Soil organic carbon sequestration in relation to revegetation on the Loess Plateau, China

Man Cheng (1) , Zhijing Xue (1) , Yun Xiang (1) , Frédéric Darboux (2) , Shaoshan An (3)

1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau
2 URSols - Unité de Science du Sol (Orléans)
3 Institute of Soil and Water Conservation

Estimating the distribution of soil organic carbon (SOC) is essential for improving SOC sequestration. Our objectives were (1) to quantify the dependency of SOC stocks on vegetation type; (2) to identify in which aggregate sizes and chemical forms the SOC was stored; and (3) to determine which vegetation type was the most effective at sequestering SOC.

The studied vegetation types were shrubland CK16 (16-year-old Caragana korshinskii Kom.), shrubland CK26 (26-year-old C. korshinskii Kom.), shrubland AS (Armeniaca sibirica Lam.), natural grassland and artificial pasture. We investigated SOC stocks and measured soil carbon, in <0.25, 0.25–1, 1–2, 2–5 and 5–8 mm sized aggregates, and carbon fractions [humus (HS-C), humic acid (HA-C), fulvic acid (FA-C)] from CK shrublands, natural grassland and cropland.

The SOC stocks were the greatest for CK shrublands and natural grassland. Compared with cropland, shrubland CK caused increases in >2 mm sized aggregate C stocks. The 1–2, 2–5, 5–8 mm size aggregate C stocks were the highest in the natural grassland. HS-C was 1.4, 3.1, and 4.1 Mg ha−1 greater in shrubland CK16, shrubland CK26, and natural grassland, respectively, than in cropland.

Conversion to C. korshinskii shrublands and protection of natural grassland should be promoted to improve the contribution of vegetation to SOC sequestration.

Mots clés: Revegetation; Soil organic carbon; Stocks; Aggregate; Shrubland; Grassland

Domaines: Milieux et Changements globaux

Man Cheng, Zhijing Xue, Yun Xiang, Frédéric Darboux, Shaoshan An. Soil organic carbon sequestration in relation to revegetation on the Loess Plateau, China. Plant and Soil, 2015, 397 (1), pp.31-42. ⟨10.1007/s11104-015-2486-5⟩. ⟨hal-01275655⟩