Rotifers in different environments of the Upper Paraná River floodplain (Brazil): richness, abundance and the relationship with connectivity
Rotifers in different environments of the Upper Paraná River floodplain (Brazil): richness, abundance and the relationship with connectivity
复制标题
巴拉那河上游洪泛区（巴西）不同环境中的轮虫：丰富度、丰度及其与连通性的关系
作者：
A. S. Aoyagui;C. Bonecker
在2001年丰水期(2月)和枯水期(8月)，在巴拉那河上游泛滥平原的28个地点(3条河流、12个连通的泻湖和13个孤立的泻湖)的开放水域采集了轮虫。丰水期河流物种丰富度最高。孤立的泻湖物种丰富度最低。连通的泻湖的丰度最高，其次是孤立的泻湖，然后是河流，但没有明显的空间或时间变化。丰水期一些物种主要分布在孤立的泻湖中，而枯水时一些物种主要分布在连通的泻湖中。这些结果与我们的预期相反；我们预计在水文循环的两个极端期间，在孤立的泻湖中观察到最丰富的物种和最丰富的轮虫。我们的发现表明，环境之间的连通性对轮虫物种丰富度的重要性。2001年没有发生大洪水，由于缺乏稀释和食物资源(浮游植物)的高度可获得性，在丰水期促进了轮虫种群的发展。
Rotifers were collected in the open water of twenty-eight locations (3 rivers, 12 connected lagoons and 13 isolated lagoons) of the upper Paraná River floodplain during the high water (February) and low water (August) period of 2001. Greatest species richness was found in rivers during the high water period. Isolated lagoons had the lowest species richness. Abundance was highest in connected lagoons followed by isolated lagoons and then rivers, but did not show marked spatial or temporal variation. Some species dominated in isolated lagoons during high water and others in connected lagoons during the low water. These results were contrary to our expectations; we expected to observe highest species richness and abundance of rotifers in isolated lagoons during both extremes of the hydrological cycle. Our findings suggest the importance of connectivity among environments to rotifer species richness. The absence of an intense flood during 2001 facilitated development of rotifer populations during the high water period due to lack of dilution and high availability of food resources (phytoplankton).