Preprints
https://doi.org/10.5194/egusphere-2024-1562
https://doi.org/10.5194/egusphere-2024-1562
25 Jun 2024
 | 25 Jun 2024
Status: this preprint is open for discussion.

Drought disrupts atmospheric carbon uptake in a Mediterranean saline lake

Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz

Abstract. Saline and intermittent inland lakes play a key role in the global carbon cycle, acting as dynamic zones for atmospheric carbon exchange. Given the global decline of saline lakes and the expected increase of periods of drought in a climate change scenario, changes are expected in their potential capacity to uptake or emit atmospheric carbon. In this study, we conducted continuous measurements of CO2 and CH4 fluxes at the ecosystem scale within a saline endorheic lake of the Mediterranean region over nearly 2 years. Our focus was on determining net CO2 and CH4 exchanges with the atmosphere under both dry and flooded conditions, using the eddy covariance (EC) method. We coupled greenhouse gas flux measurements with water availability and analyzed meteorological variables like air temperature and radiation, known to influence carbon fluxes in saline lakes. This extensive data integration enabled the projection of the net carbon flux over time, accounting for both dry and wet periods on an interannual scale. We found that the system acts as a significant carbon sink by atmospheric CO2 uptake in wet conditions, with uptake ceasing in periods of drought. Moreover, increased air temperatures during wet phases slightly decrease the CO2 uptake efficiency. Regarding CH4, we measured uptake rates that exceeded those of well-aerated soils such as forest soils or grasslands. Additionally, we observed that CH4 uptake during dry periods was nearly double that of wet periods. However, the absence of continuous data prevented us from correlating CH4 uptake processes with potential environmental predictors. Our study challenges the widespread notion that wetlands are universally greenhouse gas emitters, highlighting the significant role that endorheic saline lakes can play as natural sink of atmospheric carbon. However, our work also underscores the vulnerability of these ecosystem services in the current climate change scenario, where drought episodes are expected to become more frequent and intense in the coming years.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz

Status: open (until 06 Aug 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-1562', Anonymous Referee #1, 04 Jul 2024 reply
  • RC2: 'Comment on egusphere-2024-1562', Anonymous Referee #2, 17 Jul 2024 reply
Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz
Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz

Viewed

Total article views: 240 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
194 33 13 240 19 5 5
  • HTML: 194
  • PDF: 33
  • XML: 13
  • Total: 240
  • Supplement: 19
  • BibTeX: 5
  • EndNote: 5
Views and downloads (calculated since 25 Jun 2024)
Cumulative views and downloads (calculated since 25 Jun 2024)

Viewed (geographical distribution)

Total article views: 225 (including HTML, PDF, and XML) Thereof 225 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 24 Jul 2024
Download
Short summary
Inland saline lakes are crucial in the global carbon cycle, but increased droughts may alter their carbon exchange capacity. We measured CO2 and CH4 fluxes in a Mediterranean saline lake using the Eddy Covariance method under dry and wet conditions. We found the lake acts as a carbon sink during wet periods but not during droughts. These results highlight the importance of saline lakes in carbon sequestration and their vulnerability to climate change-induced droughts.