沉降时间、抽滤速率对浮游植物定量数据影响的探讨

The effects of sedimentation time and filtration rate on phytoplankton quantitative data

浮游植物是水生生态系统中重要的初级生产者,能快速响应水质的营养状态的变化,其种类和生物量是水质和富营养化的监测、评价以及风险预警的重要指标之一。因此如何快速、准确地确定其数量是进一步水质评价和生态功能分析的基础。添加鲁哥固定液静止沉降,利用虹吸原理浓缩样品是浮游植物采集最常用的方法,而在此过程中沉降时间以及虹吸过程中的抽滤速度对浮游植物数据的影响没有统一的标准以及科学的研究。基于此,本研究通过采集野外湖泊水体样品探讨沉降时间和抽滤速率对浮游植物计数统计量的影响。结果表明,浮游植物计数统计量均表现出与沉降时间呈现正相关,与抽滤速率呈现负相关,且不同的藻类对沉降时间和抽滤速度表现出不同的响应趋势。空球藻、栅藻、针杆藻和直链藻达到完全沉降的时间分别为45、50、45、36 h,而当抽滤速度低于0. 048 L/h时浮游植物计数统计量将不受抽滤速度的影响。因此,当采集野外样品时,为获得准确浮游植物计数统计量数据需尽量延长沉降时间且降低抽滤速度。

Phytoplankton is an important primary producer in aquatic ecosystem,which can respond quickly to the changes of nutrient status of water quality,and its species and biomass are one of the important indexes for monitoring,evaluation and risk warning of water quality and eutrophication.Therefore,how to quickly and accurately quantify the quantity is the basis for further water quality assessment and ecological function analysis. The most common method for phytoplankton collection is to add logo’s reagent fixed liquid static sedimentation and concentrate samples by siphoning principle. However,there is no unified standard and scientific research on the influence of settling time and filtration rate on phytoplankton data.Based on this,this study investigated the effects of settling time and filtration rate speed on phytoplankton counts. The results showed that phytoplankton count statistics showed positive correlation with settling time and negative correlation with filtration rate,and different algae showed different response trends to settling time and filtration rate.In this study,the time of complete precipitation of chlorella,synedra,melosira,phyllorella was 45,50,45,and 36 h,respectively;phytoplankton count statistics will not be affected when the filtration rate is lower than 0. 048 L/h. Therefore,to achieve accurate results,the settling time should be extended as much as possible and the filtration rate should be reduced.