Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (12): 1211-1224.DOI: 10.17521/cjpe.2018.0202

• Research Articles • Previous Articles    

Effects of vegetation restoration on soil organic carbon mineralization in the east of Hunan, China

GU Xiang1,ZHANG Shi-Ji1,LIU Zhao-Dan1,LI Lei-Da1,CHEN Jin-Lei1,WANG Liu-Fang1,FANG Xi1,2,3,*()   

  1. 1 School of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China
    2 National Engineering Laboratory of South China Forestry Ecology Applicable Technologies, Changsha 410004, China
    3 Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, Hunan 438107, China
  • Received:2018-08-16 Revised:2018-11-01 Online:2018-12-20 Published:2019-04-04
  • Contact: FANG Xi ORCID: 0000-0003-1236-2335
  • Supported by:
    Supported by the National Forestry Public Welfare Industry Research Project.(201504411);the National Natural Science Foundation of China(30771720);the National Natural Science Foundation of China(31170426)


Aims Soil organic carbon (SOC) mineralization and its controlling factors are critical for understanding the mechanisms that regulate C storage and loss processes. Our objectives were to accurately assess the impacts of vegetation restoration on SOC mineralization and to illustrate the underlying mechanism of changes in SOC stability with vegetation restoration in the mid-subtropical region of China.

Methods Four types of vegetation communities (Loropetalum chinense-Vaccinium bracteatum-Rhododendron mariesiiscrub-grass-land (LVR), Loropetalum chinense-Cunninghamia lanceolata-Quercus fabri shrubbery (LCQ), Pinus massoniana-Lithocarpus glaber-Loropetalum chinense coniferous-broad leaved mixed forest (PLL) and Lithocarpus glaber-Cleyera japonica-Cyclobalanopsis glauca evergreen broad-leaved forest (LAG) ) were selected for a successional sequence of the secondary forest in a hilly region of eastern Hunan Province, China. Soil samples (0-40 cm) were collected from four depths (0-10, 10-20, 20-30 and 30-40 cm). SOC mineralization was determined by the laboratory incubation method (alkali absorption method). Principal component analysis and stepwise regression were applied to analyze the relationships between SOC cumulative mineralization (Cm), the percentage of Cm to SOC content and vegetation factors and soil factors.

Important findings 1) SOC mineralization rate displayed similar trends during the four restoration stages: during the early incubation period, SOC mineralization was high and decreased fast, and then the rate decreased slowly and tend to stabilize during the middle and late periods. The pattern was well fitted with the reciprocal equation. 2) SOC mineralization rate and Cm increased significantly with the vegetation restoration stage with the LAG having both the highest SOC mineralization rate and the highest Cm. In 0-40 cm soil layer, Cm in LAG soil was 359.06%-716.31%, 112.38%-232.61%, 94.40%-105.74% higher than that in LVR, LCQ, PLL soils, respectively. 3) The percentage of Cm to SOC content were 2.13%-4.99%, 3.42%-4.18%, 4.05%-4.64%, and 4.02%- 5.64% in 0-10, 10-20, 20-30, 30-40 cm soil layers, respectively. However, there was no significant difference in the percentage of Cm to SOC content among the different restoration stages. 4) Among different vegetation restoration stages, total nitrogen (TN) content and root biomass (RB) were the key factors affecting Cm. TN content and RB together explained 97.8% variations in Cm, of which TN content explained 96.9%. However, C:N was the dominant factor affecting the percentage of Cm to SOC content and it alone explained 49.4% variation. Vegetation restoration promoted SOC mineralization rate and reduced the percentage of Cm to SOC content in our study, which might be related to the changes in RB and soil nutrient during vegetation restoration.

Key words: mid-subtropical region of China, vegetation restoration, soil organic carbon mineralization, vegetation factor, soil factor