亚热带马尾松与樟树林土壤呼吸速率特征比较

Comparison of soil respirations between Pinus massoniana and Cinnamomum camphora forests in subtropics

2009年6月至2010年6月,采用LI-COR-6400-09测定了马尾松和樟树人工林的土壤呼吸速率,并分析了5cm土壤温度对土壤呼吸的影响。结果表明:马尾松和樟树人工林中地下5cm土壤温度之间差异性不显著(P>0.05)。马尾松和樟树林土壤呼吸速率呈现显著的季节性变化(P<0.001),呈现相似的曲线格局,2种森林土壤呼吸速率年均值分别为1.490和2.373μmol/(m2.s)。马尾松和樟树林土壤呼吸速率与土壤温度之间呈指数方程关系,樟树林的土壤呼吸速率与土壤温度之间相关性显著(P<0.05),马尾松林则不显著(P>0.05)。

Seasonal variations of soil respiration in two forest types,Pinus massoniana and Cinnamomum camphora forests,were measured in Tianjiling National Forestry Park of Changsha,Hunan,China.CO2 effluxes rate was monitored using an infrared gas exchange analyzer（LI-COR 6400-09） from June 2009 to May 2010,such as soil temperature and moisture were also recorded in the two forests.The results show that the two forests had significant different patterns in seasonal soil respiration processes.The two forests exhibited irregular fluctuated curves during the study period with mean rates of soil respiration were 1.490 and 2.373 μmol/（m2·s） in Pinus massoniana and Cinnamomum camphora forests,respectively.Relationships were found between soil respiration rate and soil temperature at 5 cm soil depth in both forests,which could be best described by exponential equations.The relationship between both soil respiration rate（y） and the two variables of soil temperature（t） at 5 cm soil depth could be described by the following regression equation： y=1.346e0.009t（R2=0.088,P0.05）,y=0.187e0.017t（R2=0.561,P0.01）,respectiviely.