Editorial: Organic carbon pools in permafrost regions on the Qinghai–Xizang (Tibetan) Plateau

C Mu,G Cheng,B Cao,Q Wu,T Zhang,X Peng,X Zhang

doi:10.5194/tc-9-479-2015

Abstract

Abstract. The current Northern Circumpolar Soil Carbon Database did not include organic carbon storage in permafrost regions on the Qinghai–Xizang (Tibetan) Plateau (QXP). In this study, we reported a new estimation of soil organic carbon (SOC) pools in the permafrost regions on the QXP up to 25 m depth using a total of 190 soil profiles. The SOC pools were estimated to be 17.3 ± 5.3 Pg for the 0–1 m depth, 10.6 ± 2.7 Pg for the 1–2 m depth, 5.1 ± 1.4 Pg for the 2–3 m depth and 127.2 ± 37.3 Pg for the layer of 3–25 m depth. The percentage of SOC storage in deep layers (3–25 m) on the QXP (80%) was higher than that (39%) in the yedoma and thermokarst deposits in arctic regions. In total, permafrost regions on the QXP contain approximately 160 ± 87 Pg SOC, of which approximately 132 ± 77 Pg (83%) stores in perennially frozen soils and deposits. Total organic carbon pools in permafrost regions on the QXP was approximately 8.7% of that in northern circumpolar permafrost region. The present study demonstrates that the total organic carbon storage is about 1832 Pg in permafrost regions on northern hemisphere.

Highlights

Soil organic carbon (SOC) storage in permafrost regions has received worldwide attention due to its direct contribution to the atmospheric greenhouse gas contents (Ping et al, 2008a; Tarnocai et al, 2009; Zimov et al, 2009)
The present knowledge of SOC pool in permafrost regions only limited to the circum-Arctic areas
SOC contents decreased with depth in most deep boreholes, while SOC contents in deeper layers were higher than those in the top layer at the XSH, KL150 and KL300 (Fig. 4)

Summary

Introduction

Soil organic carbon (SOC) storage in permafrost regions has received worldwide attention due to its direct contribution to the atmospheric greenhouse gas contents (Ping et al, 2008a; Tarnocai et al, 2009; Zimov et al, 2009). It has been estimated that permafrost regions of circum-Arctic areas contain approximately 1672 Pg of organic carbon, which include 495.8 Pg for the 0–1 m depth, 1024 Pg for the 0– 3 m depth and 648 Pg for 3–25 m depth. The thawing of permafrost would expose the frozen organic carbon to microbial decomposition, and may initiate a positive permafrost carbon feedback on climate (Schuur et al, 2008). The present knowledge of SOC pool in permafrost regions only limited to the circum-Arctic areas. Little is known about the SOC pools in the low-altitude permafrost regions

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Conclusion