AME 80:93-99 (2017)  -  DOI: https://doi.org/10.3354/ame01844

Nitrogen incorporation by epiphytic algae via Vallisneria natans using 15N tracing in sediment with increasing nutrient availability

Yuzhi Song1,2,*, Jinqi Wang1, Yongxia Gao2, Boqiang Qin3

1Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, Jiangsu 210044, PR China
2Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Nanjing University of Information Science & Technology, Nanjing, Jiangsu 210044, PR China
3Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, Jiangsu 210008, PR China
*Corresponding author:

ABSTRACT: We performed a tracer experiment using the stable isotope 15N to investigate nitrogen incorporation by epiphytic algae via its host plant, Vallisneria natans, from the sediment with increasing nutrients in the water column. 15N was added as 15NH4Cl to the sediment, and its fate was traced with increasing nutrient availability in the water column and sediment. Samples of epiphytic algae and V. natans were examined for δ15N. The results indicated that with increased nitrogen and phosphorus availability in the water column, the ability of epiphytic algae and the leaves of V. natans to utilize nitrogen originating from sediment was significantly decreased (p < 0.05), while the ability of the roots of V. natans to utilize nitrogen from sediment changed very little (p > 0.05). Under the same nutrient levels in the water column, the ability of the roots and leaves of V. natans to utilize nitrogen originating from sediment was higher in high-nutrient sediment than that in low-nutrient sediment (p < 0.05), while the ability of epiphytic algae to utilize nitrogen from sediment changed very little (p > 0.05). Thus, epiphytic algae and the tissues of V. natans can be arranged with respect to their accumulated 15N as follows: epiphytic algae < leaves < roots; nitrogen incorporation by epiphytic algae originating from sediment was negligible compared to the tissues of V. natans in this experiment. This suggested that when concentrations of nitrogen and phosphorus are >1.0 and 0.1 mg l-1 in the water column, respectively, sediment as a nitrogen source is negligible for the growth of epiphytic algae.


KEY WORDS: Nitrogen incorporation · Epiphytic algae · Vallisneria natans · 15N labeling · Sediment


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Cite this article as: Song Y, Wang J, Gao Y, Qin B (2017) Nitrogen incorporation by epiphytic algae via Vallisneria natans using 15N tracing in sediment with increasing nutrient availability. Aquat Microb Ecol 80:93-99. https://doi.org/10.3354/ame01844

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