稳定性氮同位素技术研究太湖梅梁湾区域营养盐差异  

Evaluation of Nitrogen Isotopes as Indicators of Spatial Nutrient Difference in Meiliangwan Bay,Tai Lake,China

作　　者：曾庆飞[1] 孔繁翔[1] 毛志刚[1,2] 孙明波[1,2] 谷先坤[1,2] 

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]中国科学院研究生院,北京100049

出　　处：《农业环境科学学报》2012年第4期813-818,共6页Journal of Agro-Environment Science

基　　金：国家自然科学基金资助项目(30900207);江苏省自然基金资助项目(SBK201021370);所长专项基金项目(09SL021002)

摘　　要：稳定同位素技术通常用于指示外源输入对环境的影响,采用该技术分析了太湖北部不同湖区悬浮颗粒有机物和浮游动物的碳氮稳定同位素比值的差异。结果表明,不同粒径的悬浮颗粒有机物和浮游动物稳定同位素比值存在显著的季节变化,夏季普遍高于冬季,其中δ13C高3.19‰~7.21‰,δ15N高4.20‰~9.36‰。各有机物δ13C不能有效区分各湖区的环境差异,而δ15N在各湖区存在显著差异。δ15N聚类分析显示,河口区由于受外源输入的影响,其δ15N显著低于其他湖区,单独聚为一类,而交汇处和湖心区影响较小,同河口区存在显著差异。整体来讲,总颗粒有机物和浮游动物δ15N同水体TP浓度呈显著正相关,同总溶解性无机氮浓度、铵根离子浓度呈显著负相关。可见,太湖北部悬浮颗粒有机物和浮游动物δ15N受环境营养盐差异的影响强烈,悬浮颗粒有机物δ15N可以作为指示湖区区域差异的有效指标。Stable isotope ratios were usually used as suitable indicators to study the anthropogenical effect on water environment.Carbon and nitrogen isotope ratios were measured in suspended organic matter and zooplankton collected from four sites along a contamination gradient in the north part of Tai Lake.Obvious seasonal variability was found in organic matter sources because of the effect of cyanobacterial blooms.The isotope ratios in collected organic matter sources were 3.19‰~7.21‰ heavier in δ13C and 4.20‰~9.36‰ heavier in δ15N during summer season than that collected in winter season.There existed very high spatial variability in the N isotope composition of the organic matter sources compared with that of δ13C.Cluster analysis showed that seston and zooplankton δ15N at Zhihugang River mouth was depleted compared to that at sites where have less anthropogenical effect,and also has a significant different with the δ15N collected at Cross and Lake Center.Bulk suspended organic matter and zooplankton δ15N was positively correlated with the concentration of total phosphorus,negatively correlated with the concentration of total inorganic nitrogen and ammonia nitrogen.The results showed that the water nutrient difference had a great effect on the suspended organic matter and zooplankton δ15N in the north part of Tai Lake,proving the use of a stable nitrogen isotopic method for predicting wastewater input.

关 键 词：稳定同位素比值 区域差异 悬浮颗粒有机物 太湖 梅梁湾 

分 类 号：S524[农业科学—作物学]