长白山红松针阔叶混交林主要树种树干呼吸速率

Stem respiration of dominant tree species in broad-leaved Korean pine mixed forest in Changbai Mountains

采用土壤呼吸气室,于2003年4—10月原位测定了长白山红松针阔叶混交林主要树种红松、蒙古栎、水曲柳和紫椴的树干呼吸,监测了树干温度及林内温度.结果表明:4个树种的树干呼吸速率均有明显的季节变化,其中7月的呼吸速率最高,10月最低,呈单峰曲线.各树种的树干呼吸速率日变化均为"S"型曲线,并在4:00达到最低,而呼吸速率峰值出现时间有所不同,红松、蒙古栎、水曲柳和紫椴的呼吸速率峰值分别在18:00、20:00、16:00和14:00.不同树种的树干呼吸对温度变化的响应也不相同,其树干呼吸Q10值在2.24～2.91之间变化,为水曲柳>蒙古栎>红松>紫椴.

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. manclshurica 〉 Q. mongolica 〉 P. koraiensis 〉 T. amurensis.