长白山阔叶红松林二氧化碳浓度特征

采用红外气体分析仪对长白山阔叶红松林2003年度CO₂浓度特征进行了分层连续监测，并结合同步气象资料进行了分析.结果表明，长白山阔叶红松林CO₂浓度存在明显的日变化、季变化与垂直变化，这些变化与植被生理活动、土壤呼吸及林内湍流交换强度有关.生长季林内全天CO₂浓度最高值出现在凌晨5:00左右的近地面层，最低值出现在午后15:00左右的冠层部位；日出前后，随着逆温层的打破，林下CO₂有一明显的释放过程.观测期间林内O₂平均浓度为377 μmol·mol^-1，月平均最高值出现在1月，为388 μmol·mol^-1，最低值出现在8月，为352 μmol·mol^-1.生长季夜间森林表现为CO₂的排放，日间表现为CO₂的吸收汇；非生长季日间与夜间森林都主要表现为CO₂的排放源，但在午间冠层部位仍有数小时表现为CO₂的吸收过程.

CO2 concentration character in broad-leaved Korean pine forest of Changbai Mountains

The CO2 concentration in broad-leaved Korean pine forest of Changbai Mountains was measured continuously with a CO2 infra-red analyzer in 2003. The results showed that the CO2 concentration in the forest had striking characteristics of temporal-spatial variations, which were mainly influenced by the physiological processes of plants, soil respiration, and intensity of turbulence exchange. In growing season, the daily maximum and minimum CO2 concentration appeared mostly on the surface floor at about 5:00 in the early morning and at canopy location at about 15:00 in the afternoon, respectively. There was an obviously process of forest CO2 emission when the inversion broke at dawn. The average CO2 concentration in forest was 377 micromol x mol(-1) in 2003, the maximum of monthly average appeared in January as 388 micromol x mol(-1), and the minimum of monthly average appeared in August as 352 micromol x mol(-1). The forest acted as CO2 source in night time and turned to sink in daytime, during growing season. In non-growing season, the forest acted as CO2 source in both daytime and night time, but still had a clear evidence of CO2 assimilation at noon, with canopy location during non-growing season.