Chin J Plant Ecol ›› 2009, Vol. 33 ›› Issue (4): 739-747.DOI: 10.3773/j.issn.1005-264x.2009.04.012

Special Issue: 生态系统碳水能量通量

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WANG Guang-Jun1,2, TIAN Da-Lun1,2,*(), YAN Wen-De1,2, ZHU Fan1,2, XIANG Wen-Hua1,2, LIANG Xiao-Cui1   

  1. 1Central-South University of Forestry & Technology, National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, China
    2Huitong National Field Station for Scientific Observation & Experiment for Chinese Fir Ecosystem, Huitong, Hunan 418307, China
  • Received:2008-06-26 Revised:2009-02-09 Online:2009-06-26 Published:2009-07-30
  • Contact: TIAN Da-Lun


Aims Soil respiration is the largest carbon flux in forest ecosystems except for canopy photosynjournal, but the effect of litter on soil respiration in Cunninghamia lanceolata plantations is poorly understood. Our objectives were to examine quantitative differences in changes in soil respiration induced by litter exclusion and addition and to determine how litter manipulation affects soil CO2 flux in C. lanceolata plantation ecosystems.
Methods We measured soil respiration with an infrared gas exchange analyzer (Li-6400-09) in Tianjiling National Forestry Park, Changsha, Hunan, China from January to December 2007. In the litter exclusion treatment, all ground litter was removed and aboveground litter input was excluded. In the litter addition treatment, litter removed from litter exclusion plots was added to produce double litter. Soil temperature and moisture were measured at 5 cm depth at the same time as soil respiration measurements.
Important findings The treatments of litter exclusion and addition had significantly different seasonal patterns of CO2 flux processes. Average soil respiration rates of litter exclusion and addition plots were 159.2 and 216.8 mg CO2·m-2·h-1, respectively. The soil respiration rate with litter exclusion was 15.0% lower than the control (180.9 mg CO2·m-2·h-1) and with litter addition was 17.0% higher than the control. Significant exponential relationships were found between soil temperature and soil respiration rate under both treatments, and soil temperature could explain 85.3% and 89.6% of the seasonal changes in soil respiration in the litter exclusion and litter addition plots, respectively. The relationship between soil respiration rate (y) and soil temperature (t) was described by the regression equations: y=27.33e0.087 2t(R2=0.853, p<0.001) and y=37.25e0.088 8t(R2=0.896, p<0.001) in the litter exclusion and addition plots, respectively. The Q10 values in the litter exclusion and litter addition plots were 2.39 and 2.43, higher than the control (2.26). The results indicated that litter-fall is an important factor affecting soil CO2 efflux in forests.

Key words: Cunninghamia lanceolata plantation, soil respiration, soil temperature, soil moisture, Q10 value