富营养化湖泊刚毛藻建群特征及其影响因素

摘要

为研究富营养化湖泊刚毛藻建群过程及其影响因素,在草海沿岸带水深为5,25,45,65,85cm处分别放置大理石板作为刚毛藻建群的人工基质,监测人工基质上刚毛藻群落的生物量、藻丝长度以及附着硅藻的密度和组成.结果发现,2周后,水下25cm处的刚毛藻群落的生物量最大,为9.0mg/cm2.4周后,水下5cm处刚毛藻群落的生物量为14.0mg/cm2,是25cm处刚毛藻群落生物量的1.62倍.整个实验期间,水下65,85cm处刚毛藻群落的生物量一直较少,生物量分别为2.86,1.39mg/cm2.相对其它深度,5cm处刚毛藻藻丝长度最长,最高值为11.8cm.在第6周,水下5cm处刚毛藻群落中附着硅藻的密度最大,为7.8×106cell/cm2.分析结果显示,NH4+-N浓度、水下光照强度和SRP浓度是显著影响刚毛藻群落特征(刚毛藻群落生物量、刚毛藻藻丝长度和附着硅藻密度)的因子,而NH4+-N浓度和pH值是影响硅藻群落组成的显著性环境因子.%In order to study theCladophora community characteristics and the factors influenced the process in eutrophic lakes, the marble plates were placed in the depth of 5, 25, 45, 65, 85cm in coastal of Caohai Lake used for the measurement of the biomass of Cladophora community, the length of Cladophora and the density and composition of attached diatom. After two weeks, the biggest biomass of Cladophora community was 9.0mg/cm2 at underwater 25cm. Four weeks later, the biggest biomass of theCladophora community was 14.0mg/cm2 at underwater 5cm, which was 1.62 times that of the Cladophora community underwater 25cm. During the experiment, the Cladophora community biomass at 65cm and 85cm were 2.86mg/cm2 and 1.39mg/cm2, respectively, which are less than those of other depth of water. The longest length of the Cladophora filaments was 11.8cm at the depth of 5cm. At the 6th week, the biggest density of attached diatoms community was 7.8×106 cells/cm2 at the depth of 5cm. Statistical analysis indicated that the characteristics of Cladophora community were significantly affected by NH4+-N concentration, underwater light intensity and SRP concentration, and species composition of attached diatom were significantly affected by NH4+-N concentration and pH value.