The invention belongs to the technical field of constructed wetlands, and provides a method for reducing
greenhouse gas emission in a freezing and thawing period of a
constructed wetland in a cold region. Before the
constructed wetland enters the freezing and thawing period, the surface of the
constructed wetland is covered with the
snow quilt with the thickness of 20-30 cm, the
water content of a matrix in the freezing and thawing period can be increased, the oxidation-
reduction potential (ORP) can be reduced, the anaerobic environment can be created,
microbial metabolism can be regulated and controlled, aerobic
respiration and
nitrogen circulation can be inhibited, anaerobic
fermentation and a
methanogenesis pathway can be promoted, emission of CO2 and N2O and the
global warming potential (GWP) can be reduced, and the constructed
wetland has the advantages of being capable of improving the
water content of the matrix in the freezing and thawing period. The
greenhouse effect can be relieved. Meanwhile, accumulation of
fungus residues is promoted through the arrangement of the
snow quilt, accumulation of bacterial residues is reduced, and the stability of matrix organic carbon and the
carbon sequestration function of the constructed
wetland are enhanced. Finally, the method provided by the invention makes up the vacancy in the artificial
wetland management in the freezing and thawing period in the prior art, and expands the management and application range of the artificial wetland.