Subterranean CO2 ventilation and its role in the net ecosystem carbon balance of a karstic shrubland Pérez Sánchez-Cañete, Enrique Serrano Ortiz, Penélope Kowalski, Andrew Oyonarte, C. Domingo Poveda, Francisco Ecosystem carbon Karstic shrubland Subterranean ventilation Atmospheric composition Atmosphere interactions Recent studies of carbonate ecosystems suggest a possible contribution of subterranean ventilation to the net ecosystem carbon balance. However, both the overall importance of such CO2 exchange processes and their drivers remain unknown. Here we analyze several dry-season episodes of net CO2 emissions to the atmosphere, along with soil and borehole CO2 measurements. Results highlight important events where rapid decreases of underground CO2 molar fractions correlate well with sizeable CO2 release to the atmosphere. Such events, with high friction velocities, are attributed to ventilation processes, and should be accounted for by predictive models of surface CO2 exchange. 2012-11-19T12:56:21Z 2012-11-19T12:56:21Z 2011 info:eu-repo/semantics/article Sanchez-Cañete, E. P., P. Serrano-Ortiz, A. S. Kowalski, C. Oyonarte, and F. Domingo. Subterranean CO2 ventilation and its role in the net ecosystem carbon balance of a karstic shrubland. Geophysical Research Letters 38: L09802 (2011). [http://hdl.handle.net/10481/22437] 0094-8276 http://hdl.handle.net/10481/22437 eng info:eu-repo/grantAgreement/EC/FP7/24122 http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License American Geophysical Union