Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (4): 282-291.DOI: 10.17521/cjpe.2015.0199

• Research Articles • Previous Articles     Next Articles

Spatial pattern of soil organic carbon of the main forest soils and its influencing factors in Guangxi, China

Hu DU1,2, Fu-Ping ZENG1,2,*(), Tong-Qing SONG1,2, Yuan-Guang WEN3, Chun-Gan LI3,4, Wan-Xia PENG1,2, Hao ZHANG1,2, Zhao-Xia ZENG1,2   

  1. 1Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China

    2Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi 547100, China

    3Forestry College of Guangxi University, Nanning 530004, China

    4Guangxi Forest Inventory & Planning Institute, Nanning 530004, China
  • Received:2015-06-03 Accepted:2015-12-27 Online:2016-04-29 Published:2016-04-30
  • Contact: Fu-Ping ZENG


Our objectives were to study the spatial distribution of soil organic carbon (SOC) density and its influencing factors in the main forest ecosystems in Guangxi.
A total of 345 sample plots were established in Guangxi, and the size of each plot was 50 m × 20 m. Based on the forest resource inventory data and field investigation, the SOC storage of the main forests in Guangxi was estimated. Geostatistics was applied to analyze the spatial pattern of SOC density and the main influencing factors on SOC density were also explored by principal component analysis and stepwise regression.
Important findings
The total SOC storage in the main forests in Guangxi was 1686.88 Tg, and the mean SOC density was 124.70 Mg·hm-2, which is lower than that of China. The best fitted semivariogram model of SOC density was exponential model, and the spatial autocorrelation was medium. The contour map based on Kriging indicated that northeastern Guangxi had high SOC density and northwestern Guangxi had low SOC density, which corresponded to high SOC density in non-karst region and low SOC density in karst region. The SOC density followed the sequence of bamboo forest > deciduous broadleaf forest > warm coniferous forest > mixed evergreen and deciduous broadleaf forest > evergreen broadleaf forest, and yellow soil > red soil > lateritic red soil > limestone soil. The dominant environment factors affecting SOC density included soil depth, longitude, latitude, and altitude. Soil depth was the most influential factor, which was mainly attributed to the karst landscape.

Key words: soil organic carbon, spatial heterogeneity, influencing factor, forest type, Guangxi