| 冬小麦田O3气孔与非气孔沉降及风险评估 |
| 摘要点击 1509 全文点击 475 投稿时间：2017-02-21 修订日期：2017-05-09 |
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| 中文关键词 O3干沉降 冬小麦 气孔与非气孔O3沉降通道 产量损失评估 |
| 英文关键词 ozone dry deposition winter wheat stomatal and non-stomatal pathways yield risk assessment |
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| 中文摘要 |
| 为了深入了解农田生态系统的O3干沉降过程，并基于O3通量（尤其是气孔O3累积通量）指标进行风险评估，利用涡度相关系统对冬小麦田的O3干沉降过程进行了连续动态观测，初步分析O3浓度和总O3通量的变化过程，着重探析气孔O3沉降和非气孔O3沉降的变化特征及其与主要气象因子的关系，并基于剂量指标（AOT40）和通量指标（DFs06）分别推算出冬小麦的产量损失率.结果表明，观测期间（自2016年3月16日至5月30日）日平均O3浓度（cO3）为32.9 nL·L-1；白天（08：00~18：00）和夜间平均总O3通量（FO3）分别为-7.6 nmol·（m2·s）-1和-3.1 nmol·（m2·s）-1，日均FO3为-5.1 nmol·（m2·s）-1.逐日平均气孔O3通量（Fs）的变化范围为0~-5.1 nmol·（m2·s）-1，日均Fs为-1.43 nmol·（m2·s）-1.逐日平均非气孔O3通量（Fns）的变化范围为-1.43~-10.31 nmol·（m2·s）-1，日均Fns为-3.66 nmol·（m2·s）-1.较强的太阳辐射（SR）、较高的温度（T）和适度湿润的条件有利于冬小麦气孔沉降；较强的SR、适度的T和湿润条件是有利于冬小麦非气孔沉降.在整个观测期间，总O3累积吸收通量（DFO3）、气孔O3累积吸收通量（DFs）和非气孔O3累积吸收通量（DFns）分别为31.58、9.99和21.59 mmol·m-2，总DFs和总DFns分别占总DFO3的32%和68%.通过剂量指标AOT40和通量指标DFs06响应方程计算出的冬小麦产量损失率分别为11.58%~20.37%和20%~23.56%. |
| 英文摘要 |
| To better understand the ozone deposition and risk assessment over agroecosystems based on the ozone flux indices, an eddy-covariance system was used for measuring the ozone deposition continuously and dynamically in a winter wheat field. We analyzed the variations in ozone concentration, total ozone flux, and stomatal and non-stomatal flux. The relationships between stomatal/non-stomatal ozone deposition velocity and the main meteorological factors were investigated. Finally, the yield losses of winter wheat based on the ozone-dose index (AOT40) and ozone flux index (DFs06) were calculated. Results showed that average daily ozone concentration (cO3) was 32.9 nL·L-1. The daytime (08:00-18:00) and nighttime total ozone flux (FO3) were -7.6 nmol·(m2·s)-1 and -3.1 nmol·(m2·s)-1, respectively, and the mean diurnal FO3 was -5.1 nmol·(m2·s)-1. The mean daily stomatal ozone flux (Fs) and non-stomatal ozone flux (Fns) ranged from 0 to -5.1 nmol·(m2·s)-1 and from -1.43 to -10.31 nmol·(m2·s)-1, respectively. The mean diurnal Fs and Fns were -1.43 nmol·(m2·s)-1 and -3.66 nmol·(m2·s)-1. High solar radiation (SR), high temperature (T), and moderate humidity were used to analyze stomatal ozone deposition; high SR, moderate T, and high humidity were suitable to analyze non-stomatal ozone deposition. The cumulative total ozone flux (DFO3), cumulative stomatal ozone flux (DFs), and cumulative non-stomatal ozone flux (DFns) were 31.58, 9.99, and 21.59 mmol·m-2 during the entire experimental period, and DFs and DFns accounted for 32% and 68% of DFO3. The ranges of yield loss in winter wheat were estimated at 11.58%-20.37% and 20%-23.56% using different assessment models based on the ozone dose index AOT40 and ozone flux index DFs06, respectively. |
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