Ground-level ozone (O3) pollution occurs across many important agricultural regions in Europe, North America, and Asia, negatively impacting O3-sensitive crops such as wheat. Risk assessment methods to quantify the magnitude and spatial extent of O3 pollution have often used dose-response relationships. In Europe, the dose metrics used in these relationships have evolved from concentration- to flux-based metrics since stomatal O3 flux has been found to correlate better with yield losses. Estimates of stomatal conductance (gsto) have to date used an empirical multiplicative model. However, other more mechanistic approaches are available, namely the coupled photosynthetic-stomatal conductance (Anetgsto) model. This study used a European O3 OTC and solardome fumigation experimental dataset (comprising 6 cultivars, 4 countries and 14 years) to develop a new flux-based dose-response relationship for wheat yield using the mechanistic Anetgsto model (Anetgstomech). The Anetgstomech model marginally improved the regression of the dose-response relationship (R2 = 0.74) when compared to the flux-response models derived from empirical gsto models. In addition, the Anetgstomech model was somewhat better at predicting the effect of high O3 concentrations on diurnal and seasonal profiles of gsto and Anet. It was also better able to simulate changes of up to 7 and 12 days, respectively, in the start (SOS) and end (EOS) of senescence, an important determinant of yield loss, over a range of O3 treatments. We conclude that Anetgstomech model can be used to derive robust flux-response relationships.

中文翻译：

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小麦的臭氧剂量-反应关系可以使用基于光合作用的气孔导度模型得出


地面臭氧 (O3) 污染发生在欧洲、北美和亚洲的许多重要农业地区，对小麦等 O3 敏感作物产生负面影响。量化 O3 污染的程度和空间范围的风险评估方法经常使用剂量反应关系。在欧洲，这些关系中使用的剂量指标已从基于浓度的指标演变为基于通量的指标，因为人们发现气孔 O3 通量与产量损失具有更好的相关性。迄今为止，气孔导度（gsto）的估计必须使用经验乘法模型。然而，还有其他更机械的方法，即耦合光合气孔导度（Anetgsto）模型。本研究使用欧洲 O3 OTC 和 Solardome 熏蒸实验数据集（包括 6 个品种、4 个国家和 14 年），利用机械 Anetgsto 模型 (Anetgstomech) 开发了一种新的基于通量的小麦产量剂量响应关系。与源自经验 gsto 模型的通量响应模型相比，Anetgstomech 模型略微改善了剂量响应关系的回归 (R2 = 0.74)。此外，Anetgstomech 模型在预测高 O3 浓度对 gsto 和 Anet 的昼夜和季节特征的影响方面稍有优势。它还能够更好地分别模拟衰老开始 (SOS) 和结束 (EOS) 时长达 7 天和 12 天的变化，这是一系列 O3 处理中产量损失的重要决定因素。我们得出结论，Anetgstomech 模型可用于导出稳健的通量响应关系。