三峡水库营养元素的分布及其与藻类生长的关系  

THE DISTRIBUTION OF NUTRIENTS IN THE THREE GORGES RESERVOIR AND THE EFFECTS ON THE GROWTH OF ALGAE

作　　者：王司阳 周子俊[1,2] 汪志聪[1] 李慧[1,2] 曹秀云[1] 宋春雷[1] 周易勇[1] 

机构地区：[1]中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉430072 [2]中国科学院大学,北京100049

出　　处：《水生生物学报》2015年第5期910-919,共10页Acta Hydrobiologica Sinica

基　　金：中国长江三峡集团公司科研项目(No.CT-12-08-01)资助

摘　　要：为进一步研究三峡水库(尤其是支流)氮和磷等营养元素的时空分布格局及其与藻类生长的关系,于2012年8月、11月与2013年1月、4月在三峡库区木洞至秭归的5个断面采样分析了不同形态氮和磷以及叶绿素a(Chl.a)的浓度,并对藻类进行了胞外碱性磷酸酶的荧光标记(Enzyme Labelled Fluoresce,ELF)。结果表明,春夏季总磷(TP)与Chl.a浓度均高,但二者的正相关性在空间尺度上并未得到充分的体现,干流的TP浓度显著高于支流(P<0.05),而Chl.a浓度则反之。巫山断面干流与支流的TP浓度显著低于其他断面(P<0.05),而Chl.a浓度则无显著差异,秭归断面显著增高的TP浓度改变了其沿水流方向下降的趋势。从总体上讲,Chl.a浓度与TP、溶解性总磷(DTP)、溶解反应性磷(SRP)和硝态氮(NO3–-N)浓度均极显著负相关(P<0.01),而与总氮(TN)浓度、TN/TP、NO3–-N/SRP等均极显著正相关(P<0.01),因此,氮对藻类的生长可能具有一定的促进作用,而泥沙对磷的吸附与沉降有效降低了其生物可利用性。巫山断面底层显著较高的TP与颗粒态磷(PP)浓度支持了上述推测,不同断面不同藻类胞外磷酸酶的标记进一步说明了磷对其生长的关键限制性作用。因此,在水质管理、富营养化防治和渔业资源管理过程中必须充分考虑不同营养元素的存在状态及其与水文条件的交互作用。Signs of accelerated eutrophication have appeared in the Three Gorges Reservoir （TGR）, and algal blooms have occurred in some areas especially the tributaries. However, little is known about the spatial and temporal distribu- tion of the nutrients, such as phosphorus and nitrogen, and how it affects the growth of algae. To answer this question, we collected water samples from five different sections of the TGR in August and November of 2012 and in January and April of 2013. We analyzed the concentrations of chlorophyll-a （Chl.a） and nitrogen/phosphorus in different forms in the samples. We also applied the enzyme labeled fluoresce （ELF） method to detect the extracellular alkaline phosphatase excreted from algal cells. The concentrations of total phosphorus （TP） and Chl.a showed the same seasonal trend but unrelated spatial patterns. The concentrations of both were higher in spring and summer. The level of TP was higher in the main stream than that in the tributaries, whereas the level of Chl.a was higher in the tributaries （P〈0.05）. Among the five sections, the concentration of TP was the lowest in Wushan in both the main stream and the tributaries （P〈0.05）, but the concentration of Chl.a did not significantly vary between different sections. The level of TP decreased along the direction of the water flow until it reached Zigui where the TP level was significantly elevated. There was significantly negative correlation between the concentration of Chl.a and those of TP, dissolved total phosphorus （DTP）, soluble re- active phosphorus （SRP）, and nitrate nitrogen （NO3-N）（P〈0.01）. In the contrast, the level of Chl.a was positively corre- lated to the levels of total nitrogen （TN）, TN/TP and NO3/SRP （P〈0.01）. These suggested that nitrogen might modera- tely promote the growth of algae. Furthermore, sorption and deposition of phosphorus by suspended solids may decrease its bioavailability, and this was supported by the fact that the concentrations of TP and Particu

关 键 词：氮 磷 富营养化 叶绿素A 三峡水库 

分 类 号：Q142[生物学—生态学]