Effects of Warming and Precipitation on Soil CO 2 Flux and Its Stable Carbon Isotope Composition in the Temperate Desert Steppe

Na Guo, Shijie Lv, Guangyi Lv, Xuebao Xu, Hongyun Yao, Zhihui Yu, Xiao Qiu, Zhanyi Wang and Chengjie Wang
Additional contact information
Na Guo: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China
Shijie Lv: College of Science, Inner Mongolia Agricultural University, Hohhot 010019, China
Guangyi Lv: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China
Xuebao Xu: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China
Hongyun Yao: School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
Zhihui Yu: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China
Xiao Qiu: Inner Mongolia Academy of Agricultural & Animal Husbandry Science, Hohhot 010031, China
Zhanyi Wang: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China
Chengjie Wang: College of Grassland, Resources and Environmental, Inner Mongolia Agricultural University, Hohhot 010019, China

Sustainability, 2022, vol. 14, issue 6, 1-17

Abstract: The stable carbon (C) isotope of soil CO 2 efflux (δ 13 CO 2e ) is closely associated with soil C dynamics, which have a complex feedback relationship with climate. Three levels of warming (T0: ambient temperature (15.7 °C); T1: T0 + 2 °C; T2: T0 + 4 °C) were combined with three levels of increased precipitation (W0: ambient precipitation (245.2 mm); W1: W0 + 25%; W2: W0 + 50%) in order to quantify soil CO 2 flux and its δ 13 CO 2e values under nine treatment conditions (T0W0, T0W1, T0W2, T1W0, T1W1, T1W2, T2W0, T2W1, and T2W2) in desert steppe in an experimental beginning in 2015. A non-steady state chamber system relying on Keeling plots was used to estimate δ 13 CO 2e . The temperature (ST) and moisture (SM) of soil as well as soil organic carbon content (SOC) and δ 13 C values (δ 13 C soil ) were tested in order to interpret variations in soil CO 2 efflux and δ 13 CO 2e . Sampling was carried out during the growing season in 2018 and 2019. During the experiment, the ST and SM correspondingly increased due to warming and increased precipitation. CO 2 flux ranged from 37 to 1103 mg m −2 ·h −1 , and emissions peaked in early August in the desert steppe. Warming of 2 °C to 4 °C stimulated a 14% to 30.9% increase in soil CO 2 efflux and a 0.4‰ to 1.8‰ enrichment in δ 13 CO 2e , respectively. Increased precipitation raised soil CO 2 efflux by 14% to 19.3%, and decreased δ 13 CO 2e by 0.5‰ to 0.9‰. There was a positive correlation between soil CO 2 efflux and ST and SOC indicating that ST affected soil CO 2 efflux by changing SOC content. Although the δ 13 CO 2e was positively correlated with ST, it was negatively correlated to SM. The decline of δ 13 CO 2e with soil moisture was predominantly due to intensified and increased diffusive fractionation. The mean δ 13 CO 2e value (−20.2‰) was higher than that of the soil carbon isotope signature at 0–20 cm (δ 13 C soil = −22.7‰). The difference between δ 13 CO 2e and δ 13 C soil (Δ e-s ) could be used to evaluate the likelihood of substrate utilization. 13 C enriched stable C pools were more likely to be utilized below 20 cm under warming of 2 °C in the desert steppe. Moreover, the interaction of T × W neither altered the CO 2 emitted by soil nor the δ 13 CO 2e or Δ e-s , indicating that warming combined with precipitation may alleviate the SOC oxidation of soil enriched in 13 C in the desert steppe.

Keywords: climate change; flux; stable carbon isotope; soil organic carbon; desert steppe (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/14/6/3351/pdf (application/pdf)
https://www.mdpi.com/2071-1050/14/6/3351/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:14:y:2022:i:6:p:3351-:d:769993

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().