An evaluation of topsoil carbon storage in Chinese deserts

Guoru Wei; Chunlai Zhang; Qing Li; Hongtao Wang; Rende Wang; Yajing Zhang; Yixiao Yuan

doi:10.1016/j.scitotenv.2023.162284

An evaluation of topsoil carbon storage in Chinese deserts

Sci Total Environ. 2023 May 10:872:162284. doi: 10.1016/j.scitotenv.2023.162284. Epub 2023 Feb 16.

Authors

Guoru Wei¹, Chunlai Zhang², Qing Li³, Hongtao Wang⁴, Rende Wang³, Yajing Zhang¹, Yixiao Yuan¹

Affiliations

¹ State Key Laboratory of Earth Surface Processes and Resource Ecology, MOE Engineering Research Center of Desertification and Blown-sand Control, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
² State Key Laboratory of Earth Surface Processes and Resource Ecology, MOE Engineering Research Center of Desertification and Blown-sand Control, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China. Electronic address: clzhang@bnu.edu.cn.
³ Hebei Engineering Research Center for Geographic Information Application, Institute of Geographical Sciences, Hebei Academy of Sciences, Shijiazhuang 050011, China.
⁴ Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.

PMID: 36801314
DOI: 10.1016/j.scitotenv.2023.162284

Abstract

Deserts are important components of the terrestrial ecosystem, and significantly affect the terrestrial carbon cycle. However, their carbon storage is poorly understood. To evaluate the topsoil carbon storage in Chinese deserts, we systematically collected topsoil samples (to a depth of 10 cm) from 12 deserts in northern China and analyzed their organic carbon storage. We used partial correlation and boosted regression tree (BRT) analysis to analyze the factors influencing the spatial distribution of soil organic carbon density based on climate, vegetation, soil grain-size distribution, and element geochemistry. The total organic carbon pool of Chinese deserts was 4.83 × 10⁸ t, the mean soil organic carbon density was 1.37 ± 0.18 kg C m^-2, and the mean turnover time was 16.50 ± 2.66 yr. With the largest area, the Taklimakan Desert had the highest topsoil organic carbon storage (1.77 × 10⁸ t). The organic carbon density was high in the east and low in the west, whereas the turnover time showed the opposite trend. The soil organic carbon density was >2 kg C m^-2 in the four sandy lands in the eastern region, and was greater than the values for the eight deserts (0.72 to 1.22 kg C m^-2). Grain-size (i.e., the silt and clay contents) had the strongest influence on the organic carbon density in Chinese deserts, followed by element geochemistry. Precipitation was the main climatic factor that affected the distribution of organic carbon density in the deserts. Based on climate and vegetation cover trends during the past 20 years, Chinese deserts have a high potential for future organic carbon sequestration.

Keywords: Chinese deserts; Climate; Geochemistry; Organic carbon density; Topsoil carbon pool.