Dual stable isotopes approach reveals the nitrogen sources, transformations, and effects on phytoplankton community structure in a large floodplain lake

被引：0

作者：

Ha, Xianrui ^{[1
,2
]}

Lin, Shunhe ^{[1
,3
]}

Jia, Junjie ^{[1
,2
]}

Wang, Jing ^{[1
]}

Wu, Fan ^{[1
]}

Sun, Kun ^{[2
]}

Lu, Yao ^{[1
,2
]}

Wang, Shuoyue ^{[1
,2
]}

Gao, Yang ^{[1
,2
]}

机构：

[1] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[3] Fujian Matern & Child Hlth Hosp, Dept Obstet & Gynecol, Fuzhou 350102, Fujian, Peoples R China

来源：

ECOLOGICAL PROCESSES | 2025年 / 14卷 / 01期

基金：

中国国家自然科学基金;

关键词：

Nitrogen cycling; Phytoplankton assimilation; Nitrification; Phytoplankton biomass; Lake Poyang; POYANG LAKE; FRESH-WATER; GREEN-ALGAE; NITRATE; DENITRIFICATION; ASSIMILATION; SEDIMENTS; SYSTEM; GROWTH; CYANOBACTERIA;

D O I：

10.1186/s13717-025-00579-z

中图分类号：

Q14 [生态学（生物生态学）];

学科分类号：

071012 ; 0713 ;

摘要：

Background Anthropogenic activities have led to increased N input and changes of N transformation processes in lake systems. However, changes in phytoplankton community structure caused by phytoplankton's preference for N utilization under the increasing N input remain poorly understood. This study used nitrate isotopes (delta N-15-NO3- and delta O-18-NO3-) to investigate seasonal differences in N cycling as well as associated response of phytoplankton biomass and community composition. Results Results showed that the average delta N-15-NO3- values in spring, summer, autumn, and winter were 7.6 +/- 0.7 parts per thousand, 6.1 +/- 0.7 parts per thousand, 5.5 +/- 1.8 parts per thousand, and 7.4 +/- 1.2 parts per thousand, respectively. Accordingly, the average delta O-18-NO3- values showed the following order: winter (12.8 +/- 1.0 parts per thousand) > summer (11.5 +/- 0.9 parts per thousand) > spring (10.3 +/- 0.9 parts per thousand) > autumn (7.9 +/- 1.7 parts per thousand). The main nitrate sources in Lake Poyang were soil N, N fertilizer, and the manure and sewage in all seasons, contributing 93.8%, 3.3%, and 2.8%, respectively. Nitrification and algal-derived nitrate (NO3--N) assimilation were the main biochemical processes affecting N. In spring, the signal of nitrification was stronger, while in autumn, the signals of N assimilation by algae were more pronounced. The phytoplankton community composition varied with the seasonal changes of N concentrations and forms. The total biomass of phytoplankton in winter was the lowest of all four seasons and it was negatively correlated with NO3--N concentration (P < 0.05). Conclusions The results of this study contribute to a better understanding of the role of available forms of N in floodplain lake and provide essential support for prediction of phytoplankton growth and functions. Our work deciphers the role of phytoplankton in the lake N cycle, providing theoretical support to management of phytoplankton community to future environmental changes.

引用

页数：16