Restoration of soil carbon with different tree species in a post-mining land in eastern Loess Plateau, China

Vegetation restoration tends to enhance soil carbon storage in severely degraded lands, which is of great significance to mitigate climate change. In this study, soil organic carbon, inorganic carbon and soil properties were investigated in a restored post-mining area in Shanxi province, eastern Loess Plateau. Through artificially planting Rhus typhina, Quercus liaotungensis and Pinus tabuliformis (referred to as RT, QL and PT, respectively), soil water and total nitrogen contents increased significantly. Soil organic carbon in restored sites increased by 101.9% compared with that of a non-restored site. Accumulation of litter and withered root with vegetation succession led to the increases of input of organic matter, which was beneficial to improve soil organic carbon storage. QL had significantly higher organic carbon sequestration rate (1.59 t ha(-1) yr(-1)) than those of other tree species, which might be attributed to higher nitrogen content and litter input. Soil inorganic carbon accounted averagely for 70.1% of the total carbon storage. However, re-vegetation had no significant influence on soil inorganic carbon which was closely related with soil parent material and climate. Our results suggested that abandoned mine lands might serve as C sinks through appropriate restoration management. Indigenous QL would be suitable to be recommended as the preferred species for reclamation management of degraded lands. Because of a short duration of restoration, the dynamics of soil inorganic carbon during vegetation succession needs to be further studied to reveal potential C sequestration mechanism in arid and semi-arid regions.