Effect of shrub land on soil carbon storage in the Loess Plateau

Abstract

With the increasing atmospheric CO2 concentrations in the current years, afforestation implemented on lands with poor fertility is considered to be an effective measure for mitigating CO2 emissions. However, little studies have focused on the comparation of effects of different shrub lands on soil carbon storage. In this case, 16-year-old Caragana Korshinskii K. (CK) land and 16-year-old Hippophae rhamnoides L. (HR) land were investigated in Huining County, Gansu Province, to explore the differences in soil carbon storage between them. The results showed that the total soil carbon storage at the 1.0 m soil depth for the CK land and HR land was 46.55 Mg·ha-1 and 56.73 Mg·ha-1, respectively, with a significant difference in total soil carbon storage between them. The soil organic carbon (SOC) decreased with the soil depth, and was significantly negatively correlated to soil bulk density, but positively correlated to STN. However, SOC showed no significant correlations with soil pH, STP and soil moisture content. The SOC arising was not significant affected by the interactions between land use type and soil depth, demonstrating that the SOC is generally affected by soil either depth or stand type, rather than both in this area. This study expects to advance new understanding of the relationships between soil carbon storage and shrub land in the Loess Plateau, and it could also have wider implications for other regions where land use and land cover change is being addressed by afforestation options.