naa a22 4500 528784927 20180924065517.0 cr unu---uuuuu 180924e20110608xx s 000 0 eng 10.3929/ethz-b-000037488 doi 10.1371/journal.pone.0020105 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/37488 Global Change Could Amplify Fire Effects on Soil Greenhouse Gas Emissions [Elektronische Daten] [Audrey Niboyet, Jamie R. Brown, Paul Dijkstra, Joseph C. Blankinship, Paul W. Leadley, Xavier Le Roux, Laure Barthes, Romain L. Barnard, Christopher B. Field, Bruce A. Hungate] PLoS ONE Open access ethresearch Background Little is known about the combined impacts of global environmental changes and ecological disturbances on ecosystem functioning, even though such combined impacts might play critical roles in shaping ecosystem processes that can in turn feed back to climate change, such as soil emissions of greenhouse gases. Methodology/Principal Findings We took advantage of an accidental, low-severity wildfire that burned part of a long-term global change experiment to investigate the interactive effects of a fire disturbance and increases in CO2 concentration, precipitation and nitrogen supply on soil nitrous oxide (N2O) emissions in a grassland ecosystem. We examined the responses of soil N2O emissions, as well as the responses of the two main microbial processes contributing to soil N2O production - nitrification and denitrification - and of their main drivers. We show that the fire disturbance greatly increased soil N2O emissions over a three-year period, and that elevated CO2 and enhanced nitrogen supply amplified fire effects on soil N2O emissions: emissions increased by a factor of two with fire alone and by a factor of six under the combined influence of fire, elevated CO2 and nitrogen. We also provide evidence that this response was caused by increased microbial denitrification, resulting from increased soil moisture and soil carbon and nitrogen availability in the burned and fertilized plots. Conclusions/Significance Our results indicate that the combined effects of fire and global environmental changes can exceed their effects in isolation, thereby creating unexpected feedbacks to soil greenhouse gas emissions. These findings highlight the need to further explore the impacts of ecological disturbances on ecosystem functioning in the context of global change if we wish to be able to model future soil greenhouse gas emissions with greater confidence. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Niboyet Audrey joint author Brown Jamie R. joint author Dijkstra Paul joint author Blankinship Joseph C. joint author Leadley Paul W. joint author Le Roux Xavier joint author Barthes Laure joint author Barnard Romain L. joint author Field Christopher B. joint author Hungate Bruce A. joint author PLoS ONE San Francisco, CA, USA : Public Library of Science 6 (6), p. e20105 1932-6203 http://hdl.handle.net/20.500.11850/37488 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/37488 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Niboyet Audrey joint author ETHRESEARCH 700 1- Brown Jamie R. joint author ETHRESEARCH 700 1- Dijkstra Paul joint author ETHRESEARCH 700 1- Blankinship Joseph C. joint author ETHRESEARCH 700 1- Leadley Paul W. joint author ETHRESEARCH 700 1- Le Roux Xavier joint author ETHRESEARCH 700 1- Barthes Laure joint author ETHRESEARCH 700 1- Barnard Romain L. joint author ETHRESEARCH 700 1- Field Christopher B. joint author ETHRESEARCH 700 1- Hungate Bruce A. joint author ETHRESEARCH 773 0- PLoS ONE San Francisco, CA, USA : Public Library of Science 6 (6), p. e20105 1932-6203 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access