Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Discussion papers
https://doi.org/10.5194/bg-2020-27
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-2020-27
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 11 Feb 2020

Submitted as: research article | 11 Feb 2020

Review status
This preprint is currently under review for the journal BG.

Seasonal dynamics of the COS and CO2 exchange of a managed temperate grassland

Felix M. Spielmann, Albin Hammerle, Florian Kitz, Katharina Gerdel, and Georg Wohlfahrt Felix M. Spielmann et al.
  • Department of Ecology, University of Innsbruck, Innsbruck, 6020, Austria

Abstract. Gross primary productivity (GPP), the CO2 uptake by means of photosynthesis, cannot be measured directly on ecosystem scale, but has to be inferred from proxies or models. One newly emerged proxy is the trace gas carbonyl sulfide (COS). COS diffuses into plant leaves in a fashion very similar to CO2, but is generally not emitted by plants. Laboratory studies on leaf level gas exchange have shown promising correlations between the leaf relative uptake (LRU) of COS to CO2 under controlled conditions. However, in situ measurements including daily to seasonal environmental changes are required, to test the applicability of COS as a tracer for GPP at larger temporal scales. To this end, we conducted concurrent ecosystem scale CO2 and COS flux measurements above an agriculturally managed temperate mountain grassland. We also determined the magnitude and variability of the soil COS exchange, which can affect the LRU on ecosystem level. The cutting and removal of the grass at the site had a major influence on the soil as well as the total exchange of COS. The grassland acted as a major sink for CO2 and COS during periods of high leaf area. The sink strength decreased after the cuts and the grassland turned into a net source for CO2 and COS on ecosystem level. The soil acted as a small sink for COS when the canopy was undisturbed, but also turned into a source after the cuts, which we linked to higher incident radiation hitting the soil surface. However, the soil contribution was not large enough to explain the COS emission on ecosystem level, hinting to an unknown COS source possibly related to dead plant matter degradation. Over the course of the season, we observed a concurrent decrease of CO2 and COS uptake on ecosystem level. With the exception of the short periods after the cuts, the LRU under high light conditions was rather stable and indicates a high correlation between the COS flux and GPP across the growing season.

Felix M. Spielmann et al.

Interactive discussion

Status: open (until 24 Mar 2020)
Status: open (until 24 Mar 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Felix M. Spielmann et al.

Felix M. Spielmann et al.

Viewed

Total article views: 167 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
126 39 2 167 13 0 1
  • HTML: 126
  • PDF: 39
  • XML: 2
  • Total: 167
  • Supplement: 13
  • BibTeX: 0
  • EndNote: 1
Views and downloads (calculated since 11 Feb 2020)
Cumulative views and downloads (calculated since 11 Feb 2020)

Viewed (geographical distribution)

Total article views: 144 (including HTML, PDF, and XML) Thereof 143 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 25 Feb 2020
Publications Copernicus
Download
Short summary
Carbonyl sulfide (COS) can be used as a proxy for plant photosynthesis on ecosystem scale. However, the relationships between COS and CO2 fluxes and their dependence on daily to seasonal changes in environmental drivers still are poorly understood. We examined COS and CO2 ecosystem fluxes above an agriculturally used mountain grassland for 6 months. The harvesting of the grassland disturbed the otherwise stable COS to CO2 uptake ratio. We even found the canopy to release COS during those times.
Carbonyl sulfide (COS) can be used as a proxy for plant photosynthesis on ecosystem scale....
Citation