Leaching of dissolved organic carbon from a Scots pine forest under future rainfall regimes

Ariza Carricondo, Cristina

Title

Author

Abstract

Future extreme climate events are expected to increase in frequency and intensity with more rainfall events in the wet winter and longer droughts during summer with occasional extreme precipitation events. Such altered climatic conditions will potentially affect the soil's biochemical properties and structure and could cause event-driven carbon exports through dissolved losses. The increased frequency and intensity of high rainfall events can be expected to alter the production and leaching of dissolved organic carbon (DOC), impacting on the C balance at the ecosystem level and potentially at regional and global scale. In order to quantify DOC leaching, it is essential to accurately quantify the amount of water passing from the surface to deeper layers in the soil. The method applied in this thesis was based on a self-designed 3D printed Zero Tension Lysimeter (ZTL3D) validated with a Water Bucket Model (WBM). DOC concentrations from the leachate captured by the ZTLs3D, together with the water drainage estimations by the WBM, provided a reliable method to quantify DOC exports. Once this methodology was achieved, I focused on studying the concentrations and fluxes of DOC produced under specific rain simulation experiments in the field. The first rain simulation experiment took advantage of the natural summer drought in 2019. The main finding of this simulation during summer showed the importance of the soil's hydrological state prior to a heavy rain event. The second rainfall simulation showed a clear effect of vegetation dormancy and revealed a clear relation between the amount of water added and the size of the DOC flux during both, autumn and winter. It can be concluded that DOC leaching was clearly affected by the extreme rainfall events. Comparison with previous research conducted under long-term average conditions showed that extreme events would increase up to double the DOC average flux calculated previously for the site, meaning a total of up to 1.4 t (C) ha−1 year−1 export from the ecosystem, representing up to 20% of the net ecosystem production (NEP). Bigger DOC exports caused by extreme rainfall events might affect the ecosystem functioning. The findings from this doctoral thesis show the importance of accounting not only for DOC exports in the C balance but also the need to account for the potential DOC export under future extreme events.

Language

English

Publication

Antwerp : University of Antwerp, Faculty of Science, Department of Biology , 2022

Volume/pages

180 p.

Note

Supervisor: Janssens, Ivan [Supervisor]

Supervisor: Vincke, Caroline [Supervisor]

Supervisor: Verreydt, Goedele [Supervisor]

Full text (open access)

https://repository.uantwerpen.be/docstore/d:irua:13825

Faculty/Department				Faculty of Sciences. Biology

Research group				Plant and Ecosystems (PLECO) - Ecology in a time of change Ecosphere

Publication type				Doctoral thesis

Subject				Biology

Affiliation				Publications with a UAntwerp address

Identifier

c:irua:190088

Creation

07.09.2022

Last edited

25.09.2022

To cite this reference

https://hdl.handle.net/10067/1900880151162165141