大气臭氧污染对冬小麦气孔吸收通量的影响机制及其时空格局

发布时间：2018-08-14 10:17

【摘要】：近地层臭氧作为一种二次污染物,其不断增加的浓度及其对作物的影响已经成为各国政府和公众关注的焦点.本文以冬小麦为研究对象,基于大田OTC试验,对OTC内气象因子和气孔导度进行连续观测.引进气孔导度模型,并进行本地参数化研究,结合通量模型,研究冬小麦气孔臭氧吸收通量的变化特征,并对江苏省各市冬小麦气孔导度和O_3吸收通量的时空分布进行模拟.结果表明,O_3浓度增加会限制其叶片气孔导度,浓度越高,限制作用越明显;利用修订后的气孔导度模型对冬小麦叶片气孔导度进行模拟,表明模型解释了实测气孔导度90%、77%和83%的变异性.结合通量模型对冬小麦气孔O_3通量进行模拟,则CK(约为53.67 n L·L~(-1))、100 n L·L~(-1)和150 n L·L~(-1)O_3浓度处理下冬小麦在整个O_3熏期的累积吸收通量分别为6.42、12.27和13.90 mmol·m-2;江苏地区冬小麦在其生长季期间O_3浓度呈逐渐增加的趋势,冬小麦平均气孔导度的大小表现为:中期后期前期的时间变化特点,在整个中期时段气孔O_3累积吸收通量最多.
[Abstract]:As a secondary pollutant, the increasing concentration of near-ground ozone and its impact on crops have become the focus of attention of governments and the public. In this paper, the meteorological factors and stomatal conductance of winter wheat in OTC were observed continuously on the basis of field OTC test. The stomatal conductance model was introduced and local parameterized study was carried out. Combined with flux model, the variation characteristics of stomatal ozone absorption flux of winter wheat were studied, and the spatial and temporal distribution of stomatal conductance and O _ 3 absorption flux of winter wheat in Jiangsu Province were simulated. The results showed that the stomatal conductance of winter wheat leaves was limited by increasing the concentration of Apo3, and the higher the concentration was, the more obvious the limiting effect was, and the modified stomatal conductance model was used to simulate the stomatal conductance of winter wheat leaves. It shows that the model explains the variability of the measured stomatal conductance of 90% and 83%. Combined with flux model, the fluxes of stomata O\ {}\ The cumulative absorption fluxes of winter wheat treated with CK (about 53.67 n L L ~ (-1) 100n L L ~ (-1) and 150 n L L ~ (-1) O _ 3 during the whole O _ 3 fumigation period were 6.422 ~ (12.27) and 13.90 mmol ~ (-2) m ~ (-2), respectively. The mean stomatal conductance of winter wheat was characterized by the time variation in the early stage of the middle stage, and the cumulative absorption flux of stomata O _ (3) was the highest in the whole middle period.
【作者单位】：南京信息工程大学中国气象局气溶胶与云降水重点开放实验室;南京信息工程大学大气物理学院;南京信息工程大学环境科学与工程学院;
【基金】：国家自然科学基金项目(41475108)
【分类号】：S512.11;X515

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