Critical levels for ozone effects on vegetation in Europe
Critical levels for ozone effects on vegetation in Europe
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DOI：
10.1016/s0269-7491(97)00067-5
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发表时间：
1997-01-01
影响因子：
8.9
通讯作者：
Ashmore, MR
中科院分区：
文献类型：
--
作者：
Fuhrer, J;Skarby, L;Ashmore, MR
臭氧对欧洲植被产生有害影响的证据，以及根据污染物的影响制定国际控制政策以减少臭氧暴露的需要，导致人们试图定义所谓的臭氧临界水平，高于该水平可能会对树木、农作物和自然植被产生不利影响。本次审查是对用于定义臭氧临界水平的概念的科学基础的严格评估，并确定了所涉及的关键限制和不确定性。此次审查的重点是I级临界水平方法，该方法提供了环境标准或阈值，以最大限度地减少臭氧对敏感受体的影响，但并不寻求量化现场条件下超过临界水平的影响。使用 AOT（超过阈值的累积暴露）来定义长期臭氧暴露的概念已被证明适用于几种经济上重要的物种。使用 40 ppb（给出 AOT40 指数）作为阈值浓度，可以很好地线性拟合来自开顶室的耕作作物的实验数据，但不太确定它是否为树木或半自然群落的数据提供了最佳拟合。定义临界水平值的主要不确定性与响应参数和物种的选择有关；缺乏许多受体的数据，特别是地中海地区的数据，并且从相对短期的开顶室实验推断到现场条件。长寿生物体（例如森林树木）的临界水平的推导可能需要使用基于实验研究的生理数据的建模技术。用于得出临界水平的暴露响应数据不应用于估计大面积臭氧的影响，因为与开顶室方法外推相关的不确定性，特别是对于森林树木，并且由于大气和环境条件的空间变化，这可能会改变臭氧吸收。 (C) 1997 爱思唯尔科学有限公司。
The evidence of detrimental effects of ozone on vegetation in Europe, and the need to develop international control policies to reduce ozone exposures which are based on the effects of the pollutant, has led to attempts to define so-called critical levels of ozone above which adverse effects on trees, crops and natural vegetation may occur. This review is a critical assessment of the scientific basis of the concepts used to define critical levels for ozone and identifies the key limitations and uncertainties involved. The review focuses on the Level I critical level approach, which provides an environmental standard or threshold to minimise the effects of ozone on sensitive receptors, but does not seek to quantify the impacts of exceeding the critical level under field conditions. The concept of using the AOT (accumulated exposure over a threshold) to define long-term ozone exposure is demonstrated to be appropriate for several economically important species. The use of 40 ppb (giving the AOT40 index) as a threshold concentration gives a good linear fit to experimental data from open-top chambers for arable crops, but it is less certain that it provides the best fit to data for trees or semi-natural communities. Major uncertainties in defining critical level values relate to the choice of response parameter and species; the absence of data for many receptors, especially those of Mediterranean areas, and extrapolation to field conditions from relatively shortterm open-top chamber experiments. The derivation of critical levels for long-lived organisms, such as forest trees, may require the use of modelling techniques based on physiological data from experimental studies. The exposure-response data which have been applied to derive critical levels should not be used to estimate the impacts of ozone over large areas, because of the uncertainties associated with extrapolation from the open-top chamber method, especially for forest trees, and because of spatial variation in atmospheric and environmental conditions, which may alter ozone uptake. (C) 1997 Elsevier Science Ltd.