Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (3): 288-296.DOI: 10.17521/cjpe.2017.0068

• Research Articles • Previous Articles     Next Articles

Distribution and storage of soil organic carbon across the desert grasslands in the southeastern fringe of the Tengger Desert, China

YANG Hao-Tian,WANG Zeng-Ru*(),JIA Rong-Liang   

  1. Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
  • Online:2018-03-20 Published:2017-06-16
  • Contact: Zeng-Ru WANG
  • Supported by:
    Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05050406-1);the National Natural Science Foundation of China(41501110);the West Light Program for Talent Cultivation of Chinese Academy of Sciences.(41401112)

Abstract:

Aims The complexity of environments and high spatial heterogeneity of desert ecosystems are important factors contributing to the uncertainty in the estimation of soil organic carbon storage.

Methods Ten types of desert grassland communities in the southeastern fringe of the Tengger Desert, China were investigated. The content and vertical distribution of soil organic carbon (SOC) content in seven soil depths (0-5, 5-10, 10-20, 20-30, 30-50, 50-70 and 70-100 cm) and the underlying drivers were examined. Soil organic carbon density (SOCD) of four soil profiles (0-5, 0-20, 0-50 and 0-100 cm) were quantified.

Important findings We found significant differences in SOC content among the 10 vegetation communities, and the shrub community type was an important factor affecting SOC content. Two types of trends in SOC content changes with soil depth were observed: 1) monotonic decrease, 2) increase followed by decrease. The SOC content was significantly positively correlated with clay content, total N, total P and conductivity, but negatively correlated with sand content. There were significant differences in SOCD for soil profiles of 0-5, 0-20, 0-50 and 0-100 cm among different communities, of which the mean values of SOCD were 0.118, 0.478, 1.159 and 1.936 kg·m-2, respectively. Our results show that SOCD is far below the mean value of global or national grasslands. Using the average values of SOCD across either global or national grasslands (including the grassland in this study) to estimate the SOC storage of desert ecosystems may lead to the overestimation or underestimation. Using the SOCD of specific communities may greatly increase the accuracy of SOC storage estimation in desert grasslands.

Key words: the Tengger Desert, desert grassland, soil organic carbon content, soil organic carbon density