Acta Geographica Sinica ›› 2018, Vol. 73 ›› Issue (11): 2150-2167.doi: 10.11821/dlxb201811008

• Ecosystem and Carrying Capacity • Previous Articles     Next Articles

Changes of soil organic carbon storage in Chinese terrestrial ecosystems from the 1980s to the 2010s

XU Li1(),YU Guirui1,2(),HE Nianpeng1,2   

  1. 1. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2017-12-08 Online:2018-11-25 Published:2018-11-22
  • Supported by:
    National Key Research Project of China, No.2016YFC050020; National Natural Science Foundation of China, No.31290221, No.41571130043, No.31570471; The Chinese Academy of Sciences Strategic Priority Research Program, No.XDA19020302, No.XDA05050702

Abstract:

Soils store a large amount of the terrestrial ecosystem carbon (C) and play an important role in maintaining global C balance. However, very few studies have addressed the regional patterns of soil organic carbon (SOC) storage and the main factors influencing its changes in Chinese terrestrial ecosystems, especially using field measured data. In this study, we collected information on SOC storage in the main types of ecosystems (forest, grassland, cropland, and wetland) across 18 regions of China during the 1980s (from the Second National Soil Survey of China, SNSSC) and the 2010s (from studies published between 2004 and 2014), and evaluated whether trends changed over the 30-year period. The SOC storage (0-100 cm) in China was 83.46±11.89 Pg C in the 1980s and 86.50±8.71 Pg C in the 2010s, and the net increase over 30 years was 3.04±1.65 Pg C, with a rate of 0.101±0.055 Pg C yr-1. This increase was mainly observed in the topsoil (0-20 cm). Forest, grassland, and cropland SOC storage increased by 2.52±0.77, 0.40±0.78, and 0.07±0.31 Pg C, respectively, which can be attributed to the several ecological restoration projects and agricultural practices implemented. On the other hand, SOC storage in wetlands declined by 0.76±0.29 Pg C, most likely due to the decrease in wetland area and SOC density. These results, combined with those of vegetation C sink (0.100 Pg C yr-1), show that the net C sink in Chinese terrestrial ecosystems was about 0.201±0.061 Pg C yr-1, which offsets 14.85%-27.79% of the C emissions from fossil fuels from the 1980s to the 2010s. These estimates of soil C sink based on field measured data supported the premise that China's terrestrial ecosystems have a large C sequestration potential, and further emphasized the importance of forest protection and reforestation to increase SOC storage capacity.

Key words: Chinese terrestrial ecosystems, soil organic carbon, storage, change