Abstract:By using soil respiration chamber, the stem respiration of dominant tree species Pinus koraiensis, Quercus mongolica, Fraxinus mandshurica and Tilia amurensis in broad-leaved Korean pine mixed forest of Changbai Mountains was measured from April to October 2003. The temperature on the stem surface and in the forest was determined simultaneously. The results demonstrated that the stem respiration rate of test tree species had an obvious seasonal variation, with the maximum occurred in July and the minimum in October. The diurnal variation of the stem respiration rate was in a ‘S’ curve, with the minimum at 6:00 for all test tree species, and the maximum at 18:00, 20:00, 16:00, and 14:00 for P. koraiensis, Q. mongolica, F. mandshurica, and T. amuremis, respectively. The response of stem respiration to temperature differed with tree species, and the Q10 value ranged from 2.24 to 2.9, which were decreased in the order of F. mandshurica>Q. mongolica>P. koraiensis>T. amurensis.