ENEA, CR Casaccia, SSPT-MET-INAT, Via Anguillarese 301, 00123 Rome, Italy.
Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy.
Sci Total Environ. 2017 Oct 15;596-597:396-404. doi: 10.1016/j.scitotenv.2017.03.135. Epub 2017 Apr 25.
Ground-level ozone (O) affects trees through visible leaf injury, accelerating leaf senescence, declining foliar chlorophyll content, photosynthetic activity, growth, carbon sequestration, predisposing to pests attack and a variety of other physiological effects. Tree crown defoliation is one of the most important parameters that is representative of forest health and vitality. Effects of air pollution on forests have been investigated through manipulative experiments that are not representative of the real environmental conditions observed in the field. In this work we investigated the role of O concentration and other metrics (AOT40 and POD0) in affecting crown defoliation in temperate Romanian forests. The impacts of O were estimated in combination with nitrogen pollutants, climatic factors and orographic conditions, by applying a non-linear modelling approach (Random Forest and Generalised Regression Models). Ozone concentration and AOT40 under Romanian conditions were more important than meteorological parameters in affecting crown defoliation. In these particular conditions, POD0 never exceeded the critical level suggested by previous literature for forest protection, and thus was not important in affecting crown defoliation.
地面臭氧（O）通过可见的叶片伤害影响树木，加速叶片衰老，降低叶片叶绿素含量、光合作用活性、生长、碳固存，易受虫害侵袭以及各种其他生理效应。树冠落叶是代表森林健康和活力的最重要参数之一。通过非代表性的实际田间环境条件的操作实验研究了空气污染对森林的影响。在这项工作中，我们研究了 O 浓度和其他指标（AOT40 和 POD0）在影响罗马尼亚温带森林树冠落叶中的作用。通过应用非线性建模方法（随机森林和广义回归模型），结合氮污染物、气候因素和地形条件来估算 O 的影响。在罗马尼亚的条件下，臭氧浓度和 AOT40 比气象参数更能影响树冠落叶。在这些特殊条件下，POD0 从未超过先前文献建议的保护森林的临界水平，因此对树冠落叶的影响并不重要。
