Fish assemblage dynamics in a Neotropical floodplain relative to aquatic macrophytes and the homogenizing effect of a flood pulse
Fish assemblage dynamics in a Neotropical floodplain relative to aquatic macrophytes and the homogenizing effect of a flood pulse
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DOI：
10.1007/s10750-011-0870-6
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发表时间：
2012-04-01
期刊：
影响因子：
2.6
通讯作者：
Miranda, L. E.
中科院分区：
文献类型：
--
作者：
Gomes, L. C.;Bulla, C. K.;Miranda, L. E.
水生植物的存在是一个关键因素，在选择栖息地的鱼在洪泛区湖泊，因为这些植物提高了水生栖息地的物理和生物的复杂性。季节性洪水脉冲可能会影响这种相互作用，但没有资料在文献中的影响，洪水事件可能对水生植物组合及其相关的影响，鱼类组合。因此，本文的目的是调查是否物种丰富度，均匀度和相似性的鱼类组合组成之间的沿岸的地区与水生植物植被和无植被的地区，洪水前后的差异。我们在巴拉那河上游流域的洪泛区采集了三个湖泊的样本。在洪水事件之前（2004年12月和2005年1月）和之后（2005年3月初、3月底和5月）进行了取样。总体而言，物种丰富度和均匀度较高的大型植物覆盖的地区。洪水前，鱼类组合的组成是不同的，当比较植被和无植被的地区。洪水后，鱼类组合组成的相似性较高，表明洪水的均匀化效应的鱼类栖息在沿岸的地区的洪泛平原湖泊。洪水后，机会主义物种占主导地位的水生植物中的鱼类组合，显然重组组合在沿岸的，重新启动的演替过程。因此，所观察到的洪水的均质化效应可以最大限度地减少生物相互作用，并可能导致鱼类组合开始一个新的结构化过程。
The presence of aquatic macrophytes is a key factor in the selection of habitats by fish in floodplain lakes because these plants enhance the physical and biological complexities of aquatic habitats. The seasonal flood pulse may influence this interaction, but there is no information in the literature about the effects that flood events may have on macrophytes assemblages and its associated effects on fish assemblages. Thus, this article aimed to investigate whether species richness, evenness and similarities in fish assemblage composition differed between littoral areas vegetated with macrophytes and unvegetated areas, before and after a flood. We sampled three lakes in the floodplain of the upper Parana River basin. Sampling was conducted before (December 2004 and January 2005) and after (early March, late March and May 2005) a flood event. Overall, species richness and evenness were higher in macrophytes-covered areas. Before the flood, the composition of fish assemblages was distinct when comparing vegetated and unvegetated areas. After the flood, the similarity in fish assemblage composition was higher, indicating a homogenization effect of floods for fish inhabiting littoral areas of floodplain lakes. After the flood, opportunistic species dominated the fish assemblages in aquatic macrophytes, apparently restructuring assemblages in the littoral, restarting a succession process. Thus, the observed homogenization effect of the flood could minimize biological interactions and could induce fish assemblages to begin a new process of structurization.