JOURNAL OF YANGTZE RIVER SCIENTIFIC RESEARCH INSTI ›› 2020, Vol. 37 ›› Issue (5): 50-58.DOI: 10.11988/ckyyb.20190170


Characteristics of δ15N of Foliage and Soil at Typical IsletWetland in Poyang Lake

XIAO Yang1, ZHANG Xiang2, WANG Meng1, DENG Zhi-min1, LIN Yu-ru3   

  1. 1. Changjiang Water Resources Protection Institute, Changjiang Water Resources Commission,Wuhan 430051,China;
    2. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University,Wuhan 430072, China;
    3. Water Resources Department, Yangtze River Scientific Research Institute,Wuhan 430010, China
  • Received:2019-02-25 Online:2020-05-01 Published:2020-06-10

Abstract: To study the characteristics of δ15N of foliage and soil at typical islet wetland in Poyang Lake, we took the islet wetland between Benghu Lake and Xiushui River as the research object. We analyzed the relation between foliar δ15N and soil δ15N at typical section from October to December, 2015 and in April, 2016. We also examined the influence of moisture content of soil and inorganic nitrogen (ammonium nitrogen and nitrate nitrogen) content on foliar δ15N and soil δ15N. Results demonstrated that foliar δ15N of most C3 plants were larger than that of C4 plants. The foliar δ15N and soil δ15N in wet period were larger than those in drought period; however, in both wet and dry periods, the 15N was more enriched in foliage than in soil. Ammonium nitrogen is the major inorganic nitrogen in the wetland soil, accounting for 87.43%, whereas in wetland plants, nitrate nitrogen was dominantly adsorbed. The opening degree of nitrogen cycle in the study area is small, and the soil δ15N decreased with the increase of available nitrogen but increased with the rising of soil water content. There is a significant positive correlation between foliar δ15N and soil δ15N, and foliar δ15N is mainly affected by soil’s nitrogen content and nitrogen isotope fractionation.

Key words: islet wetland, plant foliage, δ15N, nitrogen cycle, nitrogen content, water content in soil, ammonium nitrogen, nitrate nitrogen, Poyang Lake

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