Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (4): 321-333.DOI: 10.17521/cjpe.2020.0353

• Review •     Next Articles

Effects of nitrogen input on carbon cycle and carbon budget in a coastal salt marsh

HAN Guang-Xuan*(), LI Juan-Yong, QU Wen-Di   

  1. CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; and University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-10-26 Accepted:2021-01-18 Online:2021-04-20 Published:2021-04-28
  • Contact: HAN Guang-Xuan
  • Supported by:
    National Natural Science Foundation of China(42071126)

Abstract:

Coastal salt marshes are an effective blue carbon sink to mitigate climate warming, but their ecosystem stability and carbon sink function are threatened by the large amount of nitrogen input caused by coastal eutrophication. Under the action of regular tides, the high nitrogen content in the coastal waters will have a profound effect on the key processes of carbon cycle such as plant photosynthetic carbon fixation, carbon allocation in plant-soil system, and soil carbon release in the salt marsh. This study reviewed the effects of nitrogen input on plant photosynthetic carbon fixation, carbon allocation in plant-soil system, decomposition of soil organic carbon, formation and release of soil dissolved organic carbon (DOC), and carbon sequestration in the salt marsh. Based on the shortcomings of current research, this review proposed the directions of future research, including the effects of nitrogen input on plant photosynthetic carbon fixation and carbon allocation in plant-soil system, the microbial mechanism of soil organic carbon decomposition, production and lateral exchange of soil DOC, and the potential impact of different forms of nitrogen input on soil carbon sequestration in the salt marsh. Overall, this study aims to improve the understanding of impacts of nitrogen input on the key carbon processes and the mechanisms of carbon sequestration in a salt marsh, and to provide new ideas for assessing the potential changes of carbon pools under the influence of eutrophication of coastal waters in the salt marsh wetlands.

Key words: nitrogen input, carbon cycle, carbon allocation, carbon sink, coastal salt marsh, tidal action