Chin J Plan Ecolo ›› 2016, Vol. 40 ›› Issue (4): 292-303.DOI: 10.17521/cjpe.2015.0314

• Research Articles • Previous Articles     Next Articles

Soil organic carbon density and influencing factors in tropical virgin forests of Hainan Island, China

Huai YANG1,2, Yi-De LI1,*(), Hai REN3, Tu-Shou LUO1, Ren-Li CHEN1, Wen-Jie LIU4, De-Xiang CHEN1, Han XU1, Zhang ZHOU1, Ming-Xian LIN1, Qiu YANG4, Hai-Rong YAO4, Guo-Yi ZHOU3   

  1. 1Research Institute of Tropical Forestry, Chinese Academy of Forestry, Forest Ecosystem State Field Scientific Observation Station of Jianfenglin, Hainan, Guangzhou 510520, China

    2Key Laboratory of Forest Ecology and Environment of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China

    3South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
    and
    4College of Environment and Plant Protection, Hainan University, Haikou 570228, China
  • Received:2015-09-06 Accepted:2016-02-19 Online:2016-04-29 Published:2016-04-30
  • Contact: Yi-De LI

Abstract:

Aims
Estimating soil organic carbon (SOC) density and influence factors of tropical virgin forests in Hainan Island provide new insight in basic data for SOC pool estimation and its dynamics study.
Methods
The main distribution areas of tropical virgin forests in Jianfengling (JFL), Bawangling (BWL), Wu- zhishan (WZS), Diaoluoshan (DLS), Yinggeling (YGL) of Hainan Island were selected, and soil samples (0-100 cm) were sampled and analyzed. SOC density was estimated by soil vertical fitting method and soil stratification method to discover the distribution characteristics of soil organic carbon in tropical virgin forests of Hainan Island.
Important findings
Results showed that: (1) The average SOC density using soil vertical fitting method in JFL, BWL, WZS, DLS and YGL was 14.98, 18.46, 16.48, 18.81, 16.66 kg·m-2, respectively, which was significantly higher (p < 0.05) than the estimated average SOC density using soil stratification method in these areas (14.73, 16.24, 15.50, 16.91, 15.03 kg·m-2, respectively). It is better to use soil vertical fitting method for SOC density estimation when the soil was natural without disturbance. (2) The proportion of SOC content in the first 0-30 cm depth interval out of SOC in the whole 0-100 cm soil profiles in JFL, BWL, WZS, DLS and YGL was 50.50%, 48.56%, 43.49%, 47.37%, 42.88%, respectively. (3) SOC density was significantly negative correlated with Shannon-Wiener index, Simpson index, species richness, and soil bulk density; and was significantly positive correlated with altitude, soil porosity, and soil nitrogen. However, SOC density was not significantly correlated to slope, biomass, average diameter at breast height, or average height. (4) Our study area Hainan was located in low latitude area with high rainfall and high temperature, which accelerated the decomposition of organic matter and nutrient recycling, resulting in significantly lower SOC densities in this tropical virgin forests of Hainan Island than the average value in China.

Key words: Hainan tropical virgin forests, soil vertical fitting method, soil stratification method, soil organic carbon density