title: [Temporal and spatial variation of water nutrient level after exogenous nutrient input].
abstract: In order to study the spatial and temporal variations of nitrogen (N) and phosphorous (P) nutrition in artificial wetlands after a single exogenous nutrient input, 6 mosaic communities of 7 plant species were set up in a cement channel in the greenhouse. After the addition of N and P nutritional solutions, the concentrations of dissolved total nitrogen (DTN), dissolved total phosphorous (DTP), ammonia nitrogen (NH4(+)-N), nitrate nitrogen (NO3(-) -N) and nitrite nitrogen (NO2(-) -N) in the surface, middle, and bottom layers of the bulk water were determined regularly within 22 days. The results show that: (1) the water depth and measuring date have significant effects on nutritional contents while the type of plant communities have no such an influence; (2) the diffusion of nutrient from surface to the middle water layers is relatively slow, which costs 6 days under the current experimental condition; (3) in the bottom water layer, nutritional concentrations had no significant changes except for NO2-N, thus the exogenous nutrient input mainly affects the nutrient contents of surface and middle-level bulk water; (4) DTP and NH4(+) -N contents gradually decline to similar levels that before the nutritional input event until the end of experimental period, though DTN and NO3(-) -N content decrease much more slowly; (5) the fact that NO2(-) -N contents rise in water layers of all depths demonstrates that nitrification and denitrification in the process of N circulation are enhanced. It is concluded that exogenous nutrient inputs not only harm aquatic ecosystems but also directly threat human health.
authors.forename: Ling
authors.initials: L
authors.lastname: Fu
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.forename: Guo-Xiang
authors.initials: GX
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ou
authors.forename: Zhou
authors.initials: Z
authors.lastname: Fan
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Mao
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.forename: Rui-Ming
authors.initials: RM
authors.lastname: Han
mesh_terms: D000641:Ammonia / Q000032:analysis; D058440:Denitrification; D009566:Nitrates / Q000032:analysis; D058465:Nitrification; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D062211:Spatio-Temporal Analysis; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical; D053833:Wetlands
chemical_list: D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D014867:Water; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen