Distribution characteristics and influencing factors of soil organic
carbon in alpine desert ecosystem of Qinghai Province
Abstract
Alkaline deserts soils acted as important soil pools in arid and
semiarid regions. Contents of soil organic carbon (SOC) and its driven
factors remained still not clear in alpine deserts on the Tibetan
Plateau. In this study, we analyzed 223 soil organic carbon contents and
total nitrogen and pH values, and its space distribution pattern under
0-30 cm. It was indicated that average and median SOC were approximate
4.86 and 3.80 g/kg with variation coefficient of 81.14%. SOC contents
ranged from 0.54 to 24.34 g/kg. Soils organic carbon contents were
divided into four groups. The largest group was around 3.32 g/kg (145
sites) when air temperature and altitude were higher than 1.49 oC and
2793 m. Alpine desert SOC were mainly controlled by total nitrogen (TN)
and pH and precipitation with R2 of 0.87 (P<0.001).
Furthermore, soil pH was positively affected by air temperature not
precipitation (P<0.05). Models may predict SOC through
precipitation, air temperature and altitude (R2= 0.40,
P<0.001). In addition, increasing regional precipitation
perhaps decreased desert soils organic carbon storage in future climate
scenarios.