GEOGRAPHICAL RESEARCH ›› 2011, Vol. 30 ›› Issue (10): 1825-1834.doi: 10.11821/yj2011100009

• Environment and Ecology • Previous Articles     Next Articles

Spatial distribution of topsoil labile organic carbon of Pinus elliottii ecosystem in the central subtropical region

CHEN Xiao-lin1,2, LI Zhong-wu1,2, WANG Xiao-yan3, SHEN Wei-ping4, ZHANG Xue1,2, GUO Wang1,2, ZHANG Yue-nan1,2   

  1. 1. College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;
    2. Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education Changsha 410082, China;
    3. College of Civil Engineering and Architecture,
    Changsha University of Science and Technology, Changsha 410076, China;
    4. Soil and Water Conservation Research Institute of Shaoyang, Shaoyang 422002, China
  • Received:2011-05-09 Revised:2011-08-03 Online:2011-10-20 Published:2011-10-20

Abstract: Labile organic carbon is more sensitive to changes in land management or environment conditions than stable carbon, although it is a smaller fraction of soil organic carbon. It also has a disproportionately large effect on nutrient-supplying capacity and the structural stability of soils. Therefore, the spatial distribution and its influencing factors (topography, vegetation and soil properties) have been analyzed in Pinus elliottii ecosystem of central subtropical region. Results indicated that the mean of soil labile organic carbon was 1.92g/kg, accounting for 29.12% of soil organic carbon, and the coefficient of variability was 46.15%. Labile organic carbon and carbon lability in gully areas were significantly higher than that in slope position. The results of correlation analysis showed that labile organic carbon was negatively correlated with elevation and aboveground biomass of arbor layer, positively correlated with aboveground biomass of shrubs, but highly significantly positive with soil organic carbon, total nitrogen, total phosphorus, available nitrogen, available phosphorus and available potassium. Principal component analysis in Canoco showed that the first and second axes were the principal component axes. Soil organic carbon, total nitrogen and available nitrogen were the first principal component axis affecting labile organic carbon, followed by altitude, pH, total phosphorus and above-ground biomass of shrubs. However, carbon lability had no significant correlation with affecting factors.

Key words: labile organic carbon, spatial distribution, influencing factors, Pinus elliottii ecosystem, central subtropical region