巢湖底泥蓝藻时空分布特征及其环境影响因子  

Spatial-temporal variations of the benthic cyanobacteria and their environmental factors in Lake Chaohu,China

作　　者：阳振[1] 高芮 张民[1] 陈开宁[1] 史小丽[1] Yang Zhen;Gao Rui;Zhang Min;Chen Kaining;Shi Xiaoli(State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;Institute of Lake Ecology and Environment,Chaohu Lake Bureau of Anhui Province,Hefei 230601,P.R.China)

机构地区：[1]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 [2]安徽省巢湖管理局湖泊生态环境研究院,合肥230601

出　　处：《湖泊科学》2024年第6期1672-1680,共9页Journal of Lake Sciences

基　　金：巢湖生物资源调查研究项目(2020-340181-77-01-037328);国家自然科学基金项目(31971476)联合资助。

摘　　要：水华蓝藻在浮力下降后会沉入湖底,不但导致底泥污染加重,一些蓝藻细胞在低温和黑暗条件可维持低活性状态休眠越冬,并有可能在温度回升或风浪扰动后上浮至水柱,成为蓝藻水华暴发的种源。为了确定巢湖底泥蓝藻的时空分布特征及其环境影响因子,本研究对巢湖底泥蓝藻开展了8周年的野外调查。结果表明,巢湖底泥蓝藻含量在2016-2023年呈现先升高后下降的变化趋势,2019-2020年达到峰值;底泥蓝藻含量在空间分布上与水体蓝藻含量基本相似,呈现出由西向东逐渐减少的格局;巢湖底泥蓝藻含量季节变化明显,受微囊藻和长孢藻下沉休眠的影响,分别在11月和3月达到峰值,而春季至夏季由于蓝藻复苏上浮,7-8月份达到最低值。逐步回归分析发现,底泥总氮含量、风速、底泥总磷含量、温度可能是影响底泥蓝藻含量时空变化的主要环境因子。研究结果揭示了巢湖水华蓝藻在底泥中的时空分布规律,对湖泊内源污染的管控与蓝藻水华控制具有重要的科学意义。Cyanobacteria cells migrate into sediment due to a decrease in buoyancy,leading to increased sediment pollution.Some of cyanobacteria cells can overwinter as vegetative cells at low temperature and dark condition,and serve as a“seed bank”that can revive into the water column to form pelagic blooms as temperature rise and wind-wave disturbance.To study the spatial-temporal variations of benthic cyanobacteria and their environmental factors,an eight-year field investigation of the cyanobacteria in sediment was carried out in Lake Chaohu.The results showed that chlorophyll-a(Chl.a)content of sediment increased firstly and then decreased from 2016-2023 with the peak in 2019-2020.Chl.a content of water and sediment both decreased from west to east in space.The high Chl.a content of sediment occurred in March and November was related to the sink and dormancy of Microcystis and Dolichospermum,while the low Chl.a content occurred in July and August due to the cyanobacteria cells recruitment.Stepwise regression analysis showed that the total nitrogen in sediments,wind speed,total phosphorus in sediment,and water temperature were important influencing factors of Chl.a content of sediment.These results revealed the spatial and temporal distribution of cyanobacteria in the bottom of Lake Chaohu,which have important scientific significance for the control of lake internal pollution and cyanobacteria blooms.

关 键 词：底泥 内源污染 蓝藻水华 种源 巢湖 

分 类 号：X524[环境科学与工程—环境工程]