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近地层高浓度臭氧(O3)对农作物生长和产量形成有明显的影响。利用在中国科学院禹城综合试验站(山东省)冬小麦(Triticum aestivum)农田生态系统上观测的O3浓度及微气象资料,分析了鲁西北平原冬小麦农田生态系统O3浓度的日变化和季节变化规律,在此基础上初步分析了O3浓度与CO2通量(Fc)的关系,并用欧洲和美国科学家在实验室得到的O3浓度-冬小麦产量关系模型估算了O3对冬小麦产量的潜在影响。结果表明:O3浓度存在明显的日变化规律,日最小值和最大值分别出现在7:00和16:00左右。整个观测期间(2011年3-5月)平均O3浓度为(30.4±20.1)nL·L-1(平均值±标准误差);30min平均浓度的最大值为93.1nL·L-1。在冬小麦春季生长季节,O3浓度日平均值呈现逐步增加的趋势,O3浓度日均增加约为0.17nL·L-1·d-1;白天7h和12h平均浓度(M7和M12)分别为45.7和43.1nL·L-1;O3浓度超过40nL·L-1的3个月累积值(AOT40)为9.8μL·L-1·h;超过60nL·L-1的O3浓度累积值(SUM06)为12.6μL·L-1·h;经过权重修正的O3污染指标W126为10.1μL·L-1·h。在高浓度O3(>60nL·L-1)情况下,CO2通量与O3浓度呈现负相关关系,鲁西北平原O3对冬小麦光合作用影响的阈值取60nL·L-1比较合适,该值高于欧洲国家普遍采用的40nL·L-1。基于以上结果,初步估算得出:在目前的O3浓度水平下,鲁西北平原近地层O3可能会使冬小麦产量减少5.2%-8.8%。
High concentrations of ozone (O3) in the near-surface layer have a significant effect on crop growth and yield formation. The daily and seasonal variations of winter wheat O3 concentrations in winter wheat field in the northwestern Shandong were analyzed using the O3 concentrations and micrometeorological data observed on the farmland ecosystems of the Triticum aestivum at the Yucheng Integrated Experiment Station (Chinese Academy of Sciences) On this basis, the relationship between O3 concentration and CO2 flux (Fc) was analyzed preliminarily. The potential effect of O3 on the yield of winter wheat was estimated using the O3 concentration-winter wheat yield model between European and American scientists in laboratory. The results showed that there was a clear diurnal variation of O3 concentration, and the daily minimum and maximum appeared at about 7:00 and 16:00, respectively. The average O3 concentration was (30.4 ± 20.1) nL·L-1 (mean ± standard error) during the whole observation period (March-May 2011). The maximum average concentration of 30 min was 93.1 nL·L-1. The daily average of O3 showed a gradual increasing trend in spring wheat growing season, and the daily average increase of O3 concentration was about 0.17nL·L-1 · d-1. The mean concentrations of M7 and M12 at 7h and 12h were 45.7 and 43.1nL·L -1; the three-month cumulative value (AOT40) of more than 40nL·L -1 of O3 was 9.8μL·L-1 · h; the cumulative O3 concentration (SUM06) of more than 60nL·L-1 was 12.6 μL · L-1 · h. The weight-corrected O3 pollution index W126 was 10.1 μL · L-1 · h. Under the condition of high concentration of O3 (> 60nL·L-1), the CO2 flux and O3 concentration showed a negative correlation, and the threshold of O3 on the photosynthesis of winter wheat in the northwestern plain of Shandong was 60nL·L-1, which was higher than Commonly used in European countries 40nL · L-1. Based on the above results, preliminary estimates indicate that under the current level of O3 concentration, the O3 in the LWP may reduce the yield of winter wheat by 5.2% -8.8%.