Clark A J, Landolt W, Bucher J B, Strasser R J
Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland.
Environ Pollut. 2000 Sep;109(3):501-7. doi: 10.1016/s0269-7491(00)00053-1.
This paper describes a relationship between ozone exposure, biomass, visual symptoms and a chlorophyll a fluorescence performance index for young beech trees (Fagus sylvatica). The plants were exposed to four levels of ozone in open-top fumigation chambers (50, 85, 100% of ambient, and 50% of ambient+30 nl l(-1) ozone) that fluctuated in parallel with ambient ozone during a single growing season. The trees were fumigated in the four treatments with ozone levels corresponding to an AOT40 (accumulated exposure above a threshold of 40 nl l(-1)) of 0.01, 3.35, 7.06 and 19.70 microl l(-1) h, respectively. Highly significant differences were found between the 50% of ambient+30 nl l(-1) ozone treatment and all other treatments, with a 70.5% reduction in primary photosynthetic performance, as measured with the PI index. The reduction of the PI values demonstrated a high correlation with visual symptom development (r(2)=0.98), and by the end of September with biomass loss (r(2)=0.99). A significant ozone exposure-response relationship was found between AOT40 and primary photochemistry (r(2)=0.97). Thus, analysis of PI provides an alternative method for regional monitoring of tree health within the context of the currently employed AOT40.
本文描述了年轻山毛榉树（欧洲山毛榉）的臭氧暴露、生物量、视觉症状与叶绿素a荧光性能指数之间的关系。在一个生长季节中，这些植物在开顶式熏蒸箱中暴露于四个臭氧水平（环境水平的50%、85%、100%以及环境水平的50% + 30 nl l⁻¹臭氧），这些水平与环境臭氧平行波动。树木在四种处理中进行熏蒸，臭氧水平分别对应AOT40（高于40 nl l⁻¹阈值的累积暴露）为0.01、3.35、7.06和19.70 μl l⁻¹ h。在环境水平的50% + 30 nl l⁻¹臭氧处理与所有其他处理之间发现了极显著差异，用PI指数测量，初级光合性能降低了70.5%。PI值的降低与视觉症状发展高度相关（r² = 0.98），到9月底与生物量损失也高度相关（r² = 0.99）。在AOT40与初级光化学之间发现了显著的臭氧暴露 - 响应关系（r² = 0.97）。因此，PI分析为在当前使用的AOT40背景下区域监测树木健康提供了一种替代方法。
