Effects of Caragana microphylla plantations on organic carbon sequestration in total and labile soil organic carbon fractions in the Horqin Sandy Land, northern China
1 State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating, Gansu Desert Control Research Institute, Lanzhou 730070, China;
2 Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
Abstract Afforestation is conducive to soil carbon (C) sequestration in semi-arid regions. However, little is known about the effects of afforestation on sequestrations of total and labile soil organic carbon (SOC) fractions in semi-arid sandy lands. In the present study, we examined the effects of Caragana microphylla Lam. plantations with different ages (12- and 25-year-old) on sequestrations of total SOC as well as labile SOC fractions such as light fraction organic carbon (LFOC) and microbial biomass carbon (MBC). The analyzed samples were taken from soil depths of 0–5 and 5–15 cm under two shrub-related scenarios: under shrubs and between shrubs with moving sand dunes as control sites in the Horqin Sandy Land of northern China. The results showed that the concentrations and storages of total SOC at soil depths of 0–5 and 5–15 cm were higher in 12- and 25-year-old C. microphylla plantations than in moving sand dunes (i.e., control sites), with the highest value observed under shrubs in 25-year-old C. microphylla plantations. Furthermore, the concentrations and storages of LFOC and MBC showed similar patterns with those of total SOC at the same soil depth. The 12-year-old C. microphylla plantations had higher percentages of LFOC concentration to SOC concentration and MBC concentration to SOC concentration than the 25-year-old C. microphylla plantations and moving sand dunes at both soil depths. A significant positive correlation existed among SOC, LFOC, and MBC, implying that restoring the total and labile SOC fractions is possible by afforestation with C. microphylla shrubs in the Horqin Sandy Land. At soil depth of 0–15 cm, the accumulation rate of total SOC under shrubs was higher in young C. microphylla plantations (18.53 g C/(m2•a); 0–12 years) than in old C. microphylla plantations (16.24 g C/(m2•a); 12–25 years), and the accumulation rates of LFOC and MBC under shrubs and between shrubs were also higher in young C. microphylla plantations than in old C. microphylla plantations. It can be concluded that the establishment of C. microphylla in the Horqin Sandy Land may be a good mitigation strategy for SOC sequestration in the surface soils.
Fund: This study was funded by the National Natural Science Foundation of China (31640012, 41271007, 31660232), the One Hundred Person Project of the Chinese Academy of Sciences (Y551821), and the Opening Foundation of the State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating, Gansu Desert Control Research Institute (GSDC201505).
Corresponding Authors: LI Yuqiang
E-mail: liyq@lzb.ac.cn
Cite this article:
. Effects of Caragana microphylla plantations on organic carbon sequestration in total and labile soil organic carbon fractions in the Horqin Sandy Land, northern China[J]. Journal of Arid Land, 2017, 9(5): 688-700.
2017, Vol. 9 
