2024-03-19T12:56:24Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/2010552020-12-13T00:05:45Zcom_10261_16com_10261_8col_10261_269
Moya, M.R
Sánchez-Cañete, Enrique P.
Vargas, R.
López-Ballesteros, A
Oyonarte, Cecilio
Kowalski, Andrew S.
Serrano-Ortiz, Penélope
Domingo, Francisco
2020-02-18T10:12:43Z
2020-02-18T10:12:43Z
2019
Journal of Geophysical Research: Biogeosciences 124: 902- 917 (2019)
http://hdl.handle.net/10261/201055
10.1029/2018JG004961
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100006393
Due to their large carbon storage capacity and ability to exchange subterranean CO with the atmosphere, soils are key components in the carbon balance in semi-arid ecosystems. Most studies have focused on shallow (e.g., <30 cm depth) soil CO
dynamics neglecting processes in deeper soil layers where highly CO
-enriched air can be stored or transported through soil pores and fissures. Here, we examine the relationship among variations in subterranean CO
molar fraction, volumetric water content, soil temperature and atmospheric pressure during three years within soil profiles (0.15, 0.50, and 1.50 m depths) in two semi-arid grasslands located in southeastern Spain. We applied a wavelet coherence analysis to study the temporal variability and temporal correlation between the CO
molar fraction and its covariates (soil temperature, soil moisture and atmospheric pressure). Our results show that CO
dynamics are strongly influenced by changes in atmospheric pressure from semidiurnal, diurnal and synoptic to monthly time-scales for all soil depths. In contrast, only weak daily dependencies were found at the surface level (0.15 m) regarding soil temperature and volumetric water content. Atmospheric pressure changes substantially influence variations in the CO
content (with daily fluctuations of up to 2000 ppm) denoting transportation through soil layers. These results provide insights into the importance of subterranean storage and non-diffusive gas transport that could influence soil CO
efflux rates, processes that are not considered when applying the flux-gradient approach and, which can be especially important in ecosystems with high air permeability between the unsaturated porous media and the atmosphere.
openAccess
CO 2 Dynamics Are Strongly Influenced by Low Frequency Atmospheric Pressure Changes in Semiarid Grasslands
artículo