Evaluating the simulated mean soil carbon transit times by Earth system models using observations - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Biogeosciences Year : 2019

Evaluating the simulated mean soil carbon transit times by Earth system models using observations

Jing Wang
  • Function : Author
Jianyang Xia
  • Function : Author
Xuhui Zhou
  • Function : Author
Kun Huang
  • Function : Author
Jian Zhou
  • Function : Author
Lifen Jiang
  • Function : Author
Xia Xu
  • Function : Author
Junyi Liang
  • Function : Author
Ying-Ping Wang
  • Function : Author
Xiaoli Cheng
  • Function : Author
Yiqi Luo
  • Function : Author

Abstract

One known bias in current Earth system models (ESMs) is the underestimation of global mean soil carbon (C) transit time (τsoil), which quantifies the age of the C atoms at the time they leave the soil. However, it remains unclear where such underestimations are located globally. Here, we constructed a global database of measured τsoil across 187 sites to evaluate results from 12 ESMs. The observations showed that the estimated τsoil was dramatically shorter from the soil incubation studies in the laboratory environment (median = 4 years; interquartile range = 1 to 25 years) than that derived from field in situ measurements (31; 5 to 84 years) with shifts in stable isotopic C (13C) or the stock-over-flux approach. In comparison with the field observations, the multi-model ensemble simulated a shorter median (19 years) and a smaller spatial variation (6 to 29 years) of τsoil across the same site locations. We then found a significant and negative linear correlation between the in situ measured τsoil and mean annual air temperature. The underestimations of modeled τsoil are mainly located in cold and dry biomes, especially tundra and desert. Furthermore, we showed that one ESM (i.e., CESM) has improved its τsoil estimate by incorporation of the soil vertical profile. These findings indicate that the spatial variation of τsoil is a useful benchmark for ESMs, and we recommend more observations and modeling efforts on soil C dynamics in regions limited by temperature and moisture.
Fichier principal
Vignette du fichier
bg-16-917-2019.pdf (2.97 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03721883 , version 1 (14-07-2022)

Licence

Attribution

Identifiers

Cite

Jing Wang, Jianyang Xia, Xuhui Zhou, Kun Huang, Jian Zhou, et al.. Evaluating the simulated mean soil carbon transit times by Earth system models using observations. Biogeosciences, 2019, 16, pp.917-926. ⟨10.5194/bg-16-917-2019⟩. ⟨insu-03721883⟩
24 View
9 Download

Altmetric

Share

Gmail Facebook X LinkedIn More