Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (3): 236-245.DOI: 10.17521/cjpe.2015.0364

• Research Articles • Previous Articles     Next Articles

Characteristics of soil organic carbon mineralization at different temperatures in severely eroded red soil

Xi Qiu1,2, Mao-Kui LÜ1,2, Jin-Xue HUANG1,2, Wei LI1,2, Ben-Jia ZHAO1,2, Hao ZHANG1,2, En-Xi WANG1,2, Jin-Sheng XIE1,2,3,*()   

  1. 1School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China

    2State Key Laboratory Breeding Base of Humid Subtropical Mountain Ecology, Fuzhou 350007, China

    3Institute of Geography, Fujian Normal University, Fuzhou 350007, China
  • Received:2015-10-13 Revised:2016-01-18 Online:2016-03-10 Published:2016-03-25
  • Contact: Jin-Sheng XIE

Abstract: Aims It is crucial to study the soil organic matter decomposition and its temperature sensitivity for in-depth understanding of soil organic carbon (SOC) dynamic changes in severely eroded red soil. Methods We selected the severely eroded red soil on the bare land from Hetian town of Changting County as the research object. To study the influences of temperature on SOC mineralization and their temperature sensitivity (Q10), the SOC mineralization rate, the associated soil microbial biomass carbon (MBC), and dissolved organic carbon (DOC) under different incubation temperatures (10, 20 and 30 °C) were measured.Important findings The results showed that the incubation temperature significantly influenced the SOC mineralization. The mineralization ratio and the cumulative SOC mineralization rate increased with temperature. During the incubation period, the cumulative SOC mineralization was positively and significantly correlated with the soil MBC, and negatively correlated with soil DOC, indicating that soil microbes and C availability can significantly influence the SOC mineralization. During the 180 days incubation period, the accumulation mineralization rate of the severely eroded red soil was as high as 22.2%-33.3% under the conditions of the SOC content being only 1.54 g·kg-1, which indicates that the eroded red soil is easily mineralized. For the severely eroded red soil, its SOC temperature sensitivity (Q10) value was 1.41 at low temperatures (10-20 °C), but decreased to 1.06 at high temperatures (20-30 °C). The relatively low Q10 value at low temperatures was partly attributed to the low soil SOC quality. Furthermore, the long-time exposure to sunshine for the severely eroded red soil in the summer leads to the soil microbial adaptability to high temperature. As a result, its Q10 value is close to 1 at high temperatures. This study implies that it is of great significance to restore vegetation to minimize loss SOC caused by mineralization of the eroded red soil under climate changes in the future.

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Key words: cumulative C mineralization, temperature sensitivity, soil organic carbon (SOC), microbial quotients, soil metabolic quotients