王小冬1,2,刘兴国1,朱 浩1,车 轩1,顾兆俊1,田昌凤1,李 月1
(1十大网投正规信誉官网 农业部渔业装备与工程重点开放实验室,上海 200092;
2 中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京 210008)
摘要:假设蓝藻水华的形成与蓝藻门植物能够耐受低浓度营养盐有关,为了验证是否只有蓝藻门浮游植物才能够耐受低浓度的营养盐,选用绿藻门的纤维藻属(Ankistrodesmus)占绝对优势的天然水体在不添加外源营养盐的温室条件下进行试验。试验持续了18 d。试验期间在8:30、14:00时平均水温分别为31.6 oC、34.6 oC。试验水体总氮、总磷、溶解性总氮、溶解性总磷、活性磷浓度的变化范围依次为0.7~1.5、0.03~0.09、0.45~0.70、0.02~0.05、0~0.022mg/L;试验初始的叶绿素a含量约为190 µg/L,结束时降低至30 µg/L左右。试验期间一直维持绿藻门的纤维藻属优势。结果表明,在没有添加外源营养盐时,绿藻门浮游植物也能够耐受低浓度的营养盐,天然水体中蓝藻水华的发生与蓝藻能够耐受低浓度氮磷营养盐没有必然联系;同时推断:绿藻在初始占优势时,在低营养盐条件及环境条件没有特别变化时,蓝藻不可能逆转成为优势种。
关键词:绿藻门;蓝藻门;营养盐;耐受
The tolerance of chlorophyta phytoplankton to low concentrations of nutrients
WANG Xiao-dong 1,2, LIU Xing-guo 1, ZHU Hao 1, CHE Xuan 1, GU Zhao-jun 1, TIAN Chang-feng 1, LI Yue 1
(1 Fishery Machinery and Instrument Research Institute, Chinese Academy of Fisheries Sciences Key Laboratory of Fishery Equipment and Engineering, Ministry of Agriculture, Shanghai 200092, China; 2 State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China)
Abstract: The formation of cyanobacteria bloom was considered to be related to their tolerance of low concentrations of nutrients on the basis of the previous experiment result. In order to verify the hypothesis that cyanobacteria can tolerate low concentrations of nutrients alone, natural water of Ankistrodesmus (Chlorophyta) dominance was studied in greenhouse without added nutrients for 18 d. The mean water temperature at 08:30 a.m. and 14:00 p.m. of the experiment was 31.6 oC and 34.6 oC, respectively. The ranges of concentrations of total nitrogen, total phosphorus, dissolved total nitrogen, dissolved total phosphorus and soluble reactive phosphorus were 0.7-1.5, 0.03-0.09, 0.45-0.70, 0.02-0.05 and 0-0.022 mg/L, respectively. The initial chlorophyll a concentration was about 190 µg/L, and that at the end of the experiment reduced to about 30 µg/L. Ankistrodesmus (Chlorophyta) maintained dominance throughout all the experiment. It showed Chlorophyta could tolerate low concentrations of nutrients when there was no external nutrients addition. Thus, there was not inevitable relationship between the formation of cyanobacteria bloom and their tolerance of low concentrations of nutrients. Further deduction: initial Chlorophyta dominance can’t turn to cyanobacteria dominance with low concentrations of nutrients and no specific changes of the environment.
Key words: Chlorophyta; Cyanobacteria; nutrients; tolerate
基金项目:湖泊与环境国家重点实验室开放基金(2010SKL006);公益性行业(农业)科研专项(201203083)
作者简介:王小冬(1981—),女,助理研究员,博士,主要研究水体富营养化。E-mail:wangxd1201@163.com
(来源:《渔业现代化》2012,39(5):21-26)