| 引用本文: | 朱广伟,秦伯强,张运林,许海,朱梦圆,杨宏伟,李宽意,闵屾,沈睿杰,钟春妮.2005-2017年北部太湖水体叶绿素a和营养盐变化及影响因素.湖泊科学,2018,30(2):279-295. DOI:10.18307/2018.0201 |
| ZHU Guangwei,QIN Boqiang,ZHANG Yunlin,XU Hai,ZHU Mengyuan,YANG Hongwei,LI Kuanyi,MIN Shen,SHEN Ruijie,ZHONG Chunni.Variation and driving factors of nutrients and chlorophyll-a concentrations in northern region of Lake Taihu, China, 2005-2017. J. Lake Sci.2018,30(2):279-295. DOI:10.18307/2018.0201 |
|
| |
|
|
| 本文已被：浏览 16297次 下载 6918次 |
码上扫一扫！ |
|
|
| 2005-2017年北部太湖水体叶绿素a和营养盐变化及影响因素 |
|
朱广伟, 秦伯强, 张运林, 许海, 朱梦圆, 杨宏伟, 李宽意, 闵屾, 沈睿杰, 钟春妮
|
|
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, 太湖湖泊生态系统研究站, 南京 210008
|
|
| 摘要: |
| 利用国家生态观测网络太湖湖泊生态系统研究站对北部太湖14个监测点2005-2017年的营养盐和叶绿素a浓度逐月监测数据，分析了北部太湖2005年以来水体营养盐和叶绿素a变化特征，探讨了叶绿素变化的影响因素.结果表明，2015年以来，北部太湖水体叶绿素a浓度呈现显著增高特征，特别是5-7月的蓝藻水华灾害关键期，水体叶绿素a浓度增幅更加明显；营养盐方面，氮、磷对治理的响应完全不同：水体总氮、溶解性总氮、氨氮的降幅很明显，甚至在春末夏初的蓝藻生长旺盛期出现了供给不足的征兆；但水体总磷降幅却不明显，加之蓝藻水华的磷"泵吸作用"，近3 a来水体总磷浓度反而有升高趋势，溶解性总磷浓度也无明显下降趋势.不同湖区的营养盐变化也不相同：西北湖区溶解性总氮、溶解性总磷浓度显著高于梅梁湾、贡湖湾和湖心区，而且后3个湖区的水质呈现均一化趋势.统计分析表明，北部太湖水体叶绿素a浓度与颗粒氮、颗粒磷、总磷、高锰酸盐指数均呈显著正相关，与溶解态氮呈负相关；5-7月水华关键期北部太湖水体叶绿素a浓度与上半年（1-6月）逐日水温积温、总降雨量、年平均水位均呈显著正相关关系.从研究结果可以看出，近年来北部太湖水体叶绿素a浓度的波动很大程度上受水文气象因子的影响；2007年以来太湖流域一系列生态修复工程的实施，虽然明显降低了湖泊氮浓度，但由于流域和湖体的氮磷本底较高，磷的缓冲能力大，致使水体营养盐水平仍未降到能显著抑制蓝藻生长的水平，年际之间的水文气象条件差异成为蓝藻水华暴发强度差异的主控因素.为此，仍需加大对太湖流域氮、磷负荷的削减，使湖体氮、磷浓度降低到能显著影响蓝藻生长的水平，才能摆脱水文气象条件对蓝藻水华情势的决定作用. |
| 关键词: 太湖 叶绿素a 营养盐 蓝藻水华 极端降雨 气候变化 |
| DOI：10.18307/2018.0201 |
| 分类号: |
| 基金项目:国家国际科技合作专项（2015DFG91980）、国家自然科学基金项目（41671494，41501532）和中国科学院前沿科学重点研究项目（QYZDJ-SSW-DQC008）联合资助. |
|
| Variation and driving factors of nutrients and chlorophyll-a concentrations in northern region of Lake Taihu, China, 2005-2017 |
|
ZHU Guangwei, QIN Boqiang, ZHANG Yunlin, XU Hai, ZHU Mengyuan, YANG Hongwei, LI Kuanyi, MIN Shen, SHEN Ruijie, ZHONG Chunni
|
|
Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
|
| Abstract: |
| The long-term variation of nutrients and phytoplankton chlorophyll-a (Chl.a) concentrations in northern Lake Taihu, a large shallow eutrophic lake, were characterized using the monthly monitoring data in northern 14 sites during 2005 to 2017. The relationships between Chl.a and nutrients, as well as hydrological and climatic factors were analyzed to identify the key driving factors of Chl.a and nutrients variations. The results showed that average Chl.a concentration significantly increased since 2015, especially during the key cyanobacteria bloom period of May to July. Total nitrogen (TN), dissolved total nitrogen (DTN) and ammonia concentrations in northern Lake Taihu showed a significant decreasing trend since 2005. The growth of cyanobacteria appeared nitrogen-limit phenomenon during early summer bloom season in recent years. While total phosphorus (TP) and dissolved total phosphorus (DTP) did not show significant decreasing trend in recent years, partly owing to the internal phosphorus supply stimulated by algal bloom in summer. Moreover, the TP and DTP even showed increasing trend in recent 3 years, with higher fluctuation than the past 10 years. Spatially, northwestern Lake Taihu region showed significant higher nutrient and Chl.a concentrations than those in Meiliang Bay, Gonghu Bay and central lake. It appeared a homogenization trend of nutrients among Meiliang Bay, Gonghu Bay and central lake. Statistical analysis showed that Chl.a significantly positive related to particulate nitrogen, particulate phosphorus, TP and permanganate index, but negatively related to dissolved nitrogen. And Chl.a concentration during May to July significantly positive related to daily accumulated water temperature, total precipitation during January to June, and to annual average water level of the lake. The research indicated that hydrological and climatic factors played more important roles than nutrients in the long-term variation of phytoplankton biomass and cyanobacteria bloom intensity, partly because the nutrients concentrations were still relatively sufficient for phytoplankton growth. Consequently, much more nutrients reduction in the catchment, include nitrogen and phosphorus, were need in future to ultimately control the cyanobacteria bloom in Lake Taihu. |
| Key words: Lake Taihu chlorophyll-a nutrients cyanobacteria bloom extreme rainfall climate change |
|
|
|
|
