华北南部低丘山地刺槐林地非主要生长季土壤微生物的呼吸特征

采用树木环割法,于2009-11—2010-03,利用Li-8100土壤呼吸自动观测系统,观测研究了位于河南省济源市的华北山区南部低丘山地40a生刺槐林土壤微生物呼吸速率（Rh）的时间变化特征及其与土壤温度和湿度的关系。结果表明：（1）在非主要生长季,Rh日变化不明显,但呈现出明显的日际变化特征;Rh平均值为0.426μmol.m-2.s-1。（2）林地5cm深处土壤温度与Rh之间存在显著的指数相关关系（P〈0.01）,且Rh随5cm深处土壤温度的升高而增大,表示二者关系的参数Q10值是1.86,说明非主要生长季Rh对温度的变化十分敏感;Rh与土壤含水量呈显著的线性相关关系（P〈0.01）,且Rh与5cm深处的土壤温度和土壤体积含水量均有很好的复相关关系（P〈0.01）。比较偏相关系数表明,影响Rh的主要土壤物理因子是土壤水分。

Character of Soil Heterotrophic Respiration of Robinia pseudoacacia Plantation During the Minor Growing Season in South Hilly Area of North China

Rate of soil heterotrophic respiration（Rh）of a 40-year-old Robinia pseudoacacia plantation during the minor growing season in the south hilly region of north China were analyzed.The experiments were conducted in Jiyuan city of Henan province from Nov.2009 to Mar.2010,and soil heterotrophic respiration rate was measured by Li-8100 automatic monitoring system.The main results were as follows：（1）the diurnal variation of Rh was not apparent but the daily Rh changed significantly during this season.The averaged Rh was 0.426μmol·m-2·s-1 in the whole minor growing season.（2）Significant relationship was found between Rh and soil temperature at the 5cm depth（P0.01）,which could be well described by exponential equations.Rh increased with the increasing of Ts at the 5cm depth and Q10 was 1.86.Rh was significantly related to soil temperature（Ts） and soil moisture（SW） at 5cm depth.SW was the most important soil physical parameter that effected on Rh through comparing the partial coefficient of Ts and SW at the 5cm depth.