CO_2倍增对稻田CH_4排放的影响

EFFECTS OF CO_2 ENRICHMENT ON CH_4 EMISSION FROM RICE PADDIES

利用开顶室熏气装置 ,研究了 CO2 倍增对稻田 CH4 排放的影响。发现 CO2 倍增在分蘖初期、孕穗期、抽穗期、灌浆期和成就期对稻田 CH4 排放具有明显的促进作用 ,分别比对照增加了 2 53%、2 88%、2 73%、2 73%、和 1 57%。在分蘖末期至灌浆期有一个高峰 ,排放通量约为 1 .91 mg CH4 · d- 1·p- 1。这种促进作用可能主要是由于 CO2 倍增使水稻根系生物量以及根系代谢活性发生变化造成的。

An experiment was carried out in the open top chambers for elucidating the effect of CO 2 enrichment on CH 4 emission from rice.Significant stimulation of CO 2 enrichment on CH 4 emission was found in the tillering,panicle initiation,booting,grain filling and maturity stages with the CH 4 emission increments of 253%,288%,273% and 157%,respectively.The highest flux,1 91mgCH 4·d -1 ·p -1 ,occurred in 106 days after transplanting.We propose that the increase in rice root biomass and root exudate might be the major reason for the stimulation of CH 4 emission.