滩地人工杨树林土壤呼吸变化规律与环境因子的关系研究

Studies on Soil Respiration Change and Its Relation with Environmental Factors in Poplar Plantation on Beach Land

为揭示滩地人工杨树林土壤呼吸特征及其与环境因子的关系,采用红外气体分析(IRGA)法对滩地人工杨树林土壤CO2释放量进行测定,分析温度、水分、林下植被结构等因素对林地土壤呼吸日变化动态的影响。结果表明:滩地人工杨树林生态系统土壤呼吸日动态变化呈单峰曲线,在11:00-13:00达到最大值。土壤呼吸速率大小的排列顺序为:2006年6月>2005年10月>2006年3月>2006年10月。日均土壤呼吸速率为2.29±0.75μmol/(m2.s)(P<0.05,n=13),变异系数为54.40%。土壤呼吸对地表温度的敏感性大于对地下5cm处温度的敏感性。土壤呼吸温度敏感性指标Q10值为1.28±0.79(P<0.05,n=13),低于不包括湿地在内的全球尺度水平。土壤水分与土壤呼吸相关性差,不是滩地林地土壤CO2释放量的限制因子。林下植被亦是影响土壤呼吸速率的一个重要因素。

In order to reveal the soil respiration change and its relation with environmental factors,soil CO2 emission rates in artificial poplar plantation on Beach Land were investigated by using Infra Red Gas Analysis（IRGA） technique,and the soil respiration changes in relation to environmental factors such as temperature,soil water content and vegetation structure underforest were analyzed.The results showed that the diurnal dynamics of soil respiration presented a single peak curve with the maximum occurring around 11：00-13：00.The order of soil CO2 emission rates is Jun-2006〉Oct-2005〉Mar-2006〉Oct-2006.The mean value of efflux is 2.29±0.75 μmol/（m2·s）（P〈0.05,n=13） and a coefficient of variation is 54.40%.The sensitivity of the soil respiration to the temperature above ground is superior to the soil temperature at 5 cm.The Temperature susceptibility indexes Q10 value is 1.28±0.79（P〈0.05,n=13）,which is less than the global level except for beach land.The relationship between soil moisture and soil respiration is not good,so the soil moisture is not the limitational factor to the efflux of CO2.The vegetation structure is also the one influence factor controlling soil respiration.