【摘要】 利用静态暗箱/气相色谱法,在毛苔草(Carex lasiocarp)4个生长期(开花期、果熟期、果后营养期和立枯期),对三江平原毛苔草沼泽CO2排放通量的日变化进行了观测实验。结果表明,在开花期和果熟期,沼泽CO2日平均排放通量较大,分别为1 286.79 mg/(m2.h)和829.28 mg/(m2.h),在果后营养期和立枯期,沼泽CO2日平均排放通量较小,分别为472.54 mg/(m2.h)和237.27 mg/(m2.h);在开花期、果熟期和果后营养期,沼泽CO2排放通量的日变化与温度的相关性不明显,而在立枯期,沼泽CO2排放通量的日变化与气温和地表温度(水温)呈显著正相关(n=11,p<0.05)。各生长期的沼泽CO2日平均排放通量之间具有显著差异(n=4,p<0.01)。从整个生长季来看,CO2日排放通量与气温、地表温度(水温)、5 cm地温和10 cm地温呈显著正相关(n=40,p<0.01),与15 cm地温也呈显著正相关(n=40,p<0.05)。更多还原

【Abstract】 In order to investigate diurnal variation of CO2 emission fluxes from Carex lasiocarp marsh in the Sanjiang Plain in the whole growing season,CO2 emission fluxes in 4 growing stages were measured by closed opaque chamber and gas chromatography system.The growing stages are flowing stage,fruiting stage,post grain-filling stage and standing blight stage.The observation date was selected on June 27th-28th,August 3rd-4th,August 29th-30th,September 29th-30th in 2003,respectively.The results showed that there was greater daily change of CO2 emission fluxes on June 27th-28th,caused by the overcast weather condition.The curve of daily variation of CO2 emission fluxes was single peak on August 3rd-4th,August 29th-30th,September 29th-30th.The average of CO2 emission fluxes was greater during flowering stage and fruiting stage,they were 1 286.79 mg/(m2·h) and 829.28 mg/(m2·h),respectively.While the average of CO2 emission fluxes was smaller during post grain-filling stage and standing blight stage,they were 472.54 mg/(m2·h) and 237.27 mg/(m2·h),respectively.The averages’ difference resulted from different temperature and plants growing condition.There was no obvious correlation between CO2 emission flux and temperature in flowering stage,fruiting stage and post grain-filling stage.It indicated that other factors could impact on CO2 emission except temperature.While there was obvious positive correlation between CO2 emission flux and air temperature,surface temperature in standing blight stage(n=11,p<0.05).There was significant difference among CO2 emission fluxes in various growing stage(n=4,p<0.01).There was obvious positive correlation between CO2 emission flux and air temperature,surface temperature,5cm and 10cm ground temperature in the whole growing season(n=40,p<0.01).And there was obvious positive correlation between CO2 emission flux and 15 cm ground temperature(n=40,p<0.05).It indicated that temperature was an important factor impacting on CO2 emission flux.更多还原