Abstract:The rate of Carbon dioxide emission was determined in the Mat cryo-sod soil covered with alpine Kobresia humilis meadow in the region of Haibei Alpine Meadow Ecosystem Research Station, using a CI-301PS photosynthetic instrument during the plant growing period (May~Sept.). The results indicated that: The CO 2 emission rate had significant diel fluctuation and seasonal dynamics.Maximum rate of CO 2 emission appeared at 14:00~16:00 and minimum at 6:00~8:00. The maximum diel amplitude was 797.75 mg/m 2·h (...