您好,欢迎访问福建省农业科学院 机构知识库!

The co-regulation of nitrate and temperature on denitrification at the sediment-water interface in the algae-dominated ecosystem of Lake Taihu, China

文献类型: 外文期刊

作者: Zhong, Jicheng 1 ; Yu, Juhua 1 ; Wang, Jianjun 1 ; Liu, Dehong 1 ; Chen, Chao 4 ; Fan, Chengxin 1 ;

作者机构: 1.Chinese Acad Sci, Nanjing Inst Geog & Limnol, State Key Lab Lake Sci & Environm, Nanjing 210008, Peoples R China

2.Fujian Acad Agr Sci, Inst Soil & Fertilizer, Fuzhou 350013, Peoples R China

3.Henan Univ Sci & Technol, Agr Coll, Luoyang 471003, Peoples R China

4.China West Normal Univ, Coll Environm Sci & Engn, Nanchong 637009, Peoples R China

关键词: Denitrification; Eutrophication; Lake Taihu; Nitrogen budget; Sediment-water interface

期刊名称:JOURNAL OF SOILS AND SEDIMENTS ( 影响因子:3.308; 五年影响因子:3.586 )

ISSN: 1439-0108

年卷期: 2020 年 20 卷 4 期

页码:

收录情况: SCI

摘要: Purpose Sediment denitrification is a dominant mechanism for nitrogen removal and can help to minimize lake eutrophication. However, the spatio-temporal variability of denitrification rates and its controlling factors in sediments of large shallow lakes are poorly understood. In this study, we investigated the controlling factors on the temporal and spatial variability of denitrification rates in Meiliang Bay in Taihu Lake, China, to determine the contribution of denitrification on the total lacustrine nitrogen budget. Materials and methods We collected 18 intact monthly sediment cores and an additional 36 seasonal sediment cores from January 2013 to January 2014. Cores were collected from the inner and outer sections of Meiliang Bay for analysis of denitrification rates and sediment properties. We also collected in situ surface water samples for water quality analysis. Denitrification rates at the sediment-water interface (SWI) were measured using acetylene inhibition techniques and intact sediment core incubation. We used a t test to determine the differences in water quality and sediment properties between the two sites and a one-way ANOVA to identify seasonal differences in denitrification rates, water quality, and sediment properties. We also applied Pearson's correlation, distance-based redundancy analysis (db-RDA) and random forest model to identify the relationships between denitrification rates and environmental factors. Results and discussion Denitrification rates ranged from 0.76 to 40.94 mu mol N m(-2) h(-1) and 0.13 to 52.55 mu mol N m(-2) h(-1), with annual mean values of 19.97 and 17.15 mu mol N m(-2) h(-1) for the Inner and Outer Bay, respectively. Sediment denitrification rates in the Inner and Outer Bay showed similar seasonal variability, with the highest values in spring and summer and the lowest values in autumn. Nitrate addition was shown to significantly increase denitrification rates in summer and autumn (P < 0.05); however, carbon addition showed no significant influence on denitrification rates in the four seasons. Our results imply that denitrification rates were nitrate-limited in summer and autumn. Distance-based redundancy analysis (db-RDA) and random forest model showed that denitrification rates were mainly determined by nitrate, temperature, and chlorophyll a (Chla), and that nitrate in the water column was the most important predictor of denitrification rates. Conclusions In general, denitrification rates showed significant seasonal variability in Meiliang Bay due to the co-regulation of both water temperature and nitrate concentrations. The dominance of each controlling factor on denitrification rates varied in different seasons. Based on our calculations, nitrogen removal by denitrification accounted for approximately 10.7% of the total nitrogen input to Taihu Lake. Therefore, we suggest the need for effective measures to reduce external nitrogen inputs of to Lake Taihu to prevent on-going eutrophication.

  • 相关文献
作者其他论文 更多>>