淡水超微型浮游植物的生态学及其研究方法概述

对淡水超微型浮游植物的研究方法和生态学进行了概述。为防止细胞的自溶和荧光特性的改变,淡水超微型浮游植物通常采用多聚甲醛和戊二醛作为固定剂并在低温下保存。在表面荧光显微镜下可以观察到含藻红素的蓝藻（PE 细胞）、含藻蓝素的蓝藻（PC细胞）以及以叶绿素为主要色素的超微型真核浮游植物（EU 细胞）3 种类群。在淡水生态系统中，影响超微型浮游植物变化的环境因子主要有温度、营养盐的可获得性、摄食、光照以及环境的污染。总体而言，高温有利于超微型蓝藻、低温利于真核藻类的生长。超微型浮游植物的丰度随着水体的营养增加而增加，但其贡献率却减少。淡水超微型浮游植物的研究主要集中在温带水体，对热带和亚热带水体的研究需要加强，而我国对淡水超微型浮游植物生态学研究基本处于空白。

A REVIEW OF RESEARCH METHOD AND ECOLOGY OF FRESHWATER PICOPHYTOPLANKTON

Research method and ecology of freshwater picophytoplankton were reviewed.Glutaraldehyde or paraformaldehyde was usually used to fix picophytoplankton.The preserved sample should be put into refrigerator in order to prevent it from disintegration and loss of autofluorescence.Three different categories including picoeukaryotes,phycoerythrin rich picocyanobacteria and phycocyanin rich picocyanobacteria can be detected under epifluorescence microscope.Temperature,nutrient availability,grazing,light and pollution are the main factors that influence picophytoplankton.Basically,high temperature is favorable to picocyanobacteria and low temperature is favorable to picoeukaryotes.With the increasing of nutriens,picocyanobacteria numbers increased,but their contribution to the total phytoplankton biomass decreased.The researches of freshwater picophytoplankton were mainly done in temperate waters.Research in tropical and subtropical areas is rare,especielly in China.Such studies should be strengthened to understand more about freshwater picophytoplankton.