内蒙古乌拉山天然油松林土壤呼吸特征研究

Characteristics of Soil Respiratory of Pinus tabulaeformis Natural Forest in Wulashan,Inner Mongolia

用Li-820测定并研究内蒙古乌拉山天然油松林生长季土壤呼吸速率的日及季节变化规律,分析土壤呼吸与土壤水热因子的关系。结果表明:土壤呼吸速率有明显的日及季节变化规律。在季节变化尺度上,各月土壤呼吸平均速率大小为:8月>9月>7月>6月>5月,总体表现为:雨季和秋季的呼吸速率大于早春和夏季干旱月份。土壤呼吸速率日变化规律为:在干旱月份呈双峰曲线,雨季则呈单峰曲线。在旱季,土壤呼吸速率与土壤温度呈负相关关系,雨季则呈正相关关系。土壤呼吸速率与土壤水分含量之间的正相关关系极显著,相关回归方程为y=0.501e0.13x(R2=0.953),表明土壤水分含量是影响干旱区森林土壤呼吸作用的主导因子。

The rule of diurnal and seasonal variation of soil respiratory rate has been measured by use of Li - 820 in growing season of Pinus tabulaeformis natural forest in Wulashan, the relation between soil respiratory and hydrothermal factors has been analyzed. The results show that there is obvious rule of diurnal and seasonal variation of soil respiratory. In seasonal change, the order of the average soil respiratory rate in each month is August 〉 September 〉 July 〉 June 〉 May. The respiratory rate in rainy season and Autumn is higher than the one in early Spring and dry months in Summer. The rule of diurnal variation of soil respiratory rate is double - peak curve for dry months and single -peak curve for rainy season. In drought season, there is negative correlation between soil respiratory rate and soil temperature. In rainy season, there is positive correlation between soil respiratory rate and soil temperature. There is obviously positive correlation between soil respiratory rate and soil water content. The correlated regression equation is y = 0. 501e^0.13x （ R^2 = 0. 953 ）, which shows soil water content is a dominant factor for influencing the soil respiratory of forest in arid area.