CO2浓度升高对冬小麦叶片特性及蒸散影响研究初报

利用开顶式气室(OTC)设置不同CO2浓度处理,观测分析了CO2浓度升高对冬小麦叶片特性与蒸散的影响。结果表明,CO2浓度增加100%、50%和25%后冬小麦叶面积指数(LAI)、叶重、厚度及蒸散量均有不同程度的增加。其中,在叶片发育最旺盛的抽穗期LAI和叶重分别增加23%、11.4%、5.6%和21.3%、9.4%、4.3%;抽穗后,冬小麦平均旗叶面积和叶厚分别增加25.1%、8.4%、4.1%和12.9%、8.8%、7.5%;而旗叶叶绿素无明显变化;蒸散量在拔节-孕穗期略有增加,在孕穗-抽穗期分别增加33.8%、26.8%、11.9%,在开花-乳熟期分别增加了44%、23.9%、8.3%。可见,CO2浓度增加有利于冬小麦生物量的积累,但同时增加了农田生态系统的耗水量。

Effect of Elevated Atmospheric CO2 concentration on leaf characteristic and evapotranspiration in winter wheat

An Open-Top Chamber experiment was conducted by set different CO₂ concentration disposal to observe and analyse the effect of higher CO₂ concentration on leaf characteristic and evapotranspiration in winter wheat. The results showed that the LAI, green leaf dry weight, leaf thickness and evapotranspiration of winter wheat will increase in different degree by the CO₂ concentration elevating 100%, 50%, 25%. The heading period which leaf developed exuberantly LAI and green leaf dry weight increased 23%, 11.4%, 5.6% and 21.3%, 9.4%, 4.3% respectively. After heading, the average flag leaf area and thickness increased 25.1%, 8.4%, 4.1% and 12.9%, 8.8%, 7.5% respectively. But the flag leaf chlorophyll changed inconspicuously. The evapotranspiration increased slightly at jointing-booting period, increased 33.8%, 26.8%, 11.9% at booting-heading period and 44%, 23.9%, 8.3% at anthesis-milk ripeness period respectively. So it can be see that higher CO₂ concentration will accumulate more biomass of winter wheat but at same time expend more farmland ecosystem water.