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The effect of hydrologic pulses on nitrogen biogeochemistry in created riparian wetlands in midwestern USA

Hernandez, Maria Elizabeth
http://rave.ohiolink.edu/etdc/view?acc_num=osu1154448558

Abstract Details

2006, Doctor of Philosophy, Ohio State University, Environmental Science.
The effect of hydrologic conditions on nitrogen biogeochemistry was investigated in two identical 1-ha surface-flow created riverine wetlands in Columbus, Ohio, USA. These wetlands, created in 1993-1994, are fed with water from Olentangy River. For two years (2003-2004), both wetlands experienced seasonal (winter-spring) controlled hydrologic flood pulses followed by one year (2005) in which they received a steady flow rate of water. Nitrogen gas flux measurements were made in plots distributed along a transverse gradient (edge plots and high marsh plots with alternate wet and dry conditions, and low marsh plots and open water plots with permanent flooding). Highest average N2O fluxes were observed in high marsh plots followed by edge plots, open water plots , and low marsh plots. In permanently flooded plots without vegetation, nitrous oxide fluxes were low, regardless of flood pulse conditions.N2O fluxes were higher in plots with vegetation than in plots without vegetation only when plots were inundated. Denitrification in all plots was significantly correlated with soil temperature and was significantly correlated with the nitrate concentration in the inflow surface water in the growing season in permanently flooded zones. Highest mean denitrification rates were observed in the low marsh and open water zonesfollowed by high marsh and edge zones. In permanently flooded areas, denitrification rates were significantly higher near the inflow than near the outflow. Denitrification appeared to be nitrogen limited in low marsh, high marsh and edge plots, but both carbon and nitrogen limited in open water. NO2- + NO3- mass retention was similar under pulsing and steady flow conditions. Total nitrogen (TN) retention was lower under pulsing than steady flow conditions as a result of an export of organic nitrogen occurred under pulsing conditions. Aboveground biomass productivity in the pulsing year was significantly lower than in the steady-flow flow. Belowground biomass productivities were similar in both years. Nitrogen accumulation in plants represented 54- 44% of total nitrogen removed. Denitrification accounted for 8-12 % of nitrate removed. Less than 1% of the total nitrogen removed was converted to N2O, regardless of hydrologic conditions.
William Mitsch (Advisor)
195 p.
Denitrification; Created wetlands; Nitrous oxide emissions; Nitrate pollution; Organic matter in wetlands

Recommended Citations

Citations

  • Hernandez, M. E. (2006). The effect of hydrologic pulses on nitrogen biogeochemistry in created riparian wetlands in midwestern USA [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1154448558

    APA Style (7th edition)

  • Hernandez, Maria. The effect of hydrologic pulses on nitrogen biogeochemistry in created riparian wetlands in midwestern USA. 2006. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1154448558.

    MLA Style (8th edition)

  • Hernandez, Maria. "The effect of hydrologic pulses on nitrogen biogeochemistry in created riparian wetlands in midwestern USA." Doctoral dissertation, Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1154448558

    Chicago Manual of Style (17th edition)

osu1154448558
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© 2006, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.