江汉平原稻-油连作系统冠层CO2通量变化特征

采用涡度相关法,于2010年和2011年对江汉平原水稻-油菜连作田冠层CO2通量进行周年观测,研究该系统CO2源、汇的季节和日变化规律。结果表明,CO2通量的日变化特征明显,各生育期平均CO2通量日变化幅度较大。将观测期通量数据插值后得到CO2净交换通量(NEE)的逐日变化过程,油菜收割后闲置期-中稻移栽期、分蘖期、拔节-抽穗期、乳熟期的平均NEE分别为1.63、-11.86、-20.61、-4.65g.m-2.d-1;水稻收割后的闲置期、油菜苗期-现蕾期、抽薹期、开花期、绿熟期平均NEE值分别为2.18、0.43、-5.00、-11.70、-13.91g.m-2.d-1。全年稻-油连作农田生态系统净CO2吸收量为19.26 t.hm-2。

CO2 Flux Variation over Canopy Rice-rape Succession System in Jianghan Plain

The canopy CO2 flux over rice -rape succession system in Jianghan plain was measured during 2010 and 2011 based on eddy covariance system, the daily and seasonal variation of CO2 source and sink over cropland ecosystem was analyzed. The results showed that daily variation of CO2 flux was obvious. The daily CO： flux variation of NEE （Net Ecosystem CO2 Exchange ） was obtained by using interpolated method. The average NEE in the stages of mid-season rice transplanting, tillering, jointing - heading and milky were 1.63, - 11.86, - 20. 61, - 4.65 2 -1 g ~ m ~ d respectively, and the average NEE in the stages of idle, rape seedling - bud, bolting, flowering and pod bearing were 2. 18, 0.43, -5.00, - 11.70, - 13.91g·m-2·d-1 respectively. Rice - rape succession ecosystem absorbed 19.26 t C · ha-1 CO2 from atmosphere during the whole year.