Influence of extreme water pulses on greenhouse gas fluxes from soils
| Author(s) | Petrakis, Sandra | |
| Date Accessioned | 2017-01-19T13:20:47Z | |
| Date Available | 2017-01-19T13:20:47Z | |
| Publication Date | 2016 | |
| Abstract | Climate models predict increased frequency and intensity of storm events, but it is unclear how extreme precipitation events influence the dynamics of soil fluxes for multiple greenhouse gases (GHGs). Intact soil mesocosms (0-10 cm depth) from a temperate forested watershed (soils from two forested upland locations, a wetland, and a creek bank) were exposed to experimental water pulses with periods of drying, forcing soils towards extreme wet conditions under controlled temperature. We used automated measurements (hourly resolution) to monitor CO2, CH4, and N2O fluxes, coupled with analyses of soil water chemistry (i.e., pH, Eh, Fe, S, NO3 - ), and microbial community structure characterized with polymerase chain reactiondenaturing gradient gel electrophoresis (PCR-DGGE). The experiment showed unexpected increases in emissions up to 244% for CO2 (Wetland), 50988.4% for CH4 (Creek) and 55024.3% for N2O (Forest Site 1). The Creek soil produced the largest soil CO2 emissions, the Wetland soil the largest CH4 emissions, and the Forest Site 2 the largest N2O emissions among all soils during the experiment. Using carbon dioxide equivalencies of the three GHGs, we determined that the Creek soil contributed the most to a 20-year global warming potential (GWP; 30.3%), but Forest Site 2 contributed the most to the 100-year GWP (53.7%) as a result of large N2O emissions. These results show rapid shifts in total C, total N, microbial community structure, and porewater chemistry providing insights on the underlying mechanisms and non-linear responses of soil GHGs dynamics following experimental water pulse events. | en_US |
| Advisor | Vargas, Rodrigo | |
| Degree | M.S. | |
| Program | University of Delaware, Water Science and Policy Program | |
| Unique Identifier | 969127305 | |
| URL | http://udspace.udel.edu/handle/19716/19981 | |
| Publisher | University of Delaware | en_US |
| URI | https://search.proquest.com/docview/1840892709?accountid=10457 | |
| Title | Influence of extreme water pulses on greenhouse gas fluxes from soils | en_US |
| Type | Thesis | en_US |