沉积物再悬浮对浮游动物群落结构影响的模拟实验

Experimental study on the effect of sediment resuspension on zooplankton community

沉积物再悬浮是浅水湖泊的重要特征之一.通过模拟实验,比较不同再悬浮程度下浮游动物群落结构的变化,以探讨沉积物再悬浮对浮游动物的影响.结果显示,不同处理下总悬浮物与叶绿素a浓度差异显著.再悬浮组中枝角类简弧象鼻溞(Bosmina coregoni)、角突网纹溞(Ceriodaphnia cornuta)和轮虫占优势,而对照组中大型枝角类溞属(Daphniasp.)占优势,再悬浮使浮游动物群落组成趋于小型化.不同再悬浮条件下隆线溞(Daphnia carinata)、简弧象鼻溞(Bosmina coregoni)和轮虫的丰度差异显著,角突网纹溞(Ceriodaphnia cornuta)和桡足类丰度差异不显著.总悬浮物浓度与轮虫和简弧象鼻溞丰度显著正相关,与隆线溞丰度显著负相关,与其它浮游动物种群丰度无显著相关性.本研究显示,沉积物再悬浮是决定浮游动物群落结构变化的重要过程之一.

Sediment resuspension is one of the important characteristics of hydrodynamic processes in shallow lakes. This experimental study was compared with the changes of zooplankton community in different levels of the resuspension to investigate the effect of sediment resuspension on zooplankton. The result shows significantly difference when using different treatments of concentrations of TSS and Chl. a. The cladoceran Bosmina coregoni, Ceriodaphnia cornuta and Rotifers are dominant in resuspended groups, but Daphnia sp. is dominant in no resuspended group. Resuspension produced an effect of deducing size of the composition of zooplankton communities. The abundances of Daphnia cari nata, Bosmina coregoni and Rotifers are significant different in different resuspended levels,but Ceriodaphnia cornuta and Calanoidas show no signiticant different. The concentration of TSS is significant positive correlation with abundances of Rotifers and Bosmina coregoni, but significant and negative correlation with Daphnia sp. abundance, while there is none correlation with other populations. The research shows that the sediment resuspention is one of the important processes determining zooplankton community structure.