LIU Yu-jie1, 2, WANG Shi-jie1*, LIU Xiu-ming1, LIU Fang3
(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;
2. Graduate University of the Chinese Academy of Sciences, Beijing 100049, China;
3. Institute of Environment and Resource, Guizhou University, Guiyang 550025, China)
Abstract: Soil microbial biomass carbon (BC), nitrogen (BN) and their correlations with soil physico-chemical properties were studied in four sites of the Maolan karst area: virgin forest, secondaryforest, shrubbery and grassland. The data from the surface soil samples (the soil depth was 0~15cm) showed that: (1) with positive succession (from grassland to shrubbery, then to secondaryforest, and then to virgin forest), BC and BNincreased, and tended to be highest in winter and lowest in summer. Besides, there were significant differences among the four sites. Furthermore, the ratios of soil organic carbon (OC) to total nitrogen (TN) and BC to OC both showed an ascending trend while BC to BN and BN to TN both showed a descending trend; (2) the contributions of BC to OC and BN to TN were 0.8%~1.8% and 4.1%~7.8%, respectively; (3) BC and BN had significant (p<0.05) or very significant (p<0.01) correlations with soil pH, OC, TN, available nitrogen (AN), silty particles (0.002~0.02 mm) and microaggregates (<0.25 mm), respectively. Moreover, there was a significantly (p<0.01) positive correlation between BC and BN. On the whole , these results suggested that BC and BN acted as the reservoir of plant available nutrients during winter and as the source in summer. In addition, they could be considered as sensitive indicators of soil fertility in the experimental sites.
Key Words: Karst; Soil microbial biomass carbon; Soil microbial biomass nitrogen; Vegetation succession
EARTH AND ENVIRONMENT Vol. 39, No.2, Tot No.283, 2011, Page 188-195
