Effects of vegetation rehabilitation on soil organic and inorganic carbon stocks in the Mu Us Desert, northwest China

Abstract

In arid and semiarid areas, the importance of soil inorganic carbon (SIC) is at least as high as that of soil organic carbon (SOC) in affecting the regional carbon budget following vegetation rehabilitation. However, variations in SIC have been uncertain, and few studies have analyzed the interactions between the SOC and SIC pools. We measured SIC, SOC, δ13C‐SIC, and δ13C‐SOC after planting Mongolian pine (MP) and Artemisia ordosica (AO) on shifting sand land (SL) over 10 years in the Mu Us Desert, northwest China. The results showed that, compared to SL, SIC stocks at 0–100 cm in MP and AO lands significantly increased by 12.6 and 25.8 Mg ha−1, respectively; SOC stocks in MP and AO lands significantly increased by 24.0 and 38.4 Mg ha−1, respectively. Both δ13C‐SIC and δ13C‐SOC in the 2 plantation lands were significantly lower than those in SL were. All 315 samples exhibited a negatively linear relationship between SIC content and δ13C‐SIC (R2 = .70, p < .01) and showed positively linear relationships between SIC content and SOC content (R2 = .69, p < .01) and between δ13C‐SIC and δ13C‐SOC (R2 = .61, p < .01). The results demonstrated that vegetation rehabilitation on SL has a high potential to sequester SIC and SOC in semiarid deserts. The reduction in δ13C‐SIC and the relationship of SIC with δ13C‐SIC following vegetation rehabilitation suggested that SIC sequestration is likely caused by the formation of pedogenic inorganic carbon. The relationships between SIC and SOC and between δ13C‐SIC and δ13C‐SOC implied that the pedogenic inorganic carbon formation may be closely related to the SOC accumulation.

Fractions of soil organic and inorganic carbon and their relationships in typical loess cropland of Fenggu Basin

“…Our analysis shows no clear relationship between SIC and SOC stocks in YCB, but a signi cant negative correlation between SIC and SOC stocks in the LFB. The overall negative correlation of SIC and SOC in this study area disagrees with our previous ndings of a positive correlation in the loess cropland of North China Plain (Guo et al 2016, Shi et al 2017b, and under various land uses in northwest China (Gao et al 2018, Wang et al 2015b. There is also evidence of a negative SIC-SOC relationship in the cropland of Hebei Plain (Li et al 2010) and under various land use types in the Loess Plateau, north China (Zhao et al 2016).…”

Total and dissolved soil organic and inorganic carbon and their relationships in typical loess cropland of Fengu Basin

“…7 Correlation between DOC and SOC content in the LFB, YCB and combined data (black dash lines) over (a) 0-20 cm and (b) 20-100 cm. One asterisk indicates significance at P < 0.05, and two asterisks at P < 0.01 disagrees with our previous findings of a positive correlation in the loess cropland of North China Plain (Guo et al 2016;Shi et al 2017b), and under various land uses in northwest China (Gao et al 2018;Wang et al 2015b). There is also evidence of a negative SIC-SOC relationship in the cropland of Hebei Plain (Li et al 2010) and under various land use types in the Loess Plateau, north China (Zhao et al 2016).…”

Climate change versus land-use change—What affects the ecosystem services more in the forest-steppe ecotone?

“…The conversion of other land use types into cropland may also change multiple ecological processes. For example, the conversion of the forest into cropland increases the potential SF (Dupont et al, 2014;Gao et al, 2018), since a vegetation cover of less than 20% is little effective to decline the velocity on the soil surface (Zhao et al, 2017). The cropland expansion from the forest or grassland increases the WY by decreasing the water loss from the evapotranspiration (Yosef et al, 2018).…”