积雪对长白山阔叶红松林土壤温度的影响

Effects of snow cover on soil temperature in broad-leaved Korean pine forest in Changbai Mountains

2004—2007年对长白山阔叶红松林林地进行遮雪试验,观测了有雪、无雪覆盖的森林土壤温度和气温.结果表明:积雪对土壤温度变化有明显的缓冲作用,有雪覆盖减缓了土壤温度的变化;积雪对浅层(0～20cm)土壤有较好的保温作用,随雪深的增加,保温作用增大,雪深从10cm增至20cm时保温作用的增幅最大,当雪深超过30cm时,保温作用的增幅不明显;融雪期土温经历0℃左右的恒温期后缓慢上升,恒温期的持续时间主要由冬季的雪深及其时间分布所决定.

A snow-shading experiment was conducted in a broad-leaved Korean pine forest in Changbai Mountains from 2004 to 2007 to observe the soil temperature with and without snow cover. Snow cover played an important buffering role in the change of soil temperature,namely,slowed down the change process of soil temperature. The effect of snow cover on preserving soil heat was quite obvious in shallow soil layer （ 0-20 cm） ,and enhanced with increasing snow depth. When the snow depth increased from 10 to 20 cm,the effect enhanced significantly. However,when the snow depth exceeded 30 cm,the increasing trend turned to indistinctive. In the period of snowmelting,soil temperature kept around 0 ℃ for some time,and after then,increased gradually. The length of the period keeping soil temperature around 0 ℃ was determined by snow depth and the duration of snow cover.