明水期松花江哈尔滨段着生藻类分层特征

Stratified Characteristics of Periphyton in Harbin Section of Songhua River in Ice-free Period

2015年5月—2016年5月明水期,依人为干扰类型的不同,在松花江哈尔滨段设8个样点,逐月分别采集表层(水面下27cm)和底层(水面下52cm)的着生藻类,研究明水期松花江哈尔滨段着生藻类群落结构的分层特征。结果表明,表层着生藻类共计7门121种(含未定种);底层6门119种(含未定种);表层、底层数量分别为6.74×10~4ind./cm^2、5.651×10~4ind./cm^2,生物量均值分别为0.1375 mg/cm^2、0.116 mg/cm^2,表层略高于底层,且表、底层着生藻类各门的数量、生物量的排序规律相同。对种类组成、优势种、数量和生物量的分析表明:硅藻是明水期调查江段着生藻类第一优势藻门。基于着生藻类分层特征,调查、评估河流着生藻类优势种类、数量和生物量时,建议采集策略优化为表层采集,而基于着生藻类种类的研究和评价工作采集表、底层混合水样。

The stratification characteristics of epiphytic algae community were monthly surveyed in surface layer(27 cm below water surface)and bottom layer(52 cm below water surface)of 8 sampling sites according to different types of human disturbance in Harbin section of Songhua River from May to November in 2015(ice-free period).A total of 121 species(including non-identified species)of periphyton were found in surface and 119 species(including non-identified species)of periphyton at bottom during the study period.There was dominant species similarity of as high as 0.85 between surface and bottom,with average periphyton density of6.74×10~4ind./cm^2and periphyton biomass of 0.1375 mg/cm^2in surface and average periphyton density of 5.651×10~4ind./cm^2and periphyton biomass of 0.116 mg/cm^2at bottom.Quite similar rank charts between periphyton abundance or biomass and frequency was observed in surface and at bottom.Analysis of different periphyton community structure revealed that diatom was the first dominant periphyton in Harbin section of Songhua River in ice-free period,with slight advantage periphyton community in surface periphyton community structure.It is suggested that the collection strategy should be optimized to the surface collection based on the stratified characteristics of the algae,and that the research and evaluation work based on the algae species should collect the mixed water samples from surface and bottom.