[Transfer of Soil Organic Carbon to Inorganic Carbon in Arid Oasis Based on Stable Carbon Isotope Technique]

Yang-Mei Li; Lu Gong; Shen-Qun An; Li Sun; Xin Chen

doi:10.13227/j.hjkx.201711211

[Transfer of Soil Organic Carbon to Inorganic Carbon in Arid Oasis Based on Stable Carbon Isotope Technique]

Huan Jing Ke Xue. 2018 Aug 8;39(8):3867-3875. doi: 10.13227/j.hjkx.201711211.

[Article in Chinese]

Authors

Yang-Mei Li^{1

2}, Lu Gong^{1

2}, Shen-Qun An^{1

2}, Li Sun^{1

2}, Xin Chen^{1

2}

Affiliations

¹ College of Resources and Environment Science, Xinjiang University, Urumqi 830046, China.
² Key Laboratory of Oasis Ecology, Ministry of Education, Xinjiang University, Urumqi 830046, China.

PMID: 29998696
DOI: 10.13227/j.hjkx.201711211

Abstract

The northern margin oasis of the Tarim Basin in the central arid region of Asia was selected as the study area. The study analyzed the δ¹³C values of the SIC(soil inorganic carbon) and distinguished the pedogenic carbonate in soil from the total SIC using the stable carbon isotope techniques and models. Based on the relationship between soil organic carbon and inorganic carbon contents in soil, the transfer of SOC to SIC was discussed. The results showed that the δ¹³C values of the SIC of 4 types of arid oasis soil were significantly different (P<0.01), the δ¹³C values of the SIC of aeolian sandy soil was (0.32±0.04)‰, which increased with increase in depth. This indicates that the lithogenic carbonates of the sandy soil are advantageous. The δ¹³C values of the SIC of irrigated desert soil, brown desert soil, and saline soil were (-0.30±0.24)‰, (-1.96±0.66)‰ and (-1.24±0.49)‰, respectively, and decreased with increase in depth. This indicates that the lithogenic carbonates dominated the irrigated desert soil, and the pedogenic carbonates dominated brown desert and saline soils. In the aeolian sandy, irrigated desert, brown desert, and saline soils, pedogenic carbonate accounted for 1.33%, 4.72%, 15.01%, and 35.71% of SIC, respectively, which were less than 50%. This shows that the level of soil pedogenic carbonates was low in arid oasis. During pedogenic carbonate formation or recrystallization, the aeolian sandy, irrigated desert, brown desert, and saline soils fixed 0.30, 2.44, 4.96, and 12.40 g·kg^-1 of soil CO₂, respectively, the average amount of CO₂ fixed from the atmosphere was 0.18, 0.79, 1.45, and 8.67 g·kg^-1, respectively. Furthermore, the transfer of SOC to SIC was 0.06, 0.83, 1.62, and 1.86 g·kg^-1, respectively. The total transfer of SOC to SIC was between 0.03 and 2.38 g·kg^-1, with an average of 1.09 g·kg^-1 of CO₂. This shows that the proportion of soil pedogenic carbonates and the contribution of SOC were not high in the arid oasis area.

Keywords: arid oasis; pedogenic carbonate(PC); soil inorganic carbon; soil organic carbon; stable carbon isotope.

Publication types

English Abstract