000210178 001__ 210178
000210178 005__ 20181203023936.0
000210178 0247_ $$2doi$$a10.1002/2013JG002552
000210178 022__ $$a2169-8953
000210178 037__ $$aARTICLE
000210178 245__ $$aScales and drivers of temporal
000210178 260__ $$c2014
000210178 269__ $$a2014
000210178 336__ $$aJournal Articles
000210178 520__ $$aThe role of inland waters for the global carbon cycle is now recognized and evidence increasingly suggests that stream ecosystems disproportionately contribute to the carbon cycle. Understanding the dynamics and drivers of stream water partial pressure of CO2 (pCO2) and CO2 evasion fluxes from streams to the atmosphere is imperative for assessing the role of climate change on the carbon cycle in stream ecosystems. Monitoring pCO2 over 3 years, we here report on the seasonal, diurnal, and event-driven dynamics of pCO2 in the hyporheic zone and stream water of an Alpine stream and assess possible drivers of these dynamics. Our findings suggest that both catchment-derived CO2 delivered by shallow groundwater into the stream and in-stream respiration continuously build up pCO2 in the hyporheic zone. Depending on stream water temperature and assumedly on primary production (inferred from photosynthetically active radiation), hyporheic CO2 contributes to stream water pCO2 and ultimately to CO2 outgassing to the atmosphere. Diurnal patterns of stream water pCO2 increasingly built up during extended base flow and streambed-scouring storms caused the collapse of these diurnal patterns. Post storm recovery of the diurnal pCO2 patterns was generally rapid. Our findings suggest that decreasing gas exchange velocity related to receding discharge drives recovery dynamics. We found that average CO2 outgassing fluxes during night exceeded those during day by up to 1.8 times. Our study highlights temperature and hydrology—key components of climate change—as major drivers of pCO2 dynamics in Alpine streams. They also underscore the necessity to consider day-night differences in CO2 outgassing fluxes to properly establish carbon budgets and regional estimates of CO2 outgassing to the atmosphere.
000210178 700__ $$0249153$$aPeter, Hannes$$g262293
000210178 700__ $$aSinger, Gabriel A.
000210178 700__ $$aPreiler, Christian
000210178 700__ $$aChifflard, Peter
000210178 700__ $$aSteniczka, Gertraud
000210178 700__ $$0248756$$aBattin, Tom J.$$g253102
000210178 773__ $$j119$$k6$$q1078-1091$$tJournal of Geophysical Research: Biogeosciences
000210178 909C0 $$0252520$$pSBER$$xU13006
000210178 909CO $$ooai:infoscience.tind.io:210178$$particle$$pENAC
000210178 917Z8 $$x221818
000210178 937__ $$aEPFL-ARTICLE-210178
000210178 973__ $$aOTHER$$rREVIEWED$$sPUBLISHED
000210178 980__ $$aARTICLE