Differential characteristics of soil organic carbon and its driving
factors in the northeastern Qinghai-Tibet Plateau
Abstract
Clarifying the spatial distribution of soil organic carbon (SOC) can
provide a theoretical basis for mitigating carbon emissions. The
characteristics of SOC and soil organic carbon density (SOCD) change in
different vegetation and soil types, and the response mechanism of SOC
content to environmental factors are unclear. Thus, 131 sites were
selected for sampling from the 0‒30 cm soil layer to study regional SOC
and SOCD spatial distribution. The results showed that the SOCD in the
northwestern region was lower than that in the southeastern in the
northeast of the Qinghai-Tibet Plateaue. Both SOC and SOCD were affected
by the vegetation type. The order of vegetation types was swamp
> meadow > steppe > desert.
Furthermore, SOC content decreased with increasing soil depth in the
0‒30 cm soil layer. The SOC and SOCD contents also differed among the
different soil types. The order of SOC from largest to smallest was
alpine meadow soil > bog soil > chestnut soil
> saline-alkali soil > alpine steppe soil
> grey-brown desert. The path analysis showed that TN
significantly positively affected SOC (P < 0.001). This study
aimed to provide a scientific basis for grassland carbon sink management
in the Qinghai-Tibet Plateau.