.2009.09.001
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发表时间：
2010-09
期刊：
影响因子：
1.7
通讯作者：
M. Mihaljević;Dubravka Špoljarić;F. Stević;Vanda Cvijanović;Branimir Hackenberger Kutuzović
中科院分区：
文献类型：
--
作者：
M. Mihaljević;Dubravka Špoljarić;F. Stević;Vanda Cvijanović;Branimir Hackenberger Kutuzović
2006年多瑙河极端洪水对浮游植物的物种组成和垂直分布的影响进行了研究，在一个浅洪泛区湖，Sakada湖（Kopački Rit自然公园，克罗地亚），在过去的几十年中，是在一个浑浊的状态，其特点是高浮游植物浓度。由于洪水泛滥，整个洪泛区（约16平方公里）成为一个具有发达的大型植物植被的静水生境。湖泊叶绿素a（Chl a）浓度的季节变化具有浅水湖泊的特征。极低的平均浮游植物丰度和生物量被发现在非常高的营养盐浓度的条件下。浮游植物的优势种是硅藻和绿球藻绿色藻类的混合环境的功能组的特点。典范对应分析（CCA）表明，营养盐和温度是显着的环境变量对他们的发展。浮游植物的季节性，浮游植物的垂直分布，以及快速适应浮游植物的形式（R-战略家）的统治顺序表明明确的，良好的混合条件和高度干扰的环境。我们的研究结果表明，极端洪水的发生可以是一个压力源足够高的过渡，从一个混浊的河漫滩湖到一个明确的状态。可能的是，在洪泛区生态系统的替代稳定状态之间的周期性变化，可以预期的气候变化引起的极端水文事件的影响的结果。
The influence of extreme floods from the River Danube in 2006 on the species composition and vertical distributions of phytoplankton was studied in a shallow floodplain lake, Lake Sakadaš (Kopački Rit Nature Park, Croatia) which in the last few decades was in a turbid state characterised by high phytoplankton concentrations. As a consequence of extremely high floods, the whole floodplain area (approximately 16km2) became one lentic habitat with well developed macrophyte vegetation. Seasonal dynamics of chlorophyll a (Chl a) concentration in the lake had a characteristic pattern for the shallow lakes with dense macrophyte vegetation. Extremely low mean phytoplankton abundance and biomass were found in the conditions of very high nutrient concentrations. Dominant phytoplankton species were diatoms and chlorococcal green algae from the functional groups characteristic for a mixed environment. The canonical correspondence analysis (CCA) demonstrated that nutrients and temperature were significant environmental variables for their development. The sequence of phytoplankton seasonality, vertical distribution of phytoplankton, as well as the domination of rapidly acclimating phytoplankton forms (R-strategists) indicated clear, well-mixed conditions and a highly disturbed environment. Our results suggest that the occurrence of extreme flooding can be a stressor high enough for the transition from a turbid to a clear state of the floodplain lake. Possibly, cyclic shifts between alternative stable states in floodplain ecosystems can be expected as a consequence of the impact of extreme hydrological events induced by a climate change.