【摘要】 利用静态暗箱/气相色谱法对三江平原由小叶章草甸垦殖后的旱田(大豆地)进行CO2排放通量的日变化观测实验。结果表明旱田土壤—植物系统和旱田土壤的CO2通量均具有明显的日变化规律,旱田土壤—植物系统CO2通量最大值出现在10∶00,最小值出现在6∶00,其变化趋势与气温和0cm地温呈显著正相关;旱田土壤CO2通量最大值出现在16∶00,最小值出现在6∶00,且其变化趋势与气温、5cm、10cm、15cm和20cm地温均呈显著或极显著正相关。旱田土壤—植物系统CO2通量的主要贡献者是植物的暗呼吸作用,且土壤—植物系统CO2通量的日变化幅度大于土壤。图5,表3,参16。更多还原

【Abstract】 Diurnal variation of CO2 emission fluxes from dryland cultivated from Calamagrostis angustifoli meadow in Sanjiang Plain were measured by closed opaque chamber and gas chromatography system.The results showed that CO2 emission fluxes from dryland soil-plant system and dryland soil both had obvious diurnal variation discipline.CO2 emission flux of dryland soil-plant system showed maximum at 10∶00,while minimum at 6∶00.The variation of CO2 emission flux had obvious positive correlation to air temperature and 0cm ground temperature.CO2 emission flux of dryland soil showed maximum at 16∶00,while minimum at 6∶00.The variation of CO2 emission flux had obvious positive correlation to air temperature,5cm,10cm,15cm,and 20cm ground temperature as well.The main contributor of CO2 emission flux of dryland soil-plant system was dark respiration of plants aboveground.The variation degree of CO2 emission flux from dryland soil-plant system was higher than that from dry soil.更多还原