Synergistic Effects of Aquatic Plants and Cyanobacterial Blooms on the Nitrous Oxide Emission from Wetlands

Bull Environ Contam Toxicol. 2022 Mar;108(3):579-584. doi: 10.1007/s00128-021-03332-2. Epub 2021 Jul 7.

Abstract

Wetlands provide a habitat for the symbiosis of multiple plants and play a significant role in global N2O emissions. The metabolic traits and effects on microorganisms, which regulate the conversion of nitrogen to N2O, varies with plant species. The frequent occurrences of cyanobacterial blooms in wetlands can also have a positive or negative effect on denitrification, entangling N2O emissions. In situ observations of the Dongting Lake reveal that the fluxes in N2O emissions vary with the vegetation. Maximum emissions occurred in the mud flat, while the zone with the minimum emissions was populated with carex. In 210-day batch cultures, the addition of cyanobacteria synergistically enhanced N2O production during the degredation of phalaris and reed. The abundance of the nirS and nirK genes decreased over time except in the phalaris-algae group. To mitigate the N2O emissions from wetlands, the macrophyte communities need to be protected, and the cyanobacterial blooms need to be avoided by reducing the nitrogen pollution.

Keywords: Denitrification; Eutrophication; Greenhouse gas; Macrophyte; Nitrogen; Sediment.

MeSH terms

  • Cyanobacteria* / metabolism
  • Denitrification
  • Greenhouse Gases* / analysis
  • Nitrous Oxide / analysis
  • Nitrous Oxide / metabolism
  • Plants / metabolism
  • Wetlands

Substances

  • Greenhouse Gases
  • Nitrous Oxide