生态学杂志2018，Vol.37Issue(3)：763-770,8.DOI:10.13292/j.1000-4890.201803.033
深水湖泊沉积物不同形态氮的生物地球化学特征——以百花湖为例
Biogeochemical characteristics of nitrogenous species in sediments of Baihua Lake
摘要
Abstract
Deep lakes experience altemate oxidation and reduction environment,which may affect the biogeochemical processes of nitrogen.Lake sediments generally have a unique reduction environment with complicated biogeochemical processes of nitrogen.In the present study,vertical sediments were collected from a typical plateau deep lake,Baihua Lake,during summer stratification.The concentration of nitrogenous species in pore water,water-soluble,adsorption-soluble,and particle organic nitrogen (PON) with δ15N-PON in the different depths of sediments were analyzed.The results showed that the concentration of total nitrogen (TN) in the pore water,ranging from 6.9 to 42.8 mg · L-1,was mainly composed of NH4+-N,ranging from 6.6 to 25.6 mg · L-1,and dissolved organic nitrogen.The concentrations of nitrate and nitrite were under detection line,indicating that the nitrate was used by denitrification or the potential dissimilatory reduction.The concentration of adsorption-soluble NH4+-N was higher than that of water-soluble NH4+-N.The concentration of PON in the sediment ranged from 0.22％ to 0.60％.Meanwhile,its variation tendency was well fit to the exponential decay pattern,suggesting that the variation of PON concentration in the sediment may be due to the diagenetic effect and mineralization.The δ15N-PON value above 31 cm depth decreased with depth,ranging from 3.4‰ to 10.0‰ and with an average of 6.4‰.It showed a more decrease tendency above 10 cm depth,which may be caused by the microbial degradation activity and the water exchange between pore water and lake water.The trend of δ15 N-PON value below 31 cm depth was opposite to that of the surface,which may be the result of diagenesis at early stage.TN in pore water had higher δ15N value than did water-soluble and adsorption-soluble N.TN in water-soluble and adsorption-soluble N had similar δ15N value,which was higher than the δ15N-PON.The results suggested that the increases of NH4+-N concentration in pore water may be related to the dissimilatory reduction process.关键词
沉积物/孔隙水/水溶态氮/吸附态氮/氮同位素Key words
sediment/pore water/water-soluble nitrogen/adsorption-soluble nitrogen/nitrogen isotope引用本文复制引用
司霞莉,岳甫均,王忠军,曾杰,贾国栋,钟君,李思亮..深水湖泊沉积物不同形态氮的生物地球化学特征——以百花湖为例[J].生态学杂志,2018,37(3):763-770,8.基金项目
科技部国家重点研发计划项目(2016YFA0601000)、中国博士后基金(2014M552389)和国家自然科学基金项目(41571130072、41403105)资助. （2016YFA0601000）
