title: Effect of plant harvesting on the performance of constructed wetlands during winter: radial oxygen loss and microbial characteristics.
abstract: The aboveground tissue of plants is important for providing roots with constant photosynthetic resources. However, the aboveground biomass is usually harvested before winter to maintain the permanent removal of nutrients. In this work, the effects of harvest on plants' involvement in oxygen input as well as in microbial abundance and activity were investigated in detail. Three series of constructed wetlands with integrated plants ("unharvested"), harvested plants ("harvested"), and fully cleared plants ("cleared") were set up. Better performance was found in the unharvested units, with the radial oxygen loss (ROL) rates ranging from 0.05 to 0.59 μmol O₂/h/plant, followed by the harvested units that had relatively lower ROL rates (0.01 to 0.52 μmol O₂/h/plant). The cleared units had the lowest removal efficiency, which had no rhizome resources from the plants. The microbial population and activity were highest in the unharvested units, followed by the harvested and cleared units. Results showed that bacterial abundances and enhanced microbial activity were ten times higher on root surfaces compared with sands. These results indicate that late autumn harvesting of the aboveground biomass exhibited negative effects on plant ROL as well as on the microbial population and activity during the following winter.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Huijun
authors.initials: H
authors.lastname: Xie
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Shuang
authors.initials: S
authors.lastname: Liang
authors.forename: Huu Hao
authors.initials: HH
authors.lastname: Ngo
authors.forename: Wenshan
authors.initials: W
authors.lastname: Guo
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.forename: Congcong
authors.initials: C
authors.lastname: Zhao
authors.forename: Hao
authors.initials: H
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018533:Biomass; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D006109:Poaceae / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology*; D012621:Seasons; D013997:Time Factors; D053833:Wetlands
chemical_list: D010100:Oxygen