01 Sep 2023
 | 01 Sep 2023
Status: this preprint is currently under review for the journal BG.

Nine years of warming and nitrogen addition in the Tibetan grassland promoted loss of soil organic carbon but did not alter the bulk change of chemical structure

Huimin Sun, Michael W. I. Schmidt, Jintao Li, Jinquan Li, Xiang Liu, Nicholas O. E. Ofiti, Shurong Zhou, and Ming Nie

Abstract. Understanding the changes in soil organic carbon (SOC) storage and chemical stabilization dynamics is important for accurately predicting ecosystem C sequestration and/or potential C loss, but the relevant information, especially for the intervention of environmental controls on grassland soil is limited in Tibetan plateau regions. Here we used a 9-year two-way factorial experiment involving warming with open top chambers (+1.80 °C in the daytime and +0.77 °C in the nighttime at the soil surface) and multilevel nitrogen (N) enrichment treatments (0, 5, 10, and 15 g m-2 year-1) in the Tibetan plateau to investigate the changes in SOC pool size and chemical structure. 9-year warming treatment significantly decreased SOC stock in the Tibetan grassland. We observed decreasing SOC concentrations which may be related to changes in the C-degrading enzymes. Surprisingly, the SOC molecular structure remained unchanged in all N enrichment and warmed plots, suggesting that both treatments had affected all forms of SOC, from simple and complex polymeric in a similar way. Our results suggest that long-term warming stimulates soil C loss but no preference in SOC loss with different chemical structure.

Huimin Sun et al.

Status: open (until 29 Oct 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Huimin Sun et al.

Huimin Sun et al.


Total article views: 193 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
144 41 8 193 13 3 6
  • HTML: 144
  • PDF: 41
  • XML: 8
  • Total: 193
  • Supplement: 13
  • BibTeX: 3
  • EndNote: 6
Views and downloads (calculated since 01 Sep 2023)
Cumulative views and downloads (calculated since 01 Sep 2023)

Viewed (geographical distribution)

Total article views: 191 (including HTML, PDF, and XML) Thereof 191 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 24 Sep 2023
Short summary
The SOC molecular structure suggested that the easily decomposable and stabilized SOC are similarly affected after 9-year warming and N treatments despite the large changes in SOC stocks. Given the long residence time of some SOC, the similar loss of all measurable chemical forms of SOC under global change treatments could have important climate consequences.