Impact of plant harvest management on function and community structure of nitrifiers and denitrifiers in a constructed wetland

• Published in: FEMS microbiology ecology Vol. 91; no. 2; pp. 1 - 10
• Main Authors: Tanaka, Takashi S. T., Irbis, Chagan, Wang, Pengyun, Inamura, Tatsuya
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.02.2015
• Subjects: Ammonia; Ammonia monooxygenase; Aquatic plants; Archaea - enzymology; Archaea - genetics; Artificial wetlands; Bacteria - enzymology; Bacteria - genetics; Community structure; Constructed wetlands; Construction planning; Denaturing Gradient Gel Electrophoresis; Denitrification; Ecology; Electrophoresis; Environmental aspects; Gel electrophoresis; Harvesting; Management; Methods; Microbial colonies; Microbiology; Microclimate; Microenvironments; NirK protein; Nitrate reduction; Nitrates; Nitrification; Nitrite reductase; Nitrite Reductases - genetics; Oxidoreductases - genetics; Plant communities; Poaceae - microbiology; Reductases; Reduction; Rhizosphere; Structure-function relationships; Wetlands; China; PCR-DGGE; denitrification; nitrification; harvesting reed
• ISSN: 1574-6941; 0168-6496; 1574-6941
• DOI: 10.1093/femsec/fiu019

Plant harvest is one of the most important management practices in constructed wetlands. In this study, we evaluated the impact of harvesting Phragmites australis (Cav.) Trin. ex Steudel on the activity and community structure of nitrifiers and denitrifiers in a free-water surface constructed wetland. The nitrifiers were targeted using bacterial and archaeal-amoA that encode ammonia monooxygenase, and the denitrifiers were targeted using nirK and nirS that encode the nitrite reductase. The community structures were evaluated using denaturing gradient gel electrophoresis. The potential nitrification and nitrate reduction rates were shown to be significantly higher in the harvested plant rhizosphere than in a non-harvested control plot. The potential nitrification rate positively correlated with the potential nitrate reduction rate and influenced the community structure of nirK. In addition, plant canopy developed differently after harvest and simultaneously changed the microclimate beneath the plant community. These results suggest that plant harvest management could change subsequent plant development and associated microenvironments, thereby affecting the function and community structure of nitrifiers and denitrifiers. Our study highlights the importance of plant harvest management within constructed wetlands to regulate the functions of nitrification and denitrification. Plant harvest treatment could change subsequent plant development and associated microenvironments in a constructed wetland, and affecting the function and community structure of nitrifiers and denitrifiers.