中文摘要：

从2007年1月至12月，在长沙天际岭国家森林公园，通过改变杉木林凋落物输入，研究杉木（Cunninghamialanceolata）人工林群落去除凋落物、加倍凋落物土壤呼吸速率及5cm土壤温、湿度的季节变化。结果表明：去除和加倍凋落物对土壤温度和湿度产生的差异不显著（P〉0．05），对土壤呼吸全年产生的差异接近显著（Marginalsignificant）（p=0．058）。按植物生长期分别分析，去除和加倍凋落物对土壤呼吸产生的差异，在生长旺盛期差异显著（P=0．003），在生长非旺盛期差异性不显著（P=0．098）。去除凋落物年均土壤呼吸速率为159．2mgCO2m^2·h^-1，比对照处理土壤呼吸速率（180．9mgCO2m^2·h^-1）低15．0％，加倍凋落物的土壤呼吸为216．8mgCO2m^2·h^-1，比对照处理高17．0％。去除和加倍凋落物土壤呼吸季节动态趋势与5cm深度土壤温度相似，它们之间呈显著指数相关，模拟方程分别为：y=27．33e^0.0872t（R2=0．853，p〈0．001），y=37．25e^0.0888t（R2=0．896，p〈0．001）。去除和加倍凋落物的Q10值分别为2．39和2．43，均比对照2．26大。去除和加倍凋落物土壤呼吸与土壤湿度之间关系不显著（p〉0．05）。这一结果使我们能够在较短时间内观察到改变凋落物输入对土壤呼吸的影响，证明凋落物是影响土壤CO2通量的重要因子之一。

英文摘要：

Aims Soil respiration is the largest carbon flux in forest ecosystems except for canopy photosynthesis, 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 measure- ments. lmportantfindings 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 mgCO2m^2·h^-1, respectively. The soil respiration rate with litter exclusion was 15.0% lower than the control （180.9 mgCO2m^2·h^-1） and with litter addition was 17.0% higher than the conrol. 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=27.33e^0.0872t （R2=0.853, p〈0.001） and y=37.25e^0.0888t （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 contro