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为评价稻田生态系统大气CO2的收支状况,2008～2009年江西省农业气象试验站利用涡度相关技术对稻田生态系统的CO2通量进行了为期一年的连续观测.对观测的数据进行处理和分析表明:在生长季,稻田生态系统CO2通量总体表现为负值,为CO2的汇.稻田生态系统CO2通量具有明显的日变化特征,白天净吸收CO2的量大于夜间呼吸释放CO2的量.水稻拔节到乳熟阶段吸收CO2的效率以及分蘖至抽穗期CO2的净固定量均明显高于生长初期和生长后期.在非生长季的10月中旬晚稻收获后至次年4月,除了3月稻田生态系统略向大气吸收CO2外,其余各月份均向大气释放CO2,非生长季稻田生态系统为大气CO2的源.在一个年周期内,进一步累加生长季稻田净吸收和非生长季净释放的CO2量可知,试验区稻田生态系统从大气中净吸收CO2的量为14.35t.hm-2,其中早稻吸收CO2为8.81t.hm-2,晚稻吸收CO2为11.71.thm-2,非生长季向大气释放CO2为6.17.thm-2,稻田生态系统总体表现为CO2的汇.
In order to assess the balance of CO2 emissions in the paddy field ecosystem, a series of one-year continuous observations of carbon dioxide flux in paddy field ecosystems were conducted by using the eddy covariance technique from 2008 to 2009. The observed data were processed And the analysis showed that in the growing season, the CO2 flux of paddy field ecosystem showed a negative value as a whole, and the CO2 flux of paddy field ecosystem had obvious diurnal variation characteristics, the amount of net CO2 absorbed during daytime was larger than that of night-time CO2 The efficiency of CO2 absorption from jointing stage to milky stage and the net amount of CO2 fixation from tillering stage to heading stage were significantly higher than those in early growth stage and late growth stage.In late October after non-growing season, In March, the paddy field ecosystem slightly absorbed CO2 into the atmosphere, and all other months released CO2 into the atmosphere, while the non-growing season paddy ecosystem was the source of atmospheric CO2. In one year, the net absorption and non-growth season of the paddy field were further accumulated The net amount of CO2 released shows that the net amount of CO2 absorbed by the paddy ecosystem in the experimental area from the atmosphere is 14.35t.hm-2, of which the CO2 uptake by early rice is 8.81t.hm-2 and the CO2 uptake by late rice is 11.71 thm-2, Non-students Quarter release CO2 into the atmosphere as 6.17.thm-2, the overall performance of paddy ecosystem exchange of CO2.